Search Results

Search found 21965 results on 879 pages for 'array map'.

Page 813/879 | < Previous Page | 809 810 811 812 813 814 815 816 817 818 819 820  | Next Page >

• 2-column table with two foreign keys. Performance/design question.

  - by Emanuel

  Hello everyone! I recently ran into a quite complex problem and after looking around a lot I couldn't find a solution to it. I've found answers to my questions many times before on stackoverflow.com, so I decided to post here. So I'm making a user/group managment system for a web-based project, and I'm storing all related data into a postgreSQL database. This system relies on three tables: USERS GROUPS GROUP_USERS The two first tables simply define all the users and all the groups on the site, and the last table, GROUP_USERS, stores the groups every user is part of. It only has two columns: USER_ID GROUP_ID Since every user can be a member of several groups, I decided to make a separate table for this purpose, rather than storing a comma separated column in the USERS-table. Now, both columns are foreign keys, and I want to make them both primary keys as well, this since each combination of USER_ID and GROUP_ID has to be unique, and if I give them the constraint UNIQUE pgAdmin tells me that each table should have at least one Primary key. But now I am stuck with what seems to be a lot of indexes and relations to a very small table only containing numbers. In the end, I want this table to be as fast as possible, even if containing tens of thousands of rows. Size on disk shouldn't be a problem since its just all numbers anyway, but it feels quite stupid to have a full-sized index refering to a smaller table. Should I stick with my current solution, store comma-separated values in a column in the USERS-table or is there any other solution I should be aware of. PS. I don't want to use an array-column, even if they are supported by postgreSQL. I want to be as generic as possible so I can switch database later on, if necessary. EDIT: I other words, will using a compound primary key and two foreign keys in one table with only two columns have a negative impact on performance rather than the opposite due to the size of the generated index? Thank you!

  Read the article

• Rails controller not rendering correct view when form is force-submitted by Javascript

  - by whazzmaster

  I'm using Rails with jQuery, and I'm working on a page for a simple site that prints each record to a table. The only editable field for each record is a checkbox. My goal is that every time a checkbox is changed, an ajax request updates that boolean attribute for the record (i.e., no submit button). My view code: <td> <% form_remote_tag :url => admin_update_path, :html => { :id => "form#{lead.id}" } do %> <%= hidden_field :lead, :id, :value => lead.id %> <%= check_box :lead, :contacted, :id => "checkbox"+lead.id.to_s, :checked => lead.contacted, :onchange => "$('#form#{lead.id}').submit();" %> <% end %> </td> In my routes.rb, admin_update_path is defined by map.admin_update 'update', :controller => "admin", :action => "update", :method => :post I also have an RJS template to render back an update. The contents of this file is currently just for testing (I just wanted to see if it worked, this will not be the ultimate functionality on a successful save)... page << "$('#checkbox#{@lead.id}').hide();" When clicked, the ajax request is successfully sent, with the correct params, and the action on the controller can retrieve the record and update it just fine. The problem is that it doesn't send back the JS; it changes the page in the browser and renders the generated Javascript as plain text rather than executing it in-place. Rails does some behind-the-scenes stuff to figure out if the incoming request is an ajax call, and I can't figure out why it's interpreting the incoming request as a regular web request as opposed to an ajax request. I may be missing something extremely simple here, but I've kind-of burned myself out looking so I thought I'd ask for another pair of eyes. Thanks in advance for any info!

  Read the article

• How can i get my delete messages function just appear for the user's own messages left on their friends page?

  - by Hannah_B

  I had been working on this trying the delete message button to work on my own profile page of my site. When I delete a message left by a friend it not only deletes it from the screen but deletes it from the database. The messages in the database have 4 fields: message_id, from, to and message. Here is my profile view that shows how Im deleting messages from my friends: if(!empty($messages)){ foreach($messages as $message): $delete = $message['message_id']; //var_dump($message); ?> <li><?=$message['from']?> says...: "<?=$message['message']?>"(<?=anchor("home/deleteMsg/$delete", 'delete')?>)</li> //this is where the delete button appears beside messages left <?php endforeach?> <?php }else{ ?> <?php echo 'No messages left yet !!!'; }?> Here is my controller showing the deleteMsg function called: function deleteMsg($messageid) { $this->messages->deleteMsg($messageid); redirect('home'); } Here is the messages model showing the deleteMsg model itself: function deleteMsg($message_id) { $this->db->where(array('message_id' => $message_id)); $this->db->delete('messages'); } Here is my friendprofile view where I want to implement the delete message command just so the button appears for messages Ive left and I can delete them. The delete button will not appear beside other friends comments on this page: <li><?=$message['from']?> says...: "<?=$message['message']?>"</li> Now I've tried creating a new delete Message function to no success so far, am I better off doing this than calling the same function? As this didnt work either.

