Search Results

Search found 12398 results on 496 pages for 'in memory oltp'.

Page 432/496 | < Previous Page | 428 429 430 431 432 433 434 435 436 437 438 439  | Next Page >

• How to create a CGBitmapContext which works for Retina display and not wasting space for regular display?

  - by ????

  Is it true that if it is in UIKit, including drawRect, the HD aspect of Retina display is automatically handled? So does that mean in drawRect, the current graphics context for a 1024 x 768 view is actually a 2048 x 1536 pixel Bitmap context? (is there a way to print this size out to verify it). We actually enjoy the luxury of 1 point = 4 pixels automatically handled for us. However, if we use CGBitmapContextCreate, then those will really be pixels, not points? (at least if we provide a data buffer for that bitmap, the size is not for the higher resolution, but for the standard resolution, and even if we pass NULL as the buffer so that CGBitmapContextCreate handles the buffer for us, the size probably is the same as if we pass in a data buffer, and it is just standard resolution, not Retina's resolution). We can always create 2048 x 1536 for iPad 1 and iPad 2 as well as the New iPad, but it will waste memory and processor and GPU power, as it is only needed for the New iPad. So do we have to use a if () { } else { } to create such a bitmap context and how do we actually do so? And all our code CGContextMoveToPoint has to be adjusted for Retina display to use x * 2 and y * 2 vs non-retina display of just using x, y as well? That can be quite messy for the code. (or maybe we can define a local variable scaleFactor and set it to 1 for standard resolution and 2 if it is retina, so our x and y will always be x * scaleFactor, y * scaleFactor instead of just x and y.) It seems that UIGraphicsBeginImageContextWithOptions can create one for Retina automatically if the scale of 0.0 is passed in, but I don't think it can be used if I need to create the context and keep it (and using ivar or property of UIViewController to hold it). If I don't release it using UIGraphicsEndImageContext, then it stays in the graphics context stack, so it seems like I have to use CGBitmapContextCreate instead. (or do we just let it stay at the bottom of the stack and not worry about it?)

  Read the article

• NHibernate IQueryable Collection as Property of Root

  - by Khalid Abuhakmeh

  Hello and thank you for taking the time to read this. I have a root object that has a property that is a collection. For example : I have a Shelf object that has Books. // now public class Shelf { public ICollection<Book> Books {get; set;} } // want public class Shelf { public IQueryable<Book> Books {get;set;} } What I want to accomplish is to return a collection that is IQueryable so that I can run paging and filtering off of the collection directly from the the parent. var shelf = shelfRepository.Get(1); var filtered = from book in shelf.Books where book.Name == "The Great Gatsby" select book; I want to have that query executed specifically by NHibernate and not a get all to load a whole collection and then parse it in memory (which is what currently happens when I use ICollection). The reasoning behind this is that my collection could be huge, tens of thousands of records, and a get all query could bash my database. I would like to do this implicitly so that when NHibernate sees and IQueryable on my class it knows what to do. I have looked at NHibernates Linq provider and currently I am making the decision to take large collections and split them into their own repository so that I can make explicit calls for filtering and paging. Linq To SQL offers something similar to what I'm talking about.

  Read the article

• How to allow users to define financial formulas in a C# app

  - by Peter Morris

  I need to allow my users to be able to define formulas which will calculate values based on data. For example //Example 1 return GetMonetaryAmountFromDatabase("Amount due") * 1.2; //Example 2 return GetMonetaryAmountFromDatabase("Amount due") * GetFactorFromDatabase("Discount"); I will need to allow / * + - operations, also to assign local variables and execute IF statements, like so var amountDue = GetMonetaryAmountFromDatabase("Amount due"); if (amountDue > 100000) return amountDue * 0.75; if (amountDue > 50000) return amountDue * 0.9; return amountDue; The scenario is complicated because I have the following structure.. Customer (a few hundred) Configuration (about 10 per customer) Item (about 10,000 per customer configuration) So I will perform a 3 level loop. At each "Configuration" level I will start a DB transaction and compile the forumlas, each "Item" will use the same transaction + compiled formulas (there are about 20 formulas per configuration, each item will use all of them). This further complicates things because I can't just use the compiler services as it would result in continued memory usage growth. I can't use a new AppDomain per each "Configuration" loop level because some of the references I need to pass cannot be marshalled. Any suggestions?

