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  • Partner Blog Series: PwC Perspectives - The Gotchas, The Do's and Don'ts for IDM Implementations

    - by Tanu Sood
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mso-tstyle-border-bottom-themecolor:accent6; font-family:"Arial Narrow","sans-serif"; mso-ascii-font-family:Georgia; mso-ascii-theme-font:major-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:major-fareast; mso-hansi-font-family:Georgia; mso-hansi-theme-font:major-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:major-bidi;} table.MsoTableMediumList1Accent6LastRow {mso-style-name:"Medium List 1 - Accent 6"; mso-table-condition:last-row; mso-style-priority:65; mso-style-unhide:no; mso-tstyle-border-top:1.0pt solid #E0301E; mso-tstyle-border-top-themecolor:accent6; mso-tstyle-border-bottom:1.0pt solid #E0301E; mso-tstyle-border-bottom-themecolor:accent6; color:#968C6D; mso-themecolor:text2; mso-ansi-font-weight:bold; mso-bidi-font-weight:bold;} table.MsoTableMediumList1Accent6FirstCol {mso-style-name:"Medium List 1 - Accent 6"; mso-table-condition:first-column; mso-style-priority:65; mso-style-unhide:no; mso-ansi-font-weight:bold; mso-bidi-font-weight:bold;} table.MsoTableMediumList1Accent6LastCol {mso-style-name:"Medium List 1 - Accent 6"; mso-table-condition:last-column; mso-style-priority:65; mso-style-unhide:no; mso-tstyle-border-top:1.0pt solid #E0301E; mso-tstyle-border-top-themecolor:accent6; mso-tstyle-border-bottom:1.0pt solid #E0301E; mso-tstyle-border-bottom-themecolor:accent6; mso-ansi-font-weight:bold; mso-bidi-font-weight:bold;} table.MsoTableMediumList1Accent6OddColumn {mso-style-name:"Medium List 1 - Accent 6"; mso-table-condition:odd-column; mso-style-priority:65; mso-style-unhide:no; mso-tstyle-shading:#F7CBC7; mso-tstyle-shading-themecolor:accent6; mso-tstyle-shading-themetint:63;} table.MsoTableMediumList1Accent6OddRow {mso-style-name:"Medium List 1 - Accent 6"; mso-table-condition:odd-row; mso-style-priority:65; mso-style-unhide:no; mso-tstyle-shading:#F7CBC7; mso-tstyle-shading-themecolor:accent6; mso-tstyle-shading-themetint:63;} It is generally accepted among business communities that technology by itself is not a silver bullet to all problems, but when it is combined with leading practices, strategy, careful planning and execution, it can create a recipe for success. This post attempts to highlight some of the best practices along with dos & don’ts that our practice has accumulated over the years in the identity & access management space in general, and also in the context of R2, in particular. Best Practices The following section illustrates the leading practices in “How” to plan, implement and sustain a successful OIM deployment, based on our collective experience. Planning is critical, but often overlooked A common approach to planning an IAM program that we identify with our clients is the three step process involving a current state assessment, a future state roadmap and an executable strategy to get there. It is extremely beneficial for clients to assess their current IAM state, perform gap analysis, document the recommended controls to address the gaps, align future state roadmap to business initiatives and get buy in from all stakeholders involved to improve the chances of success. When designing an enterprise-wide solution, the scalability of the technology must accommodate the future growth of the enterprise and the projected identity transactions over several years. Aligning the implementation schedule of OIM to related information technology projects increases the chances of success. As a baseline, it is recommended to match hardware specifications to the sizing guide for R2 published by Oracle. Adherence to this will help ensure that the hardware used to support OIM will not become a bottleneck as the adoption of new services increases. If your Organization has numerous connected applications that rely on reconciliation to synchronize the access data into OIM, consider hosting dedicated instances to handle reconciliation. Finally, ensure the use of clustered environment for development and have at least three total environments to help facilitate a controlled migration to production. If your Organization is planning to implement role based access control, we recommend performing a role mining exercise and consolidate your enterprise roles to keep them manageable. In addition, many Organizations have multiple approval flows to control access to critical roles, applications and entitlements. If your Organization falls into this category, we highly recommend that you limit the number of approval workflows to a small set. Most Organizations have operations managed across data centers with backend database synchronization, if your Organization falls into this category, ensure that the overall latency between the datacenters when replicating the databases is less than ten milliseconds to ensure that there are no front office performance impacts. Ingredients for a successful implementation During the development phase of your project, there are a number of guidelines that can be followed to help increase the chances for success. Most implementations cannot be completed without the use of customizations. If your implementation requires this, it’s a good practice to perform code reviews to help ensure quality and reduce code bottlenecks related to performance. We have observed at our clients that the development process works best when team members adhere to coding leading practices. Plan for time to correct coding defects and ensure developers are empowered to report their own bugs for maximum transparency. Many organizations struggle with defining a consistent approach to managing logs. This is particularly important due to the amount of information that can be logged by OIM. We recommend Oracle Diagnostics Logging (ODL) as an alternative to be used for logging. ODL allows log files to be formatted in XML for easy parsing and does not require a server restart when the log levels are changed during troubleshooting. Testing is a vital part of any large project, and an OIM R2 implementation is no exception. We suggest that at least one lower environment should use production-like data and connectors. Configurations should match as closely as possible. For example, use secure channels between OIM and target platforms in pre-production environments to test the configurations, the migration processes of certificates, and the additional overhead that encryption could impose. Finally, we ask our clients to perform database backups regularly and before any major change event, such as a patch or migration between environments. In the lowest environments, we recommend to have at least a weekly backup in order to prevent significant loss of time and effort. Similarly, if your organization is using virtual machines for one or more of the environments, it is recommended to take frequent snapshots so that rollbacks can occur in the event of improper configuration. Operate & sustain the solution to derive maximum benefits When migrating OIM R2 to production, it is important to perform certain activities that will help achieve a smoother transition. At our clients, we have seen that splitting the OIM tables into their own tablespaces by categories (physical tables, indexes, etc.) can help manage database growth effectively. If we notice that a client hasn’t enabled the Oracle-recommended indexing in the applicable database, we strongly suggest doing so to improve performance. Additionally, we work with our clients to make sure that the audit level is set to fit the organization’s auditing needs and sometimes even allocate UPA tables and indexes into their own table-space for better maintenance. Finally, many of our clients have set up schedules for reconciliation tables to be archived at regular intervals in order to keep the size of the database(s) reasonable and result in optimal database performance. For our clients that anticipate availability issues with target applications, we strongly encourage the use of the offline provisioning capabilities of OIM R2. This reduces the provisioning process for a given target application dependency on target availability and help avoid broken workflows. To account for this and other abnormalities, we also advocate that OIM’s monitoring controls be configured to alert administrators on any abnormal situations. Within OIM R2, we have begun advising our clients to utilize the ‘profile’ feature to encapsulate multiple commonly requested accounts, roles, and/or entitlements into a single item. By setting up a number of profiles that can be searched for and used, users will spend less time performing the same exact steps for common tasks. We advise our clients to follow the Oracle recommended guides for database and application server tuning which provides a good baseline configuration. It offers guidance on database connection pools, connection timeouts, user interface threads and proper handling of adapters/plug-ins. All of these can be important configurations that will allow faster provisioning and web page response times. Many of our clients have begun to recognize the value of data mining and a remediation process during the initial phases of an implementation (to help ensure high quality data gets loaded) and beyond (to support ongoing maintenance and business-as-usual processes). A successful program always begins with identifying the data elements and assigning a classification level based on criticality, risk, and availability. It should finish by following through with a remediation process. Dos & Don’ts Here are the most common dos and don'ts that we socialize with our clients, derived from our experience implementing the solution. Dos Don’ts Scope the project into phases with realistic goals. Look for quick wins to show success and value to the stake holders. Avoid “boiling the ocean” and trying to integrate all enterprise applications in the first phase. Establish an enterprise ID (universal unique ID across the enterprise) earlier in the program. Avoid major UI customizations that require code changes. Have a plan in place to patch during the project, which helps alleviate any major issues or roadblocks (product and database). Avoid publishing all the target entitlements if you don't anticipate their usage during access request. Assess your current state and prepare a roadmap to address your operations, tactical and strategic goals, align it with your business priorities. Avoid integrating non-production environments with your production target systems. Defer complex integrations to the later phases and take advantage of lessons learned from previous phases Avoid creating multiple accounts for the same user on the same system, if there is an opportunity to do so. Have an identity and access data quality initiative built into your plan to identify and remediate data related issues early on. Avoid creating complex approval workflows that would negative impact productivity and SLAs. Identify the owner of the identity systems with fair IdM knowledge and empower them with authority to make product related decisions. This will help ensure overcome any design hurdles. Avoid creating complex designs that are not sustainable long term and would need major overhaul during upgrades. Shadow your internal or external consulting resources during the implementation to build the necessary product skills needed to operate and sustain the solution. Avoid treating IAM as a point solution and have appropriate level of communication and training plan for the IT and business users alike. Conclusion In our experience, Identity programs will struggle with scope, proper resourcing, and more. We suggest that companies consider the suggestions discussed in this post and leverage them to help enable their identity and access program. This concludes PwC blog series on R2 for the month and we sincerely hope that the information we have shared thus far has been beneficial. For more information or if you have questions, you can reach out to Rex Thexton, Senior Managing Director, PwC and or Dharma Padala, Director, PwC. We look forward to hearing from you. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:12.0pt; mso-para-margin-left:0in; line-height:12.0pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Arial","sans-serif"; mso-ascii-font-family:Arial; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Arial; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Meet the Writers: Dharma Padala is a Director in the Advisory Security practice within PwC.  He has been implementing medium to large scale Identity Management solutions across multiple industries including utility, health care, entertainment, retail and financial sectors.   Dharma has 14 years of experience in delivering IT solutions out of which he has been implementing Identity Management solutions for the past 8 years. Praveen Krishna is a Manager in the Advisory Security practice within PwC.  Over the last decade Praveen has helped clients plan, architect and implement Oracle identity solutions across diverse industries.  His experience includes delivering security across diverse topics like network, infrastructure, application and data where he brings a holistic point of view to problem solving. Scott MacDonald is a Director in the Advisory Security practice within PwC.  He has consulted for several clients across multiple industries including financial services, health care, automotive and retail.   Scott has 10 years of experience in delivering Identity Management solutions. John Misczak is a member of the Advisory Security practice within PwC.  He has experience implementing multiple Identity and Access Management solutions, specializing in Oracle Identity Manager and Business Process Engineering Language (BPEL).

