Search Results

Search found 20163 results on 807 pages for 'struct size'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 10/807 | < Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >

  • File IO with Streams - Best Memory Buffer Size

    - by AJ
    I am writing a small IO library to assist with a larger (hobby) project. A part of this library performs various functions on a file, which is read / written via the FileStream object. On each StreamReader.Read(...) pass, I fire off an event which will be used in the main app to display progress information. The processing that goes on in the loop is vaired, but is not too time consuming (it could just be a simple file copy, for example, or may involve encryption...). My main question is: What is the best memory buffer size to use? Thinking about physical disk layouts, I could pick 2k, which would cover a CD sector size and is a nice multiple of a 512 byte hard disk sector. Higher up the abstraction tree, you could go for a larger buffer which could read an entire FAT cluster at a time. I realise with today's PC's, I could go for a more memory hungry option (a couple of MiB, for example), but then I increase the time between UI updates and the user perceives a less responsive app. As an aside, I'm eventually hoping to provide a similar interface to files hosted on FTP / HTTP servers (over a local network / fastish DSL). What would be the best memory buffer size for those (again, a "best-case" tradeoff between perceived responsiveness vs. performance).

    Read the article

  • A queue in C using structs and dynamic memory allocation (linked list)

    - by Martin Pugh
    I am tasked with making a queue data structure in C, as a linked list. Our lecturer gave us a large amount of code to implement a stack, but we have to adapt it to create a queue. The code our lecturer gave us ends up not compiling and segfaulting at the exact same point as the code I wrote for the queue. I'm very new to structs, malloc and C in general, so there could be something painfully obvious I've overlooked. Here is the code I am using: #include <stdio.h> #include <stdlib.h> struct node{ int data; //contains the actual data struct node *prev; //pointer to previous node (Closer to front) struct node *next; //pointer to next node (Closer to back) }; typedef struct node *Nodepointer; struct queue{ Nodepointer front; Nodepointer back; }; typedef struct queue *Queuepointer; main(){ Queuepointer myqueue; //create a queue called myqueue init(myqueue); //initialise the queue Nodepointer new = (Nodepointer)malloc(sizeof(struct node)); myqueue->front = new; } int init(Queuepointer q){ q = (Queuepointer)malloc(sizeof(struct queue)); q->front = NULL; q->back = NULL; } The idea is that the queue struct 'contains' the first and last nodes in a queue, and when a node is created, myqueue is updated. However, I cannot even get to that part (pop and push are written but omitted for brevity). The code is segfaulting at the line myqueue->front = new; with the following gdb output: Program received signal SIGSEGV, Segmentation fault. 0x08048401 in main () at queue.c:27 27 myqueue->front = new; Any idea what I'm doing wrong?

    Read the article

  • How is it legal to reference an undefined type inside a structure?

    - by paxdiablo
    As part of answering another question, I came across a piece of code like this, which gcc compiles without complaint. typedef struct { struct xyz *z; } xyz; int main (void) { return 0; } This is the means I've always used to construct types that point to themselves (e.g., linked lists) but I've always thought you had to name the struct so you could use self-reference. In other words, you couldn't use xyz *z within the structure because the typedef is not yet complete at that point. But this particular sample does not name the structure and it still compiles. I thought originally there was some black magic going on in the compiler that automatically translated the above code because the structure and typedef names were the same. But this little beauty works as well: typedef struct { struct NOTHING_LIKE_xyz *z; } xyz; What am I missing here? This seems a clear violation since there is no struct NOTHING_LIKE_xyz type defined anywhere. When I change it from a pointer to an actual type, I get the expected error: typedef struct { struct NOTHING_LIKE_xyz z; } xyz; qqq.c:2: error: field `z' has incomplete type Also, when I remove the struct, I get an error (parse error before "NOTHING ...). Is this allowed in ISO C?

