Search Results

Search found 10366 results on 415 pages for 'const char pointer'.

Page 356/415 | < Previous Page | 352 353 354 355 356 357 358 359 360 361 362 363  | Next Page >

• Who's setting TCP window size down to 0, Indy or Windows?

  - by François

  We have an application server which have been observed sending headers with TCP window size 0 at times when the network had congestion (at a client's site). We would like to know if it is Indy or the underlying Windows layer that is responsible for adjusting the TCP window size down from the nominal 64K in adaptation to the available throughput. And we would be able to act upon it becoming 0 (nothing gets send, users wait = no good). So, any info, link, pointer to Indy code are welcome... Disclaimer: I'm not a network specialist. Please keep the answer understandable for the average me ;-) Note: it's Indy9/D2007 on Windows Server 2003 SP2. More gory details: The TCP zero window cases happen on the middle tier talking to the DB server. It happens at the same moments when end users complain of slowdowns in the client application (that's what triggered the network investigation). 2 major Network issues causing bottlenecks have been identified. The TCP zero window happened when there was network congestion, but may or may not be caused by it. We want to know when that happen and have a way to do something (logging at least) in our code. So where to hook (in Indy?) to know when that condition occurs?

  Read the article

• Implementing list position locator in C++?

  - by jfrazier

  I am writing a basic Graph API in C++ (I know libraries already exist, but I am doing it for the practice/experience). The structure is basically that of an adjacency list representation. So there are Vertex objects and Edge objects, and the Graph class contains: list<Vertex *> vertexList list<Edge *> edgeList Each Edge object has two Vertex* members representing its endpoints, and each Vertex object has a list of Edge* members representing the edges incident to the Vertex. All this is quite standard, but here is my problem. I want to be able to implement deletion of Edges and Vertices in constant time, so for example each Vertex object should have a Locator member that points to the position of its Vertex* in the vertexList. The way I first implemented this was by saving a list::iterator, as follows: vertexList.push_back(v); v->locator = --vertexList.end(); Then if I need to delete this vertex later, then rather than searching the whole vertexList for its pointer, I can call: vertexList.erase(v->locator); This works fine at first, but it seems that if enough changes (deletions) are made to the list, the iterators will become out-of-date and I get all sorts of iterator errors at runtime. This seems strange for a linked list, because it doesn't seem like you should ever need to re-allocate the remaining members of the list after deletions, but maybe the STL does this to optimize by keeping memory somewhat contiguous? In any case, I would appreciate it if anyone has any insight as to why this happens. Is there a standard way in C++ to implement a locator that will keep track of an element's position in a list without becoming obsolete? Much thanks, Jeff

  Read the article

• Is it possible to get the parsed text of a SqlCommand with SqlParameters?

  - by Burg

  What I am trying to do is create some arbitrary sql command with parameters, set the values and types of the parameters, and then return the parsed sql command - with parameters included. I will not be directly running this command against a sql database, so no connection should be necessary. So if I ran the example program below, I would hope to see the following text (or something similar): WITH SomeTable (SomeColumn) AS ( SELECT N':)' UNION ALL SELECT N'>:o' UNION ALL SELECT N'^_^' ) SELECT SomeColumn FROM SomeTable And the sample program is: using System; using System.Data; using System.Data.SqlClient; namespace DryEraseConsole { class Program { static void Main(string[] args) { const string COMMAND_TEXT = @" WITH SomeTable (SomeColumn) AS ( SELECT N':)' UNION ALL SELECT N'>:o' UNION ALL SELECT @Value ) SELECT SomeColumn FROM SomeTable "; SqlCommand cmd = new SqlCommand(COMMAND_TEXT); cmd.CommandText = COMMAND_TEXT; cmd.Parameters.Add(new SqlParameter { ParameterName = "@Value", Size = 128, SqlDbType = SqlDbType.NVarChar, Value = "^_^" }); Console.WriteLine(cmd.CommandText); Console.ReadKey(); } } } Is this something that is achievable using the .net standard libraries? Initial searching says no, but I hope I'm wrong.