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  • How to switch off wifi on startup or from the console

    - by mit
    I have installed ubuntu 10.04 on a laptop. Wifi is switched on by default on startup. I can disable it rightclicking the network manager icon in the gnome bar. How can I set it to have wifi switched off as default? Alternatively, how can I switch off wifi on the console? I tried already the rfkill command but it does not list any devices and it does not switch off wifi, I tried different parameters. This is a standard install of the Ubuntu 10.04 i386 Desktop Live CD on an IBM T40 Laptop. EDIT A: This is the output of some rfkill commands on my system, and it does not affect the wifi of the laptop: $ rfkill --help Usage: rfkill [options] command Options: --version show version (0.4) Commands: help event list [IDENTIFIER] block IDENTIFIER unblock IDENTIFIER where IDENTIFIER is the index no. of an rfkill switch or one of: <idx> all wifi wlan bluetooth uwb ultrawideband wimax wwan gps fm $ rfkill list $ rfkill list wifi $ rfkill list all $ rfkill list wlan $ sudo rfkill list all $ sudo rfkill block all $ sudo rfkill block wlan $ sudo rfkill block wifi $ EDIT B: Now I found out that sudo ifconfig eth1 down turns it off. And I can turn it on through the gnome network applet again. But the applet does not reflect the change from the commandline, it stills believes wifi is switched on. I have to switch it off and on again on the applet to switch it on again, when I switched it off from the console. Is there a better way? This is what the syslog looks like when I switch wireless off and on again from the network manager: NetworkManager: <info> (eth1): device state change: 3 -> 2 (reason 0) NetworkManager: <info> (eth1): deactivating device (reason: 0). NetworkManager: <info> Policy set '24' (eth0) as default for routing and DNS. NetworkManager: <info> (eth1): taking down device. avahi-daemon[660]: Withdrawing address record for fe80::202:8aff:feba:d798 on eth1. kernel: [ 971.472116] airo(eth1): cmd:3 status:7f03 rsp0:0 rsp1:0 rsp2:0 NetworkManager: <info> (eth1): bringing up device. NetworkManager: <info> (eth1): supplicant interface state: starting -> ready NetworkManager: <info> (eth1): device state change: 2 -> 3 (reason 42) avahi-daemon[660]: Registering new address record for fe80::202:8aff:feba:d798 on eth1.*. kernel: [ 965.512048] eth1: no IPv6 routers present

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  • Effectiveness and Efficiency

    - by Daniel Moth
    In the professional environment, i.e. at work, I am always seeking personal growth and to be challenged. The result is that my assignments, my work list, my tasks, my goals, my commitments, my [insert whatever word resonates with you] keep growing (in scope and desired impact). Which in turn means I have to keep finding new ways to deliver more value, while not falling into the trap of working more hours. To do that I continuously evaluate both my effectiveness and my efficiency. EFFECTIVENESS The first thing I check is my effectiveness: Am I doing the right things? Am I focusing too much on unimportant things? Am I spending more time doing stuff that is important to my team/org/division/business/company, or am I spending it on stuff that is important to me and that I enjoy doing? Am I valuing activities that maybe I have outgrown and should be delegated to others who are at a stage I have surpassed (in Microsoft speak: is the work I am doing level appropriate or am I still operating at the previous level)? Notice how the answers to those questions change over time and due to certain events, so I have to remind myself to revisit them frequently. Events that force me to re-examine them are: change of role, change of team/org/etc, change of direction of team/org/etc, re-org, new hires on the team that take on some of the work I did, personal promotion, change of manager... and if none of those events has occurred since the last annual review, I ask myself those at each annual review anyway. If you think you are not being effective at work, make a list of the stuff that you do and start tracking where your time goes. In parallel, have a discussion with your manager about where they think your time should go. Ultimately your time is finite and hence it is your most precious investment, don't waste it. If your management doesn't value as highly what you spend your time on, then either convince your management, or stop spending your time on it, or find different management: Lead, Follow, or get out of the way! That's my view on effectiveness. You have to fix that before moving to being efficient, or you may end up being very efficient at stuff that nobody wants you to be doing in the first place. For example, you may be spending your time writing blog posts and becoming better and faster at it all the time. If your manager thinks that is not even part of your job description, you are wasting your time to satisfy your inner desires. Nobody can help you with your effectiveness other than your management chain and your management peers - they are the judges of it. EFFICIENCY The second thing I check is my efficiency: Am I doing things right? For me, doing things right means that I deliver the same quality of work faster [than what I used to, and than my peers, and than expected of me]. The result is that I can achieve more [than what I used to, and than my peers, and than expected of me]. Notice how the efficiency goal is a more portable one. If, by whatever criteria, you think you are the best at [insert your own skill here], this can change at two events: because you have new colleagues (who are potentially better than your older ones), and it can change with a change of manager (who has potentially higher expectations). That's about it. Once you are efficient at something, you carry that with you... All you need to really be doing here is, when taking on new kinds of work that you haven't done before, try a few approaches and devise a system so that you can become efficient at this new activity too... Just keep "collecting" stuff that you are efficient at. If you think you are not being efficient at something, break it down: What are the steps you take to complete that task? How long do you spend on each step? Talk to others about what steps they take, to see if you can optimize some steps away or trade them for better steps, or just learn how to complete a step faster. Have a system for every task you take so that you can have repeatable success. That's my view on efficiency. You have to fix it so that you can free up time to do more. When you plan a route from A to B - all else being equal - you try to get there as fast as possible so why would you not want to do that with your everyday work? For example, imagine you are inefficient at processing email: You spend more time than necessary dealing with email, and you still end up with dropped email threads and with slower response times than others. How can you improve? Talk to someone that you think is good at this, understand their system (e.g. here is my email processing system) and come up with one that works for you. Parting Thoughts Are you considered, by your colleagues and manager, an effective and efficient person at your workplace? If you are, what would you change if you were asked by your management to do the job of two people? Seriously, think about that! Your immediate reaction may be "that is not possible", but it actually is. You just have to re-assess what things that were previously important will now stop being important, by discussing them with your management and reaching agreement on relative priorities. For example, stuff that was previously on your plate may now have to be delegated or dropped. Where you thought you were efficient, maybe now you have to find an even faster path to completion, perhaps keeping in mind that Perfect is the Enemy of “Good Enough”. My personal experience (from both observing others and from my own reflection) is that when folks are struggling to keep up at work it is because of two reasons: They are investing energy in stuff that they enjoy doing which the business regards as having a lower priority than a lot of other things on their plate. They are completing tasks to a level of higher quality than what is required (due to personal pride) missing the big picture which almost always mandates completing three tasks at good enough quality than knocking only one of them out of the park while the other two come in late or not at all. There is a lot of content on the web, so I strongly encourage you to use your favorite search engine to read other views on effectiveness and efficiency (Bing, Google). Comments about this post by Daniel Moth welcome at the original blog.

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  • Creating an object that is ready to be used & unset properties - with IoC

    - by GetFuzzy
    I have a question regarding the specifics of object creation and the usage of properties. A best practice is to put all the properties into a state such that the object is useful when its created. Object constructors help ensure that required dependencies are created. I've found myself following a pattern lately, and then questioning its appropriateness. The pattern looks like this... public class ThingProcesser { public List<Thing> CalculatedThings { get; set; } public ThingProcesser() { CalculatedThings = new List<Thing>(); } public double FindCertainThing() { CheckForException(); foreach (var thing in CalculatedThings) { //do some stuff with things... } } public double FindOtherThing() { CheckForException(); foreach (var thing in CalculatedThings) { //do some stuff with things... } } private void CheckForException() { if (CalculatedThings.Count < 2) throw new InvalidOperationException("Calculated things must have more than 2 items"); } } The list of items is not being changed, just looked through by the methods. There are several methods on the class, and to avoid having to pass the list of things to each function as a method parameter, I set it once on the class. While this works, does it violate the principle of least astonishment? Since starting to use IoC I find myself not sticking things into the constructor, to avoid having to use a factory pattern. For example, I can argue with myself and say well the ThingProcessor really needs a List to work, so the object should be constructed like this. public class ThingProcesser { public List<Thing> CalculatedThings { get; set; } public ThingProcesser(List<Thing> calculatedThings) { CalculatedThings = calculatedThings; } } However, if I did this, it would complicate things for IoC, and this scenario hardly seems appropriate for something like the factory pattern. So in summary, are there some good guidelines for when something should be part of the object state, vs. passed as a method parameter? When using IoC, is the factory pattern the best way to deal with objects that need created with state? If something has to be passed to multiple methods in a class, does that render it a good candidate to be part of the objects state?

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  • How should compound words be handled when coding? Is there a definitive list of compound words? [closed]

    - by Ray
    QUESTION: How should you handle compound words when programming? Are there any good lists available online for developers of generally accepted technology-related compound words? I can see how this is highly ambiguous, so should I just use common-sense? EXAMPLE: I would be inclined to do this: filename NOT FileName or login NOT LogIn However, the microsoft documentation indicates that filename is not compound. So I wonder, is there a more definitive source? See also, this english.stackexchange discussion on filename. Under the section "Capitalization Rules for Compound Words and Common Terms" located here: Microsoft .NET Capitalization Conventions only offers a limited introduction into the topic, and leaves it up to the developer to use their intuition with the rest.

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  • Should Item Grouping/Filter be in the ViewModel or View layer?

    - by ronag
    I'm in a situation where I have a list of items that need to be displayed depending on their properties. What I'm unsure of is where is the best place to put the filtering/grouping logic of the viewmodel state? Currently I have it in my view using converters, but I'm unsure whether I should have the logic in the viewmodel? e.g. ViewModel Layer: class ItemViewModel { DateTime LastAccessed { get; set; } bool IsActive { get; set; } } class ContainerViewModel { ObservableCollection<Item> Items {get; set;} } View Layer: <TextView Text="Active Items"/> <List ItemsSource={Binding Items, Converter=GroupActiveItemsByDay}/> <TextView Text="Active Items"/> <List ItemsSource={Binding Items, Converter=GroupInActiveItemsByDay}/> or should I build it like this? ViewModel Layer: class ContainerViewModel { ObservableCollection<IGrouping<string, Item>> ActiveItemsByGroup {get; set;} ObservableCollection<IGrouping<string, Item>> InActiveItemsByGroup {get; set;} } View Layer: <TextView Text="Active Items"/> <List ItemsSource={Binding ActiveItemsGroupByDate }/> <TextView Text="Active Items"/> <List ItemsSource={Binding InActiveItemsGroupByDate }/> Or maybe something in between? ViewModel Layer: class ContainerViewModel { ObservableCollection<IGrouping<string, Item>> ActiveItems {get; set;} ObservableCollection<IGrouping<string, Item>> InActiveItems {get; set;} } View Layer: <TextView Text="Active Items"/> <List ItemsSource={Binding ActiveItems, Converter=GroupByDate }/> <TextView Text="Active Items"/> <List ItemsSource={Binding InActiveItems, Converter=GroupByDate }/> I guess my question is what is good practice in terms as to what logic to put into the ViewModel and what logic to put into the Binding in the View, as they seem to overlap a bit?