  Read the article

• Symfony form->bind fails

  - by Shawn Craver

  I'm working with a few custom forms, and one of them isn't binding it's values on a POST. I'm using the same logic for each, and only one of them isn't working. Here's the code: public function executeMediaFileUpload(sfWebRequest $request) { $this->form = new MediaFileUploadForm(); if (!$request->isMethod('POST')) $psk = $request->getParameter('psk'); else { $this->form->bind($request->getParameter($this->form->getName()), $request->getFiles($this->form->getName())); $this->logMessage('VALUE: ' . $this->form->getValue('version')); $psk = $this->form->getValue('application'); } $this->logMessage('PSK: ' . $psk); $app = Doctrine::getTable('Application')->find(array($psk)); $this->form->setDefault('application', $app->getPsk()); $this->form->setDefault('version', $app->getVersion()->getLast()->getPsk()); On the initial GET, I can see the value passed in via psk getting set as the default for application in the generated HTML, and all the values show up in the POST request in Firebug, but after I bind the form, it still contains no values.

  Read the article

• Is it not possible to make a C++ application "Crash Proof"?

  - by Enno Shioji

  Let's say we have an SDK in C++ that accepts some binary data (like a picture) and does something. Is it not possible to make this SDK "crash-proof"? By crash I primarily mean forceful termination by the OS upon memory access violation, due to invalid input passed by the user (like an abnormally short junk data). I have no experience with C++, but when I googled, I found several means that sounded like a solution (use a vector instead of an array, configure the compiler so that automatic bounds check is performed, etc.). When I presented this to the developer, he said it is still not possible.. Not that I don't believe him, but if so, how is language like Java handling this? I thought the JVM performs everytime a bounds check. If so, why can't one do the same thing in C++ manually? UPDATE By "Crash proof" I don't mean that the application does not terminate. I mean it should not abruptly terminate without information of what happened (I mean it will dump core etc., but is it not possible to display a message like "Argument x was not valid" etc.?)

  Read the article

• get_browser not working

  - by tazphoenix

  it's not working.i mean i have many scripts to get ip and os but anyway get_browser is internal function and should work but its not.when i try to get a print_r on the function i get. Array ( [browser_name_regex] => §^.*$§ [browser_name_pattern] => * [browser] => Default Browser [version] => 0 [majorver] => 0 [minorver] => 0 [platform] => unknown [alpha] => [beta] => [win16] => [win32] => [win64] => [frames] => 1 [iframes] => [tables] => 1 [cookies] => [backgroundsounds] => [cdf] => [vbscript] => [javaapplets] => [javascript] => [activexcontrols] => [isbanned] => [ismobiledevice] => [issyndicationreader] => [crawler] => [cssversion] => 0 [supportscss] => [aol] => [aolversion] => 0 ) I'm using win7 and firefox.

  Read the article

• Creating mock Objects in PHP unit

  - by Mike

  Hi, I've searched but can't quite find what I'm looking for and the manual isn't much help in this respect. I'm fairly new to unit testing, so not sure if I'm on the right track at all. Anyway, onto the question. I have a class: <?php class testClass { public function doSomething($array_of_stuff) { return AnotherClass::returnRandomElement($array_of_stuff); } } ?> Now, clearly I want the AnotherClass::returnRandomElement($array_of_stuff); to return the same thing every time. My question is, in my unit test, how do I mockup this object? I've tried adding the AnotherClass to the top of the test file, but when I want to test AnotherClass I get the "Cannot redeclare class" error. I think I understand factory classes, but I'm not sure how I would apply that in this instance. Would I need to write an entirely seperate AnotherClass class which contained test data and then use the Factory class to load that instead of the real AnotherClass? Or is using the Factory pattern just a red herring. I tried this: $RedirectUtils_stub = $this->getMockForAbstractClass('RedirectUtils'); $o1 = new stdClass(); $o1->id = 2; $o1->test_id = 2; $o1->weight = 60; $o1->data = "http://www.google.com/?ffdfd=fdfdfdfd?route=1"; $RedirectUtils_stub->expects($this->any()) ->method('chooseRandomRoot') ->will($this->returnValue($o1)); $RedirectUtils_stub->expects($this->any()) ->method('decodeQueryString') ->will($this->returnValue(array())); in the setUp() function, but these stubs are ignored and I can't work out whether it's something I'm doing wrong, or the way I'm accessing the AnotherClass methods. Help! This is driving me nuts.