  Read the article

• How to partition bits in a bit array with less than linear time

  - by SiLent SoNG

  This is an interview question I faced recently. Given an array of 1 and 0, find a way to partition the bits in place so that 0's are grouped together, and 1's are grouped together. It does not matter whether 1's are ahead of 0's or 0's are ahead of 1's. An example input is 101010101, and output is either 111110000 or 000011111. Solve the problem in less than linear time. Make the problem simpler. The input is an integer array, with each element either 1 or 0. Output is the same integer array with integers partitioned well. To me, this is an easy question if it can be solved in O(N). My approach is to use two pointers, starting from both ends of the array. Increases and decreases each pointer; if it does not point to the correct integer, swap the two. int * start = array; int * end = array + length - 1; while (start < end) { // Assume 0 always at the end if (*end == 0) { --end; continue; } // Assume 1 always at the beginning if (*start == 1) { ++start; continue; } swap(*start, *end); } However, the interview insists there is a sub-linear solution. This makes me thinking hard but still not get an answer. Can anyone help on this interview question?

  Read the article

• Newbie: Render RGB to GTK widget -- howto?

  - by Billy Pilgrim

  Hi All, Big picture: I want to render an RGB image via GTK on a linux box. I'm a frustrated GTK newbie, so please forgive me. I assume that I should create a Drawable_area in which to render the image -- correct? Do I then have to create a graphics context attached to that area? How? my simple app (which doesn't even address the rgb issue yet is this: int main(int argc, char** argv) { GdkGC * gc = NULL; GtkWidget * window = NULL; GtkDrawingArea * dpage = NULL; GtkWidget * page = NULL; gtk_init( &argc, & argv ); window = gtk_window_new( GTK_WINDOW_TOPLEVEL ); page = gtk_drawing_area_new( ); dpage = GTK_DRAWING_AREA( page ); gtk_widget_set_size_request( page, PAGE_WIDTH, PAGE_HEIGHT ); gc = gdk_gc_new( GTK_DRAWABLE( dpage ) ); gtk_widget_show( window ); gtk_main(); return (EXIT_SUCCESS); } my dpage is apparently not a 'drawable' (though it is a drawing area). I am confused as to a) how do I get/create the graphics context which is required in subsequent function calls? b) am I close to a solution, or am I so completely *#&@& wrong that there is no hope c) a baby steps tutorial. (I started with hello world as my base, so I got that far). any and all help appreciated. bp

  Read the article

• Undefined return value

  - by yynneejj

  what's wrong to my code..where my return value found undefind... var so; var imgid_callback1; const DIV_ID = 'locationsample'; function setup(){ try { so = device.getServiceObject("Service.Location", "ILocation"); } catch (e) { alert('<setup> ' +e); } } function getLocation(imgId) { var updateoptions = new Object(); // Setting PartialUpdates to 'FALSE' ensures that user get atleast // BasicLocationInformation (Longitude, Lattitude, and Altitude.) updateoptions.PartialUpdates = false; var criteria = new Object(); criteria.LocationInformationClass = "BasicLocationInformation"; criteria.Updateoptions = updateoptions; try { var result = so.ILocation.GetLocation(criteria); if(!checkError("ILocation::getLocation",result,DIV_ID,imgId)) { document.getElementById(DIV_ID).innerHTML = showObject(result.ReturnValue); } } catch (e) { alert ("getLocation: " + e); } } function getLocationAsync(imgId) { var updateoptions = new Object(); updateoptions.PartialUpdates = false; var criteria = new Object(); criteria.LocationInformationClass = "BasicLocationInformation"; criteria.Updateoptions = updateoptions; imgid_callback1 = imgId; try { var result = so.ILocation.GetLocation(criteria, callback1); if(!checkError("ILocation::getLocationAsync",result,DIV_ID,imgId)) { showIMG(imgId,""); } } catch (e) { alert ("getLocationAsync: " + e); } } function callback1(transId, eventCode, result){ var latitude = result.ReturnValue.Latitude; //<-----Error: Undefined Value var longitude = result.ReturnValue.Longitude; var req = null; try { req = new XMLHttpRequest(); if (typeof req.overrideMimeType != "undefined") { req.overrideMimeType("text/xml"); } req.onreadystatechange = function() { if (req.readyState == 4) { if (req.status == 200) { } } else { alert("Error"); } } req.open("POST","http://localhost:8080/GPS/location",true); req.setRequestHeader("longitude",+longitude); req.setRequestHeader("latitude",+latitude); req.send(); } catch (ex) { alert(ex); } }