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  • Creating static NAT blocks outbound traffic Cisco ASA

    - by natediggs
    Hi Everyone, I have two web servers sitting behind a Cisco ASA 5505, which I don't have much experience with. I'm trying to create two static NATs. One static NAT that goes to xx.xx.xx.150 and another that goes to xx.xx.xx.151. I've created the static NAT for the .150 web server and it works FINE. Incoming and outgoing traffic work great. This is the staging web server. I now need to duplicate the setup for the production web server. So, I connect the webserver to the firewall, change the public IP address on one of the NICs reboot the server and I have outbound internet access. Then I run the command: static (inside,outside) xx.xx.xx.150 192.168.1.x which is successful. I then run the command: access-list acl-outside permit tcp any host xx.xx.xx.150 eq 80 Which is successful. I then try to browse the internet and I get nothing. I try to telnet in through port 80 and I get nothing (though I'm guessing because the response to the telnet request is being blocked). I've tried this with the production web server and then I tried it with another web server that is for internal testing and have the exact same problem. Both work fine until I run the static NAT rule and then no outbound internet access. I have a feeling that it's something simple that I'm missing, but my limited experience with this device is killing me. Below I've pasted the current configuration. I'm currently trying to get this to work on the .153 server which is the internal testing server. Once I can verify that works, I'll try it with production. : Saved : ASA Version 8.2(4) ! hostname QG domain-name XX.com enable password passwd names ! interface Ethernet0/0 switchport access vlan 2 ! interface Ethernet0/1 ! interface Ethernet0/2 ! interface Ethernet0/3 ! interface Ethernet0/4 ! interface Ethernet0/5 ! interface Ethernet0/6 ! interface Ethernet0/7 ! interface Vlan1 nameif inside security-level 100 ip address 192.168.1.1 255.255.255.0 ! interface Vlan2 nameif outside security-level 0 ip address XX.XX.XX.148 255.255.255.0 ! interface Vlan3 shutdown no forward interface Vlan1 nameif dmz security-level 50 ip address dhcp ! boot system disk0:/asa824.bin ftp mode passive clock timezone EST -5 clock summer-time EDT recurring dns server-group DefaultDNS domain-name fw.XXgroup.com same-security-traffic permit inter-interface access-list acl-outside extended permit tcp any host XX.XX.XX.150 eq www access-list acl-outside extended permit tcp any host XX.XX.XX.150 eq https access-list acl-outside extended permit tcp any host XX.XX.XX.151 eq www access-list acl-outside extended permit tcp any host XX.XX.XX.151 eq https access-list acl-outside extended permit tcp any host XX.XX.XX.153 eq www access-list inside_access_in extended permit ip 192.168.1.0 255.255.255.0 any access-list inside_nat0_outbound extended permit ip any 192.168.1.32 255.255.255.240 pager lines 24 logging enable logging asdm informational mtu inside 1500 mtu outside 1500 mtu dmz 1500 ip local pool VPNIPs 192.168.1.35-192.168.1.44 mask 255.255.255.0 icmp unreachable rate-limit 1 burst-size 1 asdm image disk0:/asdm-635.bin no asdm history enable arp timeout 14400 global (outside) 1 interface nat (inside) 0 access-list inside_nat0_outbound nat (inside) 1 0.0.0.0 0.0.0.0 static (inside,outside) XX.XX.XX150 192.168.1.100 netmask 255.255.255.255 static (inside,outside) XX.XX.XX153 192.168.1.102 netmask 255.255.255.255 access-group acl-outside in interface outside route outside 0.0.0.0 0.0.0.0 XX.XX.XX129 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00 timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00 timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute timeout tcp-proxy-reassembly 0:01:00 dynamic-access-policy-record DfltAccessPolicy aaa authorization command LOCAL http server enable http 192.168.1.0 255.255.255.0 inside http 0.0.0.0 0.0.0.0 outside no snmp-server location no snmp-server contact snmp-server enable traps snmp authentication linkup linkdown coldstart crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac crypto ipsec security-association lifetime seconds 28800 crypto ipsec security-association lifetime kilobytes 4608000 crypto dynamic-map outside_dyn_map 20 set pfs group1 crypto dynamic-map outside_dyn_map 20 set transform-set ESP-3DES-SHA crypto map outside_map 65535 ipsec-isakmp dynamic outside_dyn_map crypto map outside_map interface outside crypto isakmp enable outside crypto isakmp policy 10 authentication crack encryption 3des hash sha group 2 lifetime 86400 no crypto isakmp nat-traversal client-update enable telnet timeout 5 ssh timeout 5 console timeout 0 dhcpd auto_config outside ! dhcpd address 192.168.1.2-192.168.1.33 inside dhcpd dns 208.77.88.4 interface inside dhcpd enable inside ! threat-detection basic-threat threat-detection statistics access-list no threat-detection statistics tcp-intercept webvpn enable outside svc image disk0:/sslclient-win-1.1.0.154.pkg 1 svc image disk0:/anyconnect-win-2.5.2019-k9.pkg 2 svc enable group-policy ATSAdmin internal group-policy ATSAdmin attributes dns-server value 208.77.88.4 208.85.174.9 vpn-tunnel-protocol IPSec svc webvpn webvpn url-list none svc keep-installer installed svc rekey method ssl svc ask enable username qgadmin password /oHfeGQ/R.bd3KPR encrypted privilege 15 username benl password 0HNIGQNI0uruJvhW encrypted privilege 0 username benl attributes vpn-group-policy ATSAdmin username kuzma password rH7MM7laoynyvf9U encrypted privilege 0 username kuzma attributes vpn-group-policy ATSAdmin username nate password BXHOURyT37e4O5mt encrypted privilege 0 username nate attributes vpn-group-policy ATSAdmin tunnel-group ATSAdmin type remote-access tunnel-group ATSAdmin general-attributes address-pool VPNIPs default-group-policy ATSAdmin tunnel-group SSLVPN type remote-access tunnel-group SSLVPN general-attributes address-pool VPNIPs default-group-policy ATSAdmin ! class-map inspection_default match default-inspection-traffic ! ! policy-map type inspect dns preset_dns_map parameters message-length maximum 512 policy-map global_policy class inspection_default inspect dns preset_dns_map inspect ftp inspect h323 h225 inspect h323 ras inspect rsh inspect rtsp inspect esmtp inspect sqlnet inspect skinny inspect sunrpc inspect xdmcp inspect sip inspect netbios inspect tftp inspect ip-options ! service-policy global_policy global privilege cmd level 3 mode exec command perfmon privilege cmd level 3 mode exec command ping privilege cmd level 3 mode exec command who privilege cmd level 3 mode exec command logging privilege cmd level 3 mode exec command failover privilege show level 5 mode exec command running-config privilege show level 3 mode exec command reload privilege show level 3 mode exec command mode privilege show level 3 mode exec command firewall privilege show level 3 mode exec command interface privilege show level 3 mode exec command clock privilege show level 3 mode exec command dns-hosts privilege show level 3 mode exec command access-list privilege show level 3 mode exec command logging privilege show level 3 mode exec command ip privilege show level 3 mode exec command failover privilege show level 3 mode exec command asdm privilege show level 3 mode exec command arp privilege show level 3 mode exec command route privilege show level 3 mode exec command ospf privilege show level 3 mode exec command aaa-server privilege show level 3 mode exec command aaa privilege show level 3 mode exec command crypto privilege show level 3 mode exec command vpn-sessiondb privilege show level 3 mode exec command ssh privilege show level 3 mode exec command dhcpd privilege show level 3 mode exec command vpn privilege show level 3 mode exec command blocks privilege show level 3 mode exec command uauth privilege show level 3 mode configure command interface privilege show level 3 mode configure command clock privilege show level 3 mode configure command access-list privilege show level 3 mode configure command logging privilege show level 3 mode configure command ip privilege show level 3 mode configure command failover privilege show level 5 mode configure command asdm privilege show level 3 mode configure command arp privilege show level 3 mode configure command route privilege show level 3 mode configure command aaa-server privilege show level 3 mode configure command aaa privilege show level 3 mode configure command crypto privilege show level 3 mode configure command ssh privilege show level 3 mode configure command dhcpd privilege show level 5 mode configure command privilege privilege clear level 3 mode exec command dns-hosts privilege clear level 3 mode exec command logging privilege clear level 3 mode exec command arp privilege clear level 3 mode exec command aaa-server privilege clear level 3 mode exec command crypto privilege cmd level 3 mode configure command failover privilege clear level 3 mode configure command logging privilege clear level 3 mode configure command arp privilege clear level 3 mode configure command crypto privilege clear level 3 mode configure command aaa-server prompt hostname context call-home profile CiscoTAC-1 no active destination address http https://tools.cisco.com/its/service/oddce/services/DDCEService destination address email [email protected] destination transport-method http subscribe-to-alert-group diagnostic subscribe-to-alert-group environment subscribe-to-alert-group inventory periodic monthly subscribe-to-alert-group configuration periodic monthly subscribe-to-alert-group telemetry periodic daily Cryptochecksum:0ed0580e151af288d865f4f3603d792a : end asdm image disk0:/asdm-635.bin no asdm history enable

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  • How LINQ to Object statements work

