Search Results

Search found 22721 results on 909 pages for 'block level storage'.

Page 147/909 | < Previous Page | 143 144 145 146 147 148 149 150 151 152 153 154  | Next Page >

  • Should mutex.WaitOne() inside or before the try/finally block.

    - by chillitom
    Hi Guys, I was wondering which of the following was the suggested pattern when using Mutex (or Semaphores or ReadWriteLockSlims etc.). Should the initial lock happen inside or outside of the try statement? Is it unimportant? _mutex.WaitOne() try { // critical code } finally { _mutex.ReleaseMutex(); } or try { _mutex.WaitOne() // critical code } finally { _mutex.ReleaseMutex(); }

    Read the article

  • How can I do more than one level of cascading deletes in Linq?

    - by Gary McGill
    If I have a Customers table linked to an Orders table, and I want to delete a customer and its corresponding orders, then I can do: dataContext.Orders.DeleteAllOnSubmit(customer.Orders); dataContext.Customers.DeleteOnSubmit(customer); ...which is great. However, what if I also have an OrderItems table, and I want to delete the order items for each of the orders deleted? I can see how I could use DeleteAllOnSubmit to cause the deletion of all the order items for a single order, but how can I do it for all the orders?

    Read the article

  • Objective-C / Cocoa: Uploading Images, Working Memory, And Storage.

    - by Finley Still
    Hello. I'm in the process of porting an application originally in java to cocoa, but I'm rewriting it to make it much better, since I prefer cocoa a lot anyway. One of the problems I had in the application, was that when you uploaded images to it, I had the images created, (as say an NSImage object) and then I just had them sitting in memory, the more I uploaded the more memory they took up, and I ended up running out of memory. My question is this: if I am going to have users upload images to this application in cocoa, how should I go about storing them? I don't just want to copy the file paths, because I want what is saved to contain the images, etc. Is there any way to upload an image and copy it into a different place only for my application? Then load that image with the new path name as needed? Only I would like it all to be consolidated. I'm going to implement saving by archiving one "master" object into an NSData*- so I'd like the images to be saved with that. Is there a temporary location maybe where I could write the images to disk for my application, and then when I saved, they would all be archived into a single file? Also, how do I do this? Thanks.

    Read the article

  • Is there performance to be gained by moving storage allocation local to a member function to its cla

    - by neuviemeporte
    Suppose I have the following C++ class: class Foo { double bar(double sth); }; double Foo::bar(double sth) { double a,b,c,d,e,f a = b = c = d = e = f = 0; /* do stuff with a..f and sth */ } The function bar() will be called millions of times in a loop. Obviously, each time it's called, the variables a..f have to be allocated. Will I gain any performance by making the variables a..f members of the Foo class and just initializing them at the function's point of entry? On the other hand, the values of a..f will be dereferenced through this-, so I'm wondering if it isn't actually a possible performance degradation. Is there any overhead to accessing a value through a pointer? Thanks!

    Read the article

  • What should i do for accomodating large scale data storage and retrieval?

    - by kailashbuki
    There's two columns in the table inside mysql database. First column contains the fingerprint while the second one contains the list of documents which have that fingerprint. It's much like an inverted index built by search engines. An instance of a record inside the table is shown below; 34 "doc1, doc2, doc45" The number of fingerprints is very large(can range up to trillions). There are basically following operations in the database: inserting/updating the record & retrieving the record accoring to the match in fingerprint. The table definition python snippet is: self.cursor.execute("CREATE TABLE IF NOT EXISTS `fingerprint` (fp BIGINT, documents TEXT)") And the snippet for insert/update operation is: if self.cursor.execute("UPDATE `fingerprint` SET documents=CONCAT(documents,%s) WHERE fp=%s",(","+newDocId, thisFP))== 0L: self.cursor.execute("INSERT INTO `fingerprint` VALUES (%s, %s)", (thisFP,newDocId)) The only bottleneck i have observed so far is the query time in mysql. My whole application is web based. So time is a critical factor. I have also thought of using cassandra but have less knowledge of it. Please suggest me a better way to tackle this problem.