  Read the article

• Segmenting and masking all shades of red from an image using opencv

  - by vrinda

  I am trying to segment all shades of red form an image using hue saturation values and use InRangeS function to create a mask which should have all red areas whitened and all others blacked(a new 1 channel image). Thwn Inpaint them to kind of obscure the segmented portions. My code is as given. However I am unable to get an output image, it doesnt segment the desired color range. Any pointers on my approach and why it isnt working. ? using namespace std; int main() { IplImage *img1=cvLoadImage("/home/techrascal/projects/test1/image2.jpeg"); //IplImage *img3; IplImage *imghsv; IplImage *img4; CvSize sz=cvGetSize(img1); imghsv=cvCreateImage(sz,IPL_DEPTH_8U,3); img4=cvCreateImage(sz,IPL_DEPTH_8U,1); int width = img1->width; int height = img1->height; int bpp = img1->nChannels; cvNamedWindow("original", 1); cvNamedWindow("hsv",1); cvNamedWindow("Blurred",1); int r,g,b; // create inpaint mask: img 4 will behave as mask cvCvtColor(img1,imghsv,CV_BGR2HSV); CvScalar hsv_min = cvScalar(0, 0, 0, 0); CvScalar hsv_max = cvScalar(255, 0, 0, 0); //cvShowImage("hsv",imghsv); cvInRangeS( imghsv, hsv_min, hsv_max, img4 ); cvInpaint(img1, img4, img1, 3,CV_INPAINT_NS ); cvShowImage("Blurred",img1); cvReleaseImage(&img1); cvReleaseImage(&imghsv); cvReleaseImage(&img4); //cvReleaseImage(&img3); char d=cvWaitKey(10000); cvDestroyAllWindows(); return 0;}

  Read the article

• Boost Property_Tree iterators, how to handle them?

  - by Andry

  Hello... I am sorry but I asked a question about the same argument before, but my problem concerns another aspect of the one described in that question (How to iterate a boost...). My problem is this, take a look at the following code: #include <iostream> #include <string> #include <boost/property_tree/ptree.hpp> #include <boost/property_tree/xml_parser.hpp> #include <boost/algorithm/string/trim.hpp> int main(int argc, char** argv) { using boost::property_tree::ptree; ptree pt; read_xml("try.xml", pt); ptree::const_iterator end = pt.end(); for (ptree::const_iterator it = pt.begin(); it != end; it++) std::cout << "Here " << it->? << std::endl; } Well, as told me in the previous question, there is the possibility to use iterators on property_tree in Boost, but I do not know what type it is... and what methods or properties I can use... Well, I assume that it must be another ptree or something representing another xml hierarchy to be browsed again (if I want) but documentation about this is very bad... I do not know why, but in boost docs I cannot find nothing good about this... just something about a macro to browse nodes, but this approach is one I would really like to avoid... Well, the question is so... Once getting the iterator on a ptree, how can I access node name, value, parameters (a node in a xml file)? Thankyou

  Read the article

• Static Vs Non-Static Method Performance C#

  - by dotnetguts

  Hello All, I have few global methods declared in public class in my asp.net web application. I have habbit of declaring all global methods in public class in following format public static string MethodName(parameters) { } I want to know how it would impact on performance point of view? 1) Which one is Better? Static Method or Non-Static Method? 2) Reason why it is better? Following link shows Non-Static methods are good because, static methods are using locks to be Thread-safe. The always do internally a Monitor.Enter() and Monitor.exit() to ensure Thread-safety. http://bytes.com/topic/c-sharp/answers/231701-static-vs-non-static-function-performance And Following link shows Static Methods are good static methods are normally faster to invoke on the call stack than instance methods. There are several reasons for this in the C# programming language. Instance methods actually use the 'this' instance pointer as the first parameter, so an instance method will always have that overhead. Instance methods are also implemented with the callvirt instruction in the intermediate language, which imposes a slight overhead. Please note that changing your methods to static methods is unlikely to help much on ambitious performance goals, but it can help a tiny bit and possibly lead to further reductions. http://dotnetperls.com/static-method I am little confuse which one to use? Thanks

