Search Results

Search found 12588 results on 504 pages for 'memory allocation'.

Page 395/504 | < Previous Page | 391 392 393 394 395 396 397 398 399 400 401 402  | Next Page >

  • reading specific lines from a file

    - by MacUsers
    What's the best way of reading only the specific lines (based on matching text) from a file? This is what I'm doing now: match_txt = "lhcb" for inFile in os.listdir('.'): readFile = open(inFile, 'r') lines = readFile.readlines() readFile.close() for line in lines: if line.find(match_txt)==0: #< do stuff here > i.e. I'm reading the lines, only with "lhcb" in it, from all the files in the present directory one by one. Is it the best way of doing that? Can it be done without loading the whole file in the memory in the first place?

    Read the article

  • What's the reason why core data takes care of the life-cycle of modeled properties?

    - by mystify
    The docs say that I should not release any modeled property in -dealloc. For me, that feels like violating the big memory management rules. I see a big retain in the header and no -release, because Core Data seems to do it at any other time. Is it because Core Data may drop the value of a property dynamically, at any time when needed? And what's Core Data doing when dropping an managed object? If there's no -dealloc, then how and when are the properties getting freed up?

    Read the article

  • UIScrollView with over 100 images

    - by tikkips
    I have implemented a UIScrollView on the iPhone that contains 100 image slots which I fill only the currently visible page, the one before it, and the one after it as the user scrolls. Everything works fine until we get up to image 97 or 98, the entire view disappears! The only thing I can do at that point is navigate back to the previous view. Nothing works as far as the scroll view after this. I am not receiving any memory warnings an the rest of the app functions fine. Any ideas? Has anyone created a UIScrollView in paging mode with over 100 pages? Rick

    Read the article

  • Authenticating a SOAP service in Java (password security)

    - by user1686448
    I am writing an application, in Java, which needs to log in to a remote SOAP service (JIRA) prior to calling methods on that service. I have looked at examples of how to do this, for example http://www.j-tricks.com/1/post/2010/8/jira-soap-client.html, however I am concerned that I need to put the password in memory at some point. I've read that I should store the password as a char[] but still, I'm concerned about storing the password in the clear at all. How should I store the password used by my client to log into the SOAP service? And how should I read it and pass it to JIRA?

    Read the article

  • Perl: getting handle for stdin to be used in cgi-bin script

    - by Daniel
    Using perl 5.8.8 on windows server I am writing a perl cgi script using Archive::Zip with to create on fly a zip that must be download by users: no issues on that side. The zip is managed in memory, no physical file is written to disk using temporary files or whatever. I am wondering how to allow zip downloading writing the stream to the browser. What I have done is something like: binmode (STDOUT); $zip->writeToFileHandle(*STDOUT, 0); but i feel insecure about this way to get the STDOUT as file handle. Is it correct and robust? There is a better way? Many thanks for your advices

    Read the article

  • What is a cross-platform way to get the current directory?

    - by rubenvb
    I need a cross-platform way to get the current working directory (yes, getcwd does what I want). I thought this might do the trick: #ifdef _WIN32 #include <direct.h> #define getcwd _getcwd // stupid MSFT "deprecation" warning #elif #include <unistd.h> #endif #include <string> #include <iostream> using namespace std; int main() { string s_cwd(getcwd(NULL,0)); cout << "CWD is: " << s_cwd << endl; } I got this reading: _getcwd at MSDN getcwd at Kernel.org getcwd at Apple.com There should be no memory leaks, and is should work on a Mac as well, correct?

    Read the article

  • What is the best way to declare a property?

    - by Simon
    Hi. We declare properties using the @property keyword and synthesize it in the implementation file. My question is, What if I declare a property using the @property keyword and also declare a variable in the interface block with the same name? For example, consider the following code, Interface: @interface myClass : NSObject { NSString *myClass_name; // LINE 1 } @property(nonatomic, retain) NSString *myClass_name; // LINE 2 @end Implementation: @implementation myClass @synthesize myClass_name // LINE 3 @end Declaring myClass_name in LINE 1 will make any problem? Like any reference problem or any unnecessary memory consumption problem?