    Read the article

  • Updating or inserting high scores in SQL

    - by Roger Gilbrat
    I've been racking my brain over this for the past few days and I'm not sure it's possible, but figured I ask here. Is it possible for a single SQL statement to update a high score if your score is greater or insert it if your first score? My Score table has a UserID, Level and Score columns and I like it to follow the following logic: If your new score is greater than your last score for this Level, then replace it. If you don't have a score for this Level then add it. If your score for this Level is less than your highest score for this Level then do nothing. Is this possible in a single SQL statement or do I have to use two, one to see if you have a new high score and if so, replace it? Each UserID would have only one score in the table for each Level. I'm using MySQL.

    Read the article

  • How do you set page level, page-SPECIFIC javascript events using a ContentPlaceHolder?

    - by donde
    I previously asked how to include Javascript in my page when I split the page into a MasterPage and ContentPlaceHolder (.NET 2.0 app) The issue was I only wanted the javascript functions on THAT page so I couldn't just put them on the masterpage. Based on the answers, I will inlcude common fucntions through MasterPage and can put the page-specific function right on the content page. However, 1 question remains: Events. I have 2 Javascript functions that I wanted to load when the page loads ala the HTML below. How do you load javascript page events on the specific content page? Or in the case below, the OnKeyPress event? <body onkeypress="javascript:keypressed();" onload="javascript:setDivVisibility();">

    Read the article

  • Processing an n-ary ANTLR AST one child at a time

    - by Chris Lieb
    I currently have a compiler that uses an AST where all children of a code block are on the same level (ie, block.children == {stm1, stm2, stm3, etc...}). I am trying to do liveness analysis on this tree, which means that I need to take the value returned from the processing of stm1 and then pass it to stm2, then take the value returned by stm2 and pass it to stm3, and so on. I do not see a way of executing the child rules in this fashion when the AST is structured this way. Is there a way to allow me to chain the execution of the child grammar items with my given AST, or am I going to have to go through the painful process of refactoring the parser to generate a nested structure and updating the rest of the compiler to work with the new AST? Example ANTLR grammar fragment: block : ^(BLOCK statement*) ; statement : // stuff ; What I hope I don't have to go to: block : ^(BLOCK statementList) ; statementList : ^(StmLst statement statement+) | ^(StmLst statement) ; statement : // stuff ;

    Read the article

  • Does C# compile code inside an if(false) block?

    - by aximili
    I am just wondering if these code blocks gets compiled into .dll I don't think this one gets compiled at all #if SOMETHING_UNDEFINED // some code - this is ignored by the compiler #endif Now what about these? 1. if(false) { // some code - is this compiled? } 2. const bool F = false; if(F) { // some code - is this compiled? } 3. bool F = false; if(F) { // some code - is this compiled? }

    Read the article

  • How do actually castings work at the CLR level?

    - by devoured elysium
    When doing an upcast or downcast, what does really happen behind the scenes? I had the idea that when doing something as: string myString = "abc"; object myObject = myString; string myStringBack = (string)myObject; the cast in the last line would have as only purpose tell the compiler we are safe we are not doing anything wrong. So, I had the idea that actually no casting code would be embedded in the code itself. It seems I was wrong: .maxstack 1 .locals init ( [0] string myString, [1] object myObject, [2] string myStringBack) L_0000: nop L_0001: ldstr "abc" L_0006: stloc.0 L_0007: ldloc.0 L_0008: stloc.1 L_0009: ldloc.1 L_000a: castclass string L_000f: stloc.2 L_0010: ret Why does the CLR need something like castclass string? There are two possible implementations for a downcast: You require a castclass something. When you get to the line of code that does an castclass, the CLR tries to make the cast. But then, what would happen had I ommited the castclass string line and tried to run the code? You don't require a castclass. As all reference types have a similar internal structure, if you try to use a string on an Form instance, it will throw an exception of wrong usage (because it detects a Form is not a string or any of its subtypes). Also, is the following statamente from C# 4.0 in a Nutshell correct? Upcasting and downcasting between compatible reference types performs reference conversions: a new reference is created that points to the same object. Does it really create a new reference? I thought it'd be the same reference, only stored in a different type of variable. Thanks

    Read the article

  • Avoiding Nested Blocks

    - by Helium3
    If there is a view controller that wants to execute a number of block based tasks one at a time, how can the control be given back to the view controller after a completion block has executed. Lets say ViewControllerOne wants to execute a number of tasks, each relying on the result of the previous one, how would this control be given back to the viewcontroller after each completion block has been executed? I started thinking about this and I was heading towards a deeply nested block pattern that will surely only cause confusion to whoever else reads or tests it. A task executes and the completion block returns the result or error which is needed by the next task, which has its own completion task, that the next task relies on and so forth. How can the control be managed in one place, the viewcontroller? Would the completion block just call the next function that handles the next task, using a pointer to the view controller?