    - by rajbk
    This post goes into detail as to now LINQ statements work when querying a collection of objects. This topic assumes you have an understanding of how generics, delegates, implicitly typed variables, lambda expressions, object/collection initializers, extension methods and the yield statement work. I would also recommend you read my previous two posts: Using Delegates in C# Part 1 Using Delegates in C# Part 2 We will start by writing some methods to filter a collection of data. Assume we have an Employee class like so: 1: public class Employee { 2: public int ID { get; set;} 3: public string FirstName { get; set;} 4: public string LastName {get; set;} 5: public string Country { get; set; } 6: } and a collection of employees like so: 1: var employees = new List<Employee> { 2: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 3: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 4: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 5: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 6: }; Filtering We wish to  find all employees that have an even ID. We could start off by writing a method that takes in a list of employees and returns a filtered list of employees with an even ID. 1: static List<Employee> GetEmployeesWithEvenID(List<Employee> employees) { 2: var filteredEmployees = new List<Employee>(); 3: foreach (Employee emp in employees) { 4: if (emp.ID % 2 == 0) { 5: filteredEmployees.Add(emp); 6: } 7: } 8: return filteredEmployees; 9: } The method can be rewritten to return an IEnumerable<Employee> using the yield return keyword. 1: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 2: foreach (Employee emp in employees) { 3: if (emp.ID % 2 == 0) { 4: yield return emp; 5: } 6: } 7: } We put these together in a console application. 1: using System; 2: using System.Collections.Generic; 3: //No System.Linq 4:  5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 15: }; 16: var filteredEmployees = GetEmployeesWithEvenID(employees); 17:  18: foreach (Employee emp in filteredEmployees) { 19: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 20: emp.ID, emp.FirstName, emp.LastName, emp.Country); 21: } 22:  23: Console.ReadLine(); 24: } 25: 26: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 27: foreach (Employee emp in employees) { 28: if (emp.ID % 2 == 0) { 29: yield return emp; 30: } 31: } 32: } 33: } 34:  35: public class Employee { 36: public int ID { get; set;} 37: public string FirstName { get; set;} 38: public string LastName {get; set;} 39: public string Country { get; set; } 40: } Output: ID 2 First_Name Jim Last_Name Ashlock Country UK ID 4 First_Name Jill Last_Name Anderson Country AUS Our filtering method is too specific. Let us change it so that it is capable of doing different types of filtering and lets give our method the name Where ;-) We will add another parameter to our Where method. This additional parameter will be a delegate with the following declaration. public delegate bool Filter(Employee emp); The idea is that the delegate parameter in our Where method will point to a method that contains the logic to do our filtering thereby freeing our Where method from any dependency. The method is shown below: 1: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 2: foreach (Employee emp in employees) { 3: if (filter(emp)) { 4: yield return emp; 5: } 6: } 7: } Making the change to our app, we create a new instance of the Filter delegate on line 14 with a target set to the method EmployeeHasEvenId. Running the code will produce the same output. 1: public delegate bool Filter(Employee emp); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, filterDelegate); 16:  17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36:  37: public class Employee { 38: public int ID { get; set;} 39: public string FirstName { get; set;} 40: public string LastName {get; set;} 41: public string Country { get; set; } 42: } Lets use lambda expressions to inline the contents of the EmployeeHasEvenId method in place of the method. The next code snippet shows this change (see line 15).  For brevity, the Employee class declaration has been skipped. 1: public delegate bool Filter(Employee emp); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 16:  17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36:  The output displays the same two employees.  Our Where method is too restricted since it works with a collection of Employees only. Lets change it so that it works with any IEnumerable<T>. In addition, you may recall from my previous post,  that .NET 3.5 comes with a lot of predefined delegates including public delegate TResult Func<T, TResult>(T arg); We will get rid of our Filter delegate and use the one above instead. We apply these two changes to our code. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12:  13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14:  15: foreach (Employee emp in filteredEmployees) { 16: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 17: emp.ID, emp.FirstName, emp.LastName, emp.Country); 18: } 19: Console.ReadLine(); 20: } 21: 22: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 23: foreach (var x in source) { 24: if (filter(x)) { 25: yield return x; 26: } 27: } 28: } 29: } We have successfully implemented a way to filter any IEnumerable<T> based on a  filter criteria. Projection Now lets enumerate on the items in the IEnumerable<Employee> we got from the Where method and copy them into a new IEnumerable<EmployeeFormatted>. The EmployeeFormatted class will only have a FullName and ID property. 1: public class EmployeeFormatted { 2: public int ID { get; set; } 3: public string FullName {get; set;} 4: } We could “project” our existing IEnumerable<Employee> into a new collection of IEnumerable<EmployeeFormatted> with the help of a new method. We will call this method Select ;-) 1: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 2: foreach (var emp in employees) { 3: yield return new EmployeeFormatted { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; 7: } 8: } The changes are applied to our app. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12:  13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14: var formattedEmployees = Select(filteredEmployees); 15:  16: foreach (EmployeeFormatted emp in formattedEmployees) { 17: Console.WriteLine("ID {0} Full_Name {1}", 18: emp.ID, emp.FullName); 19: } 20: Console.ReadLine(); 21: } 22:  23: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 24: foreach (var x in source) { 25: if (filter(x)) { 26: yield return x; 27: } 28: } 29: } 30: 31: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 32: foreach (var emp in employees) { 33: yield return new EmployeeFormatted { 34: ID = emp.ID, 35: FullName = emp.LastName + ", " + emp.FirstName 36: }; 37: } 38: } 39: } 40:  41: public class Employee { 42: public int ID { get; set;} 43: public string FirstName { get; set;} 44: public string LastName {get; set;} 45: public string Country { get; set; } 46: } 47:  48: public class EmployeeFormatted { 49: public int ID { get; set; } 50: public string FullName {get; set;} 51: } Output: ID 2 Full_Name Ashlock, Jim ID 4 Full_Name Anderson, Jill We have successfully selected employees who have an even ID and then shaped our data with the help of the Select method so that the final result is an IEnumerable<EmployeeFormatted>.  Lets make our Select method more generic so that the user is given the freedom to shape what the output would look like. We can do this, like before, with lambda expressions. Our Select method is changed to accept a delegate as shown below. TSource will be the type of data that comes in and TResult will be the type the user chooses (shape of data) as returned from the selector delegate. 1:  2: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 3: foreach (var x in source) { 4: yield return selector(x); 5: } 6: } We see the new changes to our app. On line 15, we use lambda expression to specify the shape of the data. In this case the shape will be of type EmployeeFormatted. 1:  2: public class Program 3: { 4: [STAThread] 5: static void Main(string[] args) 6: { 7: var employees = new List<Employee> { 8: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 9: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 10: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 11: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 12: }; 13:  14: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 15: var formattedEmployees = Select(filteredEmployees, (emp) => 16: new EmployeeFormatted { 17: ID = emp.ID, 18: FullName = emp.LastName + ", " + emp.FirstName 19: }); 20:  21: foreach (EmployeeFormatted emp in formattedEmployees) { 22: Console.WriteLine("ID {0} Full_Name {1}", 23: emp.ID, emp.FullName); 24: } 25: Console.ReadLine(); 26: } 27: 28: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 29: foreach (var x in source) { 30: if (filter(x)) { 31: yield return x; 32: } 33: } 34: } 35: 36: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 37: foreach (var x in source) { 38: yield return selector(x); 39: } 40: } 41: } The code outputs the same result as before. On line 14 we filter our data and on line 15 we project our data. What if we wanted to be more expressive and concise? We could combine both line 14 and 15 into one line as shown below. Assuming you had to perform several operations like this on our collection, you would end up with some very unreadable code! 1: var formattedEmployees = Select(Where(employees, emp => emp.ID % 2 == 0), (emp) => 2: new EmployeeFormatted { 3: ID = emp.ID, 4: FullName = emp.LastName + ", " + emp.FirstName 5: }); A cleaner way to write this would be to give the appearance that the Select and Where methods were part of the IEnumerable<T>. This is exactly what extension methods give us. Extension methods have to be defined in a static class. Let us make the Select and Where extension methods on IEnumerable<T> 1: public static class MyExtensionMethods { 2: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 3: foreach (var x in source) { 4: if (filter(x)) { 5: yield return x; 6: } 7: } 8: } 9: 10: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 11: foreach (var x in source) { 12: yield return selector(x); 13: } 14: } 15: } The creation of the extension method makes the syntax much cleaner as shown below. We can write as many extension methods as we want and keep on chaining them using this technique. 1: var formattedEmployees = employees 2: .Where(emp => emp.ID % 2 == 0) 3: .Select (emp => new EmployeeFormatted { ID = emp.ID, FullName = emp.LastName + ", " + emp.FirstName }); Making these changes and running our code produces the same result. 1: using System; 2: using System.Collections.Generic; 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15:  16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new EmployeeFormatted { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24:  25: foreach (EmployeeFormatted emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32:  33: public static class MyExtensionMethods { 34: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48:  49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } 55:  56: public class EmployeeFormatted { 57: public int ID { get; set; } 58: public string FullName {get; set;} 59: } Let’s change our code to return a collection of anonymous types and get rid of the EmployeeFormatted type. We see that the code produces the same output. 1: using System; 2: using System.Collections.Generic; 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15:  16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24:  25: foreach (var emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32:  33: public static class MyExtensionMethods { 34: public static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: public static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48:  49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } To be more expressive, C# allows us to write our extension method calls as a query expression. Line 16 can be rewritten a query expression like so: 1: var formattedEmployees = from emp in employees 2: where emp.ID % 2 == 0 3: select new { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; When the compiler encounters an expression like the above, it simply rewrites it as calls to our extension methods.  So far we have been using our extension methods. The System.Linq namespace contains several extension methods for objects that implement the IEnumerable<T>. You can see a listing of these methods in the Enumerable class in the System.Linq namespace. Let’s get rid of our extension methods (which I purposefully wrote to be of the same signature as the ones in the Enumerable class) and use the ones provided in the Enumerable class. Our final code is shown below: 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; //Added 4:  5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 15: }; 16:  17: var formattedEmployees = from emp in employees 18: where emp.ID % 2 == 0 19: select new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: }; 23:  24: foreach (var emp in formattedEmployees) { 25: Console.WriteLine("ID {0} Full_Name {1}", 26: emp.ID, emp.FullName); 27: } 28: Console.ReadLine(); 29: } 30: } 31:  32: public class Employee { 33: public int ID { get; set;} 34: public string FirstName { get; set;} 35: public string LastName {get; set;} 36: public string Country { get; set; } 37: } 38:  39: public class EmployeeFormatted { 40: public int ID { get; set; } 41: public string FullName {get; set;} 42: } This post has shown you a basic overview of LINQ to Objects work by showning you how an expression is converted to a sequence of calls to extension methods when working directly with objects. It gets more interesting when working with LINQ to SQL where an expression tree is constructed – an in memory data representation of the expression. The C# compiler compiles these expressions into code that builds an expression tree at runtime. The provider can then traverse the expression tree and generate the appropriate SQL query. You can read more about expression trees in this MSDN article.

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • WebGrid Helper and Complex Types

    - by imran_ku07
        Introduction:           WebGrid helper makes it very easy to show tabular data. It was originally designed for ASP.NET Web Pages(WebMatrix) to display, edit, page and sort tabular data but you can also use this helper in ASP.NET Web Forms and ASP.NET MVC. When using this helper, sometimes you may run into a problem if you use complex types in this helper. In this article, I will show you how you can use complex types in WebGrid helper.       Description:             Let's say you need to show the employee data and you have the following classes,   public class Employee { public string Name { get; set; } public Address Address { get; set; } public List<string> ContactNumbers { get; set; } } public class Address { public string City { get; set; } }               The Employee class contain a Name, an Address and list of ContactNumbers. You may think that you can easily show City in WebGrid using Address.City, but no. The WebGrid helper will throw an exception at runtime if any Address property is null in the Employee list. Also, you cannot directly show ContactNumbers property. The easiest way to show these properties is to add some additional properties,   public Address NotNullableAddress { get { return Address ?? new Address(); } } public string Contacts { get { return string.Join("; ",ContactNumbers); } }               Now you can easily use these properties in WebGrid. Here is the complete code of this example,  @functions{ public class Employee { public Employee(){ ContactNumbers = new List<string>(); } public string Name { get; set; } public Address Address { get; set; } public List<string> ContactNumbers { get; set; } public Address NotNullableAddress { get { return Address ?? new Address(); } } public string Contacts { get { return string.Join("; ",ContactNumbers); } } } public class Address { public string City { get; set; } } } @{ var myClasses = new List<Employee>{ new Employee { Name="A" , Address = new Address{ City="AA" }, ContactNumbers = new List<string>{"021-216452","9231425651"}}, new Employee { Name="C" , Address = new Address{ City="CC" }}, new Employee { Name="D" , ContactNumbers = new List<string>{"045-14512125","21531212121"}} }; var grid = new WebGrid(source: myClasses); } @grid.GetHtml(columns: grid.Columns( grid.Column("NotNullableAddress.City", header: "City"), grid.Column("Name"), grid.Column("Contacts")))                    Summary:           You can use WebGrid helper to show tabular data in ASP.NET MVC, ASP.NET Web Forms and  ASP.NET Web Pages. Using this helper, you can also show complex types in the grid. In this article, I showed you how you use complex types with WebGrid helper. Hopefully you will enjoy this article too.  