  Read the article

• I can't get RedirectToAction to work

  - by DaveDev

  I have the following Action Method that I'm trying to redirect from if the user is valid. But nothing happens. The breakpoint in the redirected-to action method never gets hit. [AcceptVerbs(HttpVerbs.Post)] public ActionResult Login(User user) { try { if (ModelState.IsValid) { if (userRepository.ValidUser(user)) { return RedirectToAction("Index", "Group"); } else { return Json("Invalid"); } } } catch (Exception) { return Json("Invalid"); } } And in another Controller, I have the following Action Method that I'm trying to redirect to: // HttpVerbs.Post doesn't work either [AcceptVerbs(HttpVerbs.Get)] public ActionResult Index(int? page) { const int pageSize = 10; IEnumerable<Group> groups = GetGroups(); var paginatedGroups = new PaginatedList<Group>(groups, page ?? 0, pageSize); return View(paginatedGroups); } private IEnumerable<Group> GetGroups() { return groupRepository.GetGroups(); } Is there anything obviously wrong with what I'm doing? Could somebody suggest a different approach I could take?

  Read the article

• SWIG interface to receive an opaque struct reference in Java through function argument

  - by Beeo

  I am trying to use SWIG in order to use the Spotify API (libspotify) for Android: https://developer.spotify.com/technologies/libspotify/ I am having trouble defining the SWIG interface file to be able to successfully call the following native C function: sp_error sp_session_create(const sp_session_config * config, sp_session ** sess); Which in C would be called like this: //config struct defined previously sp_session *sess; sp_session_create(&config, &sess); But in Java I would need to call it like this: //config object defined previously sp_session javaSess = new sp_session(); sp_session_create(config, javaSess); sp_session is an opaque struct and is only defined in libspotify's API.h file as: typedef struct sp_session sp_session; I'm expecting the libspotify library to create it and give me a reference to it. The only thing I need that reference for then is to pass to other functions in the API. I believe the answer lies within the SWIG interface and typemaps, but I have been unsuccessful in trying to apply the examples I found in the documentation: http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_struct_pointer_pointer `http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_using_typemaps_return_arguments Help!

  Read the article

• Do ORMs normally allow circular relations? If so, how would they handle it?

  - by SeanJA

  I was hacking around trying to make a basic orm that has support for the one => one and one => many relationships. I think I succeeded somewhat, but I am curious about how to handle circular relationships. Say you had something like this: user::hasOne('car'); car::hasMany('wheels'); car::property('type'); wheel::hasOne('car'); You could then do this (theoretically): $u = new user(); echo $u->car->wheels[0]->car->wheels[1]->car->wheels[2]->car->wheels[3]->type; #=> "monster truck" Now, I am not sure why you would want to do this. It seems like it wastes a whole pile of memory and time just to get to something that could have been done in a much shorter way. In my small ORM, I now have 4 copies of the wheel class, and 4 copies of the car class in memory, which causes a problem if I update one of them and save it back to the database, the rest get out of date, and could overwrite the changes that were already made. How do other ORMs handle circular references? Do they even allow it? Do they go back up the tree and create a pointer to one of the parents? DO they let the coder shoot themselves in the foot if they are silly enough to go around in circles?

  Read the article

• struct and rand()

  - by teoz

  I have a struct with an array of 100 int (b) and a variable of type int (a) I have a function that checks if the value of "a" is in the array and i have generated the array elements and the variable with random values. but it doesn't work can someone help me fix it? #include <stdio.h> #include <stdlib.h> #include <time.h> typedef struct { int a; int b[100]; } h; int func(h v){ int i; for (i=0;i<100;i++){ if(v.b[i]==v.a) return 1; else return 0; } } int main(int argc, char** argv) { h str; srand(time(0)); int i; for(i=0;0<100;i++){ str.b[i]=(rand() % 10) + 1; } str.a=(rand() % 10) + 1; str.a=1; printf("%d\n",func(str)); return 0; }

  Read the article

• How do I build a filtered_streambuf based on basic_streambuf?

  - by swestrup

  I have a project that requires me to insert a filter into a stream so that outgoing data will be modified according to the filter. After some research, it seems that what I want to do is create a filtered_streambuf like this: template <class StreamBuf class filtered_streambuf: public StreamBuf { ... } And then insert a filtered_streambuf<> into whichever stream I need to be filtered. My problem is that I don't know what invariants I need to maintain while filtering a stream, in order to ensure that Derived classes can work as expected. In particular, I may find I have filtered_streambufs built over other filtered_streambufs. All the various stream inserters, extractors and manipulators work as expected. The trouble is that I just can't seem to work out what the minimal interface is that I need to supply in order to guarantee that an iostream will have what it needs to work correctly. In particular, do I need to fake the movement of the protected pointer variables, or not? Do I need a fake data buffer, or not? Can I just override the public functions, rewriting them in terms of the base streambuf, or is that too simplistic?