  Read the article

• Run a PHP script every second using CLI

  - by Saif Bechan

  Hello, I have a dedicated server running Cent OS with a Parallel PLESK panel. I need to run a php script every second, that updates my database. These is no alternative way timewise, i have checked every method, it needs to be updated every second. I can find my script using the url: http://www.mysite.com/phpfile.php?key=123, and this has to be executed every second. Does anyone have any knowledge at all on doing this, i can not seem to find the answer. I heard about doing it with CLI and putty, but i have no knowledge of this at all. Or can this be done using the PLESK Panel? And can the file be executed locally every second. Like \phpfile.php If someone helps me on answering these question i would really appreciate it. Regards EDIT It has been a few months since i added this question. I ended up using the following code: #!/user/bin/php $start = microtime(true); set_time_limit(60); for (i = 0; i < 59; ++$i) { doMyThings(); time_sleep_until($start + $i + 1); } Thank you for this code guys! My cronjob is set to every minute. I have been running this for some time now in a test environment, and this works out great. It works really supperfast, and i see no increase in CPU nor Memory usage.

  Read the article

• CUDA Kernel Not Updating Global Variable

  - by Taher Khokhawala

  I am facing the following problem in a CUDA kernel. There is an array "cu_fx" in global memory. Each thread has a unique identifier jj and a local loop variable ii and a local float variable temp. Following code is not working. It is not at all changing cu_fx[jj]. At the end of loop cu_fx[jj] remains 0. ii = 0; cu_fx[jj] = 0; while(ii < l) { if(cu_y[ii] > 0) cu_fx[jj] += (cu_mu[ii]*cu_Kernel[(jj-start_row)*Kernel_w + ii]); else cu_fx[jj] -= (cu_mu[ii]*cu_Kernel[(jj-start_row)*Kernel_w + ii]); ii++; } But when I rewrite it using a temporary variable temp, it works fine. ii = 0; temp = 0; while(ii < l) { if(cu_y[ii] > 0) temp += (cu_mu[ii]*cu_Kernel[(jj-start_row)*Kernel_w + ii]); else temp -= (cu_mu[ii]*cu_Kernel[(jj-start_row)*Kernel_w + ii]); ii++; } cu_fx[jj] = temp; Can somebody please help with this problem. Thanking in advance.

  Read the article

• XMLStreamReader and a real stream

  - by Yuri Ushakov

  Update There is no ready XML parser in Java community which can do NIO and XML parsing. This is the closest I found, and it's incomplete: http://wiki.fasterxml.com/AaltoHome I have the following code: InputStream input = ...; XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance(); XMLStreamReader streamReader = xmlInputFactory.createXMLStreamReader(input, "UTF-8"); Question is, why does the method #createXMLStreamReader() expects to have an entire XML document in the input stream? Why is it called a "stream reader", if it can't seem to process a portion of XML data? For example, if I feed: <root> <child> to it, it would tell me I'm missing the closing tags. Even before I begin iterating the stream reader itself. I suspect that I just don't know how to use a XMLStreamReader properly. I should be able to supply it with data by pieces, right? I need it because I'm processing a XML stream coming in from network socket, and don't want to load the whole source text into memory. Thank you for help, Yuri.

  Read the article

• How can I make this method more Scalalicious

  - by Neil Chambers

  I have a function that calculates the left and right node values for some collection of treeNodes given a simple node.id, node.parentId association. It's very simple and works well enough...but, well, I am wondering if there is a more idiomatic approach. Specifically is there a way to track the left/right values without using some externally tracked value but still keep the tasty recursion. /* * A tree node */ case class TreeNode(val id:String, val parentId: String){ var left: Int = 0 var right: Int = 0 } /* * a method to compute the left/right node values */ def walktree(node: TreeNode) = { /* * increment state for the inner function */ var c = 0 /* * A method to set the increment state */ def increment = { c+=1; c } // poo /* * the tasty inner method * treeNodes is a List[TreeNode] */ def walk(node: TreeNode): Unit = { node.left = increment /* * recurse on all direct descendants */ treeNodes filter( _.parentId == node.id) foreach (walk(_)) node.right = increment } walk(node) } walktree(someRootNode) Edit - The list of nodes is taken from a database. Pulling the nodes into a proper tree would take too much time. I am pulling a flat list into memory and all I have is an association via node id's as pertains to parents and children. Adding left/right node values allows me to get a snapshop of all children (and childrens children) with a single SQL query. The calculation needs to run very quickly in order to maintain data integrity should parent-child associations change (which they do very frequently). In addition to using the awesome Scala collections I've also boosted speed by using parallel processing for some pre/post filtering on the tree nodes. I wanted to find a more idiomatic way of tracking the left/right node values. After looking at the answers listed I have settled on this synthesised version: def walktree(node: TreeNode) = { def walk(node: TreeNode, counter: Int): Int = { node.left = counter node.right = treeNodes .filter( _.parentId == node.id) .foldLeft(counter+1) { (counter, curnode) => walk(curnode, counter) + 1 } node.right } walk(node,1) }

  Read the article

• How is a relative JMP (x86) implemented in an Assembler?

  - by Pindatjuh

  While building my assembler for the x86 platform I encountered some problems with encoding the JMP instruction: enc inst size in bytes EB cb JMP rel8 2 E9 cw JMP rel16 4 (because of 0x66 16-bit prefix) E9 cd JMP rel32 5 ... (from my favourite x86 instruction website, http://siyobik.info/index.php?module=x86&id=147) All are relative jumps, where the size of each encoding (operation + operand) is in the third column. Now my original (and thus fault because of this) design reserved the maximum (5 bytes) space for each instruction. The operand is not yet known, because it's a jump to a yet unknown location. So I've implemented a "rewrite" mechanism, that rewrites the operands in the correct location in memory, if the location of the jump is known, and fills the rest with NOPs. This is a somewhat serious concern in tight-loops. Now my problem is with the following situation: b: XXX c: JMP a e: XXX ... XXX d: JMP b a: XXX (where XXX is any instruction, depending on the to-be assembled program) The problem is that I want the smallest possible encoding for a JMP instruction (and no NOP filling). I have to know the size of the instruction at c before I can calculate the relative distance between a and b for the operand at d. The same applies for the JMP at c: it needs to know the size of d before it can calculate the relative distance between e and a. How do existing assemblers implement this, or how would you implement this? This is what I am thinking which solves the problem: First encode all the instructions to opcodes between the JMP and it's target, and if this region contains a variable-sized opcode, use the maximum size, i.e. 5 for JMP. Then in some conditions, the JMP is oversized (because it may fit in a smaller encoding): so another pass will search for oversized JMPs, shrink them, and move all instructions ahead), and set absolute branching instructions (i.e. external CALLs) after this pass is completed. I wonder, perhaps this is an over-engineered solution, that's why I ask this question.

  Read the article

• Anonymous union definition/declaration in a macro GNU vs VS2008

  - by Alan_m

  I am attempting to alter an IAR specific header file for a lpc2138 so it can compile with Visual Studio 2008 (to enable compatible unit testing). My problem involves converting register definitions to be hardware independent (not at a memory address) The "IAR-safe macro" is: #define __IO_REG32_BIT(NAME, ADDRESS, ATTRIBUTE, BIT_STRUCT) \ volatile __no_init ATTRIBUTE union \ { \ unsigned long NAME; \ BIT_STRUCT NAME ## _bit; \ } @ ADDRESS //declaration //(where __gpio0_bits is a structure that names //each of the 32 bits as P0_0, P0_1, etc) __IO_REG32_BIT(IO0PIN,0xE0028000,__READ_WRITE,__gpio0_bits); //usage IO0PIN = 0x0xAA55AA55; IO0PIN_bit.P0_5 = 0; This is my comparable "hardware independent" code: #define __IO_REG32_BIT(NAME, BIT_STRUCT)\ volatile union \ { \ unsigned long NAME; \ BIT_STRUCT NAME##_bit; \ } NAME; //declaration __IO_REG32_BIT(IO0PIN,__gpio0_bits); //usage IO0PIN.IO0PIN = 0xAA55AA55; IO0PIN.IO0PIN_bit.P0_5 = 1; This compiles and works but quite obviously my "hardware independent" usage does not match the "IAR-safe" usage. How do I alter my macro so I can use IO0PIN the same way I do in IAR? I feel this is a simple anonymous union matter but multiple attempts and variants have proven unsuccessful. Maybe the IAR GNU compiler supports anonymous unions and vs2008 does not. Thank you.

  Read the article

• Which key value store is the most promising/stable?

  - by Mike Trpcic

  I'm looking to start using a key/value store for some side projects (mostly as a learning experience), but so many have popped up in the recent past that I've got no idea where to begin. Just listing from memory, I can think of: CouchDB MongoDB Riak Redis Tokyo Cabinet Berkeley DB Cassandra MemcacheDB And I'm sure that there are more out there that have slipped through my search efforts. With all the information out there, it's hard to find solid comparisons between all of the competitors. My criteria and questions are: (Most Important) Which do you recommend, and why? Which one is the fastest? Which one is the most stable? Which one is the easiest to set up and install? Which ones have bindings for Python and/or Ruby? Edit: So far it looks like Redis is the best solution, but that's only because I've gotten one solid response (from ardsrk). I'm looking for more answers like his, because they point me in the direction of useful, quantitative information. Which Key-Value store do you use, and why? Edit 2: If anyone has experience with CouchDB, Riak, or MongoDB, I'd love to hear your experiences with them (and even more so if you can offer a comparative analysis of several of them)

  Read the article

• Reading Certificates on iOS Problem

  - by David Schiefer

  I am trying to read certificates from various URLs in iOS. My code however is not working well - the array that should return the information I need always returns null. What am I missing? - (void)findCertificate:(NSString *)url { NSInputStream*input = [[NSInputStream inputStreamWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"https://store.writeitstudios.com"]]] retain]; [input setDelegate:self]; [input scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode]; [input open]; NSLog(@"Status: %i",[input streamStatus]); } - (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode { NSLog(@"handle Event: %i",eventCode); if (eventCode == NSStreamStatusOpen) { NSArray *certificates = (NSArray*)CFReadStreamCopyProperty((CFReadStreamRef)aStream, kCFStreamPropertySSLPeerCertificates); NSLog(@"Certs: %@",CFReadStreamCopyProperty((CFReadStreamRef)aStream, kCFStreamPropertySSLPeerCertificates)); if ([certificates count] > 0) { SecCertificateRef certificate = (SecCertificateRef)[certificates objectAtIndex:0]; NSString *description = (NSString*)SecCertificateCopySubjectSummary(certificate); NSData *data = (NSData *)SecCertificateCopyData(certificate); NSLog(@"Description: %@",description); } } } And yes, I am aware that I am leaking memory. This is just a snippet.

  Read the article

• Collecting high-volume video viewing data

  - by DanK

  I want to add tracking to our Flash-based media player so that we can provide analytics that show what sections of videos are being watched (at the moment, we just register a view when a video starts playing) For example, if a viewer watches the first 30 seconds of a video and then clicks away to something else, we want the data to reflect that. Likewise, if someone watches the first 10 seconds, then scrubs the timeline to the last minute of the video and watches that, we want to register viewing on the parts watched and not the middle section. My first thought was to collect up the viewing data in the player and send it all to the server at the end of a viewing session. Unfortunately, Flash does not seem to have an event that you can hook into when a viewer clicks away from the page the movie is on (probably a good thing - it would be open to abuse) So, it looks like we're going to have to make regular requests to the server as the video is playing. This is obviously going to lead to a high volume of requests when there are large numbers of simultaneous viewers. The simple approach of dumping all these 'heartbeat' events from clients to a database feels like it will quickly become unmanageable so I'm wondering whether I should be taking an approach where viewing sessions are cached in memory and flushed to database when they become inactive (based on a timeout). That way, the data could be stored as time spans rather than individual heartbeats. So, to the question - what is the best way to approach dealing with this kind of high-volume viewing data? Are there any good existing architectures/patterns? Thanks, Dan.

  Read the article

• C pointers and addresses

  - by yCalleecharan

  Hi, I always thought that *&p = p = &*p in C. I tried this code: #include <stdio.h> #include <stdlib.h> char a[] = "programming"; char *ap = &a[4]; int main(void) { printf("%x %x %x\n", ap, &*(ap), *&(ap)); /* line 13 */ printf("%x %x %x\n\n", ap+1, &*(ap+1), *&(ap+1)); /* line 14 */ } The first printf line (line 13) gives me the addresses: 40b0a8 40b0a8 40b0a8 which are the same as expected. But when I added the second printf line, Borland complains: "first.c": E2027 Must take address of a memory location in function main at line 14 I was expecting to get: 40b0a9 40b0a9 40b0a9. It seems that the expression *&(ap+1) on line 14 is the culprit here. I thought all three pointer expressions on line 14 are equivalent. Why am I thinking wrong? A second related question: The line char *ap = a; points to the first element of array a. I used char *ap = &a[4]; to point to the 5th element of array a. Is the expression char *ap = a; same as the expression char *ap = &a[0]; Is the last expression only more verbose than the previous one? Thanks a lot...

  Read the article

• Is there a good way to QuickCheck Happstack.State methods?

  - by Paul Kuliniewicz

  I have a set of Happstack.State MACID methods that I want to test using QuickCheck, but I'm having trouble figuring out the most elegant way to accomplish that. The problems I'm running into are: The only way to evaluate an Ev monad computation is in the IO monad via query or update. There's no way to create a purely in-memory MACID store; this is by design. Therefore, running things in the IO monad means there are temporary files to clean up after each test. There's no way to initialize a new MACID store except with the initialValue for the state; it can't be generated via Arbitrary unless I expose an access method that replaces the state wholesale. Working around all of the above means writing methods that only use features of MonadReader or MonadState (and running the test inside Reader or State instead of Ev. This means forgoing the use of getRandom or getEventClockTime and the like inside the method definitions. The only options I can see are: Run the methods in a throw-away on-disk MACID store, cleaning up after each test and settling for starting from initialValue each time. Write the methods to have most of the code run in a MonadReader or MonadState (which is more easily testable), and rely on a small amount of non-QuickCheck-able glue around it that calls getRandom or getEventClockTime as necessary. Is there a better solution that I'm overlooking?

  Read the article

• Maintaining a pool of DAO Class instances vs doing new operator

  - by Fazal

  we have been trying to benchmark our application performance in multiple way for sometime now. I always believed that object creation in java using Class.newInstance() was not slow (at least after 1.4 version of java). But we anyways did a test to use newInstance method vs mainitain an object pool of 1000 objects. We did about 200K iterations of loading data from DB using JDBC and populating these objects. I was amazed (even shocked) to see that newInstance code compared to object pool code was almost 10 times slower. These objects represent tables with about 50 fields and all string type. Can someone share there thoughts on this issue as now I am more confused if object pooling of atleast some DAO instances is a better option. The pool size as I see right now should be large enough to meet size of average requests. There is a flip side as my memory footprint will go up but I am beginning to wonder if this kind of idea makes sense atleast for some of the DAO entities representing tables of about 50 or more columns Please share your ideas and let me know if this has been tried by someone or am I missing some point here

  Read the article

• PHPUnit reporting "Aborted" no matter what tests are run

  - by GrumpyCanuck

  Having a weird problem with PHPUnit. We're using PHPUnit as part of a continuous integration environment, that contains one app written using Zend Framework and one app written using CodeIgniter. Unit tests run just fine under Zend Framework, but whenever I run the tests for CodeIgniter using fooStack's CIUnit bridge, I always get the same problem at the end: PHPUnit 3.4.14 by Sebastian Bergmann. ............... . Time: 1 second, Memory: 7.00Mb OK (16 tests, 14 assertions) Aborted First off, I do not know what those empty spaces between the . means. Secondly, no matter what test I run (all of them or each one separately) I get the same Aborted message at the very end. The tests themselves do not contain any exit or die statements. When I run the same version of PHPUnit on my laptop (running OS-X Snow Leopard and same version of Zend Server Community Edition) I do not get that aborted message. Running PHP 5.3.2 on Ubuntu installed using Zend Server Community Edition. Any help with this would be greatly appreciated.

  Read the article

• Total Order between !different! volatile variables?

  - by andreas

  Hi all, Consider the following Java code: volatile boolean v1 = false; volatile boolean v2 = false; //Thread A v1 = true; if (v2) System.out.println("v2 was true"); //Thread B v2 = true; if (v1) System.out.println("v1 was true"); If there was a globally visible total order for volatile accesses then at least one println would always be reached. Is that actually guaranteed by the Java Standard? Or is an execution like this possible: A: v1 = true; B: v2 = true; A: read v2 = false; B: read v1 = false; A: v2 = true becomes visible (after the if) B: v1 = true becomes visible (after the if) I could only find statements about accesses to the same volatile variable in the Standard (but I might be missing something). "A write to a volatile variable (§8.3.1.4) v synchronizes-with all subsequent reads of v by any thread (where subsequent is defined according to the synchronization order)." http://java.sun.com/docs/books/jls/third_edition/html/memory.html#17.4.4 Thanks!

  Read the article

• error detection/correction/recovery in serial protocols

  - by Jason S

  I have some designing to do for a serial protocol and am running into some questions that I figure must have been considered elsewhere. So I'm wondering if there are some recommendations for best practices in designing serial protocols. (Please either state a fact that is easily verifiable, or cite a reputable source if you make a claim.) General recommendations for websites/books are also welcome. In particular I have to deal with issues like parsing a stream of bytes into packets verifying a packet is correct (easy with a CRC, for instance) identifying reasonable types of errors that can occur (e.g. in a point-to-point serial stream, sporadic single bit errors, and dropped series of bytes, are both likely, but extra phantom bytes are unlikely; whereas with a record stored in flash memory or on a disk drive the types of errors that predominate are different) error correction or recovery (if I detect an error in a packet, can I correct it? If not, can I resync to the boundary of the next packet?) how to make variable-length packets robust to error correction / recovery. Any suggestions?

  Read the article

• How to enforce foreign keys using Xerial SQLite JDBC?

  - by Space_C0wb0y

  According to their release notes, the Xerial SQLite JDBC driver supports foreign keys since version 3.6.20.1. I have tried some time now to get a foreign key constraint to be enforced, but to no avail. Here is what I came up with: public static void main(String[] args) throws ClassNotFoundException, SQLException { Class.forName("org.sqlite.JDBC"); SQLiteConfig config = new SQLiteConfig(); config.enforceForeignKeys(true); Connection connection = DriverManager.getConnection("jdbc:sqlite::memory:", config.toProperties()); connection.createStatement().executeUpdate( "CREATE TABLE artist(" + "artistid INTEGER PRIMARY KEY, " + "artistname TEXT);"); connection.createStatement().executeUpdate( "CREATE TABLE track("+ "trackid INTEGER," + "trackname TEXT," + "trackartist INTEGER," + "FOREIGN KEY(trackartist) REFERENCES artist(artistid)" + ");"); connection.createStatement().executeUpdate( "INSERT INTO track VALUES(14, 'Mr. Bojangles', 3)"); } The table definitions are taken directly from the sample in the SQLite documentation. This is supposed to fail, but it doesn't. I also checked, and it really inserts the tuple (no ignore or something like that). Does anyone have any experience with that, or knows how to make it work?

  Read the article

• Python IOError: Not a gzipped file (Gzip and Blowfish Encrypt/Compress)

  - by notbad.jpeg

  I'm having some problems with python's built-in library gzip. Looked through almost every other stack question about it, and none of them seem to work. MY PROBLEM IS THAT WHEN I TRY TO DECOMPRESS I GET THE IOError I'm Getting: Traceback (most recent call last): File "mymodule.py", line 61, in return gz.read() File "/usr/lib/python2.7/gzip.py", line 245, readself._read(readsize) File "/usr/lib/python2.7/gzip.py", line 287, in _readself._read_gzip_header() File "/usr/lib/python2.7/gzip.py", line 181, in _read_gzip_header raise IOError, 'Not a gzipped file'IOError: Not a gzipped file This is my code to send it over SMB, it might not make sense why i do things, but it's normally in a while loop and memory efficient, I just simplified it. buffer = cStringIO.StringIO(output) #output is from a subprocess call small_buffer = cStringIO.StringIO() small_string = buffer.read() #need a string to write to buffer gzip_obj = gzip.GzipFile(fileobj=small_buffer,compresslevel=6, mode='wb') gzip_obj.write(small_string) compressed_str = small_buffer.getvalue() blowfish = Blowfish.new('abcd', Blowfish.MODE_ECB) remainder = '|'*(8 - (len(compressed_str) % 8)) compressed_str += remainder encrypted = blowfish.encrypt(compressed_str) #i send it over smb, then retrieve it later Then this is the code that retrieves it: #buffer is a cStringIO object filled with data from smb retrieval decrypter = Blowfish.new('abcd', Blowfish.MODE_ECB) value = buffer.getvalue() decrypted = decrypter.decrypt(value) buff = cStringIO.StringIO(decrypted) buff.seek(0) gz = gzip.GzipFile(fileobj=buff) return gz.read() Here's the problem return gz.read()

  Read the article

• Need to call original function from detoured function

  - by peachykeen

  I'm using Detours to hook into an executable's message function, but I need to run my own code and then call the original code. From what I've seen in the Detours docs, it definitely sounds like that should happen automatically. The original function prints a message to the screen, but as soon as I attach a detour it starts running my code and stops printing. The original function code is roughly: void CGuiObject::AppendMsgToBuffer(classA, unsigned long, unsigned long, int, classB); My function is: void CGuiObject_AppendMsgToBuffer( [same params, with names] ); I know the memory position the original function resides in, so using: DWORD OrigPos = 0x0040592C; DetourAttach( (void*)OrigPos, CGuiObject_AppendMsgToBuffer); gets me into the function. This code works almost perfectly: my function is called with the proper parameters. However, execution leaves my function and the original code is not called. I've tried jmping back in, but that crashes the program (I'm assuming the code Detours moved to fit the hook is responsible for the crash). Edit: I've managed to fix the first issue, with no returning to program execution. By calling the OrigPos value as a function, I'm able to go to the "trampoline" function and from there on to the original code. However, somewhere along the lines the registers are changing and that is causing the program to crash with a segfault as soon as I get back into the original code.

  Read the article

• Unit testing opaque structure based C API

  - by Nicolas Goy

  I have a library I wrote with API based on opaque structures. Using opaque structures has a lot of benefits and I am very happy with it. Now that my API are stable in term of specifications, I'd like to write a complete battery of unit test to ensure a solid base before releasing it. My concern is simple, how do you unit test API based on opaque structures where the main goal is to hide the internal logic? For example, let's take a very simple object, an array with a very simple test: WSArray a = WSArrayCreate(); int foo = 5; WSArrayAppendValue(a, &foo); int *bar = WSArrayGetValueAtIndex(a, 0); if(&foo != bar) printf("Eroneous value returned\n"); else printf("Good value returned\n"); WSRelease(a); Of course, this tests some facts, like the array actually acts as wanted with 1 value, but when I write unit tests, at least in C, I usualy compare the memory footprint of my datastructures with a known state. In my example, I don't know if some internal state of the array is broken. How would you handle that? I'd really like to avoid adding codes in the implementation files only for unit testings, I really emphasis loose coupling of modules, and injecting unit tests into the implementation would seem rather invasive to me. My first thought was to include the implementation file into my unit test, linking my unit test statically to my library. For example: #include <WS/WS.h> #include <WS/Collection/Array.c> static void TestArray(void) { WSArray a = WSArrayCreate(); /* Structure members are available because we included Array.c */ printf("%d\n", a->count); } Is that a good idea? Of course, the unit tests won't benefit from encapsulation, but they are here to ensure it's actually working.