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  • A developer&rsquo;s WBS &ndash; 3 factors of 5

    - by johndoucette
    As a development manager, I have requested work breakdown structures (WBS) many times from the dev leads. Everyone has their own approach and why it takes sometimes days to get this simple list is often frustrating. Here is a simple way to get that elusive WBS done in 30 minutes and have 125 items in your list – well, 126. The WBS is made up of parent-child entities representing the overall outcome of the project. At the bottom of the hierarchical list should be the task item that a developer would perform in support of the branch in the list or WBS. Because I work with different dev leads on every project, I always ask the “what time value would you like to see at the lowest task in order to assign it to a developer and ensure it gets done within the timeframe”. I am particular to a task being 8 hours. Some like 8 to 24 hours. Stay away from tasks defaulting to 1 week. The task becomes way to vague and hard to manage completeness, especially on short budgets. As a developer, your focus is identifying the tasks you to accomplish in order to deliver the product. As a project manager, you will take the developer's WBS and add all the “other stuff” like quality testing, meetings, documentation, transition to maintenance, etc… Start your exercise with the name of the product you are delivering as a result of the project. You should be able to represent what you are building and deploying with one to three words. Example; XYZ Public Website Middleware BizTalk Application The reason you start with that single identifier is to always see the list as the product. It helps during each of the next three passes. Now, choose 5 tasks which in their entirety represent the product you will be delivering and add them to list under the product name you created earlier; Public Website     Security     Sites     Infrastructure     Publishing     Creative Continue this concept of seeing the list as the complete picture and decompose it one more level. You should have 25 items. Public Website     Security         Authentication         Login Control         Administration         DRM         Workflow     Sites         Masterpages         Page Layouts         Web Parts (RIA, Multimedia)         Content Types         Structures     Infrastructure         ...     Publishing         ...     Creative         ... And one more time for a total of 125 items. The top item makes the list 126. Public Website     Security         Authentication             Install (AD/ADAM/LDAP/SQL)             Configuration             Management             Web App Configuration             Implement Provider         Login Control             Login Form             Login/Logoff             pw change             pw recover/forgot             email verification         Administration             ...         DRM             ...         Workflow             ...     Sites         Masterpages         Page Layouts         Web Parts (RIA, Multimedia)         Content Types         Structures     Infrastructure         ...     Publishing         ...     Creative         ... The next step is to make sure the task at the bottom of every branch represents the “time value” you planned for the project. You can add more to the WBS and of course if you can’t find 5 items, 4 is fine. If a task can be done in a fraction of the time value you determined for the project, try to roll it up into a larger task. In the task actions (later when the iteration is being planned), decompose the details back to the simple tasks. Now, go estimate!

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  • Kinect losing tracked players with Beta2 SDK

    - by Eric B
    So i'm creating a game using the Beta2 SDK for Kinect. The issue i am having is that in the middle of gameplay if another person enters the Kinects FOV it stops tracking the player and will not track anyone else for several minutes. Same deal if the player leaves the FOV and reenters it. Here is what im using to detect players. void nui_SkeletonFrameReady(object sender, SkeletonFrameReadyEventArgs e) { int playersAlive = 0; // reset lists skeletons = new Dictionary<int, SkeletonData>(); //create a new list for skeletons menuSkeleton = new List<SkeletonData>(); initialPlayers = new Dictionary<float, SkeletonData>(); //create a new list for initialPlayers foreach (SkeletonData s in e.SkeletonFrame.Skeletons) //for each skeleton the kinect has detected { if (s.TrackingState == SkeletonTrackingState.Tracked) // players found { menuSkeleton.Add(s); if (initialized) // after initialization { skeletons.Add(s.TrackingID, s); } else // before initialization initialPlayers.Add(s.Joints[JointID.ShoulderCenter].Position.X, s); //if we are not initialized then add this player to the inital player list. playersAlive++; } } if (playersAlive == TOTAL_PLAYERS_ALLOWED) // If there is one player { if (!inMiniGame) // Before the game starts gameStart = DateTime.Now; // Reset initialization timer if (!initialized) // Before initialization // NOTE TO SELF I TOOK OUT && inMenu { InitializePlayers(); if (DateTime.Now.Subtract(gameStart).TotalMilliseconds > INITIALIZATION_WAIT_TIME) { initialized = true; // initialize timers from fixed starting time if (inMiniGame) //if the game has started { gamePause = gameStart; //TODO ERIC: Initialize any Timers Here } } } } } /// <summary> /// this function initializes the players adding them to a list /// and making one of the players the menu controller, for LIM we will need to change the code so that the /// game only recognizes and supports one player at a time /// variable names will need to be change as well. /// </summary> private void InitializePlayers() { List<float> initialPos = new List<float>(); // used to track starting positions players = new Dictionary<int, Player>(); foreach (float pos in initialPlayers.Keys) { initialPos.Add(pos); //add position of each inital player to list } float first = initialPos[0]; // left player first, right second Player player = new Player(initialPlayers[first].TrackingID, true); player.PlayerNumber = PLAYER_ONE; player.Skeleton = initialPlayers[first]; player.Specifics = new PlayerSpecifics(player.PlayerNumber); player.Specifics.PauseTimer = gameStart; players.Add(initialPlayers[first].TrackingID, player); menuController = initialPlayers[first].TrackingID; //menu controller is player 1 } This is a one player game. Also when the game starts Initialize is set to false, and gets set to true when i go from the games menu into the gameplay. So can anyone see any issues with this code block that would cause the kinect to lose players as they enter/exit the FOV? and not re-track them? Thank you for any help.

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  • SharePoint Content and Site Editing Tips

    - by Bil Simser
    A few content management and site editing tips for power users on this bacon flavoured unicorn morning. The theme here is keep it clean!Write "friendly" email addressesRemember it's human beings reading your content. So seeing something like "If you have questions please send an email to [email protected]" breaks up the readiblity. Instead just do the simple steps of writing the content in plain English and going back, highlighting the name and insert a link (note: you might have to prefix the link with mailto:[email protected]). It makes for a friendlier looking page and hides the ugliness that are sometimes in email addresses.Use friendly column and list namesThis is a big pet peeve of mine. When you first create a column or list with spaces the internal name is changed. The display name might be "My Amazing List of Animals with Large Testicles" but the internal (and link) name becomes "My_x00x20_Amazing_x00x20_List_x00x20_of_x00x20_Animals_x00x20_with_x00x20_Large_x00x20_Testicles". What's worse is if you create a publishing page named "This Website is Fueled By a Dolphin's Spleen". Not only is it incorrect grammar, but the apostrophe wreaks havoc on both the internal name for the list (with lots of crazy hex codes) as well as the hyperlink (where everything is uuencoded). Instead create the list with a distinct and compact name then go back and change it to whatever you want. The end result is a better formed name that you can both script and access in code easier.Keep your Views CleanWhen you add a column to a list or create a new list the default is to add it to the default view. Do everyone a favour and don't check this box! The default view of a list should be something similar to the Title field and nothing else. Keep it clean. If you want to set a defalt view that's different, go back and create one with all the fields and filtering and sorting columns you want and set it as default. It's a good idea to keep the original AllItems.aspx (note the lack of space in the filename!) easy and unfiltered. It's also a good idea to keep your column count down in views. Don't let every column be added by default and don't add every column just because you can. Create separate views for distinct responsibilities and try to keep the number of columns down to a single screen to prevent horizontal scrolling.Simple NavigationThe Quick Launch is a great tool for navigating around your site but don't use the default of adding all lists to it. Uncheck that box and keep navigation simple. Create custom groupings that make sense so if you don't have a site with "Documents and Lists" but "Reports and Notices" makes more sense then do it. Also hide internal lists from the Quick Launch. For example, if most users don't need to see all the lookup tables you might have on a site don't show them. You can use audience filtering on the Quick Launch if you want to hide admin items from non-admin users so consider that as an option.Enjoy!

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  • Why is this beat detection code failing to register some beats properly?

    - by Quincy
    I made this SoundAnalyzer class to detect beats in songs: class SoundAnalyzer { public SoundBuffer soundData; public Sound sound; public List<double> beatMarkers = new List<double>(); public SoundAnalyzer(string path) { soundData = new SoundBuffer(path); sound = new Sound(soundData); } // C = threshold, N = size of history buffer / 1024 B = bands public void PlaceBeatMarkers(float C, int N, int B) { List<double>[] instantEnergyList = new List<double>[B]; GetEnergyList(B, ref instantEnergyList); for (int i = 0; i < B; i++) { PlaceMarkers(instantEnergyList[i], N, C); } beatMarkers.Sort(); } private short[] getRange(int begin, int end, short[] array) { short[] result = new short[end - begin]; for (int i = 0; i < end - begin; i++) { result[i] = array[begin + i]; } return result; } // get a array of with a list of energy for each band private void GetEnergyList(int B, ref List<double>[] instantEnergyList) { for (int i = 0; i < B; i++) { instantEnergyList[i] = new List<double>(); } short[] samples = soundData.Samples; float timePerSample = 1 / (float)soundData.SampleRate; int sampleIndex = 0; int nextSamples = 1024; int samplesPerBand = nextSamples / B; // for the whole song while (sampleIndex + nextSamples < samples.Length) { complex[] FFT = FastFourier.Calculate(getRange(sampleIndex, nextSamples + sampleIndex, samples)); // foreach band for (int i = 0; i < B; i++) { double energy = 0; for (int j = 0; j < samplesPerBand; j++) energy += FFT[i * samplesPerBand + j].GetMagnitude(); energy /= samplesPerBand; instantEnergyList[i].Add(energy); } if (sampleIndex + nextSamples >= samples.Length) nextSamples = samples.Length - sampleIndex - 1; sampleIndex += nextSamples; samplesPerBand = nextSamples / B; } } // place the actual markers private void PlaceMarkers(List<double> instantEnergyList, int N, float C) { double timePerSample = 1 / (double)soundData.SampleRate; int index = N; int numInBuffer = index; double historyBuffer = 0; //Fill the history buffer with n * instant energy for (int i = 0; i < index; i++) { historyBuffer += instantEnergyList[i]; } // If instantEnergy / samples in buffer < instantEnergy for the next sample then add beatmarker. while (index + 1 < instantEnergyList.Count) { if(instantEnergyList[index + 1] > (historyBuffer / numInBuffer) * C) beatMarkers.Add((index + 1) * 1024 * timePerSample); historyBuffer -= instantEnergyList[index - numInBuffer]; historyBuffer += instantEnergyList[index + 1]; index++; } } } For some reason it's only detecting beats from 637 sec to around 641 sec, and I have no idea why. I know the beats are being inserted from multiple bands since I am finding duplicates, and it seems that it's assigning a beat to each instant energy value in between those values. It's modeled after this: http://www.flipcode.com/misc/BeatDetectionAlgorithms.pdf So why won't the beats register properly?