    Read the article

  • How to make softkeyboard candidate view not block application view?

    - by Cedric
    Hi, I am playing with the Demo SoftKeyboard the comes with the Android SDK. In portrait mode when the candidate view is shown, it doesn't move the app up as the default android keyboard does. Hence it covers part of the application view. What should be changed in order to make the candidate view in the demo softkeyboard behave as the default android keyboard does? I've also looked at the source of the android keyboard from git but found nothing related to this behavior.

    Read the article

  • Java queue and multi-dimention array question? [Beginner level]

    - by javaLearner.java
    First of all, this is my code (just started learning java): Queue<String> qe = new LinkedList<String>(); qe.add("b"); qe.add("a"); qe.add("c"); qe.add("d"); qe.add("e"); My question: Is it possible to add element to the queue with two values, like: qe.add("a","1"); // where 1 is integer So, that I know element "a" have value 1. If I want to add a number let say "2" to element a, I will have like a = 3. If this cant be done, what else in java classes that can handle this? I tried to use multi-dimention array, but its kinda hard to do the queue, like pop, push etc. (Maybe I am wrong) How to call specific element in the queue? Like, call element a, to check its value. [Note] Please don't give me links that ask me to read java docs. I was reading, and I still dont get it. The reason why I ask here is because, I know I can find the answer faster and easier.

    Read the article

  • jQuery: How to hide all HTML elements which have a value greater than a certain value for a given ta

    - by Ankur
    I display elements in a hierarchy, clicking one displays the next set of elements in the hirearchy. Each element has a tag called "level" which has some value which is 1-.... (whatever the number of levels is for that branch of the tree). When an element is clicked I want the next elements to be displayed, but if an element is clicked and it's subelements have already been displayed I want to hide all subelements. More formally: when an element with level = x is clicked if no elements with level x are displayed then display all elements such that level = x+1 but if some elements with level x are displayed then hide all elements where level x How would I create a jQuery selector that captures this.

    Read the article

  • Do I have to use Stored Procedures to get query level security or can I still do this with Dynamic S

    - by Peter Smith
    I'm developing an application where I'm concerned about locking down access to the database. I know I can develop stored procedures (and with proper parameter checking) limit a database user to an exact set of queries to execute. It's imperative that no other queries other then the ones I created in the stored procedures be allowed to execute under that user. Ideally even if a hacker gained access to the database connection (which only accepts connections from certain computers) they would only be able to execute the predefined stored procedures. Must I choose stored procedures for this or can I use Dynamic Sql with these fine grain permissions?

    Read the article

  • How can we block the user from unchecking a DataGridView checkbox?

    - by hawbsl
    We have a DataGridViewCheckBox column bound to a boolean property in our class. The property setter has some logic which says that under certain conditions a True flag cannot be changed, ie, it stays checked forever. This is on a per record basis. So the entire column can't be readonly, only certain rows. Pseudo code: Public Property Foo() As Boolean Get Return _Foo End Get Set(ByVal value As Boolean) If _Foo And Bar And value = False Then //do nothing, in this scenario once you're true, you stay true Else _Foo = value End If End Set End Property Databinding is handling all of this fine, except that the checkbox is visibly cleared when it's clicked. Then, of course, when the binding / setter is fired (as you move off that cell) it is restored to its checked status per the underlying logic. Ultimately it doesn't matter too much but it's a clumsy bit of UI. How can we intercept the user's click and keep it checked?

    Read the article

  • Does the pointer to free() have to point to beginning of the memory block, or can it point to the interior?

    - by Lambert
    The question is in the title... I searched but couldn't find anything. Edit: I don't really see any need to explain this, but because people think that what I'm saying makes no sense (and that I'm asking the wrong questions), here's the problem: Since people seem to be very interested in the "root" cause of all the problem rather than the actual question asked (since that apparently helps things get solved better, let's see if it does), here's the problem: I'm trying to make a D runtime library based on NTDLL.dll, so that I can use that library for subsystems other than the Win32 subsystem. So that forces me to only link with NTDLL.dll. Yes, I'm aware that the functions are "undocumented" and could change at any time (even though I'd bet a hundred dollars that wcstombs will still do the same exact thing 20 years from now, if it still exists). Yes, I know people (especially Microsoft) don't like developers linking to that library, and that I'll probably get criticized for the right here. And yes, those two points above mean that programs like chkdsk and defragmenters that run before the Win32 subsystem aren't even supposed to be created in the first place, because it's literally impossible to link with anything like kernel32.dll or msvcrt.dll and still have NT-native executables, so we developers should just pretend that those stages are meant to be forever out of our reaches. But no, I doubt that anyone here would like me to paste a few thousand lines of code and help me look through them and try to figure out why memory allocations that aren't failing are being rejected by the source code I'm modifying. So that's why I asked about a different problem than the "root" cause, even though that's supposedly known to be the best practice by the community. If things still don't make sense, feel free to post comments below! :)