  Read the article

• Automatic .NET code, nhibernate session, and LINQ datacontext clean-up?

  - by AverageJoe719

  Hi all, in my goal to adopt better coding practices I have a few questions in general about automatic handling of code. I have heard different answers both from online and talking with other developers/programmers at my work. I am not sure if I should have split them into 3 questions, but they all seem sort of related: 1) How does .NET handle instances of classes and other code things that take up memory? I recently found out about using the factory pattern for certain things like service classes so that they are only instantiated once in the entire application, but then I was told that '.NET handles a lot of that stuff automatically when mentioning it.' 2) How does Nhibernate's session handle automatic clean-up of un-used things? I've seen some say that it is great at handling things automatically and you should just use a session factory and that's it, no need to close it. But I have also read and seem many examples where people close the hibernate session. 3) How does LINQ's datacontext handle this? Most of the time I never .disposed my datacontext's and the app didn't see to take a performance hit (though I am not running anything super intensively), but it seems like most people recommend disposing of your datacontext after you are done with it. However, I have seen many many code examples where the dispose method is never called. Also in general I found it kind of annoying that you couldn't access even one-deep child related objects after disposing of the datacontext unless you explicity also grabbed them in the query. Thanks all. I am loving this site so far, I kind of get lost and spend hours just reading things on here. =)

  Read the article

• Space-saving character encoding for japanese?

  - by Constantin

  In my opinion a common problem: character encoding in combination with a bitmap-font. Most multi-language encodings have an huge space between different character types and even a lot of unused code points there. So if I want to use them I waste a lot of memory (not only for saving multi-byte text - i mean specially for spaces in my bitmap-font) - and VRAM is mostly really valuable... So the only reasonable thing seems to be: Using an custom mapping on my texture for i.e. UTF-8 characters (so that no space is waste). BUT: This effort seems to be same with use an own proprietary character encoding (so also own order of characters in my texture). In my specially case I got texture space for 4096 different characters and need characters to display latin languages as well as japanese (its a mess with utf-8 that only support generall cjk codepages). Had somebody ever a similiar problem (I really wonder, if not)? If theres already any approach? Edit: The same Problem is described here http://www.tonypottier.info/Unicode_And_Japanese_Kanji/ but it doesnt provide an real solution how to save these bitmapfont mappings to utf-8 space efficent. So any further help is welcome!

  Read the article

• use startActivityForResult from non-activity

  - by rayman

  Hi, I have MainActivity which is an Activity and other class(which is a simple java class), we`ll call it "SimpleClass". now i want to run from that class the command startActivityForResult. now i though that i could pass that class(SimpleClass), only MainActivity's context, problem is that, u cant run context.startActivityForResult(...); so the only way making SimpleClass to use 'startActivityForResult; is to pass the reference of MainActivity as an Activity variable to the SimpleClass something like that: inside the MainActivity class i create the instance of SimpleClass this way: SimpleClass simpleClass=new SimpleClass(MainActivity.this); now this is how SimpleClass looks like: public Class SimpleClass { Activity myMainActivity; public SimpleClass(Activity mainActivity) { super(); this.myMainActivity=mainActivity; } .... } public void someMethod(...) { myMainActivity.startActivityForResult(...); } now its working, but isnt a proper way of doing this? I`am afraid i could have some memory leaks in the future. thanks. ray.

  Read the article

< Previous Page | 428 429 430 431 432 433 434 435 436 437 438 439  | Next Page >