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  • Optimal Data Structure for our own API

    - by vermiculus
    I'm in the early stages of writing an Emacs major mode for the Stack Exchange network; if you use Emacs regularly, this will benefit you in the end. In order to minimize the number of calls made to Stack Exchange's API (capped at 10000 per IP per day) and to just be a generally responsible citizen, I want to cache the information I receive from the network and store it in memory, waiting to be accessed again. I'm really stuck as to what data structure to store this information in. Obviously, it is going to be a list. However, as with any data structure, the choice must be determined by what data is being stored and what how it will be accessed. What, I would like to be able to store all of this information in a single symbol such as stack-api/cache. So, without further ado, stack-api/cache is a list of conses keyed by last update: `(<csite> <csite> <csite>) where <csite> would be (1362501715 . <site>) At this point, all we've done is define a simple association list. Of course, we must go deeper. Each <site> is a list of the API parameter (unique) followed by a list questions: `("codereview" <cquestion> <cquestion> <cquestion>) Each <cquestion> is, you guessed it, a cons of questions with their last update time: `(1362501715 <question>) (1362501720 . <question>) <question> is a cons of a question structure and a list of answers (again, consed with their last update time): `(<question-structure> <canswer> <canswer> <canswer> and ` `(1362501715 . <answer-structure>) This data structure is likely most accurately described as a tree, but I don't know if there's a better way to do this considering the language, Emacs Lisp (which isn't all that different from the Lisp you know and love at all). The explicit conses are likely unnecessary, but it helps my brain wrap around it better. I'm pretty sure a <csite>, for example, would just turn into (<epoch-time> <api-param> <cquestion> <cquestion> ...) Concerns: Does storing data in a potentially huge structure like this have any performance trade-offs for the system? I would like to avoid storing extraneous data, but I've done what I could and I don't think the dataset is that large in the first place (for normal use) since it's all just human-readable text in reasonable proportion. (I'm planning on culling old data using the times at the head of the list; each inherits its last-update time from its children and so-on down the tree. To what extent this cull should take place: I'm not sure.) Does storing data like this have any performance trade-offs for that which must use it? That is, will set and retrieve operations suffer from the size of the list? Do you have any other suggestions as to what a better structure might look like?

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  • How can I forward ALL traffic over a site-to-site VPN on Cisco ASA?

    - by Scott Clements
    Hi There, I currently have two Cisco ASA 5100 routers. They are at different physical sites and are configured with a site-to-site VPN which is active and working. I can communicate with the subnets on either site from the other and both are connected to the internet, however I need to ensure that all the traffic at my remote site goes through this VPN to my site here. I know that the web traffic is doing so as a "tracert" confirms this, but I need to ensure that all other network traffic is being directed over this VPN to my network here. Here is my config for the ASA router at my remote site: hostname ciscoasa domain-name xxxxx enable password 78rl4MkMED8xiJ3g encrypted names ! interface Ethernet0/0 nameif NIACEDC security-level 100 ip address x.x.x.x 255.255.255.0 ! interface Ethernet0/1 description External Janet Connection nameif JANET security-level 0 ip address x.x.x.x 255.255.255.248 ! interface Ethernet0/2 shutdown no nameif security-level 100 no ip address ! interface Ethernet0/3 shutdown no nameif security-level 100 ip address dhcp setroute ! interface Management0/0 nameif management security-level 100 ip address 192.168.100.1 255.255.255.0 management-only ! passwd 2KFQnbNIdI.2KYOU encrypted ftp mode passive clock timezone GMT/BST 0 clock summer-time GMT/BDT recurring last Sun Mar 1:00 last Sun Oct 2:00 dns domain-lookup NIACEDC dns server-group DefaultDNS name-server 154.32.105.18 name-server 154.32.107.18 domain-name XXXX same-security-traffic permit inter-interface same-security-traffic permit intra-interface access-list ren_access_in extended permit ip any any access-list ren_access_in extended permit tcp any any access-list ren_nat0_outbound extended permit ip 192.168.6.0 255.255.255.0 192.168.3.0 255.255.255.0 access-list NIACEDC_nat0_outbound extended permit ip 192.168.12.0 255.255.255.0 192.168.3.0 255.255.255.0 access-list JANET_20_cryptomap extended permit ip 192.168.12.0 255.255.255.0 192.168.3.0 255.255.255.0 access-list NIACEDC_access_in extended permit ip any any access-list NIACEDC_access_in extended permit tcp any any access-list JANET_access_out extended permit ip any any access-list NIACEDC_access_out extended permit ip any any pager lines 24 logging enable logging asdm informational mtu NIACEDC 1500 mtu JANET 1500 mtu management 1500 icmp unreachable rate-limit 1 burst-size 1 asdm image disk0:/asdm-522.bin no asdm history enable arp timeout 14400 nat-control global (NIACEDC) 1 interface global (JANET) 1 interface nat (NIACEDC) 0 access-list NIACEDC_nat0_outbound nat (NIACEDC) 1 192.168.12.0 255.255.255.0 access-group NIACEDC_access_in in interface NIACEDC access-group NIACEDC_access_out out interface NIACEDC access-group JANET_access_out out interface JANET route JANET 0.0.0.0 0.0.0.0 194.82.121.82 1 route JANET 0.0.0.0 0.0.0.0 192.168.3.248 tunneled timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00 timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00 timeout uauth 0:05:00 absolute http server enable http 192.168.12.0 255.255.255.0 NIACEDC http 192.168.100.0 255.255.255.0 management http 192.168.9.0 255.255.255.0 NIACEDC no snmp-server location no snmp-server contact snmp-server enable traps snmp authentication linkup linkdown coldstart crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac crypto map JANET_map 20 match address JANET_20_cryptomap crypto map JANET_map 20 set pfs crypto map JANET_map 20 set peer X.X.X.X crypto map JANET_map 20 set transform-set ESP-AES-256-SHA crypto map JANET_map interface JANET crypto isakmp enable JANET crypto isakmp policy 10 authentication pre-share encryption aes-256 hash sha group 2 lifetime 86400 crypto isakmp policy 30 authentication pre-share encryption 3des hash sha group 2 lifetime 86400 crypto isakmp policy 50 authentication pre-share encryption aes-256 hash sha group 5 lifetime 86400 tunnel-group X.X.X.X type ipsec-l2l tunnel-group X.X.X.X ipsec-attributes pre-shared-key * telnet timeout 5 ssh timeout 5 console timeout 0 dhcpd address 192.168.100.2-192.168.100.254 management dhcpd enable management ! ! class-map inspection_default match default-inspection-traffic ! ! policy-map type inspect dns preset_dns_map parameters message-length maximum 512 policy-map global_policy class inspection_default inspect dns preset_dns_map inspect ftp inspect h323 h225 inspect h323 ras inspect rsh inspect rtsp inspect esmtp inspect sqlnet inspect skinny inspect sunrpc inspect xdmcp inspect sip inspect netbios inspect tftp inspect http ! service-policy global_policy global prompt hostname context no asdm history enable Thanks in advance, Scott

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  • C programming: hashtable insertion/search

    - by Ricardo Campos
    Hello i have a problem with my hash table its implemented like this: #define HT_SIZE 10 typedef struct _list_t_ { char key[20]; char string[20]; char prevValue[20]; struct _list_t_ *next; } list_t; typedef struct _hash_table_t_ { int size; /* the size of the table */ list_t ***table; /* first */ sem_t lock; } hash_table_t; I have a Linked list with 3 pointers because i want a hash table with several partitions (shards), here is my initialization of my Hash table: hash_table_t *create_hash_table(int NUM_SERVER_THREADS, int num_shards){ hash_table_t *new_table; int j,i; if (HT_SIZE<1) return NULL; /* invalid size for table */ /* Attempt to allocate memory for the hashtable structure */ new_table = (hash_table_t*)malloc(sizeof(hash_table_t)*HT_SIZE); /* Attempt to allocate memory for the table itself */ new_table->table = (list_t ***)calloc(1,sizeof(list_t **)); /* Initialize the elements of the table */ for(j=0; j<num_shards; j++){ new_table->table[j] = (list_t **)calloc(1,sizeof(list_t *)); for(i=0; i<HT_SIZE; i++){ new_table->table[j][i] = (list_t *)calloc(1,sizeof(list_t )); } } /* Set the table's size */ new_table->size = HT_SIZE; sem_init(&new_table->lock, 0, 1); return new_table; } Here is my search function to search in the hash table list_t *lookup_string(hash_table_t *hashtable, char *key, int shardId){ list_t *list ; int hashval = hash(key); /* Go to the correct list based on the hash value and see if key is * in the list. If it is, return return a pointer to the list element. * If it isn't, the item isn't in the table, so return NULL. */ sem_wait(&hashtable->lock); for(list = hashtable->table[shardId][hashval]; list != NULL; list =list->next) { if (strcmp(key, list->key) == 0){ sem_post(&hashtable->lock); return list; } } sem_post(&hashtable->lock); return NULL; } And my insert function: char *add_string(hash_table_t *hashtable, char *str,char *key, int shardId){ list_t *new_list; list_t *current_list; unsigned int hashval = hash(key); /*printf("|%d|%d|%s|\n",hashval,shardId,key);*/ /* Lock for concurrency */ sem_wait(&hashtable->lock); /* Attempt to allocate memory for list */ new_list = (list_t*)malloc(sizeof(list_t)); /* Does item already exist? */ sem_post(&hashtable->lock); current_list = lookup_string(hashtable, key,shardId); sem_wait(&hashtable->lock); /* item already exists, don't insert it again. */ if (current_list != NULL){ strcpy(new_list->prevValue,current_list->string); strcpy(new_list->string,str); strcpy(new_list->key,key); new_list->next = hashtable->table[shardId][hashval]; hashtable->table[shardId][hashval] = new_list; sem_post(&hashtable->lock); return new_list->prevValue; } /* Insert into list */ strcpy(new_list->string,str); strcpy(new_list->key,key); new_list->next = hashtable->table[shardId][hashval]; hashtable->table[shardId][hashval] = new_list; /* Unlock */ sem_post(&hashtable->lock); return new_list->prevValue; } My main class runs some of tests by executing the insertion / reading / delete from the elements of the hash table the problem is when i have more than 4 partitions/shards the tests stop at the first reading element saying it returned the wrong value NULL on the search function, when its less than 4 it runs perfectly well and passes all the tests. You can see my main.c in here if you want to give a look: http://hostcode.sourceforge.net/view/1105 My complete Hash table code: http://hostcode.sourceforge.net/view/1103 And other functions where hash table code is executed: .c file http://hostcode.sourceforge.net/view/1104 .h file http://hostcode.sourceforge.net/view/1106 Thank for you time, i appreciate any help you can give to me this is a college important project that I'm trying to solve and I'm stuck here for 2 days.

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  • how to fix "BusyBox v1.17.1 (Ubuntu 1:1.17.1-10ubuntu1) built-in shell (ash) Enter 'help' for a list of built-in commands?"