    Read the article

  • ntfsresize volume and size information

    - by antonio
    I am going to resize my sda2 NTFS partition. When gathering info with ntfsresize, I get: ntfsresize --info /dev/sda2 ntfsresize v2013.1.13 (libntfs-3g) Device name : /dev/sda2 NTFS volume version: 3.1 Cluster size : 4096 bytes Current volume size: 21999993344 bytes (22000 MB) Current device size: 23622320128 bytes (23623 MB) Checking filesystem consistency ... Accounting clusters ... Space in use : 10673 MB (48.5%) Collecting resizing constraints ... You might resize at 10672590848 bytes or 10673 MB (freeing 11327 MB). Please make a test run using both the -n and -s options before real resizing! Can you tell me what is the difference between volume and device size? As for device size, 23622320128 bytes / 1000^2 = 23622.3 MB. Why is 23623 MB reported instead of 23622? Note that parted confirms this value: parted /dev/sda2 unit MB p Model: Unknown (unknown) Disk /dev/sda2: 23622MB Sector size (logical/physical): 512B/512B Partition Table: loop Disk Flags: Number Start End Size File system Flags 1 0.00MB 23622MB 23622MB ntfs

    Read the article

  • forward declare typedef'd struct

    - by Steve
    I can't figure out how to forward declare a windows struct. The definition is typedef struct _CONTEXT { .... } CONTEXT, *PCONTEXT I really don't want to pull into this header, as it gets included everywhere. I've tried struct CONTEXT and struct _CONTEXT with no luck (redefinition of basic types with the actuall struct in winnt.h.

    Read the article

  • struct to bytes

    - by Dave18
    I'm trying to read encrypted struct data from file using fread(). once i get the decrypted struct bytes, I'd like to it put them back into this struct. struct data { string s1; string s2; string s3; long l; }; how would you convert a struct into bytes which can be reconstructed from bytes?

    Read the article

  • Multiplying matrices: error: expected primary-expression before 'struct'

    - by justin
    I am trying to write a program that is supposed to multiply matrices using threads. I am supposed to fill the matrices using random numbers in a thread. I am compiling in g++ and using PTHREADS. I have also created a struct to pass the data from my command line input to the thread so it can generate the matrix of random numbers. The sizes of the two matrices are also passed in the command line as well. I keep getting: main.cpp:7: error: expected primary-expression before 'struct' my code @ line 7 =: struct a{ int Arow; int Acol; int low; int high; }; My inpust are : Sizes of two matrices ( 4 arguments) high and low ranges in which o generate the random numbers between. Complete code: [headers] using namespace std; void *matrixACreate(struct *); void *status; int main(int argc, char * argv[]) { int Arow = atoi(argv[1]); // Matrix A int Acol = atoi(argv[2]); // WxX int Brow = atoi(argv[3]); // Matrix B int Bcol = atoi(argv[4]); // XxZ, int low = atoi(argv[5]); // Range low int high = atoi(argv[6]); struct a{ int Arow; // Matrix A int Acol; // WxX int low; // Range low int high; }; pthread_t matrixAthread; //pthread_t matrixBthread; pthread_t runner; int error, retValue; if (Acol != Brow) { cout << " This matrix cannot be multiplied. FAIL" << endl; return 0; } error = pthread_create(&matrixAthread, NULL, matrixACreate, struct *a); //error = pthread_create(&matrixAthread, NULL, matrixBCreate, sendB); retValue = pthread_join(matrixAthread, &status); //retValue = pthread_join(matrixBthread, &status); return 0; } void matrixACreate(struct * a) { struct a *data = (struct a *) malloc(sizeof(struct a)); data->Arow = Arow; data->Acol = Acol; data->low = low; data->high = high; int range = ((high - low) + 1); cout << Arow << endl<< Acol << endl; }// just trying to print to see if I am in the thread

    Read the article

  • C#: Struct Constructor: "fields must be fully assigned before control is returned to the caller."

    - by Rosarch
    Here is a struct I am trying to write: public struct AttackTraits { public AttackTraits(double probability, int damage, float distance) { Probability = probability; Distance = distance; Damage = damage; } private double probability; public double Probability { get { return probability; } set { if (value > 1 || value < 0) { throw new ArgumentOutOfRangeException("Probability values must be in the range [0, 1]"); } probability = value; } } public int Damage { get; set; } public float Distance { get; set; } } This results in the following compilation errors: The 'this' object cannot be used before all of its fields are assigned to Field 'AttackTraits.probability' must be fully assigned before control is returned to the caller Backing field for automatically implemented property 'AttackTraits.Damage' must be fully assigned before control is returned to the caller. Consider calling the default constructor from a constructor initializer. Backing field for automatically implemented property 'AttackTraits.Distance' must be fully assigned before control is returned to the caller. Consider calling the default constructor from a constructor initializer. What am I doing wrong?