  Read the article

• Sorting by some field and fetching whole tree from DB

  - by Niaxon

  Hello everyone, I am trying to do file browser in a tree form and have a problem to sort it somehow. I use PHP and MySQL for that. I've created mixed (nested set + adjacency) table 'element' with the following fields: element_id, left_key, right_key, level, parent_id, element_name, element_type (enum: 'folder','file'), element_size. Let's not discuss right now that it is better to move information about element (name, type, size) into other table. Function to scan specified directory and fill table work correctly. Noteworthy, i am adding elements to tree in specific order: folders first and only files. After that i can easily fetch and display whole table on the page using simple query: SELECT * FROM element WHERE 1=1 ORDER BY left_key With the result of that query and another function i can generate correct html code (<ul><li>... and so on). Now back to the question (finally, huh?). I am struggling to add sorting functionality. For example i want to order my result by size. Here i need to keep in my mind whole hierarchy of tree and rule: folders first, files later. I believe i can do that by generating in PHP recursive query: SELECT * FROM element WHERE parent_id = {$parentId} ORDER BY element_type (so folders would be first), size (or name for example) After that for each result which is folder i will send another query to get it's content. Also it's possible to fetch whole tree by left_key and after that sort it in PHP as array but i guess that would be worse :) I wonder if there is better and more efficient way to do such thing?

  Read the article

• Get class constant names in php?

  - by user151841

  I have a php class with some class constants that indicate the status of an instance. When I'm using the class, after I run some methods on it, I do some checks to make sure that the status is what I expect it to be. For instance, after calling some methods, I expect the status to be MEANINGFUL_STATUS_NAME. $objInstance->method1(); $objInstance->method2(); if ( $objInstance->status !== class::MEANINGFUL_STATUS_NAME ) { throw new Exception("Status is wrong, should not be " . class::MEANINGFUL_STATUS_NAME . "."); } However, this gives me the exception message "Status is wrong, should not be 2" when what I really want to see is "Status is wrong, should not be MEANINGFUL_STATUS_NAME" So I've lost the meaningfulness of the constant name. I was thinking of making an 'translation table' array, so I can take the constant values and translate them back into their name, but this seems cumbersome. How should I translate this back, so I get an error message that gives me a better idea of what went wrong?

  Read the article

• Check if NSString exists in custom object in NSArray

  - by Paul Peelen

  I have an NSArray with Store objects. Each Store object has two NSString objects; StoreID and Name. I would like to check quickly if an ID exists in this NSArray with Store objects. Example: Store *s1 = [[Store alloc] init]; s1.name = @"Some Name"; s1.id = @"123ABC"; Store *s2 = [[Store alloc] init]; s2.name = @"Some Other Name"; s2.id = @"ABC123"; NSArray *array = [[NSArray alloc] initWithObjects:s1, s2, nil]; NSString *myIdOne = @"ABCDEF"; NSString *myIdTwo = @"123ABC"; BOOL myIdOneExists = ...? BOOL myIdTwoExists = ...? Its the ...? I need to figure out. I know I can do this using a for loop and break when found... but this seems to me like an nasty approach since the NSArray could contain thousands of objects,... theoretically. So I would like to know about a better solution.

  Read the article

• How can I serialize functions using JSON or some other serialization library?

  - by Oragamster

  I am trying to create a program that uses javascript to write a simple textadventure that I can then post on my blog and run on my iphone. I have run into a problem though. I was trying to make it so that my program would save it's state into cookies using JSON to convert it into strings and then post it into a cookie but then I realised that I couldn't serialize the functions that are on my item object. I was trying to make it so that my item would have an associative array that would contain the name of the use as the key and the function as the value. This worked well untill I tried to serialize it. I learned that I could create a JSON like serialization for functions by storing the body into a string and using escape charectors for the double quotes but for some reason I was unable to make my cookie with the function as the string stored. When I posted the cookie and then tried to get it back the string wasn't there. My code and the over all project are on my site if you want to look at that, though my full code including the item actions are not posted yet.