    Read the article

  • SQL Server Compact Edition 3.5 performance

    - by Wili
    I am using SQL Server CE 3.5 SP1 in one of my client applications. When a user loads the program and starts using it, performance is fine. If the user lets the program sit idle for a while, it takes a considerable amount of time (10 or more seconds) for the program to respond. Every time the user asks for a new screen, a call is made to the SQL CE database to get the data for that screen. It seems like the hard drive may be going to sleep and then when the database is accessed, the hard drive has to wake back up. Is it possible to load the entire database into memory and work from that? Are there any other suggestions on how to increase performance?

    Read the article

  • FileInputStream and FileOutputStream to the same file: Is a read() guaranteed to see all write()s that "happened before"?

    - by user946850
    I am using a file as a cache for big data. One thread writes to it sequentially, another thread reads it sequentially. Can I be sure that all data that has been written (by write()) in one thread can be read() from another thread, assuming a proper "happens-before" relationship in terms of the Java memory model? Is this behavior documented? EDIT: In my JDK, FileOutputSream does not override flush(), and OutputStream.flush() is empty. That's why I'm wondering... EDIT^2: The streams in question are owned exclusively by a class that I have full control of. Each stream is guaranteed to be accesses by one thread only. My tests show that it works as expected, but I'm still wondering if this is guaranteed and documented. See also this related discussion: http://chat.stackoverflow.com/rooms/17598/discussion-between-hussain-al-mutawa-and-user946850

    Read the article

  • Reading files with Java

    - by sikas
    I would like to know how can I read a file byte by byte then perform some operation every n bytes. for example: Say I have a file of size = 50 bytes, I want to divide it into blocks each of n bytes. Then each block is sent to a function for some operations to be done on those bytes. The blocks are to be created during the read process and sent to the function when the block reaches n bytes so that I don`t use much memory for storing all blocks. I want the output of the function to be written/appended on a new file. This is what I've reached to read, yet I don't know it it is right: fc = new JFileChooser(); File f = fc.getSelectedFile(); FileInputStream in = new FileInputStream(f); byte[] b = new byte[16]; in.read(b); I haven't done anything yet for the write process.

    Read the article

  • DataSet XML export is empty

    - by Shaine
    I've got in-memory dataset with couple of tables that is populated in code. Data-bound grids on the gui show table contents without a problem. Then I try to export the dataset into XML: ds.WriteXml(fdSave.FileName, XmlWriteMode.WriteSchema); and get empty XML (with couple of lines regarding dataset names but without any tables) If I export table directly I've got all the data but dataset name is obviously wrong: ds.Fields.WriteXml(fdSave.FileName, XmlWriteMode.WriteSchema); What am I missing? Is there any reasonable way to write the whole dataset into file?

    Read the article

  • Is the use of union in this matrix class completely safe?

    - by identitycrisisuk
    Unions aren't something I've used that often and after looking at a few other questions on them here it seems like there is almost always some kind of caveat where they might not work. Eg. structs possibly having unexpected padding or endian differences. Came across this in a math library I'm using though and I wondered if it is a totally safe usage. I assume that multidimensional arrays don't have any extra padding and since the type is the same for both definitions they are guaranteed to take up exactly the same amount of memory? template<typename T> class Matrix44T { ... union { T M[16]; T m[4][4]; } m; }; Are there any downsides to this setup? Would the order of definition make any difference to how this works?

    Read the article

  • How to optimize indexing of large number of DB records using Zend_Lucene and Zend_Paginator

    - by jdichev
    So I have this cron script that is deployed and ran using Cron on a host and indexes all the records in a database table - the index is later used both for the front end of the site and the backed operations as well. After the operation, the index is about 3-4 MB. The problem is it takes a lot of resources (CPU: 30+ and a good chunk of memory) and slows the machine down. My question is about how to optimize the operation described below: First there is a select query built using the Zend Framework API, this query is then passed to a Paginator factory that returns a paginator which I am using to balance the current number of items being indexed and not iterate over too much items. The script is iterating over the current items in the paginator object using a foreach loop until reaching the end and then it starts from the beginning after getting items for the next page. I am suspecting this overhead is caused by the Zend_Lucene but no idea how this could be improved.