    Read the article

  • Why Can I Change Struct's int[] Property from Method Without Specifying "ref"?

    - by AMissico
    From a method, I can pass a struct which contains an array of integers, and change the values in the array. I am not sure I understand fully why I can do this. Can someone please explain why I can change the values stored in the int[]? private void DoIt(){ SearchInfo a = new SearchInfo(); a.Index = 1; a.Map = new int[] { 1 }; SearchInfo b = new SearchInfo(); b.Index = 1; b.Map = new int[] { 1 }; ModifyA(a); ModifyB(ref b); Debug.Assert(a.Index == 1); Debug.Assert(a.Map[0] == 1, "why did this change?"); Debug.Assert(b.Index == 99); Debug.Assert(b.Map[0] == 99); } void ModifyA(SearchInfo a) { a.Index = 99; a.Map[0] = 99; } void ModifyB(ref SearchInfo b) { b.Index = 99; b.Map[0] = 99; } struct SearchInfo { public int[] Map; public int Index; }

    Read the article

  • How can I modify the value of a string defined in a struct?

    - by Eric
    Hi, I have the following code in c++: #define TAM 4000 #define NUMPAGS 512 struct pagina { bitset<12> direccion; char operacion; char permiso; string *dato; int numero; }; void crearPagina(pagina* pag[], int pos, int dir) { pagina * paginas = (pagina*)malloc(sizeof(char) * TAM); paginas -> direccion = bitset<12> (dir); paginas -> operacion = 'n'; paginas -> permiso = 'n'; string **tempDato = &paginas -> dato; char *temp = " "; **tempDato = temp; paginas -> numero = 0; pag[pos] = paginas; } I want to modify the value of the variable called "string *dato" in the struct pagina but, everytime I want to assing a new value, the compiler throws a segmentation fault. In this case I'm using a pointer to string, but I have also tried with a string. In a few words I want to do the following: pagina - dato = "test"; Any idea? Thanks in advance!!!

    Read the article

  • Overlaying several CLR reference fields with each other in explicit struct?

    - by thr
    Edit: I'm well aware of that this works very well with value types, my specific question is about using this for reference types. I've been tinkering around with structs in .NET/C#, and I just found out that you can do this: using System; using System.Runtime.InteropServices; namespace ConsoleApplication1 { class Foo { } class Bar { } [StructLayout(LayoutKind.Explicit)] struct Overlaid { [FieldOffset(0)] public object AsObject; [FieldOffset(0)] public Foo AsFoo; [FieldOffset(0)] public Bar AsBar; } class Program { static void Main(string[] args) { var overlaid = new Overlaid(); overlaid.AsObject = new Bar(); Console.WriteLine(overlaid.AsBar); overlaid.AsObject = new Foo(); Console.WriteLine(overlaid.AsFoo); Console.ReadLine(); } } } Basically circumventing having to do dynamic casting during runtime by using a struct that has an explicit field layout and then accessing the object inside as it's correct type. Now my question is: Can this lead to memory leaks somehow, or any other undefined behavior inside the CLR? Or is this a fully supported convention that is usable without any issues? I'm aware that this is one of the darker corners of the CLR, and that this technique is only a viable option in very few specific cases.

    Read the article

  • Set page size using WIA (with scanner)

    - by Salvador Sarpi
    Hello, I'm using WIA to acquire images from a scanner with C#. I can scan the papers, but I can't set up the page size correctly, it always defaults to A4 and I need to use Letter or Legal sometimes. I tried with the WIA_DPS_PAGE_SIZE property, but when I try to set a value, I always get an error, that the value is out of the interval (tried a lot of possible values). I wan't to be able to use WIA_DPS_PAGE_SIZE = WIA_PAGE_AUTO (for automatic page size), but I can't find anything on the web related to this. Does anyone know a solution? thanks!