  Read the article

• How to use dirent.h correctly.

  - by Nick

  Hello, I am new to C++ and I am experimenting with the dirent.h header to manipulate directory entries. The following little app compiles but pukes after you supple a directory name. Can someone give me a hint? The int quit is there to provide a while loop. I removed the loop in an attempt to isolate my problem. thanks! #include <iostream> #include <dirent.h> using namespace std; int main() { char *dirname = 0; DIR *pd = 0; struct dirent *pdirent = 0; int quit = 1; cout<< "Enter a directory path to open (leave blank to quit):\n"; cin >> dirname; if(dirname == NULL) { quit = 0; } pd = opendir(dirname); if(pd == NULL) { cout << "ERROR: Please provide a valid directory path.\n"; } return 0; }

  Read the article

• How can I get type information at runtime from a DMP file in a Windbg extension?

  - by pj4533

  This is related to my previous question, regarding pulling objects from a dmp file. As I mentioned in the previous question, I can successfully pull object out of the dmp file by creating wrapper 'remote' objects. I have implemented several of these so far, and it seems to be working well. However I have run into a snag. In one case, a pointer is stored in a class, say of type 'SomeBaseClass', but that object is actually of the type 'SomeDerivedClass' which derives from 'SomeBaseClass'. For example it would be something like this: MyApplication!SomeObject +0x000 field1 : Ptr32 SomeBaseClass +0x004 field2 : Ptr32 SomeOtherClass +0x008 field3 : Ptr32 SomeOtherClass I need someway to find out what the ACTUAL type of 'field1' is. To be more specific, using example addresses: MyApplication!SomeObject +0x000 field1 : 0cae2e24 SomeBaseClass +0x004 field2 : 0x262c8d3c SomeOtherClass +0x008 field3 : 0x262c8d3c SomeOtherClass 0:000> dt SomeBaseClass 0cae2e24 MyApplication!SomeBaseClass +0x000 __VFN_table : 0x02de89e4 +0x038 basefield1 : (null) +0x03c basefield2 : 3 0:000> dt SomeDerivedClass 0cae2e24 MyApplication!SomeDerivedClass +0x000 __VFN_table : 0x02de89e4 +0x038 basefield1 : (null) +0x03c basefield2 : 3 +0x040 derivedfield1 : 357 +0x044 derivedfield2 : timecode_t When I am in WinDbg, I can do this: dt 0x02de89e4 And it will show the type: 0:000> dt 0x02de89e4 SomeDerivedClass::`vftable' Symbol not found. But how do get that inside an extension? Can I use SearchMemory() to look for 'SomeDerivedClass::`vftable'? If you follow my other question, I need this type information so I know what type of wrapper remote classes to create. I figure it might end up being some sort of case-statement, where I have to match a string to a type? I am ok with that, but I still don't know where I can get that string that represents the type of the object in question (ie SomeObject-field1 in the above example).

  Read the article

• JQuery drag, drop and save via cookie - how to?

  - by RussP

  Sorry to be back folks, but you guys & girls seem to know much more about this than I do ... anyhow, here is my question/problem I want to use drag, drop, sort (the interface plugin does me even though I have read it's out of date? but have looked at UI and to be honest is not clear and to me appears heavier than interface?) Anyhow, how do I set a cookie to save positions from this: $(document).ready( function () { $('a.closeEl').bind('click', toggleContent); $('div.groupWrapper').Sortable( { accept: 'groupItem', helperclass: 'sortHelper', activeclass : 'sortableactive', hoverclass : 'sortablehover', handle: 'div.itemHeader', tolerance: 'pointer', onChange : function(ser) { }, onStart : function() { $.iAutoscroller.start(this, document.getElementsByTagName('body')); }, onStop : function() { $.iAutoscroller.stop(); } } ); } ); var toggleContent = function(e) { var targetContent = $('div.itemContent', this.parentNode.parentNode); if (targetContent.css('display') == 'none') { targetContent.slideDown(300); $(this).html('[-]'); } else { targetContent.slideUp(300); $(this).html('[+]'); } return false; }; var ser = function (s) { serial = $.SortSerialize(s); alert(serial.hash); }; which is the "standard" interface demo, PLUS How do I then get to read that cookie so that when I next visit the page the order is as I set it in the cookie? Hopefully from that I can work out the rest .......? Thanks for help in advance.