  Read the article

• Does anyone know of any good tutorials for using the APIs from Amazon WeB Services, namely CloudWatc

  - by undefined

  Hi, I have been wrestling with Amazon's CloudWatch API with limited success. Does anyone know of any good resources (other than amazon's api docs) for using the APIs. I have tried to run them using the PHP library for CloudWatch but get nothing but error codes. I am configuring the GetMetricStatisticsSample.php file as follows: $request = array(); $endTime = date("Y-m-d G:i:s"); $yesterday = mktime (date("H"), date("i"), date("s"), date("m"), date("d")-1, date("Y")); $startTime = date("Y-m-d 00:00:00", $yesterday); $request["Statistics.member.1"] = "Average"; $request["EndTime"] = $endTime; $request["StartTime"] = $startTime; $request["MeasureName"] = "CPUUtilization"; $request["Unit"] = "Percent"; invokeGetMetricStatistics($service, $request); But this returns "Caught Exception: Internal Error Response Status Code: 400 Error Code: Error Type: Request ID: XML:" I have also tried from command line as follows - set JAVA_HOME=C:\Program Files\Java\jre1.6.0_05 set AWS_CLOUDWATCH_HOME=C:\AmazonWebServices\API_tools\CloudWatch-1.0.0.24 set PATH=%AWS_CLOUDWATCH_HOME%\bin mon-list-metrics but get C:|Program' is not recognized as an internal or external command... any suggestions? cheers

  Read the article

• Matching Class arrays

  - by frinkz

  I'm writing a routine to invoke methods, found by a name and an array of parameter Class values Matching the Method by getName works, but when trying to match the given Class[] for parameters, and Method.getParameterTypes(), I'm having trouble. I assumed that this would work: Class[] searchParams = new Class[] { float.class, String.class }; Class[] methodParams = m.getParameterTypes(); if(methodParams == searchParams) { m.invoke(this, paramValues); } But apparantly not - m.invoke is never reached. I've checked, and methodParams gives the same classes as searchParams. The code below works, and picks the right method, but it seems like a very dirty way of doing things, I'm sure I'm missing something obvious. Class[] searchParams = new Class[] { float.class, String.class }; Class[] methodParams = m.getParameterTypes(); boolean isMatch = true; for(int i = 0; i < searchParams.length; i++) { if(!searchParams.getClass().equals(methodParams.getClass())) { isMatch = false; } } if(isMatch) { m.invoke(this, paramValues); }

  Read the article

• Using functions and arrays

  - by Ordo

  Hello! My little program below shall take 5 numbers from the user, store them into an array of integers and use a function to print them out. Sincerly it doesn't work and my output is always "00000". I can't find a mistake, so i would be glad about any advice. Thanks. #include <stdio.h> void printarray(int intarray[], int n) { int i; for(i = 0; i < n; i ++) { printf("%d", intarray[i]); } } int main () { const int n = 5; int temp = 0; int i; int intarray [n]; char check; printf("Please type in your numbers!\n"); for(i = 0; i < n; i ++) { printf(""); scanf("&d", &temp); intarray[i] = temp; getchar(); getchar(); } printf("Do you want to print them out? (yes/no): "); scanf("%c", &check); if (check == 'y') printarray(intarray, n); getchar(); getchar(); return 0; }

  Read the article

• Sample twitter App

  - by Jack

  I am now running my code on a web hosting service http://xtreemhost.com/ <?php function updateTwitter($status) { $username = 'xxxxxx'; $password = 'xxxx'; $url = 'http://twitter.com/statuses/update.xml'; $postargs = 'status='.urlencode($status); $responseInfo=array(); $ch = curl_init($url); curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt ($ch, CURLOPT_POST, true); // Give CURL the arguments in the POST curl_setopt ($ch, CURLOPT_POSTFIELDS, $postargs); // Set the username and password in the CURL call curl_setopt($ch, CURLOPT_USERPWD, $username.':'.$password); // Set some cur flags (not too important) $response = curl_exec($ch); if($response === false) { echo 'Curl error: ' . curl_error($ch); } else { echo 'Operation completed without any errors<br/>'; } // Get information about the response $responseInfo=curl_getinfo($ch); // Close the CURL connection curl_close($ch); // Make sure we received a response from Twitter if(intval($responseInfo['http_code'])==200){ // Display the response from Twitter echo $response; }else{ // Something went wrong echo "Error: " . $responseInfo['http_code']; } curl_close($ch); } updateTwitter("Just finished a sweet tutorial on http://brandontreb.com"); ?> I get the following error now Curl error: Couldn't resolve host 'api.twitter.com' Error: 0 Please somebody solve my problem

  Read the article

• Solve a maze using multicores?