    Read the article

  • UIImageView size becomes equal to the size of image it holds after autoresizing

    - by abura
    Hello, I faced a strange problem. My task is to provide scaling an image to fill the UIImageView frame. The UIImageView is a subview of another view. The code is following: CGRect frame=CGRectMake(0,0,viewSize.width,viewSize.height); UIView* backView=[[UIView alloc] initWithFrame:frame]; backView.autoresizesSubviews=YES; backView.autoresizingMask=UIViewAutoresizingFlexibleWidth; UIImageView* imgView=[[UIImageView alloc]initWithFrame:viewFrame]; imgView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; imgView.contentMode=UIViewContentModeScaleToFill; [subcellBackView addSubview:imgView]; [imgView release]; When the image arrives, it is assigned the the imgView: imgView.image=img; The image is scaled according to the imgView's size. Everything is all right until the iPhone (simulator) rotation. After first autoresizing the imgView size becomes equal to the image size (which is much greater) and overlaps its superview frame. The superview frame reacts properly to the orientation change. Could you please help?

    Read the article

  • CSS size transition to stay inside parent div

    - by IlyaD
    I want to have an image frame that when I hove over it the image inside will zoom in a little (I am using size transition), but the frame will stay the same size. What happens now that even if the frame has a fixed width and height it is stilled zoomed with the image HTML: <div class="img-wrapper"> <img class="thumbnail" src="http://placekitten.com/400/200"> </div> and CSS .img-wrapper { width: 400px; } .thumbnail { width: 400px; } .thumbnail { -webkit-transition: all 0.2s ease-out; -moz-transition: all 0.2s ease-out; transition: all 0.2s ease-out; } .thumbnail:hover { width: 500px; -webkit-transition: all 0.2s ease-out; -moz-transition: all 0.2s ease-out; transition: all 0.2s ease-out; } http://codepen.io/pen/KCJny

    Read the article

  • XHR FF POST size limit

    - by usurper
    Hi, My XHR POST REQUEST is cut off. When I try to reload my page information is missing. Firebugs sends following message: ... Firebug request size limit has been reached by Firebug. ... My question is: What are my options? Would it work if I declare the content.length in the header? I added a line to my apache config file and restarted it: LimitRequestBody 0 I increased the size of transfer files in mysql config file Or it is a browser issue? The only solution I could think of was to cut the data in pieces and transmit the array one by one but I don't like this idea. The content length is 91691 according to firebug. Any suggestions?

    Read the article

  • ajax response byte size

    - by Alex Pacurar
    Im using jQuery's getJSONP and I want to log the duration of the call and the size of the response to be able to have some statistics about the usage of my application. This is a cross domain ajax call, so I need to use JSONP, but as the JSONP call is not done with an XMLHttpRequest object, the complete callback from jquery's ajax doesnt pass the response content. So my question is how to get the response size (content lenght) from a JSONP call. $.ajaxSetup( { complete:function(x,e) { log(x.responseText.length, x.responseText); } } here x is a XMLHttpRequest object for a JSON call , but for JSONP call is undefined.

    Read the article

  • Size and position of the C# form.

    - by Vytas999
    I use Visual Studio .NET to create a Windows-based application. The application includes a form named CForm. CForm contains 15 controls that enable users to set basic configuration options for the application. I design these controls to dynamically adjust when users resize CForm. The controls automatically update their size and position on the form as the form is resized. The initial size of the form should be 650 x 700 pixels. If CForm is resized to be smaller then 500 x 600 pixels, the controls will not be displayed correctly. How I must ensure that users cannot resize CForm to be smaller than 500 x 600 pixels..?

    Read the article

  • How to change font size in a pickerview?

    - by user183804
    I'm fairly new to iPhone programming and am trying to implement a double-component PickerView. At this point the picker works fine in terms of taking user input, created with Interface Builder. However, I need to change the font size to accommodate the text length in each column. I very much would appreciate any link to a straightforward method to creating a multi-component picker with an adjustable font size. Seems like it is not possible if Interface Builder is used to create the picker. So far I have not found any code links that address this issue in detail. Thanks in advance.