    - by Joseph
    So I was using Ubuntu when suddenly the whole thing froze up and I had to reboot. And from that moment on, the system when it is starting up, prompts this little selection menu: GNU GRUB version 1.99~rc1-13ubuntu3 Ubuntu, with Linux 2.6.38-10-generic ubuntu, with Linux 2.6.38-10-generic (recovery mode) Previous Linux versions Memory test (memtest86+) Memory test (memtest86+, serial console 115200) I have chosen all of the available choices but all I get is another command line system that reads: BusyBox v1.17.1 (Ubuntu 1:1.17.1-10ubuntu1) built-in shell (ash) Enter 'help' for a list of built-in commands. (initramfs): And honestly I can't do anything with it. Does anyone have any idea of what is going on and how I can get Ubuntu to work again?

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  • Happy 3rd Birthday SilverlightCream!

    - by Dave Campbell
    Happy 3rd Birthday!     Yesterday (May 16) was the 'Birthday' of SilverlightCream, which started just after MIX in 2007 with a post "Interesting Silverlight posts today: Silverlight Control & Silverlight Pad". Too many good posts flying around led me to want to archive them, particularly since I was being aggregated at a new site Silverlight.net, and I could give some of that 'reach' to the community. Saturday's post was number 862, and as of that post, there were 5697 blog posts archived in the database all tagged up and searchable at SilverlightCream.com using the search page. The search needs to be better, and that's another discussion, but it does work. The blog didn't begin life as the SilverlightCream blog, as is obvious from the name, but once I realized people were following it closely, I've tried to keep the signal-to-noise ratio very high. I even secured another blog for when I just want to rant about something to keep that stuff out of this one :) If you've been around since MIX07 days you've heard all this, but after talking to some people at MIX10 I realized not everyone knows all the ways the information is presented, so I figured doing a post like this once a year probably isn't a bad idea :) I scrounge through an ever-growing list of blogs (right now sitting at 505) looking for good stuff. I try to spin through the list every day, but with the list growing that large, it's getting tough. I usually use it as a background task while working or watching TV. If I just sit and go through the blogs it takes about an hour. The list is long enough now that from time to time, I'll only get partway through it and have 10 to 13 entries, so I'll just stop there and go on the next day... I don't like to have more than 15 in any single post. It's all pattern recognition as in "seen that", "seen that", "that's new", etc... so if you're a blogger, look at a heading below for some comments about blogging from my perspective. When I see something new, I make sure you're not pulling a 'Mike Taulty' on me and dumping 6 or 8 new posts in one day :), and I tag the ones I want to review. If there's not a lot going on, I may just push the posts as I come across them. Some days there may be 60 posts in that 'to review' list! Some are non-Silverlight, some are essentially duplicates of others, some are demos, ads, new releases of something, session materials, etc. I push lots of material into a database at WynApse.com, and the "Tagged Posts" menu on the left sidebar there takes you to a tag cloud of (at this very moment) "9224 articles tagged 13915 different ways using 459 unique tags". There are links in there on Gibson guitars, Jazz Guitar instructional stuff, Ford F-250 links, and tons of technical and non-technical stuff I've been aggregating for about 5 years now. So when I decide to blog (or shoutout) something, I first push it into the database at WynApse.com. Then I tag it all up and push it into the database at SilverlightCream.com. Then it gets pushed to @SilverlightNews. For a little over a year now, we're tracking unique IP hits on posts launched from either the blog post or from one of the SilverlightCream.com pages, and the posts with top hits from unique IP addresses in the last 7 days are displayed in a 'Skim' page at SilverlightCream... and that page needs work as well. The Skim page and tracking was the brainchild of my buddy Michael Washington. What I blog/shoutout After some time doing posts, I decided there were things that probably have no need to be searchable, but are good information, so I post those as 'Shoutouts'. Eventually I also decided the Shoutouts should get posted to @SilverlightNews, and that's now taking place. Notes to bloggers Remember I said spinning throught the Big List-o-BlogsTM is pattern recognition... that means I don't spend a lot of time on any individual blog deciding if it has new content. If you're familiar with the term 'Above the Fold', then you're probably ok. If I have to scroll the page to see if there's something new, or wade through some maze of menus, I'm probably going to miss new stuff. Likewise if you only show the latest on the front page and make it a puzzle to find the rest of them, or if you make the titles and initial graphics almost identical to the previous article, I'll miss it. Another thing is name/brand-recognition. Far be it for me (WynApse) to comment on someone blogging with a pseudonym, but if you want to get get some recognition, you are going to want your name to be available somewhere. I can think right off the top of my head of a couple good blogs that I have no idea of the individuals' real names. I can pull that off a bit because I've been around so long almost everyone knows who I am, but if you're new to the blog-o-sphere, being able to be name-recognized is as important as getting your brand out there. Kick my tires Finally, stuff happens... I may hit the wrong key and delete your blog, or a post might slip past me and I not realize it's new because of the naming, and never blog it. If you think I missed something, send me an email or use the submit page at SilverlightCream.com. Some bloggers have figured out that if they submit (one way or another) to me, their posts will go out next. I try to honor anyone that takes the time to submit with a quicker 'Cream posting. Thanks! Finally, thanks to everyone that contributes to the community as a whole... the blogs, the videos, and the presentations. A special thanks to everyone that reads SilverlightCream, or follows @WynApse or @SilverlightNews. Keep it all coming, and... Stay in the 'Light

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  • JQuery and the multiple date selector

    - by David Carter
    Overview I recently needed to build a web page that would allow a user to capture some information and most importantly select multiple dates. This functionality was core to the application and hence had to be easy and quick to do. This is a public facing website so it had to be intuitive and very responsive. On the face of it it didn't seem too hard, I know enough juery to know what it is capable of and I was pretty sure that there would be some plugins that would help speed things along the way. I'm using ASP.Net MVC for this project as I really like the control that it gives you over the generated html and javascript. After years of Web Forms development it makes me feel like a web developer again and puts a smile on my face, that can only be a good thing!   The Calendar The first item that I needed on this page was a calender and I wanted the ability to: have the calendar be always visible select/deselect multiple dates at the same time bind to the select/deselect event so that I could update a seperate listing of the selected dates allow the user to move to another month and still have the calender remember any dates in the previous month I was hoping that there was a jQuery plugin that would meet my requirements and luckily there was! The jQuery datepicker does everything I want and there is quite a bit of documentation on how to use it. It makes use of a javascript date library date.js which I had not come across before but has a number of very useful date utilities that I have used elsewhere in the project. As you can see from the image there still needs to be some styling done! But there will be plenty of time for that later. The calendar clearly shows which dates the user has selected in red and i also make use of an unordered list to show the the selected dates so the user can always clearly see what has been selected even if they move to another month on the calendar. The javascript code that is responsible for listening to events on the calendar and synchronising the list look as follows: <script type="text/javascript">     $(function () {         $('.datepicker').datePicker({ inline: true, selectMultiple: true })         .bind(             'dateSelected',             function (e, selectedDate, $td, state) {                                 var dateInMillisecs = selectedDate.valueOf();                 if (state) { //adding a date                     var newDate = new Date(selectedDate);                     //insert the new item into the correct place in the list                     var listitems = $('#dateList').children('li').get();                     var liToAdd = "<li id='" + dateInMillisecs + "' >" + newDate.toString('ddd dd MMM yyyy') + "</li>";                     var targetIndex = -1;                     for (var i = 0; i < listitems.length; i++) {                         if (dateInMillisecs <= listitems[i].id) {                             targetIndex = i;                             break;                         }                     }                     if (targetIndex < 0) {                         $('#dateList').append(liToAdd);                     }                     else {                         $($('#dateList').children("li")[targetIndex]).before(liToAdd);                     }                 }                 else {//removing a date                     $('ul #' + dateInMillisecs).remove();                 }             }         )     }); When a date is selected on the calendar a function is called with a number of parameters passed to it. The ones I am particularly interested in are selectedDate and state. State tells me whether the user has selected or deselected the date passed in the selectedDate parameter. The <ul> that I am using to show the date has an id of dateList and this is what I will be adding and removing <li> items from. To make things a little more logical for the user I decided that the date should be sorted in chronological order, this means that each time a new date is selected it need to be placed in the correct position in the list. One way to do this would be just to append a new <li> to the list and then sort the whole list. However the approach I took was to get an array of all the items in the list var listitems = ('#dateList').children('li').get(); and then check the value of each item in the array against my new date and as soon as I found the case where the new date was less than the current item remember that position in the list as this is where I would insert it later. To make this work easily I decided to store a numeric representation of each date in the list in the id attribute of each <li> element. Fortunately javascript natively stores dates as the number of milliseconds since 1 Jan 1970. var dateInMillisecs = selectedDate.valueOf(); Please note that this is the value of the date in UTC! I always like to store dates in UTC as I learnt a long time ago that it saves a lot of refactoring at a later date... When I convert the dates back to their original back on the server I will need the UTC offset that was used when calculating the dates, this and how to actually serialise the dates and get them posted back will be the subject of another post.

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  • Best practices for coding date sensitive websites

    - by Duopixel
    I'm creating a website for an event that is coming up. It has some functionality related to the event (such as "send me a reminder"), other stuff that takes place during the event, and finally some stuff that comes after the event. I need to start working on code that takes place during the event and after the event, plus some fixes for the current site (which is already live). What is the best way to approach this problem? Some solutions that occur to me are creating branches for each state and merging stuff as needed. Other one is hiding and showing functionality based on the date, i.e if (currentDate < eventDay) { reminder.show();}. Ideas?

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  • Web services, J2EE, Spring, DB integration project ideas - maybe data mining related?

    - by saral jain
    I am a graduate Computer Science student (Data Mining and Machine Learning) and have good exposure to core Java (3 years). I have read up on a bunch of stuff on the following topics: Design patterns, J2EE Web services (SOAP and REST), Spring, and Hibernate Java Concurrency - advanced features like Task and Executors. I would now like to do a project combining this stuff -- over my free time of course -- to get a better understanding of these things and to kind of make an end to end software (to learn the best design principles etc + SVN, maven). Any good project ideas would be really appreciated. I just want to build this stuff to learn, so I don't really mind re-inventing the wheel. Also, anything related to data mining would be an added bonus as it fits with my research but is absolutely not necessary since this project is more to learn to do large scale software development.

