Search Results

Search found 1192 results on 48 pages for 'grow'.

Page 38/48 | < Previous Page | 34 35 36 37 38 39 40 41 42 43 44 45  | Next Page >

  • Getting my foot in the SCADA door, how?

    - by bibby
    I keep hearing that I should learn SCADA and its PLC language to upgrade my career. While I enjoy currently being a web and mobile development privateer, the prospects of working for a municipality or industrial entity has its appeals (since I am trying to grow a family). Over the years, I've tought myself to skillfully use php, javascript, java, perl, awk, bash. Surely, these language skills can tranfer somewhat to SCADA's logic controller language. Without any formal training in CS (music major!) other than at the workplace, I wouldn't have been able to pick up those languages and run with them had it not been for their open documentation and free-to-install or already-installed interpreters/compilers. I can't see that this is true with SCADA, and I'm hoping that I'm wrong. Ideally, I'd like to be able to apply for a job that requires [A,B,C] and suggest that they hire me because I already know [A & B]; that they wouldn't have to do a ground-up training with someone that's never programmed before. So, finally, the question; How do I "learn" SCADA? Are there sites and docs? What's going to help me get my foot in the door? Any insight is appreciated. Thanks!

    Read the article

  • Image drawing library for Haskell?

    - by absz
    I'm working on a Haskell program for playing spatial games: I have a graph of a bunch of "individuals" playing the Prisoner's Dilemma, but only with their immediate neighbors, and copying the strategies of the people who do best. I've reached a point where I need to draw an image of the world, and this is where I've hit problems. Two of the possible geometries are easy: if people have four or eight neighbors each, then I represent each one as a filled square (with color corresponding to strategy) and tile the plane with these. However, I also have a situation where people have six neighbors (hexagons) or three neighbors (triangles). My question, then, is: what's a good Haskell library for creating images and drawing shapes on them? I'd prefer that it create PNGs, but I'm not incredibly picky. I was originally using Graphics.GD, but it only exports bindings to functions for drawing points, lines, arcs, ellipses, and non-rotated rectangles, which is not sufficient for my purposes (unless I want to draw hexagons pixel by pixel*). I looked into using foreign import, but it's proving a bit of a hassle (partly because the polygon-drawing function requires an array of gdPoint structs), and given that my requirements may grow, it would be nice to use an in-Haskell solution and not have to muck about with the FFI (though if push comes to shove, I'm willing to do that). Any suggestions? * That is also an option, actually; any tips on how to do that would also be appreciated, though I think a library would be easier.

    Read the article

  • [Cocoa] Core Animation with an NSView and subviews

    - by ndg
    I've subclassed NSView to create a 'container' view (which I've called TRTransitionView) which is being used to house two subviews. At the click of a button, I want to transition one subview out of the parent view and transition the other in, using the Core Animation transition type: kCATransitionPush. For the most part, I have this working as you'd expect (here's a basic test project I threw together). The issue I'm seeing relates to resizing my window and then toggling between my two views. After resizing a window, my subviews will appear at seemingly random locations within my TRTransitionView. Additionally, it appears as if the TRTransitionView hasn't stretched correctly and is clipping the contents of its subviews. Ideally, I would like subviews anchored to the top-left of their parent view at all times, and to also grow to expand the size of the parent view. The second issue relates to an NSTableView I've placed in my first subview. When my window is resized, and my TRTransitionView resizes to match its new dimensions, my TableView seems to resize its content quite awkwardly (the entire table seems to jolt around) and the newly expanded space that the table now occupies seems to 'flash' (as if in the process of being animated). Extremely difficult to describe, but is there any way to stop this? Here's my TRTransitionView class: -(void) awakeFromNib { [self setWantsLayer:YES]; [self addSubview:[self currentView]]; transition = [CATransition animation]; [transition setType:kCATransitionPush]; [transition setSubtype:kCATransitionFromLeft]; [self setAnimations: [NSDictionary dictionaryWithObject:transition forKey:@"subviews"]]; } - (void)setCurrentView:(NSView*)newView { if (!currentView) { currentView = newView; return; } [[self animator] replaceSubview:currentView with:newView]; currentView = newView; } -(IBAction) switchToViewOne:(id)sender { [transition setSubtype:kCATransitionFromLeft]; [self setCurrentView:viewOne]; } -(IBAction) switchToViewTwo:(id)sender { [transition setSubtype:kCATransitionFromRight]; [self setCurrentView:viewTwo]; }

    Read the article

  • What is the performance penalty of XML data type in SQL Server when compared to NVARCHAR(MAX)?

    - by Piotr Owsiak
    I have a DB that is going to keep log entries. One of the columns in the log table contains serialized (to XML) objects and a guy on my team proposed to go with XML data type rather than NVARCHAR(MAX). This table will have logs kept "forever" (archiving some very old entries may be considered in the future). I'm a little worried about the CPU overhead, but I'm even more worried that DB can grow faster (FoxyBOA from the referenced question got 70% bigger DB when using XML). I have read this question http://stackoverflow.com/questions/514827/microsoft-sql-server-2005-2008-xml-vs-text-varchar-data-type and it gave me some ideas but I am particulairly interrested in clarification on whether the DB size increases or decreases. Can you please share your insight/experiences in that matter. BTW. I don't currently have any need to depend on XML features within SQL Server (there's nearly zero advantage to me in the specific case). Ocasionally log entries will be extracted, but I prefer to handle the XML using .NET (either by writing a small client or using a function defined in a .NET assembly).

    Read the article

  • Python and a "time value of money" problem.

    - by jamieb
    (I asked this question earlier today, but I did a poor job of explaining myself. Let me try again) I have a client who is an industrial maintenance company. They sell service agreements that are prepaid 20 hour blocks of a technician's time. Some of their larger customers might burn through that agreement in two weeks while customers with fewer problems might go eight months on that same contract. I would like to use Python to help model projected sales revenue and determine how many billable hours per month that they'll be on the hook for. If each customer only ever bought a single service contract (never renewed) it would be easy to figure sales as monthly_revenue = contract_value * qty_contracts_sold. Billable hours would also be easy: billable_hrs = hrs_per_contract * qty_contracts_sold. However, how do I account for renewals? Assuming that 90% (or some other arbitrary amount) of customers renew, then their monthly revenue ought to grow geometrically. Another important variable is how long the average customer burns through a contract. How do I determine what the revenue and billable hours will be 3, 6, or 12 months from now, based on various renewal and burn rates? I assume that I'd use some type of recursive function but math was never one of my strong points. Any suggestions please? Edit: I'm thinking that the best way to approach this is to think of it as a "time value of money" problem. I've retitled the question as such. The problem is probably a lot more common if you think of "monthly sales" as something similar to annuity payments.

    Read the article

  • Is jQuery forcing Adobe ColdFusion to abandon the dead flash product line?

    - by crosenblum
    I have been reading a lot about how flash development/design had died, and as jQuery and in the near future html5 comes out, will this start to push Adobe/Coldfusion away from flash towards less product linking? I mean, I love coldfusion, and want that to continue to grow, however, if Adobe only bought Coldfusion from Macromedia, so they can bundle flash and coldfusion together, does the death of flash mean the death of coldfusion? http://topnews.us/content/221385-jobs-says-adobes-flash-waning-and-had-its-day http://aext.net/2010/03/javascript-jquery-killing-flash-tutorial-jquery-plugin/ I really don't mind if Flash dies, I do mind greatly if coldfusion does. Is the success of Flash linked to Coldfusion? If so, why? or why not? The purpose of this isn't to start some war about flash pro's and con's. I was only worried that Adobe would cause problems for Coldfusion, if flash had some market/financial problems. That was my main concern... And no I am not anti-flash... But my financial sanity depends on Coldfusion being a success, so that is why I stated my question. Because I WANT EVERYONE ELSE'S OPINION OF THIS SITUATION. Thank You.

    Read the article

  • Truncate C++ string fields generated by ostringstream, iomanip:setw

    - by Ian Durkan
    In C++ I need string representations of integers with leading zeroes, where the representation has 8 digits and no more than 8 digits, truncating digits on the right side if necessary. I thought I could do this using just ostringstream and iomanip.setw(), like this: int num_1 = 3000; ostringstream out_target; out_target << setw(8) << setfill('0') << num_1; cout << "field: " << out_target.str() << " vs input: " << num_1 << endl; The output here is: field: 00003000 vs input: 3000 Very nice! However if I try a bigger number, setw lets the output grow beyond 8 characters: int num_2 = 2000000000; ostringstream out_target; out_target << setw(8) << setfill('0') << num_2; cout << "field: " << out_target.str() << " vs input: " << num_2 << endl; out_target.str(""); output: field: 2000000000 vs input: 2000000000 The desired output is "20000000". There's nothing stopping me from using a second operation to take only the first 8 characters, but is field truncation truly missing from iomanip? Would the Boost formatting do what I need in one step?

    Read the article

  • Database and logic layer for ASP.NET MVC application

    - by Ismail
    I'm going to start a new project which is going to be small initially but may grow to big over the years. I'm strongly convinced that I'm going to use ASP.NET MVC with jQuery for UI. I want to go for MySQL as database for some reasons but worried on few things. I've a good years of experience working on SQL Server databases and on one project I've had a bad experience creating and managing stored procedures on MySQL database. I'm totally new to Linq but I see that it is easier to use once you are familiar with it. First thing is that accessing data should be easy. So I thought I should use MySQL to Linq but somewhere I read that it is not directly supported but MySQL .NET connector adds support for EntityFramework. I don't know what are the pros and cons of it. I would love if I can implement repository pattern as it allows to apply filter in logic layer rather than in data access layer. Will it be possible if I use Entity Framework? I'm not clear on how I should go about all this or I should just forget every thing and directly use SQL to Linq on SQL Server. I'm also concerned about the performance. Someone told me that if we use Entity framework it fetches lot of data and then filter it. Is that right? So questions basically are - Is MySQL to Linq possible? If yes where can I get more details on it? Pros and cons of using EntityFramework with MySQL? Will it be easy to access data using EntityFramework with MySQL? Will I be able to implement repository patter which allows applying filter in logic layer rather than data access layer (when I use EntityFramework with MySQL) Does it fetches hell lot of data from database and then apply filter on it? If it sounds too many questions from my side in that case, if you can just let me know what you will do (with a considerable reason) in this situation as an experienced person in this area, that should answer my question.

    Read the article

  • When is a good time to start thinking about scaling?

    - by Slokun
    I've been designing a site over the past couple days, and been doing some research into different aspects of scaling a site horizontally. If things go as planned, in a few months (years?) I know I'd need to worry about scaling the site up and out, since the resources it would end up consuming would be huge. So, this got me to thinking, when is the best time to start thinking about, and designing for, scalability? If you start too early on, you could easily over complicate your design, and make it impossible to actually build. You could also get too caught up in the details, the architecture, whatever, and wind up getting nothing done. Also, if you do get it working, but the site never takes off, you may have wasted a good chunk of extra effort. On the other hand, you could be saving yourself a ton of effort down the road. Designing it from the ground up to be big would make it much easier later on to let it grow big, with very little rewriting going on. I know for what I'm working on, I've decided to make at least a few choices now on the side of scaling, but I'm not going to do a complete change of thinking to get it to scale completely. Notably, I've redesigned my database from a conventional relational design to one similar to what was suggested on the Reddit site linked below, and I'm going to give memcache a try. So, the basic question, when is a good time to start thinking or worrying about scaling, and what are some good designs, tips, etc. for when doing so? A couple of things I've been reading, for those who are interested: http://www.codinghorror.com/blog/2009/06/scaling-up-vs-scaling-out-hidden-costs.html http://highscalability.com/blog/2010/5/17/7-lessons-learned-while-building-reddit-to-270-million-page.html http://developer.yahoo.com/performance/rules.html

    Read the article

  • What's the most efficient query?