    Read the article

  • Change the size of the panel dynamically

    - by C. Karunarathne
    Hi! I am implementing an application that needs to drag and drop image boxes in a panel.Image boxes are added dynamically from the program and so I have set the autoscroll property to true in panel.But when I have drag out the boxes at bottom in the panel the panel size got reduced.I have put autosize property false in panel.The panel is docked in another panel.I want to set the size of panel at run time.How can I achieve this. public form1(int[,] dummy, int columnSize, int rowSize) { this.dummy= dummy; numOfColumns = columnSize; numOfRows = rowSize; getData(); addIds = addIdArray; data = mylist; InitializeComponent(); //panel1.MinimumSize = new Size(columnSize * 40, rowSize * 40); //panel1.Height = rowSize * 40; //panel1.Width = columnSize * 40; //panel4.Height = rowSize * 40; //panel4.Width = columnSize * 40; int x, y; Structures.EmptyRectSpace space = new Structures.EmptyRectSpace(); for (int i = 0; i < data.Count; i++)// set picture boxes { space = (Structures.EmptyRectSpace)data[i]; x = space.startingJ; y = space.startingI; int h, w; h = space.length; w = space.width; p = new PictureBox(); p.Width = w * 40; p.Height = h * 40; p.BackColor = Color.DarkGreen; p.Image = Properties.Resources.v; p.BorderStyle = BorderStyle.FixedSingle; p.Name = addIdArray[i].ToString(); p.Location = new Point((x + 1 - w) * 40, (y + 1 - h) * 40); this.panel1.Controls.Add(p); } foreach (Control c in this.panel1.Controls) { if (c is PictureBox) { c.MouseDown += new MouseEventHandler(pictureBox1_MouseDown); } } this.panel1.DragOver += new System.Windows.Forms.DragEventHandler(this.panel1_DragOver); panel1.DragOver += new DragEventHandler(panel1_DragOver); panel1.DragDrop += new DragEventHandler(panel1_DragDrop); panel1.AllowDrop = true; panel2.AllowDrop = true; foreach (Control c in this.panel2.Controls) { c.MouseDown += new MouseEventHandler(pictureBox1_MouseDown); } this.panel2.DragOver += new System.Windows.Forms.DragEventHandler(this.panel2_DragOver); panel2.DragOver += new DragEventHandler(panel2_DragOver); panel2.DragDrop += new DragEventHandler(panel2_DragDrop); } This is the constructor of the form that contained panel.When it loaded the picture boxes must be added to the panel and there drag drop events of panel are implemented. Please give me a helping hand..

    Read the article

  • Get dimensions for dataset matlab, Size Function

    - by Tim
    Hello I have been trying to display the dimensions of a dataset, below is the following matlab code that i used...but it gives me the wrong output....i'e number of rows and columns values are wrong....any help regarding this issue would be highly appreciated [file_input,pathname] = uigetfile( ... {'*.txt', 'Text (*.txt)'; ... '*.xls', 'Excel (*.xls)'; ... '*.*', 'All Files (*.*)'}, ... 'Select files'); [pathstr, name, ext, versn] = fileparts(file_input) r = size(name,1); c = size(name,2); disp(r) disp(c)

    Read the article

  • Casting to a struct from LPVOID - C

    - by Jamie Keeling
    Hello, I am writing a simple console application which will allow me to create a number of threads from a set of parameters passed through the arguments I provide. DWORD WINAPI ThreadFunc(LPVOID threadData) { } I am packing them into a struct and passing them as a parameter into the CreateThread method and trying to unpack them by casting them to the same type as my struct from the LPVOID. I'm not sure how to cast it to the struct after getting it through so I can use it in the method itself, i've tried various combinations (Example attatched) but it won't compile. Struct: #define numThreads 1 struct Data { int threads; int delay; int messages; }; Call to method: HANDLE hThread; DWORD threadId; struct Data *tData; tData->threads = numThreads; tData->messages = 3; tData->delay = 1000; // Create child thread hThread = CreateThread( NULL, // lpThreadAttributes (default) 0, // dwStackSize (default) ThreadFunc, // lpStartAddress &tData, // lpParameter 0, // dwCreationFlags &threadId // lpThreadId (returned by function) ); My attempt: DWORD WINAPI ThreadFunc(LPVOID threadData) { struct Data tData = (struct Data)threadData; int msg; for(msg = 0; msg<5; msg++) { printf("Message %d from child\n", msg); } return 0; } Compiler error: error C2440: 'type cast' : cannot convert from 'LPVOID' to 'Data' As you can see I have implemented a way to loop through a number of messages already, I'm trying to make things slightly more advanced and add some further functionality.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >