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• Even lighter than SQLite

  - by Richard Fabian

  I've been looking for a C++ SQL library implementation that is simple to hook in like SQLite, but faster and smaller. My projects are in games development and there's definitely a cutoff point between needing to pass the ACID test and wanting some extreme performance. I'm willing to move away from SQL string style queries, allowing it to be code driven, but I haven't found anything out there that provides SQL like flexibility while also preferring performance over the ACID test. I don't want to go reinventing the wheel, and the idea of implementing an SQL library on my own is quite daunting, even if it's only going to be simple subset of all the calls you could make. I need the basic commands (SELECT, MODIFY, DELETE, INSERT, with JOIN, and WHERE), not data operations (like sorting, min, max, count) and don't need the database to be atomic, or even enforce consistency (I can use a real SQL service while I'm testing and debugging).

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• Can a variable like 'int' be considered a primitive/fundamental data structure?

  - by Ravi Gupta

  A rough definition of a data structure is that it allows you to store data and apply a set of operations on that data while preserving consistency of data before and after the operation. However some people insist that a primitive variable like 'int' can also be considered as a data structure. I get that part where it allows you to store data but I guess the operation part is missing. Primitive variables don't have operations attached to them. So I feel that unless you have a set of operations defined and attached to it you cannot call it a data structure. 'int' doesn't have any operation attached to it, it can be operated upon with a set of generic operators. Please advise if I got something wrong here.

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• Controlling new features in Spring/Apache tomcat

  - by HeretoLearn

  Is there a good way to manage roll out of new software in Spring/Tomcat configuration. The problem I am trying to address is being able to rollback newly deployed software provided there are no hard dependencies on other moving pieces. For example changed the guts of an algorithm and now want to deploy the new software with the new change off by default and then turning it on on one of the web servers. An obvious way is to build a session object which has a map of key-value pairs(property,bool) which is populated from a db on a session startup and then the value is persisted for that session. This is so that if the value is reverted back existing sessions which started with the original value retain the original value and giving application consistency. Is there a more obvious inbuilt mechanism to do this?

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• Browser-Incompatability with image alignment in CSS using YUI grid (Firefox + Opera)

  - by Rotimi

  I'm having trouble with the alignment of two images on the footer of my temporary website (http://www.rotimioyewole.com). I'm new to the YUI grid, which I think may be a factor. It should look roughly like this (works correctly in Chrome and Safari, haven't tested IE yet): (http://cl.ly/44fH) But on FF and Opera look like this: http://cl.ly/44aO If I can have some sort of consistency then the website would at least be presentable. Ideally, I would also like to align both images on the same Y axis, as well as the text next to the icons. I had trouble figuring out how to search for a solution..can anybody help me? Thanks in advance

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• .NET's double.NaN - how does this counterintuitive feature work?

  - by GeReV

  I stumbled upon the definition of double.NaN in code: public const double NaN = (double)0.0 / (double)0.0; This is done similarly in PositiveInfinity and NegativeInfinity. double.IsNaN (with removing a few #pragmas and comments) is defined as: [Pure] [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)] public static bool IsNaN(double d) { if (d != d) { return true; } else { return false; } } This is, by far, the most counterintuitive thing I have ever seen in the .NET framework. How is 0.0 / 0.0 represented "behind the scenes"? How can division by 0 be possible in double, and why does NaN != NaN?

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• Using CCSpriteFrameCache without CCSpriteBatchNode

  - by AwDogsGo2Heaven

  I want to know if there is any benefiting caching a sprite sheet and accessing the sprite by frame without using the CCSpriteBatchNode? In some parts of my game the sprite batch node is useful because there is a lot on the screen, however on another part its not, because there are just a few things, and there are requirements for layers so CCSpriteBatchNode wouldn't be useful. However, for the sake of consistency I would like to use Sprite Sheets for all my sprites, and so was beginning to wonder if I would still receive any benefit from it? (Or worse that it could some how be slower...)

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• How do I left pad a database column in FrontBase?

  - by PleaseStand

  I have a table of items (let's call it WIDGET) that each have their own eight-digit barcode numbers stored in a VARCHAR field (let's call it BARCODE; the table's primary key is in a separate integer field ID). My problem is that some personnel have omitted the leading zeros instead of entering the entire number while others have not. All new data is being entered with all eight digits present, but I would like to update all the existing records (several hundred in all) to eight digits for the sake of consistency. 1 → 00000001 234 → 00000234 5678 → 00005678 00009012 → 00009012 I know FrontBase supports all of SQL-92, but SQL-92 has no function specifically for left-padding strings. I already came up with a solution, but I am posting this question to see if anyone can think of a better way of doing this than I did.

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• Why does String.Equals(Object obj) check to see if this == null?

  - by m-y

  // Determines whether two strings match. [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)] public override bool Equals(Object obj) { //this is necessary to guard against reverse-pinvokes and //other callers who do not use the callvirt instruction if (this == null) throw new NullReferenceException(); String str = obj as String; if (str == null) return false; if (Object.ReferenceEquals(this, obj)) return true; return EqualsHelper(this, str); } The part I don't understand is the fact that it is checking for the current instance, this, against null. The comment is a bit confusing, so I was wondering what does that comment actually mean? Can anyone give an example of how this could break if that check was not there, and does this mean that I should also place that check in my classes?

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• CSS: How to set remaining width as %, but having knowledge of only pixels

  - by Mega Matt

  Hi all, I've seen this question asked in a couple other contexts on SO, but I thought it would be worth asking again for my particular case. I'm trying to create some re-usable CSS classes for more consistency and less clutter on my site, and I'm stuck on trying to standardize one thing I use frequently. I have a container div that I don't want to set the height for (because it will vary depending on where on the site it is), and inside it is a header div, and then an unordered list of items, all with CSS applied to them. It looks a lot like this: I want the unordered list to take up the remaining room in the container div, knowing that the header div is 18px tall. I just don't know how to specify the list's height as "the result of 100% minus 18px". Does anyone have any advice in this situation? Thanks very much.

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• Building vs. Buying a Master Data Management Solution

  - by david.butler(at)oracle.com

  Many organizations prefer to build their own MDM solutions. The argument is that they know their data quality issues and their data better than anyone. Plus a focused solution will cost less in the long run then a vendor supplied general purpose product. This is not unreasonable if you think of MDM as a point solution for a particular data quality problem. But this approach carries significant risk. We now know that organizations achieve significant competitive advantages when they deploy MDM as a strategic enterprise wide solution: with the most common best practice being to deploy a tactical MDM solution and grow it into a full information architecture. A build your own approach most certainly will not scale to a larger architecture unless it is done correctly with the larger solution in mind. It is possible to build a home grown point MDM solution in such a way that it will dovetail into broader MDM architectures. A very good place to start is to use the same basic technologies that Oracle uses to build its own MDM solutions. Start with the Oracle 11g database to create a flexible, extensible and open data model to hold the master data and all needed attributes. The Oracle database is the most flexible, highly available and scalable database system on the market. With its Real Application Clusters (RAC) it can even support the mixed OLTP and BI workloads that represent typical MDM data access profiles. Use Oracle Data Integration (ODI) for batch data movement between applications, MDM data stores, and the BI layer. Use Oracle Golden Gate for more real-time data movement. Use Oracle's SOA Suite for application integration with its: BPEL Process Manager to orchestrate MDM connections to business processes; Identity Management for managing users; WS Manager for managing web services; Business Intelligence Enterprise Edition for analytics; and JDeveloper for creating or extending the MDM management application. Oracle utilizes these technologies to build its MDM Hubs.  Customers who build their own MDM solution using these components will easily migrate to Oracle provided MDM solutions when the home grown solution runs out of gas. But, even with a full stack of open flexible MDM technologies, creating a robust MDM application can be a daunting task. For example, a basic MDM solution will need: a set of data access methods that support master data as a service as well as direct real time access as well as batch loads and extracts; a data migration service for initial loads and periodic updates; a metadata management capability for items such as business entity matrixed relationships and hierarchies; a source system management capability to fully cross-reference business objects and to satisfy seemingly conflicting data ownership requirements; a data quality function that can find and eliminate duplicate data while insuring correct data attribute survivorship; a set of data quality functions that can manage structured and unstructured data; a data quality interface to assist with preventing new errors from entering the system even when data entry is outside the MDM application itself; a continuing data cleansing function to keep the data up to date; an internal triggering mechanism to create and deploy change information to all connected systems; a comprehensive role based data security system to control and monitor data access, update rights, and maintain change history; a flexible business rules engine for managing master data processes such as privacy and data movement; a user interface to support casual users and data stewards; a business intelligence structure to support profiling, compliance, and business performance indicators; and an analytical foundation for directly analyzing master data. Oracle's pre-built MDM Hub solutions are full-featured 3-tier Internet applications designed to participate in the full Oracle technology stack or to run independently in other open IT SOA environments. Building MDM solutions from scratch can take years. Oracle's pre-built MDM solutions can bring quality data to the enterprise in a matter of months. But if you must build, at lease build with the world's best technology stack in a way that simplifies the eventual upgrade to Oracle MDM and to the full enterprise wide information architecture that it enables.

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• Is Cloud Security Holding Back Social SaaS?

  - by Mike Stiles

  The true promise of social data co-mingling with enterprise data to influence and inform social marketing (all marketing really) lives in cloud computing. The cloud brings processing power, services, speed and cost savings the likes of which few organizations could ever put into action on their own. So why wouldn’t anyone jump into SaaS (Software as a Service) with both feet? Cloud security. Being concerned about security is proper and healthy. That just means you’re a responsible operator. Whether it’s protecting your customers’ data or trying to stay off the radar of regulatory agencies, you have plenty of reasons to make sure you’re as protected from hacking, theft and loss as you can possibly be. But you also have plenty of reasons to not let security concerns freeze you in your tracks, preventing you from innovating, moving the socially-enabled enterprise forward, and keeping up with competitors who may not be as skittish regarding SaaS technology adoption. Over half of organizations are transferring sensitive or confidential data to the cloud, an increase of 10% over last year. With the roles and responsibilities of CMO’s, CIO’s and other C’s changing, the first thing you should probably determine is who should take point on analyzing cloud software options, providers, and policies. An oft-quoted Ponemon Institute study found 36% of businesses don’t have a cloud security policy at all. So that’s as good a place to start as any. What applications and data are you comfortable housing in the cloud? Do you have a classification system for data that clearly spells out where data types can go and how they can be used? Who, both internally and at the cloud provider, will function as admins? What are the different levels of admin clearance? Will your security policies and procedures sync up with those of your cloud provider? The key is verifiable trust. Trust in cloud security is actually going up. 1/3 of organizations polled say it’s the cloud provider who should be responsible for data protection. And when you look specifically at SaaS providers, that expectation goes up to 60%. 57% “strongly agree” or “agree” there’s more confidence in cloud providers’ ability to protect data. In fact, some businesses bypass the “verifiable” part of verifiable trust. Just over half have no idea what their cloud provider does to protect data. And yet, according to the “Private Cloud Vision vs. Reality” InformationWeek Report, 82% of organizations say security/data privacy are one of the main reasons they’re still holding the public cloud at arm’s length. That’s going to be a tough position to maintain, because just as social is rapidly changing the face of marketing, big data is rapidly changing the face of enterprise IT. Netflix, who’s particularly big on the benefits of the cloud, says, "We're systematically disassembling the corporate IT components." An enterprise can never realize the full power of big data, nor get the full potential value out of it, if it’s unwilling to enable the integrations and dataset connections necessary in the cloud. Because integration is called for to reduce fragmentation, a standardized platform makes a lot of sense. With multiple components crafted to work together, you’re maximizing scalability, optimization, cost effectiveness, and yes security and identity management benefits. You can see how the incentive is there for cloud companies to develop and add ever-improving security features, making cloud computing an eventual far safer bet than traditional IT. @mikestilesPhoto: stock.xchng

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• Big Data – Interacting with Hadoop – What is Sqoop? – What is Zookeeper? – Day 17 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned the importance of the Pig and Pig Latin in Big Data Story. In this article we will understand what is Sqoop and Zookeeper in Big Data Story. There are two most important components one should learn when learning about interacting with Hadoop – Sqoop and Zookper. What is Sqoop? Most of the business stores their data in RDBMS as well as other data warehouse solutions. They need a way to move data to the Hadoop system to do various processing and return it back to RDBMS from Hadoop system. The data movement can happen in real time or at various intervals in bulk. We need a tool which can help us move this data from SQL to Hadoop and from Hadoop to SQL. Sqoop (SQL to Hadoop) is such a tool which extract data from non-Hadoop data sources and transform them into the format which Hadoop can use it and later it loads them into HDFS. Essentially it is ETL tool where it Extracts, Transform and Load from SQL to Hadoop. The best part is that it also does extract data from Hadoop and loads them to Non-SQL (or RDBMS) data stores. Essentially, Sqoop is a command line tool which does SQL to Hadoop and Hadoop to SQL. It is a command line interpreter. It creates MapReduce job behinds the scene to import data from an external database to HDFS. It is very effective and easy to learn tool for nonprogrammers. What is Zookeeper? ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. In other words Zookeeper is a replicated synchronization service with eventual consistency. In simpler words – in Hadoop cluster there are many different nodes and one node is master. Let us assume that master node fails due to any reason. In this case, the role of the master node has to be transferred to a different node. The main role of the master node is managing the writers as that task requires persistence in order of writing. In this kind of scenario Zookeeper will assign new master node and make sure that Hadoop cluster performs without any glitch. Zookeeper is the Hadoop’s method of coordinating all the elements of these distributed systems. Here are few of the tasks which Zookeepr is responsible for. Zookeeper manages the entire workflow of starting and stopping various nodes in the Hadoop’s cluster. In Hadoop cluster when any processes need certain configuration to complete the task. Zookeeper makes sure that certain node gets necessary configuration consistently. In case of the master node fails, Zookeepr can assign new master node and make sure cluster works as expected. There many other tasks Zookeeper performance when it is about Hadoop cluster and communication. Basically without the help of Zookeeper it is not possible to design any new fault tolerant distributed application. Tomorrow In tomorrow’s blog post we will discuss about very important components of the Big Data Ecosystem – Big Data Analytics. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• overriding the Home Key Long press in a category.HOME activity.

  - by Profete162

  Hello all, I just created my own "Home" to replace the stock android one or Sense. All is working fine and I get all I want. My only problem is to replace to long press on home key ( that usually show the last 6 activities you launched) by my own launcher. I successfully replace the long press on MENU button with this code: @Override public boolean onKeyDown(int keyCode, KeyEvent event) { //Log.i(TAG,"Keycode: "+keyCode); if (keyCode == KeyEvent.KEYCODE_MENU) { // this tells the framework to start tracking for // a long press and eventual key up. it will only // do so if this is the first down (not a repeat). event.startTracking(); return true; } (...) and this part part for the long press: @Override public boolean onKeyLongPress(int keyCode, KeyEvent event) { //Log.i(TAG,"LONG"+keyCode); Toast.makeText(Launcher.this,"LONG "+keyCode, Toast.LENGTH_SHORT).show(); if (keyCode == KeyEvent.KEYCODE_MENU) { (...) But the problem is that I wasn't able to replace the KeyEvent.KEYCODE_MENU with KeyEvent.KEYCODE_HOME is that something locked in the code that avoid user to use a Home long press? Thank a lot for all the information you woulg give me.

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• ps forrest for session id

  - by azatoth

  Often I want to get a nice readout what process are running and their relationship; I usually by habit runs ps auxfww and eventual grep for the process in question. Having been thinking about the problem I tried to create an oneliner to get the process tree in ps ufww format for all processes which has the session id specified by arbitrary process name(s); ending up in following code: ps ufww --sid=$(ps -C apache2 -o sess --no-headers | sort | uniq | grep -v -E '^ +0$' | awk 'NR==1{x=$0;next}NF{x=x","$0};END{gsub(/[[:space:]]*/,"",x);print x}') giving for example following output: USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 4157 0.0 0.1 41264 3120 ? Ss Jun11 0:00 /usr/sbin/apache2 -k start www-data 4329 0.0 0.0 41264 1976 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 4330 0.0 0.0 41264 2028 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 4331 0.0 0.0 41264 2028 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 4332 0.0 0.0 41264 2028 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 4333 0.0 0.0 41264 2032 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 6648 0.0 0.0 41264 1884 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 6654 0.0 0.0 41264 1884 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start www-data 6655 0.0 0.0 41264 1884 ? S Jun11 0:00 \_ /usr/sbin/apache2 -k start I do wonder now if anyone has an better idea to solve this issue? Are there anything out there that is easier to "oneline" and gives above or better information? For example I would actually want to have included all childs relative any parent. (uncertain if this should be on SF instead, but felt it was more like an programming question)

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• PHP CURL Google Calendar using Private URL

  - by MooCow

  I'm trying to get an array of events from Google Calendar using the Private URL. I read the Google API document but I want to try doing this without using the ZEND library since I have no idea what the eventual server file structure is and avoid having other people edit the codes. I also did a search before posting and ran into the same condition where PHP CURL_EXEC returns false with the URL but I get a JSON file if the URL is open using a web browser. Since I'm using the Private URL, do I really need to authenticate against the Google server using ZEND? I'm trying to have PHP clean up the array before encoding it for Flash. $URL = <string of the private URL from Google Calendar> $ch = curl_init($URL); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); $data = curl_exec($ch); curl_close($ch); $result = json_decode($data); print '<pre>'.var_export($data,1).'</pre>'; Screen output >>> false

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• How to implement two way binding between an ActiveX control and a WPF MVVM View Model

  - by Zamboni

  I have a WPF application implemented using the MVVM framework that uses an ActiveX control and I need to keep the WPF and ActiveX UI synchronised. So far I can update the ActiveX UI when I change the WPF UI using the code at the bottom of the question that I got from the article Hosting an ActiveX Control in WPF and this question. But I cannot update the WPF UI when I make a change in the ActiveX UI. I suspect that I need to fire the PropertyChanged event from my ActiveX control but I have no idea how to do this or if it is even possible. The ActiveX controls I have written are in VB6 and MFC as I am just prototying at this time for the eventual integration of VB6 ActiveX controls in a WPF contaner application. Here is a code snipet that indicates the work done so far: System.Windows.Forms.Integration.WindowsFormsHost host = new System.Windows.Forms.Integration.WindowsFormsHost(); // Create the ActiveX control. AxTEXTBOXActiveXLib.AxTEXTBOXActiveX axWmp = new AxTEXTBOXActiveXLib.AxTEXTBOXActiveX(); // Assign the ActiveX control as the host control's child. host.Child = axWmp; axWmp.DataBindings.Add(new System.Windows.Forms.Binding("ActiveXStatus", (MainWindowViewModel)this.DataContext, "ModelStatus", true, DataSourceUpdateMode.OnPropertyChanged )); // Add the interop host control to the Grid // control's collection of child controls. this.activexRow.Children.Add(host); How to implement two way binding between an ActiveX control and a WPF MVVM View Model?

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• Virtual Lan on the Cloud -- Help Confirm my understanding?

  - by marfarma

  [Note: Tried to post this over at ServerFault, but I don't have enough 'points' for more than one link. Powers that be, move this question over there.] Please give this a quick read and let me know if I'm missing something before I start trying to make this work. I'm not a systems admin professional, and I'd hate to end up banging my head into the wall if I can avoid it. Goals: Create a 'road-warrior' capable star shaped virtual LAN for consultants who spend the majority of their time on client sites, and who's firm has no physical network or servers. Enable CIFS access to a cloud-server based installation of Alfresco Allow Eventual implementation of some form of single-sign-on ( OpenLDAP server ) access to Alfresco and other server applications implemented in the future Given: All Servers will live in the public internet cloud (Rackspace Cloud Servers) OpenVPN Server will be a Linux disto, probably Ubuntu 9.x, installed on same server as Alfresco (at least to start) Staff will access server applications and resources from client sites, hotels, trains, planes, coffee shops or their homes over various ISP, using their company laptops or personal home desktops. Based on my Research thus far, to accomplish this, I'll need: OpenVPN with Bridging Enabled to create a star shaped "virtual" LAN http://openvpn.net/index.php/open-source/documentation/miscellaneous/76-ethernet-bridging.html A Road Warrior Network Configuration, as described in this Shorewall article (lower down the page) http://www.shorewall.net/OPENVPN.html Configure bridge addressesing (probably DHCP) http://openvpn.net/index.php/open-source/faq.html#bridge-addressing Configure CIFS / Samba to accept VPN IP address http://serverfault.com/questions/137933/howto-access-samba-share-over-vpn-tunnel Set up Client software, with keys configured for access (potentially through a OpenVPN-Sa client portal) http://www.openvpn.net/index.php/access-server/download-openvpn-as/221-installation-overview.html

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• python raw_input odd behavior with accents containing strings

  - by Ryan

  I'm writing a program that asks the user for input that contains accents. The user input string is tested to see if it matches a string declared in the program. As you can see below, my code is not working: code # -*- coding: utf-8 -*- testList = ['má'] myInput = raw_input('enter something here: ') print myInput, repr(myInput) print testList[0], repr(testList[0]) print myInput in testList output in eclipse with pydev enter something here: má mv° 'm\xe2\x88\x9a\xc2\xb0' má 'm\xc3\xa1' False output in IDLE enter something here: má má u'm\xe1' má 'm\xc3\xa1' Warning (from warnings module): File "/Users/ryanculkin/Desktop/delete.py", line 8 print myInput in testList UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal False How can I get my code to print True when comparing the two strings? Additionally, I note that the result of running this code on the same input is different depending on whether I use eclipse or IDLE. Why is this? My eventual goal is to put my program on the web; is there anything that I need to be aware of, since the result seems to be so volatile?

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• Can protobuf-net serialize this combination of interface and generic collection?

  - by tsupe

  I am trying to serialize a ItemTransaction and protobuf-net (r282) is having a problem. ItemTransaction : IEnumerable<KeyValuePair<Type, IItemCollection>></code> and ItemCollection is like this: FooCollection : ItemCollection<Foo> ItemCollection<T> : BindingList<T>, IItemCollection IItemCollection : IList<Item> where T is a derived type of Item. ItemCollection also has a property of type IItemCollection. I am serializing like this: IItemCollection itemCol = someService.Blah(...); ... SerializeWithLengthPrefix<IItemCollection>(stream, itemCol, PrefixStyle.Base128); My eventual goal is to serialize ItemTransaction, but am snagged with IItemCollection. Item and it's derived types can be [de]serialized with no issues, see [1], but deserializing an IItemCollection fails (serializing works). ItemCollection has a ItemExpression property and when deserializing protobuf can't create an abstract class. This makes sense to me, but I'm not sure how to get through it. ItemExpression<T> : ItemExpression, IItemExpression ItemExpression : Expression ItemExpression is abstract as is Expression How do I get this to work properly? Also, I am concerned that ItemTransaction will fail since the IItemCollections are going to be differing and unknown at compile time (an ItemTransaction will have FooCollection, BarCollection, FlimCollection, FlamCollection, etc). What am I missing (Marc) ? [1] http://stackoverflow.com/questions/2276104/protobuf-net-deserializing-across-assembly-boundaries

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• What is the right approach to checksumming UDP packets

  - by mr.b

  I'm building UDP server application in C#. I've come across a packet checksum problem. As you probably know, each packet should carry some simple way of telling receiver if packet data is intact. Now, UDP already has 2-byte checksum as part of header, which is optional, at least in IPv4 world. Alternative method is to have custom checksum as part of data section in each packet, and to verify it on receiver. My question boils down to: is it better to rely on (optional) checksum in UDP packet header, or to make a custom checksum implementation as part of packet data section? Perhaps the right answer depends on circumstances (as usual), so one circumstance here is that, even though code is written and developed in .NET on Windows, it might have to run under platform-independent Mono.NET, so eventual solution should be compatible with other platforms. I believe that custom checksum algorithm would be easily portable, but I'm not so sure about the first one. Any thoughts? Also, shouts about packet checksumming in general are welcome.

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• Generating JavaScript in C# and subsequent testing

  - by Codebrain

  We are currently developing an ASP.NET MVC application which makes heavy use of attribute-based metadata to drive the generation of JavaScript. Below is a sample of the type of methods we are writing: function string GetJavascript<T>(string javascriptPresentationFunctionName, string inputId, T model) { return @"function updateFormInputs(value){ $('#" + inputId + @"_SelectedItemState').val(value); $('#" + inputId + @"_Presentation').val(value); } function clearInputs(){ " + helper.ClearHiddenInputs<T>(model) + @" updateFormInputs(''); } function handleJson(json){ clearInputs(); " + helper.UpdateHiddenInputsWithJson<T>("json", model) + @" updateFormInputs(" + javascriptPresentationFunctionName + @"()); " + model.GetCallBackFunctionForJavascript("json") + @" }"; } This method generates some boilerplace and hands off to various other methods which return strings. The whole lot is then returned as a string and written to the output. The question(s) I have are: 1) Is there a nicer way to do this other than using large string blocks? We've considered using a StringBuilder or the Response Stream but it seems quite 'noisy'. Using string.format starts to become difficult to comprehend. 2) How would you go about unit testing this code? It seems a little amateur just doing a string comparison looking for particular output in the string. 3) What about actually testing the eventual JavaScript output? Thanks for your input!

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• Method for defining simultaneous has-many and has-one associations between two models in CakePHP?

  - by Hobonium

  One thing with which I have long had problems, within the CakePHP framework, is defining simultaneous hasOne and hasMany relationships between two models. For example: BlogEntry hasMany Comment BlogEntry hasOne MostRecentComment (where MostRecentComment is the Comment with the most recent created field) Defining these relationships in the BlogEntry model properties is problematic. CakePHP's ORM implements a has-one relationship as an INNER JOIN, so as soon as there is more than one Comment, BlogEntry::find('all') calls return multiple results per BlogEntry. I've worked around these situations in the past in a few ways: Using a model callback (or, sometimes, even in the controller or view!), I've simulated a MostRecentComment with: $this->data['MostRecentComment'] = $this->data['Comment'][0]; This gets ugly fast if, say, I need to order the Comments any way other than by Comment.created. It also doesn't Cake's in-built pagination features to sort by MostRecentComment fields (e.g. sort BlogEntry results reverse-chronologically by MostRecentComment.created. Maintaining an additional foreign key, BlogEntry.most_recent_comment_id. This is annoying to maintain, and breaks Cake's ORM: the implication is BlogEntry belongsTo MostRecentComment. It works, but just looks...wrong. These solutions left much to be desired, so I sat down with this problem the other day, and worked on a better solution. I've posted my eventual solution below, but I'd be thrilled (and maybe just a little mortified) to discover there is some mind-blowingly simple solution that has escaped me this whole time. Or any other solution that meets my criteria: it must be able to sort by MostRecentComment fields at the Model::find level (ie. not just a massage of the results); it shouldn't require additional fields in the comments or blog_entries tables; it should respect the 'spirit' of the CakePHP ORM. (I'm also not sure the title of this question is as concise/informative as it could be.)