    - by Aaron Carlino
    I have a table named Projects that has the following relationships: has many Contributions has many Payments In my result set, I need the following aggregate values: Number of unique contributors (DonorID on the Contribution table) Total contributed (SUM of Amount on Contribution table) Total paid (SUM of PaymentAmount on Payment table) Because there are so many aggregate functions and multiple joins, it gets messy do use standard aggregate functions the the GROUP BY clause. I also need the ability to sort and filter these fields. So I've come up with two options: Using subqueries: SELECT Project.ID AS PROJECT_ID, (SELECT SUM(PaymentAmount) FROM Payment WHERE ProjectID = PROJECT_ID) AS TotalPaidBack, (SELECT COUNT(DISTINCT DonorID) FROM Contribution WHERE RecipientID = PROJECT_ID) AS ContributorCount, (SELECT SUM(Amount) FROM Contribution WHERE RecipientID = PROJECT_ID) AS TotalReceived FROM Project; Using a temporary table: DROP TABLE IF EXISTS Project_Temp; CREATE TEMPORARY TABLE Project_Temp (project_id INT NOT NULL, total_payments INT, total_donors INT, total_received INT, PRIMARY KEY(project_id)) ENGINE=MEMORY; INSERT INTO Project_Temp (project_id,total_payments) SELECT `Project`.ID, IFNULL(SUM(PaymentAmount),0) FROM `Project` LEFT JOIN `Payment` ON ProjectID = `Project`.ID GROUP BY 1; INSERT INTO Project_Temp (project_id,total_donors,total_received) SELECT `Project`.ID, IFNULL(COUNT(DISTINCT DonorID),0), IFNULL(SUM(Amount),0) FROM `Project` LEFT JOIN `Contribution` ON RecipientID = `Project`.ID GROUP BY 1 ON DUPLICATE KEY UPDATE total_donors = VALUES(total_donors), total_received = VALUES(total_received); SELECT * FROM Project_Temp; Tests for both are pretty comparable, in the 0.7 - 0.8 seconds range with 1,000 rows. But I'm really concerned about scalability, and I don't want to have to re-engineer everything as my tables grow. What's the best approach?

    Read the article

  • Help me choose a web development framework/platform that will make me learn something

    - by Sergio Tapia
    I'm having a bit of an overload of information these past two days. I'm planning to start my own website that will allow local businesses to list their items on sale, and then users can come in and search for "Abercrombie t-shirt" and the stores that sell them will be listed. It's a neat little project I'm really excited for and I'm sure it'll take off, but I'm having problems from the get go. Sure I could use ASP.Net for it, I'm a bit familiar with it and the IDE for ASP.Net pages is bar-none, but I feel this is a great chance for me to learn something new to branch out a bit and not regurgitate .NET like a robot. I've been looking and asking around but it's all just noise and I can't make an educated decision. Can you help me choose a framework/platform that will make me learn something that's a nice thing to know in the job market, but also nice for me to grow as a professional? So far I've looked at: Ruby on Rails Kohana CakePHP CodeIgniter Symfony But they are all very esoteric to me, and I have trouble even finding out which IDE to use to that will let me use auto-complete for the proprietary keywords/methods. Thank you for your time.

    Read the article

  • openssl crypto library - base64 conversion

    - by Hassan Syed
    I'm using openssl BIO objects to convert a binary string into a base64 string. The code is as follows: void ToBase64(std::string & s_in) { BIO * b_s = BIO_new( BIO_s_mem() ); BIO * b64_f = BIO_new( BIO_f_base64() ); b_s = BIO_push( b64_f , b_s); std::cout << "IN::" << s_in.length(); BIO_write(b_s, s_in.c_str(), s_in.length()); char * pp; int sz = BIO_get_mem_data(b_s, &pp); std::cout << "OUT::" << sz << endl; s_in.assign(pp,sz); //std::cout << sz << " " << std::string(pp,sz) << std::endl; BIO_free (b64_f); // TODO ret error potential BIO_free (b_s); // } The in length is either 64 or 72. However the output is always 65, which is incorrect it should be much larger than that. The documentation isn't the best in the world, AFAIK the bio_s_mem object is supposed to grow dynamically. What am I doing wrong ?

    Read the article

  • css: make background repeat-y with growing child content?

    - by mikemikemike
    I Have a three column layout. The center div is a container which holds all of my content. The outer columns is just a .png that fades into the body's background (left and right respectively). I want the .png to repeat-y to grow with the center container's content. It will only print the image once, and ignores the repeat-y. If I specify a height to the outside columns, it will print, but only to the specified height. I tried height: 100%, which does not work. Here is my code: #ultra_contain { text-align:left; width:900px; padding: 0px; position:relative; margin:0px auto; margin-top:0px; /*border:1px dashed #996;*/ } #gradientleft { float:left; position:relative; background: url("../i/gradient_left.png") repeat-y; /*border:1px dashed #996;*/ } #gradientright { float:right; position:relative; background: url("../i/gradient_right.png") repeat-y; /*border:1px dashed #996;*/ } #container { text-align:left; width:700px; position:relative; margin:5px auto; margin-top:0px; background:#fff; /*border:1px dashed #996;*/ }

    Read the article

  • What setting needs to be made to make .Net Automation responsive?

