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  • Images in the project NOT adding to array - don't know why.

    - by Sam Jarman
    Hi there, I have to sets of images. Each set has 16 images. One set is called 0.png through to 15.png the other is a0.png through to a15.png. In my app, it loads each one dependent on a variable (which by logging, I have proved it works) here is the code [MemoryManager sharedMemoryManager]; NSLog(@"THEME: %@", [MemoryManager sharedMemoryManager].themeName); imageArray = [[NSMutableArray alloc] init]; if([MemoryManager sharedMemoryManager].themeName == @"hand"){ NSLog(@"Here 2"); [imageArray addObject:[UIImage imageNamed:@"0.png"]]; // [imageArray addObject:[UIImage imageNamed:@"1.png"]];//1 [imageArray addObject:[UIImage imageNamed:@"2.png"]];//2 [imageArray addObject:[UIImage imageNamed:@"3.png"]];//3 [imageArray addObject:[UIImage imageNamed:@"4.png"]];//4 [imageArray addObject:[UIImage imageNamed:@"5.png"]];//5 [imageArray addObject:[UIImage imageNamed:@"6.png"]];//6 [imageArray addObject:[UIImage imageNamed:@"7.png"]];//7 [imageArray addObject:[UIImage imageNamed:@"8.png"]];//8 [imageArray addObject:[UIImage imageNamed:@"9.png"]];//9 [imageArray addObject:[UIImage imageNamed:@"10.png"]];//10 [imageArray addObject:[UIImage imageNamed:@"11.png"]];//11 [imageArray addObject:[UIImage imageNamed:@"12.png"]];//12 [imageArray addObject:[UIImage imageNamed:@"13.png"]];//13 [imageArray addObject:[UIImage imageNamed:@"14.png"]];//14 [imageArray addObject:[UIImage imageNamed:@"15.png"]];//15 } if([MemoryManager sharedMemoryManager].themeName == @"letters"){ NSLog(@"Here 3"); //[imageArray removeAllObjects]; [imageArray addObject:[UIImage imageNamed:@"a0.png"]]; // [imageArray addObject:[UIImage imageNamed:@"a1.png"]];//1 [imageArray addObject:[UIImage imageNamed:@"a2.png"]];//2 [imageArray addObject:[UIImage imageNamed:@"a3.png"]];//3 [imageArray addObject:[UIImage imageNamed:@"a4.png"]];//4 [imageArray addObject:[UIImage imageNamed:@"a5.png"]];//5 [imageArray addObject:[UIImage imageNamed:@"a6.png"]];//6 [imageArray addObject:[UIImage imageNamed:@"a7.png"]];//7 [imageArray addObject:[UIImage imageNamed:@"a8.png"]];//8 [imageArray addObject:[UIImage imageNamed:@"a9.png"]];//9 [imageArray addObject:[UIImage imageNamed:@"a10.png"]];//10 [imageArray addObject:[UIImage imageNamed:@"a11.png"]];//11 [imageArray addObject:[UIImage imageNamed:@"a12.png"]];//12 [imageArray addObject:[UIImage imageNamed:@"a13.png"]];//13 [imageArray addObject:[UIImage imageNamed:@"a14.png"]];//14 [imageArray addObject:[UIImage imageNamed:@"a15.png"]];//15 NSLog(@"Here 4"); } The log says 2010-05-26 21:30:57.092 Memory[22155:207] Here 1 2010-05-26 21:30:57.093 Memory[22155:207] THEME: letters 2010-05-26 21:30:57.095 Memory[22155:207] Here 3 2010-05-26 21:30:57.109 Memory[22155:207] Here 4 The images are in the same folder the .xproj file is. They simply is just not working. Any ideas? Cheers

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  • Django Error - AttributeError: 'Settings' object has no attribute 'LOCALE_PATHS'

    - by Randy Simon
    I am trying to learn django by following along with this tutorial. I am using django version 1.1.1 I run django-admin.py startproject mysite and it creates the files it should. Then I try to start the server by running python manage.py runserver but here is where I get the following error. Traceback (most recent call last): File "manage.py", line 11, in <module> execute_manager(settings) File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 362, in execute_manager utility.execute() File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 303, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 195, in run_from_argv self.execute(*args, **options.__dict__) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 213, in execute translation.activate('en-us') File "/Library/Python/2.6/site-packages/django/utils/translation/__init__.py", line 73, in activate return real_activate(language) File "/Library/Python/2.6/site-packages/django/utils/translation/__init__.py", line 43, in delayed_loader return g['real_%s' % caller](*args, **kwargs) File "/Library/Python/2.6/site-packages/django/utils/translation/trans_real.py", line 205, in activate _active[currentThread()] = translation(language) File "/Library/Python/2.6/site-packages/django/utils/translation/trans_real.py", line 194, in translation default_translation = _fetch(settings.LANGUAGE_CODE) File "/Library/Python/2.6/site-packages/django/utils/translation/trans_real.py", line 172, in _fetch for localepath in settings.LOCALE_PATHS: File "/Library/Python/2.6/site-packages/django/utils/functional.py", line 273, in __getattr__ return getattr(self._wrapped, name) AttributeError: 'Settings' object has no attribute 'LOCALE_PATHS' Now, I can add a LOCAL_PATH atribute set to an empty string to my settings.py file but then it just complains about another setting and so on. What am I missing here?

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  • Excel export displaying '#####...'

    - by Cypher
    I'm trying to export an Excel database into .txt (Tab Delimited), but some of my cells are quite large. When I export into a txt some of the cells are exported as '#######....' which is surprisingly useless. Has this happened to anyone else? Do you know an easy fix? Data from one cell of my column: Accounting, African Studies, Agricultural/Bioresource Engineering, Agricultural Economics, Agricultural Science, Anatomy/Cell Biology, Animal Biology, Animal Science, Anthropology, Applied Zoology, Architecture, Art History, Atmospheric/Oceanic Science, Biochemistry, Biology, Botanical Sciences, Canadian Studies, Chemical Engineering, Chemistry/Bio-Organic/Environmental/Materials,ChurchMusicPerformance, Civil Engineering/Applied Mechanics, Classics, Composition, Computer Engineering,ComputerScience, ContemporaryGerman Studies, Dietetics, Early Music Performance, Earth/Planetary Sciences, East Asian Studies, Economics, Electrical Engineering, English Literature/ Drama/Theatre/Cultural Studies, Entrepreneurship, Environment, Environmental Biology, Finance, Food Science, Foundations of Computing, French Language/Linguistics/Literature/Translation, Geography, Geography/ Urban Systems, German, German Language/Literature/Culture, Hispanic Languages/Literature/Culture,History,Humanistic Studies, Industrial Relations, Information Systems, International Business, International Development Studies, Italian Studies/Medieval/Renaissance, Jazz Performance, Jewish Studies, Keyboard Studies, Kindergarten/Elementary Education, Kindergarten/Elementary Education/Jewish Studies,Kinesiology, Labor/Management Relations, Latin American/Caribbean Studies, Linguistics, Literature/Translation, Management Science, Marketing, Materials Engineering,Mathematics,Mathematics/Statistics,Mechanical Engineering, Microbiology, Microbiology/Immunology, Middle Eastern Studies, Mining Engineering, Music, Music Education, MusicHistory,Music Technology,Music Theory,North American Studies, Nutrition,OperationsManagement,OrganizationalBehavior/Human Resources Management, Performing Arts, Philosophy, Physical Education, Physics, Physiology, Plant Sciences, Political Science, Psychology, Quebec Studies, Religious Studies/Scriptures/Interpretations/World Religions,ResourceConservation,Russian, Science for Teachers,Secondary Education, Secondary Education/Music, Secondary Education/Science, SocialWork, Sociology, Software Engineering, Soil Science, Strategic Management, Teaching of French/English as a Second Language, Theology, Wildlife Biology, Wildlife Resources, Women’s Studies.

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  • python manage.py runserver fails

    - by Randy Simon
    I am trying to learn django by following along with this tutorial. I am using django version 1.1.1 I run django-admin.py startproject mysite and it creates the files it should. Then I try to start the server by running python manage.py runserver but here is where I get the following error. Traceback (most recent call last): File "manage.py", line 11, in <module> execute_manager(settings) File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 362, in execute_manager utility.execute() File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 303, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 195, in run_from_argv self.execute(*args, **options.__dict__) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 213, in execute translation.activate('en-us') File "/Library/Python/2.6/site-packages/django/utils/translation/__init__.py", line 73, in activate return real_activate(language) File "/Library/Python/2.6/site-packages/django/utils/translation/__init__.py", line 43, in delayed_loader return g['real_%s' % caller](*args, **kwargs) File "/Library/Python/2.6/site-packages/django/utils/translation/trans_real.py", line 205, in activate _active[currentThread()] = translation(language) File "/Library/Python/2.6/site-packages/django/utils/translation/trans_real.py", line 194, in translation default_translation = _fetch(settings.LANGUAGE_CODE) File "/Library/Python/2.6/site-packages/django/utils/translation/trans_real.py", line 172, in _fetch for localepath in settings.LOCALE_PATHS: File "/Library/Python/2.6/site-packages/django/utils/functional.py", line 273, in __getattr__ return getattr(self._wrapped, name) AttributeError: 'Settings' object has no attribute 'LOCALE_PATHS' Now, I can add a LOCALE_PATH atribute and set to an empty tuple to my settings.py file but then it just complains about another setting and so on. What am I missing here?

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  • Rails - difference between config.cache_store and config.action_controller.cache_store?

    - by gsmendoza
    If I set this in my environment config.action_controller.cache_store = :mem_cache_store ActionController::Base.cache_store will use a memcached store but Rails.cache will use a memory store instead: $ ./script/console >> ActionController::Base.cache_store => #<ActiveSupport::Cache::MemCacheStore:0xb6eb4bbc @data=<MemCache: 1 servers, ns: nil, ro: false>> >> Rails.cache => #<ActiveSupport::Cache::MemoryStore:0xb78b5e54 @data={}> In my app, I use Rails.cache.fetch(key){ object } to cache objects inside my helpers. All this time, I assumed that Rails.cache uses the memcached store so I'm surprised that it uses memory store. If I change the cache_store setting in my environment to config.cache_store = :mem_cache_store both ActionController::Base.cache_store and Rails.cache will now use the same memory store, which is what I expect: $ ./script/console >> ActionController::Base.cache_store => #<ActiveSupport::Cache::MemCacheStore:0xb7b8e928 @data=<MemCache: 1 servers, ns: nil, ro: false>, @middleware=#<Class:0xb7b73d44>, @thread_local_key=:active_support_cache_mem_cache_store_local_cache> >> Rails.cache => #<ActiveSupport::Cache::MemCacheStore:0xb7b8e928 @data=<MemCache: 1 servers, ns: nil, ro: false>, @middleware=#<Class:0xb7b73d44>, @thread_local_key=:active_support_cache_mem_cache_store_local_cache> However, when I run the app, I get a "marshal dump" error in the line where I call Rails.cache.fetch(key){ object } no marshal_dump is defined for class Proc Extracted source (around line #1): 1: Rails.cache.fetch(fragment_cache_key(...), :expires_in => 15.minutes) { ... } vendor/gems/memcache-client-1.8.1/lib/memcache.rb:359:in 'dump' vendor/gems/memcache-client-1.8.1/lib/memcache.rb:359:in 'set_without_newrelic_trace' What gives? Is Rails.cache meant to be a memory store? Should I call controller.cache_store.fetch in the places where I call Rails.cache.fetch?

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  • Software development metrics and reporting

    - by David M
    I've had some interesting conversations recently about software development metrics, in particular how they can be used in a reasonably large organisation to help development teams work better. I know there have been Stack Overflow questions about which metrics are good to use - like this one, but my question is more about which metrics are useful to which stakeholders, and at what level of aggregation. As an example, my view is that code coverage is a useful metric in the following ways (and maybe others): For a team's own internal use when combined with other measurements. For facilitating/enabling/mentoring teams, where it might be instructive when considered on a team-by-team basis as a trend (e.g. if team A and B have coverage this month of 75 and 50, I'd be more concerned with team A than B if the previous month they'd had 80 and 40). For senior management when presented as an aggregated statistic across a number of teams or a whole department. But I don't think it's useful for senior management to see this on a team-by-team basis, as this encourages artifical attempts to bolster coverage with tests that merely exercise, rather than test, code. I'm in an organisation with a couple of levels in its management hierarchy, but where the vast majority of managers are technically minded and able (with many still getting their hands dirty). Some of the development teams are leading the way in driving towards agile development practices, but others lag, and there is now a serious mandate from the top for this to be the way the organisation works. A couple of us are starting a programme to encourage this. In this sort of an organisation, what sort of metrics do you think are useful, to whom, why, and at what level of aggregation? I don't want people to feel their performance is being assessed based on a metric that they can artificially influence; at the same time, the senior management are going to want some sort of evidence that progress is being made. What advice or caveats can you provide based on experience in your own organisations? EDIT We are definitely wanting to use metrics as a tool for organisational improvement not as a tool for individual performance measurement.

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  • Scalable / Parallel Large Graph Analysis Library?

    - by Joel Hoff
    I am looking for good recommendations for scalable and/or parallel large graph analysis libraries in various languages. The problems I am working on involve significant computational analysis of graphs/networks with 1-100 million nodes and 10 million to 1+ billion edges. The largest SMP computer I am using has 256 GB memory, but I also have access to an HPC cluster with 1000 cores, 2 TB aggregate memory, and MPI for communication. I am primarily looking for scalable, high-performance graph libraries that could be used in either single or multi-threaded scenarios, but parallel analysis libraries based on MPI or a similar protocol for communication and/or distributed memory are also of interest for high-end problems. Target programming languages include C++, C, Java, and Python. My research to-date has come up with the following possible solutions for these languages: C++ -- The most viable solutions appear to be the Boost Graph Library and Parallel Boost Graph Library. I have looked briefly at MTGL, but it is currently slanted more toward massively multithreaded hardware architectures like the Cray XMT. C - igraph and SNAP (Small-world Network Analysis and Partitioning); latter uses OpenMP for parallelism on SMP systems. Java - I have found no parallel libraries here yet, but JGraphT and perhaps JUNG are leading contenders in the non-parallel space. Python - igraph and NetworkX look like the most solid options, though neither is parallel. There used to be Python bindings for BGL, but these are now unsupported; last release in 2005 looks stale now. Other topics here on SO that I've looked at have discussed graph libraries in C++, Java, Python, and other languages. However, none of these topics focused significantly on scalability. Does anyone have recommendations they can offer based on experience with any of the above or other library packages when applied to large graph analysis problems? Performance, scalability, and code stability/maturity are my primary concerns. Most of the specialized algorithms will be developed by my team with the exception of any graph-oriented parallel communication or distributed memory frameworks (where the graph state is distributed across a cluster).

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  • android compile error: could not reserve enough space for object heap

    - by moonlightcheese
    I'm getting this error during compilation: Error occurred during initialization of VM Could not create the Java virtual machine. Could not reserve enough space for object heap What's worse, the error occurs intermittently. Sometimes it happens, sometimes it doesn't. It seems to be dependent on the amount of code in the application. If I get rid of some variables or drop some imported libraries, it will compile. Then when I add more to it, I get the error again. I've included the following sources into the application in the [project_root]/src/ directory: org.apache.httpclient (I've stripped all references to log4j from the sources, so don't need it) org.apache.codec (as a dependency) org.apache.httpcore (dependency of httpclient) and my own activity code consisting of nothing more than an instance of HttpClient. I know this has something to do with the amount of memory necessary during compile time or some compiler options, and I'm not really stressing my system while i'm coding. I've got 2GB of memory on this Core Duo laptop and windows reports only 860MB page file usage (haven't used any other memory tools. I should have plenty of memory and processing power for this... and I'm only compiling some common http libs... total of 406 source files. What gives? Android API Level: 5 Android SDK rel 5 JDK version: 1.6.0_12

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  • C# PInvoke VerQueryValue returns back OutOfMemoryException?

    - by Bopha
    Hi, Below is the code sample which I got from online resource but it's suppose to work with fullframework, but when I try to build it using C# smart device, it throws exception saying it's out of memory. Does anybody know how can I fix it to use on compact? the out of memory exception when I make the second call to VerQueryValue which is the last one. thanks, [DllImport("coredll.dll")] public static extern bool VerQueryValue(byte[] buffer, string subblock, out IntPtr blockbuffer, out uint len); [DllImport("coredll.dll")] public static extern bool VerQueryValue(byte[] pBlock, string pSubBlock, out string pValue, out uint len); // private static void GetAssemblyVersion() { string filename = @"\Windows\MyLibrary.dll"; if (File.Exists(filename)) { try { int handle = 0; Int32 size = 0; size = GetFileVersionInfoSize(filename, out handle); if (size > 0) { bool retValue; byte[] buffer = new byte[size]; retValue = GetFileVersionInfo(filename, handle, size, buffer); if (retValue == true) { bool success = false; IntPtr blockbuffer = IntPtr.Zero; uint len = 0; //success = VerQueryValue(buffer, "\\", out blockbuffer, out len); success = VerQueryValue(buffer, @"\VarFileInfo\Translation", out blockbuffer, out len); if(success) { int p = (int)blockbuffer; //Reads a 16-bit signed integer from unmanaged memory int j = Marshal.ReadInt16((IntPtr)p); p += 2; //Reads a 16-bit signed integer from unmanaged memory int k = Marshal.ReadInt16((IntPtr)p); string sb = string.Format("{0:X4}{1:X4}", j, k); string spv = @"\StringFileInfo\" + sb + @"\ProductVersion"; string versionInfo; VerQueryValue(buffer, spv, out versionInfo, out len); } } } } catch (Exception err) { string error = err.Message; } } }

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  • How to read a database record with a DataReader and add it to a DataTable

    - by Olga
    Hello I have some data in a Oracle database table(around 4 million records) which i want to transform and store in a MSSQL database using ADO.NET. So far i used (for much smaller tables) a DataAdapter to read the data out of the Oracle DataBase and add the DataTable to a DataSet for further processing. When i tried this with my huge table, there was a outofmemory exception thrown. ( I assume this is because i cannot load the whole table into my memory) :) Now i am looking for a good way to perform this extract/transfer/load, without storing the whole table in the memory. I would like to use a DataReader and read the single dataRecords in a DataTable. If there are about 100k rows in it, I would like to process them and clear the DataTable afterwards(to have free memory again). Now i would like to know how to add a single datarecord as a row to a dataTable with ado.net and how to completly clear the dataTable out of memory: My code so far: Dim dt As New DataTable Dim count As Int32 count = 0 ' reads data records from oracle database table' While rdr.Read() 'read n records and add them to a dataTable' While count < 10000 dt.Rows.Add(????) count = count + 1 End While 'transform data in the dataTable, and insert it to the destination' ' flush the dataTable after insertion' count = 0 End While Thank you very much for your response!