    Read the article

  • Best way to call other class view in iphone?

    - by aman-gupta
    Hi, Generally i call my other class view by creating a pointer of delegate and then call the other class by using its link as below:- First Way :- Mydelegate *ptr = (Mydelegate *)[[UIApplication sharedApplication]delegate]; [self.navigationController pushViewController:ptr.NextClasspointer animated:YES]; Second Way :- Create a pointer of that class which u want to call :-- NextClass *nextptr = [[NextClass alloc]initWithnibName:@"NextClass" bundle:nil]; [self.navigationController pushViewController:nextptr animated:YES]; [nextptr release]; nextptr = nil; These above two methods i generally used but my problem is that which one is best for big project so that my stack problem will be removed I mean memory issue will be solved.And is it necessary to release pointer in first and second case is the way i release is correct or wrong Please help me Thanks in Advance

    Read the article

  • PHP reporting error. DB verify how to?

    - by iamfab
    Error reporting Notice: Undefined variable: random_chars in wamp\www\php_sandbox\idgen.php on line 21 Call Stack: # Time Memory Function Location 1 0.0045 678928 {main}( ) ..\idgen.php:0 GPB7446 How do I fix this error? Using this code like an automatic unique id generator. How do I connect to DB to verify code is truly unique before allowing it to be assigned to a user creating a new account? Thanks <?php $characters = array( "A","B","E","F","G","H","J","K","M","N","P","R","S","T","W","X","Y","Z"); $keys = array(); while(count($keys) < 3) { $x = mt_rand(0, count($characters)-1); if(!in_array($x, $keys)) { $keys[] = $x; } } foreach($keys as $key){ $random_chars .= $characters[$key];} $randNum = rand(2327,9987); $randLet = rand(2327,9987); echo $random_chars . $randNum; ?>

    Read the article

  • Improving the performance of an nHibernate Data Access Layer.

    - by Amitabh
    I am working on improving the performance of DataAccess Layer of an existing Asp.Net Web Application. The scenerios are. Its a web based application in Asp.Net. DataAccess layer is built using NHibernate 1.2 and exposed as WCF Service. The Entity class is marked with DataContract. Lazy loading is not used and because of the eager-fetching of the relations there is huge no of database objects are loaded in the memory. No of hits to the database is also high. For example I profiled the application using NHProfiler and there were about 50+ sql calls to load one of the Entity object using the primary key. I also can not change code much as its an existing live application with no NUnit test cases at all. Please can I get some suggestions here?

    Read the article

  • How do I read UTF-8 characters via a pointer?

    - by Jen
    Suppose I have UTF-8 content stored in memory, how do I read the characters using a pointer? I presume I need to watch for the 8th bit indicating a multi-byte character, but how exactly do I turn the sequence into a valid Unicode character? Also, is wchar_t the proper type to store a single Unicode character? This is what I have in mind: wchar_t readNextChar (char** p) { char ch = *p++; if (ch & 128) { // This is a multi-byte character, what do I do now? // char chNext = *p++; // ... but how do I assemble the Unicode character? ... } ... }

    Read the article

  • Preparing for the next C++ standard

    - by Neil Butterworth
    The spate of questions regarding BOOST_FOREACH prompts me to ask users of the Boost library what (if anything) they are doing to prepare their code for portability to the proposed new C++ standard (aka C++0x). For example, do you write code like this if you use shared_ptr: #ifdef CPPOX #include <memory> #else #include "boost/shared_ptr.hpp" #endif There is also the namespace issue - in the future, shared_ptr will be part of the std, namespace - how do you deal with that? I'm interested in these questions because I've decided to bite the bullet and start learning boost seriously, and I'd like to use best practices in my code. Not exactly a flood of answers - does this mean it's a non-issue? Anyway, thanks to those that replied; I'm accepting jalfs answer because I like being advised to do nothing!