  - by acidzombie24

  This question is messy, i dont need a working solution, i need some psuedo code. How would i solve this maze? This is a homework question. I have to get from point green to red. At every fork i need to 'spawn a thread' and go that direction. I need to figure out how to get to red but i am unsure how to avoid paths i already have taken (finishing with any path is ok, i am just not allowed to go in circles). Heres an example of my problem, i start by moving down and i see a fork so one goes right and one goes down (or this thread can take it, it doesnt matter). Now lets ignore the rest of the forks and say the one going right hits the wall, goes down, hits the wall and goes left, then goes up. The other thread goes down, hits the wall then goes all the way right. The bottom path has been taken twice, by starting at different sides. How do i mark this path has been taken? Do i need a lock? Is this the only way? Is there a lockless solution? Implementation wise i was thinking i could have the maze something like this. I dont like the solution because there is a LOT of locking (assuming i lock before each read and write of the haveTraverse member). I dont need to use the MazeSegment class below, i just wrote it up as an example. I am allowed to construct the maze however i want. I was thinking maybe the solution requires no connecting paths and thats hassling me. Maybe i could split the map up instead of using the format below (which is easy to read and understand). But if i knew how to split it up i would know how to walk it thus the problem. How do i walk this maze efficiently? The only hint i receive was dont try to conserve memory by reusing it, make copies. However that was related to a problem with ordering a list and i dont think the hint was a hint for this. class MazeSegment { enum Direction { up, down, left, right} List<Pair<Direction, MazeSegment*>> ConnectingPaths; int line_length; bool haveTraverse; } MazeSegment root; class MazeSegment { enum Direction { up, down, left, right} List<Pair<Direction, MazeSegment*>> ConnectingPaths; bool haveTraverse; } void WalkPath(MazeSegment segment) { if(segment.haveTraverse) return; segment.haveTraverse = true; foreach(var v in segment) { if(v.haveTraverse == false) spawn_thread(v); } } WalkPath(root);

  Read the article

• In parallel.for share value more then one.

  - by user347918

  Here is problem. long sum = 0; Parallel.For(1, 10000, y => { sum1 += y;} ); Solution is .. Parallel.For<int>(0, result.Count, () => 0, (i, loop, subtotal) => { subtotal += result[i]; return subtotal; }, (x) => Interlocked.Add(ref sum, x) ); if there are two parameters in this code. For example long sum1 = 0; long sum2 = 0; Parallel.For(1, 10000, y => { sum1 += y; sum2=sum1*y; } ); what will we do ? i am guessing that have to use array ! int[] s=new int[2]; Parallel.For<int[]>(0, result.Count, () => s, (i, loop, subtotal) => { subtotal[0] += result[i]; subtotal[1] -= result[i]; return subtotal; }, (x) => Interlocked.Add(ref sum1, x[0]) //but how about sum1 i tried several way but it doesn't work. //for example like that //(x[0])=> Interlocked.Add (ref sum1, x[0]) //(x[1])=> Interlocked.Add (ref sum2, x[1]));

  Read the article

• zend_db and join

  - by premtemp

  Hello, I am trying to understand how to use Zend_DB in my program but I have some problem. The class below (DatabaseService) work when I pass it a simple query. However, if I pass it it query with a join clause my page just hangs and not error is return. I cut and paste the qry in a query browesr and it is valid Any help would be great $SQL = "select name from mytable" $db = new DatabaseService($dbinfo) $db ->fetchall($SQL ) // works ----------------------------------------------------------- $SQL = "select count(*) as cnt from EndPoints join CallID on EndPoints.`CallID` = CallID.CallID where EndPoints.LastRegister >= '2010-04-21 00:00:01' and EndPoints.LastRegister <= '2010-04-21 23:59:59' " $db = new DatabaseService($dbinfo) $db ->fetchall($SQL ) // DOES NO WORK class DatabaseService { function DatabaseService($dbinfo,$dbname="") { try { $dbConfig = array( 'host' => $this->host, 'username' => $this->username, 'password' => $password, 'dbname' => $this->dbname ); $this->db = Zend_Db::factory($this->adapter, $dbConfig); Zend_Db_Table::setDefaultAdapter($this->db); } catch(Zend_Exception $e) { $this->error = $e->getMessage(); Helper::log($this->error); return false; } } public function connnect() { if($this->db !=null) { try { $this->db->getConnection(); return true; } catch (Zend_Exception $e) { $err = "FAILED ::".$e->getMessage()." <br />"; } } return false; } public function fetchall($sql) { $res= $this->db->fetchAll($sql); return $res; } }