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  • How best to use XPath with very large XML files in .NET?

    - by glenatron
    I need to do some processing on fairly large XML files ( large here being potentially upwards of a gigabyte ) in C# including performing some complex xpath queries. The problem I have is that the standard way I would normally do this through the System.XML libraries likes to load the whole file into memory before it does anything with it, which can cause memory problems with files of this size. I don't need to be updating the files at all just reading them and querying the data contained in them. Some of the XPath queries are quite involved and go across several levels of parent-child type relationship - I'm not sure whether this will affect the ability to use a stream reader rather than loading the data into memory as a block. One way I can see of making it work is to perform the simple analysis using a stream-based approach and perhaps wrapping the XPath statements into XSLT transformations that I could run across the files afterward, although it seems a little convoluted. Alternately I know that there are some elements that the XPath queries will not run across, so I guess I could break the document up into a series of smaller fragments based on it's original tree structure, which could perhaps be small enough to process in memory without causing too much havoc. I've tried to explain my objective here so if I'm barking up totally the wrong tree in terms of general approach I'm sure you folks can set me right...

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  • image analysis and 64bit OS

    - by picciopiccio
    I developed a C# application that makes use of Congex vision library (VPro). My application is developed with Visual Studio 2008 Pro on a 32bit Windows PC with 3GB of RAM. During the startup of application I see that a large amount of memory is allocated. So far so good, but when I add many and many vision elaboration the memory allocation increases and a part of application (only Cognex OCX) stops working well. The rest of application stills to work (working threads, com on socket....) I did whatever I could to save memory, but when the memory allocated is about 700MB I begin to have the problems. A note on the documentation of Cognex library tells that /LARGEADDRESSWARE is not supported. Anyway I'm thinking to try the migration of my app on win64 but what do I have to do? Can I simply use a processor with 64bit and windows 64bit without recompiling my application that would remain a 32bit application to take advantage of 64bit ? Or I should recompile my application ? If I don't need to recompile my application, can I link it with 64bit Congnex library? If I have to recompile my application, is it possible to cross compile the application so that my develop suite is on a 32bit PC? Every help will be very appreciated!! Thank in advance

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  • implementing a download manager that supports resuming

    - by Idan K
    hi, I intend on writing a small download manager in C++ that supports resuming (and multiple connections per download). From the info I gathered so far, when sending the http request I need to add a header field with a key of "Range" and the value "bytes=startoff-endoff". Then the server returns a http response with the data between those offsets. So roughly what I have in mind is to split the file to the number of allowed connections per file and send a http request per splitted part with the appropriate "Range". So if I have a 4mb file and 4 allowed connections, I'd split the file to 4 and have 4 http requests going, each with the appropriate "Range" field. Implementing the resume feature would involve remembering which offsets are already downloaded and simply not request those. Is this the right way to do this? What if the web server doesn't support resuming? (my guess is it will ignore the "Range" and just send the entire file) When sending the http requests, should I specify in the range the entire splitted size? Or maybe ask smaller pieces, say 1024k per request? When reading the data, should I write it immediately to the file or do some kind of buffering? I guess it could be wasteful to write small chunks. Should I use a memory mapped file? If I remember correctly, it's recommended for frequent reads rather than writes (I could be wrong). Is it memory wise? What if I have several downloads simultaneously? If I'm not using a memory mapped file, should I open the file per allowed connection? Or when needing to write to the file simply seek? (if I did use a memory mapped file this would be really easy, since I could simply have several pointers). Note: I'll probably be using Qt, but this is a general question so I left code out of it.

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  • How does PHP PDO work internally ?

    - by Rachel
    I want to use pdo in my application, but before that I want to understand how internally PDOStatement->fetch and PDOStatement->fetchAll. For my application, I want to do something like "SELECT * FROM myTable" and insert into csv file and it has around 90000 rows of data. My question is, if I use PDOStatement->fetch as I am using it here: // First, prepare the statement, using placeholders $query = "SELECT * FROM tableName"; $stmt = $this->connection->prepare($query); // Execute the statement $stmt->execute(); var_dump($stmt->fetch(PDO::FETCH_ASSOC)); while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) { echo "Hi"; // Export every row to a file fputcsv($data, $row); } Will after every fetch from database, result for that fetch would be store in memory ? Meaning when I do second fetch, memory would have data of first fetch as well as data for second fetch. And so if I have 90000 rows of data and if am doing fetch every time than memory is being updated to take new fetch result without removing results from previous fetch and so for the last fetch memory would already have 89999 rows of data. Is this how PDOStatement::fetch works ? Performance wise how does this stack up against PDOStatement::fetchAll ?

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  • what exactly is the danger of an uninitialized pointer in C

    - by akh2103
    I am trying get a handle on C as I work my way thru Jim Trevor's "Cyclone: A safe dialect of C" for a PL class. Trevor and his co-authors are trying to make a safe version of C, so they eliminate uninitialized pointers in their language. Googling around a bit on uninitialized pointers, it seems like un-initialized pointers point to random locations in memory. It seems like this alone makes them unsafe. If you reference an un-itilialized pointer, you jump to an unsafe part of memory. Period. But the way Trevor talks about them seems to imply that it is more complex. He cites the following code, and explains that when the function FrmGetObjectIndex dereferences f, it isn’t accessing a valid pointer, but rather an unpredictable address — whatever was on the stack when the space for f was allocated. What does Trevor mean by "whatever was on the stack when the space for f was allocated"? Are "un-initialized" pointers initialized to random locations in memory by default? Or does their "random" behavior have to do with the memory allocated for these pointers getting filled with strange values (that are then referenced) because of unexpected behavior on the stack. Form *f; switch (event->eType) { case frmOpenEvent: f = FrmGetActiveForm(); ... case ctlSelectEvent: i = FrmGetObjectIndex(f, field); ... }

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  • Mysql Database Question about Large Columns

    - by murat
    Hi, I have a table that has 100.000 rows, and soon it will be doubled. The size of the database is currently 5 gb and most of them goes to one particular column, which is a text column for PDF files. We expect to have 20-30 GB or maybe 50 gb database after couple of month and this system will be used frequently. I have couple of questions regarding with this setup 1-) We are using innodb on every table, including users table etc. Is it better to use myisam on this table, where we store text version of the PDF files? (from memory usage /performance perspective) 2-) We use Sphinx for searching, however the data must be retrieved for highlighting. Highlighting is done via sphinx API but still we need to retrieve 10 rows in order to send it to Sphinx again. This 10 rows may allocate 50 mb memory, which is quite large. So I am planning to split these PDF files into chunks of 5 pages in the database, so these 100.000 rows will be around 3-4 million rows and couple of month later, instead of having 300.000-350.000 rows, we'll have 10 million rows to store text version of these PDF files. However, we will retrieve less pages, so again instead of retrieving 400 pages to send Sphinx for highlighting, we can retrieve 5 pages and it will have a big impact on the performance. Currently, when we search a term and retrieve PDF files that have more than 100 pages, the execution time is 0.3-0.35 seconds, however if we retrieve PDF files that have less than 5 pages, the execution time reduces to 0.06 seconds, and it also uses less memory. Do you think, this is a good trade-off? We will have million of rows instead of having 100k-200k rows but it will save memory and improve the performance. Is it a good approach to solve this problem and do you have any ideas how to overcome this problem? The text version of the data is used only for indexing and highlighting. So, we are very flexible. Thanks,

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  • Natural vs surrogate keys on support tables

    - by Bugeo
    I have read many articles about the battle between natural versus surrogate primary keys. I agree in the use of surrogate keys to identify records of tables whose contents are created by the user. But in the case of supporting tables what should I use? For example, in a hypothetical table "orderStates". If you use a natural key would have the following data: TABLE ORDERSTATES {ID: "NEW", NAME: "New"} {ID: "MANAGEMENT" NAME: "Management"} {ID: "SHIPPED" NAME: "Shipped"} If I use a surrogate key would have the following data: TABLE ORDERSTATES {ID: 1 CODE: "NEW", NAME: "New"} {ID: 2 CODE: "MANAGEMENT" NAME: "Management"} {ID: 3 CODE: "SHIPPED" NAME: "Shipped"} Now let's take an example: a user enters a new order. In the case in which use natural keys, in the code I can write this: newOrder.StateOrderId = "NEW"; With the surrogate keys instead every time I have an additional step. stateOrderId_NEW = .... I retrieve the id corresponding to the recod code "NEW" newOrder.StateOrderId = stateOrderId_NEW; The same will happen every time I have to move the order in a new status. So, in this case, what are the reason to chose one key type vs the other one?

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  • what are all the Optimize tricks that you know for asp.net code ?

    - by Aristos
    After some time of many code programming on asp.net, I discover the very big speed different between string and StringBuilder. I know that is very common and known but I just mention it for start. The second think that I have found to speed up the code, is to use the const, and not the static, for declare my configuration constants value (especial the strings). With the const, the compiler not create new object, but just place the value, on the point that you have ask it, but with the static declaration, is create a new memory object and keep its on the memory. My third trick, is when I search for string, I use hash values, and not the string itself. For example, if I need a List<string SomeValues, and place inside strings that I need to search them, I prefer to use List<int SomeHashValue, and I use the hash value to locate the strings. My forth thought that I was wandering, is if is better to place big strings in one line, or separate them in different lines with the + symbol to be more easy to read out. I make some tests and see that the compiler make a good job is some split the string, in many lines, using the + symbol. What other tricks/tips do you know and use on your programming to make it run faster, and maybe use less memory. Well I know, that some times, to make something run faster, you need more memory, more cache. My priority is on speed. Because Speed Counts.

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  • Is a call to the following method considered late binding?

    - by AspOnMyNet
    1) Assume: • B1 defines methods virtualM() and nonvirtualM(), where former method is virtual while the latter is non-virtual • B2 derives from B1 • B2 overrides virtualM() • B2 is defined inside assembly A • Application app doesn’t have a reference to assembly A In the following code application app dynamically loads an assembly A, creates an instance of a type B2 and calls methods virtualM() and nonvirtualM(): Assembly a=Assembly.Load(“A”); Type t= a.GetType(“B2”); B1 a = ( B1 ) Activator.CreateInstance ( “t” ); a.virtualM(); a.nonvirtualM(); a) Is call to a.virtualM() considered early binding or late binding? b) I assume a call to a.nonvirtualM() is resolved during compilation time? 2) Does the term late binding refer only to looking up the target method at run time or does it also refer to creating an instance of given type at runtime? thanx EDIT: 1) A a=new A(); a.M(); As far as I know, it is not known at compile time where on the heap (thus at which memory address ) will instance a be created during runtime. Now, with early binding the function calls are replaced with memory addresses during compilation process. But how can compiler replace function call with memory address, if it doesn’t know where on the heap will object a be created during runtime ( here I’m assuming the address of method a.M will also be at same memory location as a )? 2) The method slot is determined at compile time I assume that by method slot you’re referring to the entry point in V-table?

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  • c# string interning

    - by CodingThunder
    I am trying to understand string interning and why is doesn't seem to work in my example. The point of the example is to show Example 1 uses less (a lot less memory) as it should only have 10 strings in memory. However, in the code below both example use roughly the same amount of memory (virtual size and working set). Please advice why example 1 isn't using a lot less memory? Thanks Example 1: IList<string> list = new List<string>(10000); for (int i = 0; i < 10000; i++) { for (int k = 0; k < 10; k++) { list.Add(string.Intern(k.ToString())); } } Console.WriteLine("intern Done"); Console.ReadLine(); Example 2: IList<string> list = new List<string>(10000); for (int i = 0; i < 10000; i++) { for (int k = 0; k < 10; k++) { list.Add(k.ToString()); } } Console.WriteLine("intern Done"); Console.ReadLine();

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  • How do I patch a Windows API at runtime so that it to returns 0 in x64?

    - by Jorge Vasquez
    In x86, I get the function address using GetProcAddress() and write a simple XOR EAX,EAX; RET; in it. Simple and effective. How do I do the same in x64? bool DisableSetUnhandledExceptionFilter() { const BYTE PatchBytes[5] = { 0x33, 0xC0, 0xC2, 0x04, 0x00 }; // XOR EAX,EAX; RET; // Obtain the address of SetUnhandledExceptionFilter HMODULE hLib = GetModuleHandle( _T("kernel32.dll") ); if( hLib == NULL ) return false; BYTE* pTarget = (BYTE*)GetProcAddress( hLib, "SetUnhandledExceptionFilter" ); if( pTarget == 0 ) return false; // Patch SetUnhandledExceptionFilter if( !WriteMemory( pTarget, PatchBytes, sizeof(PatchBytes) ) ) return false; // Ensures out of cache FlushInstructionCache(GetCurrentProcess(), pTarget, sizeof(PatchBytes)); // Success return true; } static bool WriteMemory( BYTE* pTarget, const BYTE* pSource, DWORD Size ) { // Check parameters if( pTarget == 0 ) return false; if( pSource == 0 ) return false; if( Size == 0 ) return false; if( IsBadReadPtr( pSource, Size ) ) return false; // Modify protection attributes of the target memory page DWORD OldProtect = 0; if( !VirtualProtect( pTarget, Size, PAGE_EXECUTE_READWRITE, &OldProtect ) ) return false; // Write memory memcpy( pTarget, pSource, Size ); // Restore memory protection attributes of the target memory page DWORD Temp = 0; if( !VirtualProtect( pTarget, Size, OldProtect, &Temp ) ) return false; // Success return true; } This example is adapted from code found here: http://www.debuginfo.com/articles/debugfilters.html#overwrite .

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  • How Can I Compress Texture in OpenGL on iPhone/iPad?