    - by Greg
    Have an app that is looking for application windows being created on the desktop using class Unresponsive { private StructureChangedEventHandler m_UIAeventHandler = new StructureChangedEventHandler(OnStructureChanged); public Unresponsive() { Automation.AddStructureChangedEventHandler(AutomationElement.RootElement, TreeScope.Children, m_UIAeventHandler); } private void OnStructureChanged(object sender, StructureChangedEventArgs e) { Debug.WriteLine("Change event"); } } You can see the same issue using UISpy.exe, selecting the desktop and configuring scope for children and just the structure changed event. The problem I'm trying to resolve is that the events are not raised in a timely manner, there seems to be some grouping/delay which makes the app appear to be non responsive. If you start a new app with 1 window and wait a second you get the event, seems alright. If you start the same app several times without delay (say clicking on quickstart), it's not until all of the instances of the app get 'initialised' by the AutomationProxies that you get the notice for the first app (and in short order the other apps/windows). I've sat watching task manager as each instance of the app starts to grow as it is initialised, waiting until the last app is done and then seeing the events all come in. Similarly any time any apps are starting windows within a timeframe there seems to be some blocking. I can't see how to configure this timeframe, or get each structure changed event to be sent on as soon as it happens. Also, this process of listening for structure changed events seems to be leaking, just by listening there is a leak in native memory. (visible in UISpy and my app)

    Read the article

  • database structure

    - by jindalsyogesh
    I have a table named ActivityRecording. This table currently has 500,000 records. I need to add a lot of new inputs that relates to activityrecording table. The relation of activityrecording with these new input fields is 1 to 0,1. So, what's going to happen on screen is when user fills the ActivityRecording data, he will then be taken to a new page and this page will show a form based on the user's input (from a dropdown named service) in activityrecording. There will 6 different kinds of form (each form will have 7-8 inputs which includes textareas of size 5kb, textboxes and checkboxes). So, for one activityrecording user will fill one out of 6 forms. There are two ways I know (there could be more), I can design the data structure: Add all the inputs from all these 6 forms into the activityrecording table. So, columns belonging to 5 of these forms will be null in this table, only columns belonging to one of the forms will have values The other way would be add 6 new tables (one for each form) and add 6 foreign key columns to activityrecording table. So, out of 6 foreign keys, 5 will be null and one will actually point to a table Which approach is a better data structure design? Please take into consideration that number of rows in this table are 500,000 and are expected to grow at a faster rate now.

    Read the article

  • Linked list example using threads

    - by Carl_1789
    I have read the following code of using CRITICAL_SECTION when working with multiple threads to grow a linked list. what would be the main() part which uses two threads to add to linked list? #include <windows.h> typedef struct _Node { struct _Node *next; int data; } Node; typedef struct _List { Node *head; CRITICAL_SECTION critical_sec; } List; List *CreateList() { List *pList = (List*)malloc(sizeof(pList)); pList->head = NULL; InitializeCriticalSection(&pList->critical_sec); return pList; } void AddHead(List *pList, Node *node) { EnterCriticalSection(&pList->critical_sec); node->next = pList->head; pList->head = node; LeaveCriticalSection(&pList->critical_sec); } void Insert(List *pList, Node *afterNode, Node *newNode) { EnterCriticalSection(&pList->critical_sec); if (afterNode == NULL) { AddHead(pList, newNode); } else { newNode->next = afterNode->next; afterNode->next = newNode; } LeaveCriticalSection(&pList->critical_sec); } Node *Next(List *pList, Node *node) { Node* next; EnterCriticalSection(&pList->critical_sec); next = node->next; LeaveCriticalSection(&pList->critical_sec); return next; }

    Read the article

  • C/C++: feedback in analyzing a code example

    - by KaiserJohaan
    Hello, I have a piece of code from an assignment I am uncertain about. I feel confident that I know the answer, but I just want to double-check with the community incase there's something I forgot. The title is basically secure coding and the question is just to explain the results. int main() { unsigned int i = 1; unsigned int c = 1; while (i > 0) { i = i*2; c++; } printf("%d\n", c); return 0; } My reasoning is this: At first glance you could imagine the code would run forever, considering it's initialized to a positive value and ever increasing. This of course is wrong because eventually the value will grow so large it will cause an integer overflow. This in turn is not entirely true either, because eventally it will force the variable 'i' to be signed by making the last bit to 1 and therefore regarded as a negative number, therefore terminating the loop. So it is not writing to unallocated memory and therefore cause integer overflow, but rather violating the data type and therefore causing the loop to terminate. I am quite sure this is the reason, but I just want to double check. Any opinions?