    Read the article

  • jQuery child selector expression

    - by Saiful
    <div id="div"> <div> <!-- first level --> <div> <!-- second level --> <div>1.1</div> <!-- third level --> <div>1.2</div> </div> <div> <div></div> <div>2.2</div> </div> </div> </div> What are the jQuery selector expressions for selecting the followings: 1. div commented by first level 2. divs commented by second level 3. divs commented by third level

    Read the article

  • Most efficient way to fetch and output Content with 2-Level Comments?

    - by awegawef
    I have some content with up to 2-levels of replies. I am wondering what the most efficient way to fetch and output the replies. I should note that I am planning on storing the comments with fields content_id and reply_to, where reply_to refers to which comment it is in reply to (if any). Any criticism on this design is welcome. In pseudo-code (ish), my first attempt would be: # in outputting content CONTENT_ID all_comments = fetch all comments where content_id == CONTENT_ID root_comments = filter all_comments with reply_to == None children_comments = filter all_comments with reply_to != None output_comments = list() for each root_comment children = filter children_comments, reply_to == root_comment.id output_coments.append( (root_comment, children) ) send output_comments to template Is this the best way to do this? Thanks in advance. Edit: On second thought, I'll want to preserve date-order on the comments, so I'll have to do this a bit differently, or at least just sort the comments afterward.

    Read the article

  • What's the cleanest way to do byte-level manipulation?

    - by Jurily
    I have the following C struct from the source code of a server, and many similar: // preprocessing magic: 1-byte alignment typedef struct AUTH_LOGON_CHALLENGE_C { // 4 byte header uint8 cmd; uint8 error; uint16 size; // 30 bytes uint8 gamename[4]; uint8 version1; uint8 version2; uint8 version3; uint16 build; uint8 platform[4]; uint8 os[4]; uint8 country[4]; uint32 timezone_bias; uint32 ip; uint8 I_len; // I_len bytes uint8 I[1]; } sAuthLogonChallenge_C; // usage (the actual code that will read my packets): sAuthLogonChallenge_C *ch = (sAuthLogonChallenge_C*)&buf[0]; // where buf is a raw byte array These are TCP packets, and I need to implement something that emits and reads them in C#. What's the cleanest way to do this? My current approach involves [StructLayout(LayoutKind.Sequential, Pack = 1)] unsafe struct foo { ... } and a lot of fixed statements to read and write it, but it feels really clunky, and since the packet itself is not fixed length, I don't feel comfortable using it. Also, it's a lot of work. However, it does describe the data structure nicely, and the protocol may change over time, so this may be ideal for maintenance. What are my options? Would it be easier to just write it in C++ and use some .NET magic to use that?

    Read the article

  • How can I intercept a Tomcat request at socket level?

    - by Miguel Pardal
    Hi, I'm doing a performance study for a web application framework running on Apache Tomcat 6. I'm trying to measure the time overhead of handling HTTP requests. What I would like to do is: / // just before first request byte is read long t1 = System.nanoTime(); // request is processed... // just after final byte is written to response long t2 = System.nanoTime(); / Then I would compute the total time (t2 - t1). Is there a way to do this? Thanks for your help!

    Read the article

  • Will C++/CLI give me control over low-level devices like audio?

    - by schmoopy
    I was wondering - how much limitation is there to C++/CLI compared to classic C++ (chuckle) - I was wanting to write an application that I cannot do with c# -- I was wanting to be able to connect to the PC's audio device and detect audio (for example) - Is this something I can do with C++/CLI? I have tried using NAudio with c#, but i have been able to do this. What other advantages would C++/CLI or C++ give me over c#?

    Read the article

< Previous Page | 143 144 145 146 147 148 149 150 151 152 153 154  | Next Page >