    - by nonamelive
    Hi, I'm making an iPad app which needs OpenGL to do a flip animation. I have a front image texture and a back image texture. Both the two textures are screenshots. // Capture an image of the screen UIGraphicsBeginImageContext(view.bounds.size); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); // Allocate some memory for the texture GLubyte *textureData = (GLubyte*)calloc(maxTextureSize*4, maxTextureSize); // Create a drawing context to draw image into texture memory CGContextRef textureContext = CGBitmapContextCreate(textureData, maxTextureSize, maxTextureSize, 8, maxTextureSize*4, CGImageGetColorSpace(image.CGImage), kCGImageAlphaPremultipliedLast); CGContextDrawImage(textureContext, CGRectMake(0, maxTextureSize-size.height, size.width, size.height), image.CGImage); CGContextRelease(textureContext); // ...done creating the texture data [EAGLContext setCurrentContext:context]; glGenTextures(1, &textureToView); glBindTexture(GL_TEXTURE_2D, textureToView); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, maxTextureSize, maxTextureSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureData); // free texture data which is by now copied into the GL context free(textureData); Each of the texture takes up about 8MB memory, which is unacceptable for an iPhone/iPad app. Could anyone tell me how can I compress the texture to reduce the memory. I'm a complete newbie to OpenGL. Any help would be appreciated!

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  • C# performance methods of receiving data from a socket?

    - by Daniel
    Lets assume we have a simple internet socket, and its going to send 10 megabytes (because i want to ignore memory issues) of random data through. Is there any performance difference or a best practice method that one should use for receiving data? The final output data should be represented by a byte[]. Yes i know writing an arbitrary amount of data to memory is bad, and if I was downloading a large file i wouldn't be doing it like this. But for argument sake lets ignore that and assume its a smallish amount of data. I also realise that the bottleneck here is probably not the memory management but rather the socket receiving. I just want to know what would be the most efficient method of receiving data. A few dodgy ways can think of is: Have a List and a buffer, after the buffer is full, add it to the list and at the end list.ToArray() to get the byte[] Write the buffer to a memory stream, after its complete construct a byte[] of the stream.Length and read it all into it in order to get the byte[] output. Is there a more efficient/better way of doing this?

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  • Do entity collections and object sets implement IQueryable<T>?

    - by Chevex
    I am using Entity Framework for the first time and noticed that the entities object returns entity collections. DBEntities db = new DBEntities(); db.Users; //Users is an ObjectSet<User> User user = db.Users.Where(x => x.Username == "test").First(); //Is this getting executed in the SQL or in memory? user.Posts; //Posts is an EntityCollection<Post> Post post = user.Posts.Where(x => x.PostID == "123").First(); //Is this getting executed in the SQL or in memory? Do both ObjectSet and EntityCollection implement IQueryable? I am hoping they do so that I know the queries are getting executed at the data source and not in memory. EDIT: So apparently EntityCollection does not while ObjectSet does. Does that mean I would be better off using this code? DBEntities db = new DBEntities(); User user = db.Users.Where(x => x.Username == "test").First(); //Is this getting executed in the SQL or in memory? Post post = db.Posts.Where(x => (x.PostID == "123")&&(x.Username == user.Username)).First(); // Querying the object set instead of the entity collection. Also, what is the difference between ObjectSet and EntityCollection? Shouldn't they be the same? Thanks in advance!

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  • Unusual heap size limitations in VS2003 C++

    - by Shane MacLaughlin
    I have a C++ app that uses large arrays of data, and have noticed while testing that it is running out of memory, while there is still plenty of memory available. I have reduced the code to a sample test case as follows; void MemTest() { size_t Size = 500*1024*1024; // 512mb if (Size > _HEAP_MAXREQ) TRACE("Invalid Size"); void * mem = malloc(Size); if (mem == NULL) TRACE("allocation failed"); } If I create a new MFC project, include this function, and run it from InitInstance, it works fine in debug mode (memory allocated as expected), yet fails in release mode (malloc returns NULL). Single stepping through release into the C run times, my function gets inlined I get the following // malloc.c void * __cdecl _malloc_base (size_t size) { void *res = _nh_malloc_base(size, _newmode); RTCCALLBACK(_RTC_Allocate_hook, (res, size, 0)); return res; } Calling _nh_malloc_base void * __cdecl _nh_malloc_base (size_t size, int nhFlag) { void * pvReturn; // validate size if (size > _HEAP_MAXREQ) return NULL; ' ' And (size _HEAP_MAXREQ) returns true and hence my memory doesn't get allocated. Putting a watch on size comes back with the exptected 512MB, which suggests the program is linking into a different run-time library with a much smaller _HEAP_MAXREQ. Grepping the VC++ folders for _HEAP_MAXREQ shows the expected 0xFFFFFFE0, so I can't figure out what is happening here. Anyone know of any CRT changes or versions that would cause this problem, or am I missing something way more obvious?

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