  Read the article

• Delphi static method of a class returning property value

  - by mitko.berbatov

  I'm making a Delphi VCL application. There is a class TStudent where I have two static functions: one which returns last name from an array of TStudent and another one which returns the first name of the student. Their code is something like: class function TStudent.FirstNameOf(aLastName: string): string; var i : integer; begin for i := 0 to Length(studentsArray) - 1 do begin if studentsArray[i].LastName = aLastName then begin result := studentsArray[i].FirstName; Exit; end; end; result := 'no match was found'; end; class function TStudent.LastNameOf(aFirstName: string): string; var i : integer; begin for i := 0 to Length(studentsArray) - 1 do begin if studentsArray[i].FirstName = aFirstName then begin result := studentsArray[i].LastName; Exit; end; end; result := 'no match was found'; end; My question is how can I avoid writing almost same code twice. Is there any way to pass the property as parameter of the functions.

  Read the article

• How do I retrieve twitter xml for Flash site via php properly

  - by daidai

  Am I using TwitterScript to retrieve Twitter data for inside a Flash site. Due to Twitter's crossdomain policy, I need to setup a php proxy... Firstly I made a simple one <?php $url = $_GET['url']; readfile($url); ?> but I then get this error URL file-access is disabled in the server configuration which is only resolved by getting my host to turn fopen() on, which I don't want to do. Then I found this <?php function get_content($url) { $ch = curl_init(); curl_setopt ($ch, CURLOPT_URL, $url); curl_setopt ($ch, CURLOPT_HEADER, 0); ob_start(); curl_exec ($ch); curl_close ($ch); $string = ob_get_contents(); ob_end_clean(); return $string; } #usage: $url = $_GET['url']; $content = get_content ($url); var_dump ($content); ?> which solves that problem but the data now is the correct XML but looks like: string(39950) "<?xml version="1.0" encoding="UTF-8"?> <statuses type="array"> <status> ... </statuses>" How do I get the XML data out of that string?

  Read the article

• Writing a generic function that can take a Writer as well as an OutputStream

  - by ebruchez

  I wrote a couple of functions that look like this: def myWrite(os: OutputStream) = {} def myWrite(w: Writer) = {} Now both are very similar and I thought I would try to write a single parametrized version of the function. I started with a type with the two methods that are common in the Java OutputStream and Writer: type Writable[T] = { def close() : Unit def write(cbuf: Array[T], off: Int, len: Int): Unit } One issue is that OutputStream writes Byte and Writer writes Char, so I parametrized the type with T. Then I write my function: def myWrite[T, A[T] <: Writable[T]](out: A[T]) = {} and try to use it: val w = new java.io.StringWriter() myWrite(w) Result: <console>:9: error: type mismatch; found : java.io.StringWriter required: ?A[ ?T ] Note that implicit conversions are not applicable because they are ambiguous: both method any2ArrowAssoc in object Predef of type [A](x: A)ArrowAssoc[A] and method any2Ensuring in object Predef of type [A](x: A)Ensuring[A] are possible conversion functions from java.io.StringWriter to ?A[ ?T ] myWrite(w) I tried a few other combinations of types and parameters, to no avail so far. My question is whether there is a way of achieving this at all, and if so how. (Note that the implementation of myWrite will need, internally, to know the type T that parametrizes the write() method, because it needs to create a buffer as in new ArrayT.)