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• Using Interface Builder efficiently

  - by Aaron Wetzler

  I am new to iPhone and objective c. I have spent hours and hours and hours reading documents and trying to understand how things work. I have RTFM or at least am in the process. My main problem is that I want to understand how to specify where an event gets passed to and the only way I have been able to do it is by specifying delegates but I am certain there is an easier/quicker way in IB. So, an example. Lets say I have 20 different views and view controllers and one MyAppDelegate. I want to be able to build all of these different Xib files in IB and add however many buttons and text fields and whatever and then specify that they all produce some event in the MyAppDelegate object. To do this I added a MyAppDelegate object in each view controller in IB's list view. Then I created an IBAction method in MyAppDelegate in XCode and went back to IB and linked all of the events to the MyAppDelegate object in each Xib file. However when I tried running it it just crashed with a bad read exception. My guess is that each Xib file is putting a MyAppDelegate object pointer that has nothing to do with the eventual MyAppDelegate adress that will actually be created at runtime. So my question is...how can I do this?!!!

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• Linux network stack : adding protocols with an LKM and dev_add_pack

  - by agent0range

  Hello, I have recently been trying to familiarize myself with the Linux Networking stack and device drivers (have both similarly named O'Reilly books) with the eventual goal of offloading UDP. I have already implemented UDP on the NIC but now the hard part... Rather than ask for assistance on this larger goal I was hoping someone could clarify for me a particular snippet I found that is part of a LKM which registeres a new protocol (OTP) that acts as a filter between the device driver and network stack. http://www.phrack.org/archives/55/p55_0x0c_Building%20Into%20The%20Linux%20Network%20Layer_by_lifeline%20&%20kossak.txt (Note: this Phrack article contains three different modules, code for the OTP is at the bottom of the page) In the init function of his example he has: otp_proto.type = htons(ETH_P_ALL); otp_proto.func = otp_func; dev_add_pack(&otp_proto); which (if I understand correctly) should register otp_proto as a packet sniffer and put it into the ptype_all data structure. My question is about the dev_add_pack. Is it the case that the protocol being registered as a filter will always be placed at this layer between L2 and the device driver? Or, for instance could I make such a filtering occur between the application and transport layers (analyze socket parameters) using the same process? I apologize if this is confusing - I am having some trouble wrapping my head around the bigger picture when it comes to modules altering kernel stack functionality. Thanks

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• What library can I use to do simple, lightweight message passing?

  - by Mike

  I will be starting a project which requires communication between distributed nodes(the project is in C++). I need a lightweight message passing library to pass very simple messages(basically just strings of text) between nodes. The library must have the following characteristics: No external setup required. I need to be able to get everything up-and-running in my code - I don't want to require the user to install any packages or edit any configuration files(other than a list of IP addresses and ports to connect to). The underlying protocol which the library uses must be TCP(or if it is UDP, the library must guarantee the eventual receipt of the message). The library must be able to send and receive arbitrarily large strings(think up to 3GB+). The library needn't support any security mechanisms, fault tolerance, or encryption - I just need it to be fast, simple, and easy to use. I've considered MPI, but concluded it would require too much setup on the user's machine for my project. What library would you recommend for such a project? I would roll my own, but due to time constraints, I don't think that will be feasible.

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