    Read the article

  • Cache bandwidth per tick for modern CPUs

    - by osgx
    Hello What is a speed of cache accessing for modern CPUs? How many bytes can be read or written from memory every processor clock tick by Intel P4, Core2, Corei7, AMD? Please, answer with both theoretical (width of ld/sd unit with its throughput in uOPs/tick) and practical numbers (even memcpy speed tests, or STREAM benchmark), if any. PS it is question, related to maximal rate of load/store instructions in assembler. There can be theoretical rate of loading (all Instructions Per Tick are widest loads), but processor can give only part of such, a practical limit of loading.

    Read the article

  • Is there an automatic way to remove debugging methods for a release build?

    - by Lewis
    Note: This is an extension of an earlier question I asked here: Do additional function/method definitions increase a program's memory footprint? When I write a class, I usually end up writing several testing/debugging methods, used to make sure the class works as it should, or for printing data to help with debugging, or for unit testing, etc. Is there an easy/automatic way to make a release without these methods, or do I need to manually delete the extra code any time I want to compile a release version? I ask this question both from a C++ and a Java perspective. I'm using Code::Blocks and Eclipse as IDEs, if that plays into the answer somehow.

    Read the article

  • Address of array vs. address of array[0] - C language

    - by user324994
    My question is why does the address of an array differ from the address of its first position? I'm trying to write my own malloc, but to start out I'm just allocating a chunk of memory and playing around with the addresses. My code looks roughly like this: #define BUFF_SIZE 1024 static char *mallocbuff; int main(){ mallocbuff = malloc(BUFF_SIZE); printf("The address of mallocbuff is %d\n", &mallocbuff); printf("The address of mallocbuff[0] is %d\n", &mallocbuff[0]); } &mallocbuff is the same address every time I run it. &mallocbuff[0] is some random address every time. I was expecting the addresses to match each other. Can anyone explain why this isn't the case?

    Read the article

  • Save NSCache Contents to Disk

    - by Cory Imdieke
    I'm writing an app that needs to keep an in-memory cache of a bunch of objects, but that doesn't get out of hand so I'm planning on using NSCache to store it all. Looks like it will take care of purging and such for me, which is fantastic. I'd also like to persist the cache between launches, so I need to write the cache data to disk. Is there an easy way to save the NSCache contents to a plist or something? Are there perhaps better ways to accomplish this using something other than NSCache? This app will be on the iPhone, so I'll need only classes that are available in iOS 4+ and not just OS X. Thanks!

    Read the article

  • Can I make a pointer to the code, and pass to the next instruction?

    - by drigoSkalWalker
    Like this link http://gcc.gnu.org/onlinedocs/gcc-3.3.1/gcc/Labels-as-Values.html I can get the memory address of an label, so if I declare a label, get your address, and add your address, i will pass to next instruction? some ilustration int main () { void *ptr; label: instruction 1; instruction 2; ptr = &&label; // So if I do it... ptr = ptr + 1; // I will get the instruction 2 correct?? Thanks for all answers.

    Read the article

  • PHP+MYSQL Server Config

    - by Matias
    Hi guys, I am parsing an XML file with PHP and inserting the rows in a MYSQL database. I am using PHP simplexml_load_files to load the XML and a foreach to loop through the array and insert the rows into my database. It works perfectly fine with small files i am testing, but it comes to reality I need to parse a large 500mb XML file and nothing happens. I was wondering what was the right Php.ini config for this case ? I have a VPS Linux Cent OS, with 256 mb of dedicated Memory and MYSQL 5.0.5. I have also set php memory_limit = 256M (maximum of my server) Any suggestions, similar experiences will be greatly appreciated Thanks

    Read the article

  • Can I force MySQL to output results before query is completed?

    - by Gordon Royle
    I have a large MySQL table (about 750 million rows) and I just want to extract a couple of columns. SELECT id, delid FROM tbl_name; No joins or selection criteria or anything. There is an index on both fields (separately). In principle, it could just start reading the table and spitting out the values immediately, but in practice the whole system just chews up memory and basically grinds to a halt. It seems like the entire query is being executed and the output stored somewhere before ANY output is produced... I've searched on unbuffering, turning off caches etc, but just cannot find the answer. (mysqldump is almost what I want except it dumps the whole table - but at least it just starts producing output immediately)

    Read the article

< Previous Page | 391 392 393 394 395 396 397 398 399 400 401 402  | Next Page >