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  • The standards that fail us and the intellectual bubble

    - by Jeff
    There has been a great deal of noise in the techie community about standards, and a sudden and unexplainable hate for Flash. This noise isn't coming from consumers... the countless soccer moms, teens and your weird uncle Bob, it's coming from the people who build (or at least claim to build) the stuff those consumers consume. If you could survey the position of consumers on the topic, they'd likely tell you that they just want stuff on the Web to work.The noise goes something like this: Web standards are the correct and right thing to use across the Intertubes, and anything not a part of those standards (Flash) is bad. Furthermore, the more recent noise is centered around the idea that HTML 5, along with Javascript, is the right thing to use. The arguments against Flash are, well, the truth is I haven't seen a good argument. I see anecdotal nonsense about high CPU usage and things I'd never think to check when I'm watching Piano Cat on YouTube, but these aren't arguments to me. Sure, I've seen it crash a browser a few times, but it's totally rare.But let's go back to standards. Yes, standards have played an important role in establishing the ubiquity of the Web. The protocols themselves, TCP/IP and HTTP, have been critical. HTML, which has served us well for a very long time, established an incredible foundation. Javascript did an OK job, and thanks to clever programmers writing great frameworks like JQuery, is becoming more and more useful. CSS is awful (there, I said it, I feel SO much better), and I'll never understand why it's so disconnected and different from anything else. It doesn't help that it's so widely misinterpreted by different browsers. Still, there's no question that standards are a good thing, and they've been good for the Web, consumers and publishers alike.HTML 4 has been with us for more than a decade. In Web years, that might as well be 80. HTML 5, contrary to popular belief, is not a standard, and likely won't be for many years to come. In fact, the Web hasn't really evolved at all in terms of its standards. The tools that generate the standard markup and script have, but at the end of the day, we're still living with standards that are more than ten years old. The "official" standards process has failed us.The Web evolved anyway, and did not wait for standards bodies to decide what to do next. It evolved in part because Macromedia, then Adobe, kept evolving Flash. In the earlier days, it mostly just did obnoxious splash pages, but then it started doing animation, and then rich apps as they added form input. Eventually it found its killer app: video. Now more than 95% of browsers have Flash installed. Consumers are better for it.But I'll do it one better... I'll go out on a limb and say that Flash is a standard. If it's that pervasive, I don't care what you tell me, it's a standard. Just because a company owns it doesn't mean that it's evil or not a standard. And hey, it pains me to say that as a developer, because I think the dev tools are the suck (more on that in a minute). But again, consumers don't care. They don't even pay for Flash. The bottom line is that if I put something Flash based on the Internet, it's likely that my audience will see it.And what about the speed of standards owned by a company? Look no further than Silverlight. Silverlight 2 (which I consider the "real" start to the story) came out about a year and a half ago. Now version 4 is out, and it has come a very long way in its capabilities. If you believe Riastats.com, more than half of browsers have it now. It didn't have to wait for standards bodies and nerds drafting documents, it's out today. At this rate, Silverlight will be on version 6 or 7 by the time HTML 5 is a ratified standard.Back to the noise, one of the things that has continually disappointed me about this profession is the number of people who get stuck in an intellectual bubble, color it with dogmatic principles, and completely ignore the actual marketplace where this stuff all has to live. We aren't machines; Binary thinking that forces us to choose between "open standards" and "proprietary lock-in" (the most loaded b.s. FUD term evar) isn't smart at all. The truth is that the <object> tag has allowed us to build incredible stuff on top of the old standards, and consumers have benefitted greatly. Consumer desire, capitalism, and yes, standards ratified by nerds who think about this stuff for years have all played a role in the broad adoption of the Interwebs.We could all do without the noise. At the end of the day, I'm going to build stuff for the Web that's good for my users, and I'm not going to base my decisions on a techie bubble religion. Imagine what the brilliant minds behind the noise could do for the Web if they joined me in that pursuit.

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  • Some non-generic collections

    - by Simon Cooper
    Although the collections classes introduced in .NET 2, 3.5 and 4 cover most scenarios, there are still some .NET 1 collections that don't have generic counterparts. In this post, I'll be examining what they do, why you might use them, and some things you'll need to bear in mind when doing so. BitArray System.Collections.BitArray is conceptually the same as a List<bool>, but whereas List<bool> stores each boolean in a single byte (as that's what the backing bool[] does), BitArray uses a single bit to store each value, and uses various bitmasks to access each bit individually. This means that BitArray is eight times smaller than a List<bool>. Furthermore, BitArray has some useful functions for bitmasks, like And, Xor and Not, and it's not limited to 32 or 64 bits; a BitArray can hold as many bits as you need. However, it's not all roses and kittens. There are some fundamental limitations you have to bear in mind when using BitArray: It's a non-generic collection. The enumerator returns object (a boxed boolean), rather than an unboxed bool. This means that if you do this: foreach (bool b in bitArray) { ... } Every single boolean value will be boxed, then unboxed. And if you do this: foreach (var b in bitArray) { ... } you'll have to manually unbox b on every iteration, as it'll come out of the enumerator an object. Instead, you should manually iterate over the collection using a for loop: for (int i=0; i<bitArray.Length; i++) { bool b = bitArray[i]; ... } Following on from that, if you want to use BitArray in the context of an IEnumerable<bool>, ICollection<bool> or IList<bool>, you'll need to write a wrapper class, or use the Enumerable.Cast<bool> extension method (although Cast would box and unbox every value you get out of it). There is no Add or Remove method. You specify the number of bits you need in the constructor, and that's what you get. You can change the length yourself using the Length property setter though. It doesn't implement IList. Although not really important if you're writing a generic wrapper around it, it is something to bear in mind if you're using it with pre-generic code. However, if you use BitArray carefully, it can provide significant gains over a List<bool> for functionality and efficiency of space. OrderedDictionary System.Collections.Specialized.OrderedDictionary does exactly what you would expect - it's an IDictionary that maintains items in the order they are added. It does this by storing key/value pairs in a Hashtable (to get O(1) key lookup) and an ArrayList (to maintain the order). You can access values by key or index, and insert or remove items at a particular index. The enumerator returns items in index order. However, the Keys and Values properties return ICollection, not IList, as you might expect; CopyTo doesn't maintain the same ordering, as it copies from the backing Hashtable, not ArrayList; and any operations that insert or remove items from the middle of the collection are O(n), just like a normal list. In short; don't use this class. If you need some sort of ordered dictionary, it would be better to write your own generic dictionary combining a Dictionary<TKey, TValue> and List<KeyValuePair<TKey, TValue>> or List<TKey> for your specific situation. ListDictionary and HybridDictionary To look at why you might want to use ListDictionary or HybridDictionary, we need to examine the performance of these dictionaries compared to Hashtable and Dictionary<object, object>. For this test, I added n items to each collection, then randomly accessed n/2 items: So, what's going on here? Well, ListDictionary is implemented as a linked list of key/value pairs; all operations on the dictionary require an O(n) search through the list. However, for small n, the constant factor that big-o notation doesn't measure is much lower than the hashing overhead of Hashtable or Dictionary. HybridDictionary combines a Hashtable and ListDictionary; for small n, it uses a backing ListDictionary, but switches to a Hashtable when it gets to 9 items (you can see the point it switches from a ListDictionary to Hashtable in the graph). Apart from that, it's got very similar performance to Hashtable. So why would you want to use either of these? In short, you wouldn't. Any gain in performance by using ListDictionary over Dictionary<TKey, TValue> would be offset by the generic dictionary not having to cast or box the items you store, something the graphs above don't measure. Only if the performance of the dictionary is vital, the dictionary will hold less than 30 items, and you don't need type safety, would you use ListDictionary over the generic Dictionary. And even then, there's probably more useful performance gains you can make elsewhere.

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  • Anatomy of a .NET Assembly - CLR metadata 2

    - by Simon Cooper
    Before we look any further at the CLR metadata, we need a quick diversion to understand how the metadata is actually stored. Encoding table information As an example, we'll have a look at a row in the TypeDef table. According to the spec, each TypeDef consists of the following: Flags specifying various properties of the class, including visibility. The name of the type. The namespace of the type. What type this type extends. The field list of this type. The method list of this type. How is all this data actually represented? Offset & RID encoding Most assemblies don't need to use a 4 byte value to specify heap offsets and RIDs everywhere, however we can't hard-code every offset and RID to be 2 bytes long as there could conceivably be more than 65535 items in a heap or more than 65535 fields or types defined in an assembly. So heap offsets and RIDs are only represented in the full 4 bytes if it is required; in the header information at the top of the #~ stream are 3 bits indicating if the #Strings, #GUID, or #Blob heaps use 2 or 4 bytes (the #US stream is not accessed from metadata), and the rowcount of each table. If the rowcount for a particular table is greater than 65535 then all RIDs referencing that table throughout the metadata use 4 bytes, else only 2 bytes are used. Coded tokens Not every field in a table row references a single predefined table. For example, in the TypeDef extends field, a type can extend another TypeDef (a type in the same assembly), a TypeRef (a type in a different assembly), or a TypeSpec (an instantiation of a generic type). A token would have to be used to let us specify the table along with the RID. Tokens are always 4 bytes long; again, this is rather wasteful of space. Cutting the RID down to 2 bytes would make each token 3 bytes long, which isn't really an optimum size for computers to read from memory or disk. However, every use of a token in the metadata tables can only point to a limited subset of the metadata tables. For the extends field, we only need to be able to specify one of 3 tables, which we can do using 2 bits: 0x0: TypeDef 0x1: TypeRef 0x2: TypeSpec We could therefore compress the 4-byte token that would otherwise be needed into a coded token of type TypeDefOrRef. For each type of coded token, the least significant bits encode the table the token points to, and the rest of the bits encode the RID within that table. We can work out whether each type of coded token needs 2 or 4 bytes to represent it by working out whether the maximum RID of every table that the coded token type can point to will fit in the space available. The space available for the RID depends on the type of coded token; a TypeOrMethodDef coded token only needs 1 bit to specify the table, leaving 15 bits available for the RID before a 4-byte representation is needed, whereas a HasCustomAttribute coded token can point to one of 18 different tables, and so needs 5 bits to specify the table, only leaving 11 bits for the RID before 4 bytes are needed to represent that coded token type. For example, a 2-byte TypeDefOrRef coded token with the value 0x0321 has the following bit pattern: 0 3 2 1 0000 0011 0010 0001 The first two bits specify the table - TypeRef; the other bits specify the RID. Because we've used the first two bits, we've got to shift everything along two bits: 000000 1100 1000 This gives us a RID of 0xc8. If any one of the TypeDef, TypeRef or TypeSpec tables had more than 16383 rows (2^14 - 1), then 4 bytes would need to be used to represent all TypeDefOrRef coded tokens throughout the metadata tables. Lists The third representation we need to consider is 1-to-many references; each TypeDef refers to a list of FieldDef and MethodDef belonging to that type. If we were to specify every FieldDef and MethodDef individually then each TypeDef would be very large and a variable size, which isn't ideal. There is a way of specifying a list of references without explicitly specifying every item; if we order the MethodDef and FieldDef tables by the owning type, then the field list and method list in a TypeDef only have to be a single RID pointing at the first FieldDef or MethodDef belonging to that type; the end of the list can be inferred by the field list and method list RIDs of the next row in the TypeDef table. Going back to the TypeDef If we have a look back at the definition of a TypeDef, we end up with the following reprensentation for each row: Flags - always 4 bytes Name - a #Strings heap offset. Namespace - a #Strings heap offset. Extends - a TypeDefOrRef coded token. FieldList - a single RID to the FieldDef table. MethodList - a single RID to the MethodDef table. So, depending on the number of entries in the heaps and tables within the assembly, the rows in the TypeDef table can be as small as 14 bytes, or as large as 24 bytes. Now we've had a look at how information is encoded within the metadata tables, in the next post we can see how they are arranged on disk.

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