  Read the article

• Reading and writing in parallel

  - by Malfist

  I want to be able to read and write a large file in parallel, or if not in parallel, at least in blocks so that I don't use up so much memory. This is my current code: // Define memory stream which will be used to hold encrypted data. MemoryStream memoryStream = new MemoryStream(); // Define cryptographic stream (always use Write mode for encryption). CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write); //start encrypting using (BinaryReader reader = new BinaryReader(File.Open(fileIn, FileMode.Open))) { byte[] buffer = new byte[1024 * 1024]; int read = 0; do { read = reader.Read(buffer, 0, buffer.Length); cryptoStream.Write(buffer, 0, read); } while (read == buffer.Length); } // Finish encrypting. cryptoStream.FlushFinalBlock(); // Convert our encrypted data from a memory stream into a byte array. //byte[] cipherTextBytes = memoryStream.ToArray(); //write our memory stream to a file memoryStream.Position = 0; using (BinaryWriter writer = new BinaryWriter(File.Open(fileOut, FileMode.Create))) { byte[] buffer = new byte[1024 * 1024]; int read = 0; do { read = memoryStream.Read(buffer, 0, buffer.Length); writer.Write(buffer, 0, read); } while (read == buffer.Length); } // Close both streams. memoryStream.Close(); cryptoStream.Close(); As you can see, it reads the entire file into memory, encrypts it, then writes it out. If I happen to be encrypting files that are very large (2GB+) it tends not to work, or at the very least, consumes ~97% of my memory. How could I do it in a more effective manner?

  Read the article

• Better way to compare neighboring cells in matrix

  - by HyperCube

  Suppose I have a matrix of size 100x100 and I would like to compare each pixel to its direct neighbor (left, upper, right, lower) and then do some operations on the current matrix or a new one of the same size. A sample code in Python/Numpy could look like the following: (the comparison 0.5 has no meaning, I just want to give a working example for some operation while comparing the neighbors) import numpy as np my_matrix = np.random.rand(100,100) new_matrix = np.array((100,100)) my_range = np.arange(1,99) for i in my_range: for j in my_range: if my_matrix[i,j+1] > 0.5: new_matrix[i,j+1] = 1 if my_matrix[i,j-1] > 0.5: new_matrix[i,j-1] = 1 if my_matrix[i+1,j] > 0.5: new_matrix[i+1,j] = 1 if my_matrix[i-1,j] > 0.5: new_matrix[i-1,j] = 1 if my_matrix[i+1,j+1] > 0.5: new_matrix[i+1,j+1] = 1 if my_matrix[i+1,j-1] > 0.5: new_matrix[i+1,j-1] = 1 if my_matrix[i-1,j+1] > 0.5: new_matrix[i-1,j+1] = 1 This can get really nasty if I want to step into one neighboring cell and start from it to do a similar task... Do you have some suggestions how this can be done in a more efficient manner? Is this even possible?

  Read the article

• Input html tag not parsing properly in php

  - by Akaash

  I have a database with names that I would like displayed in the form of a table with checkboxes. Everything works until I try to place the html tag into my php code. When I put the input tag in it gives me the error: Parse error: syntax error, unexpected T_STRING, expecting ',' or ';' I can't see where I would put a comma or semi colon. <form> <?php $name = $_POST['name']; $host = "mysql16.000webhost.com"; $user_name = "a1611480_akaash"; $pwd = "****"; $database_name = "a1611480_akaash"; $db = mysql_connect($host, $user_name, $pwd); mysql_select_db($database_name); $result = mysql_query("SELECT name FROM Sort"); $var = array(); while ($row = mysql_fetch_array($result)) { $var[] = $row['name']; } $unique = array_unique($var); foreach ($unique as $value) { echo "<p class = Body_text><label>$value</label> <input type="checkbox" name="name" value="$value" /> </p>\n"; } ?> </form>

  Read the article

• Better way to download a binary file?

  - by geoff

  I have a site where a user can download a file. Some files are extremely large (the largest being 323 MB). When I test it to try and download this file I get an out of memory exception. The only way I know to download the file is below. The reason I'm using the code below is because the URL is encoded and I can't let the user link directly to the file. Is there another way to download this file without having to read the whole thing into a byte array? FileStream fs = new FileStream(context.Server.MapPath(url), FileMode.Open, FileAccess.Read); BinaryReader br = new BinaryReader(fs); long numBytes = new FileInfo(context.Server.MapPath(url)).Length; byte[] bytes = br.ReadBytes((int) numBytes); string filename = Path.GetFileName(url); context.Response.Buffer = true; context.Response.Charset = ""; context.Response.Cache.SetCacheability(HttpCacheability.NoCache); context.Response.ContentType = "application/x-rar-compressed"; context.Response.AddHeader("content-disposition", "attachment;filename=" + filename); context.Response.BinaryWrite(bytes); context.Response.Flush(); context.Response.End();

  Read the article

< Previous Page | 809 810 811 812 813 814 815 816 817 818 819 820  | Next Page >