    Read the article

  • Designing small comparable objects

    - by Thomas Ahle
    Intro Consider you have a list of key/value pairs: (0,a) (1,b) (2,c) You have a function, that inserts a new value between two current pairs, and you need to give it a key that keeps the order: (0,a) (0.5,z) (1,b) (2,c) Here the new key was chosen as the average between the average of keys of the bounding pairs. The problem is, that you list may have milions of inserts. If these inserts are all put close to each other, you may end up with keys such to 2^(-1000000), which are not easily storagable in any standard nor special number class. The problem How can you design a system for generating keys that: Gives the correct result (larger/smaller than) when compared to all the rest of the keys. Takes up only O(logn) memory (where n is the number of items in the list). My tries First I tried different number classes. Like fractions and even polynomium, but I could always find examples where the key size would grow linear with the number of inserts. Then I thought about saving pointers to a number of other keys, and saving the lower/greater than relationship, but that would always require at least O(sqrt) memory and time for comparison. Extra info: Ideally the algorithm shouldn't break when pairs are deleted from the list.

    Read the article

  • How can I improve the performance of LinqToSql queries that use EntitySet properties?

    - by DanM
    I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

    Read the article

  • SQL Server log backups "stalling"

    - by MattK
    I have interited a box running SQL Server 2008 and Windows 2003, and have had a few events where largeish (35GB) log backups "stall", both before and after the installation of SQL 2008 SP1. The server log ships to a standby, so regular log backups are taken at 15 minute intervals. However, after an index reorg causes the log to grow to about 35GB (on a DB with about 17GB of data), the next log backup runs to ~95% completion, then seems to stop. The process shows as suspended, with a wait state of BACKUPIO. CPU, read, and write activity on the SPID also does not change, and the process stays in this state for hours, when normally a backup of this size should complete in about 20 minutes. This server has a single RAID-1 volume, thus the source database files and destination backup files are on the same volume. However, I cannot determine if another process is blocking the backup. The backup SPID cannot be killed, and the only way to terminate the log backup and clear the lock on the backup file is to cycle the SQL Server service. There was one event where the backup terminated completely, with an error that another process had locked the backup file, but no details about what that process was. Can anyone suggest a cause or diagnostic process to this situation?

    Read the article

  • Observer Design Pattern - multiple event types

    - by David
    I'm currently implementing the Observer design pattern and using it to handle adding items to the session, create error logs and write messages out to the user giving feedback on their actions (e.g. You've just logged out!). I began with a single method on the subject called addEvent() but as I added more Observers I found that the parameters required to detail all the information I needed for each listener began to grow. I now have 3 methods called addMessage(), addStorage() and addLog(). These add data into an events array that has a key related to the event type (e.g. log, message, storage) but I'm starting to feel that now the subject needs to know too much about the listeners that are attached. My alternative thought is to go back to addEvent() and pass an event type (e.g. USER_LOGOUT) along with the data associated and each Observer maintains it's own list of event handles it is looking for (possibly in a switch statement), but this feels cumbersome. Also, I'd need to check that sufficient data had also been passed along with the event type. What is the correct way of doing this? Please let me know if I can explain any parts of this further. I hope you can help and see the problem I'm battling with.

    Read the article

  • Refactoring or Rewriting Monolithic PHP Spaghetti Codebase

    - by nategood
    I've inherited a really poorly designed PHP spaghetti code project. It's been gaining a good bit of traffic recently and is starting to have performance issues on top of the poor monolithic code base. Its maxing out performance on a chunky 16GB dedicated machine when it really shouldn't be. I'm planning on doing some performance tweaks right off the bat to help the performance issue, but this still won't really help the horrible code base. The team is small but expecting to grow very soon. I've read Joel's article on the troubles of doing a complete rewrite and see the concerns. But how bad does the code base have to be before you consider a rewrite? There is PHP handling logic interjected into what one would usually consider a "view". Even worse, in some places SQL statements are in these same files! The only real separation of presentation and logic are a few PHP scripts that serve as function libraries. These scripts do most of the ORM stuff... if you can even call it that. Trying to slowly refractor this seems like a nightmare. Open to your thoughts and opinions... however not interested in hearing, "Run away, Run away!".

    Read the article

  • Program structure in long running data processing python script

    - by fmark
    For my current job I am writing some long-running (think hours to days) scripts that do CPU intensive data-processing. The program flow is very simple - it proceeds into the main loop, completes the main loop, saves output and terminates: The basic structure of my programs tends to be like so: <import statements> <constant declarations> <misc function declarations> def main(): for blah in blahs(): <lots of local variables> <lots of tightly coupled computation> for something in somethings(): <lots more local variables> <lots more computation> <etc., etc.> <save results> if __name__ == "__main__": main() This gets unmanageable quickly, so I want to refactor it into something more manageable. I want to make this more maintainable, without sacrificing execution speed. Each chuck of code relies on a large number of variables however, so refactoring parts of the computation out to functions would make parameters list grow out of hand very quickly. Should I put this sort of code into a python class, and change the local variables into class variables? It doesn't make a great deal of sense tp me conceptually to turn the program into a class, as the class would never be reused, and only one instance would ever be created per instance. What is the best practice structure for this kind of program? I am using python but the question is relatively language-agnostic, assuming a modern object-oriented language features.

    Read the article

  • Is XSLT worth investing time in and are there any actual alternatives?

    - by Keeno
    I realize this has been a few other questions on this topic, and people are saying use your language of choice to manipulate the XML etc etc however, not quite fit my question exactly. Firstly, the scope of the project: We want to develop platform independent e-learning, currently, its a bunch of HTML pages but as they grow and develop they become hard to maintain. The idea: Generate up an XML file + Schema, then produce some XSLT files that process the XML into the eLearning modiles. XML to HTML via XSLT. Why: We would like the flexibilty to be able to easy reformat the content (I realize CSS is a viable alternative here) If we decide to alter the pages layout or functionality in anyway, im guessing altering the "shared" XSLT files would be easier than updating the HTML files. So far, we have about 30 modules, with up to 10-30 pages each Depending on some "parameters" we could output drastically different page layouts/structures, above and beyond what CSS can do Now, all this has to be platform independent, and to be able to run "offline" i.e. without a server powering the HTML Negatives I've read so far for XSLT: Overhead? Not exactly sure why...is it the compute power need to convert to HTML? Difficult to learn Better alternatives Now, what I would like to know exactly is: are there actually any viable alternatives for this "offline"? Am I going about it in the correct manner, do you guys have any advice or alternatives. Thanks!

    Read the article

  • What's the most DRY-appropriate way to execute an SQL command?

    - by Sean U
    I'm looking to figure out the best way to execute a database query using the least amount of boilerplate code. The method suggested in the SqlCommand documentation: private static void ReadOrderData(string connectionString) { string queryString = "SELECT OrderID, CustomerID FROM dbo.Orders;"; using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand command = new SqlCommand(queryString, connection); connection.Open(); SqlDataReader reader = command.ExecuteReader(); try { while (reader.Read()) { Console.WriteLine(String.Format("{0}, {1}", reader[0], reader[1])); } } finally { reader.Close(); } } } mostly consists of code that would have to be repeated in every method that interacts with the database. I'm already in the habit of factoring out the establishment of a connection, which would yield code more like the following. (I'm also modifying it so that it returns data, in order to make the example a bit less trivial.) private SQLConnection CreateConnection() { var connection = new SqlConnection(_connectionString); connection.Open(); return connection; } private List<int> ReadOrderData() { using(var connection = CreateConnection()) using(var command = connection.CreateCommand()) { command.CommandText = "SELECT OrderID FROM dbo.Orders;"; using(var reader = command.ExecuteReader()) { var results = new List<int>(); while(reader.Read()) results.Add(reader.GetInt32(0)); return results; } } } That's an improvement, but there's still enough boilerplate to nag at me. Can this be reduced further? In particular, I'd like to do something about the first two lines of the procedure. I don't feel like the method should be in charge of creating the SqlCommand. It's a tiny piece of repetition as it is in the example, but it seems to grow if transactions are being managed manually or timeouts are being altered or anything like that.

    Read the article

< Previous Page | 34 35 36 37 38 39 40 41 42 43 44 45  | Next Page >