  Read the article

• How is external memory, internal memory, and cache organized?

  - by goldenmean

  Consider a system as follows:= A hardware board having say ARM Cortex-A8 and Neon Vector coprocessor, and Embedded Linux OS running on Cortex-A8. On this environment, if there is some application - say, a video decoder is executing - then: How is it decided that which buffers would be in external memory, which ones would be allocated in internal SRAM, etc. When one says calloc/malloc on such system/code, the pointer returned is from which memory: internal or external? Can a user make buffers to be allocated to the memories of his choice (internal/external)? In ARM architectures, there is another memory called as Tightly coupled memory (TCM). What is that and how can user enable and use it? Can I declare buffers in this memory? Do I need to see the memory map (if any) of the hardware board to understand about all these different physical memories present in a typical hardware board? How much of a role does the OS play in distinguishing these different memories? Sorry for multiple questions, but i think they all are interlinked.

  Read the article

• ncurses - resizing glitch

  - by ryyst

  I'm writing an ncurses program and am trying to make it respond correctly to terminal resizing. While I can read the terminal dimensions correctly in my program, ncurses doesn't seem to deal with new dimensions correctly. Here's a (somewhat lengthy) sample program: #include <ncurses.h> #include <string.h> #include <signal.h> #include <sys/ioctl.h> void handle_winch(int sig){ struct winsize w; ioctl(0, TIOCGWINSZ, &w); COLS = w.ws_col; LINES = w.ws_row; wresize(stdscr, LINES, COLS); clear(); mvprintw(0, 0, "COLS = %d, LINES = %d", COLS, LINES); for (int i = 0; i < COLS; i++) mvaddch(1, i, '*'); refresh(); } int main(int argc, char *argv[]){ initscr(); struct sigaction sa; memset(&sa, 0, sizeof(struct sigaction)); sa.sa_handler = handle_winch; sigaction(SIGWINCH, &sa, NULL); while(getch() != 27) {} endwin(); return 0; } If you run it, you can see that the terminal dimensions are correctly retrieved. But the second line, which is supposed to draw *-characters across the screen, doesn't work. Try resizing the window horizontally to make it larger, the line of *s will not get larger. What's the problem here? I'm aware that one can temporarily leave curses mode, but I'd prefer a cleaner solution. Thanks!

  Read the article

• Mysql partitioning: Partitions outside of date range is included

  - by Sturlum

  Hi, I have just tried to configure partitions based on date, but it seems that mysql still includes a partition with no relevant data. It will use the relevant partition but also include the oldest for some reason. Am I doing it wrong? The version is 5.1.44 (MyISAM) I first added a few partitions based on "day", which is of type "date" ALTER TABLE ptest PARTITION BY RANGE(TO_DAYS(day)) ( PARTITION p1 VALUES LESS THAN (TO_DAYS('2009-08-01')), PARTITION p2 VALUES LESS THAN (TO_DAYS('2009-11-01')), PARTITION p3 VALUES LESS THAN (TO_DAYS('2010-02-01')), PARTITION p4 VALUES LESS THAN (TO_DAYS('2010-05-01')) ); After a query, I find that it uses the "old" partition, that should not contain any relevant data. mysql> explain partitions select * from ptest where day between '2010-03-11' and '2010-03-12'; +----+-------------+------------+------------+-------+---------------+------+---------+------+------+-------------+ | id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+------------+-------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | ptest | p1,p4 | range | day | day | 3 | NULL | 79 | Using where | +----+-------------+------------+------------+-------+---------------+------+---------+------+------+-------------+ When I select a single day, it works: mysql> explain partitions select * from ptest where day = '2010-03-11'; +----+-------------+------------+------------+------+---------------+------+---------+-------+------+-------+ | id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+------------+------+---------------+------+---------+-------+------+-------+ | 1 | SIMPLE | ptest | p4 | ref | day | day | 3 | const | 39 | | +----+-------------+------------+------------+------+---------------+------+---------+-------+------+-------+

  Read the article

• Write to memory buffer instead of file with libjpeg?

  - by Richard Knop

  I have found this function which uses libjpeg to write to a file: int write_jpeg_file( char *filename ) { struct jpeg_compress_struct cinfo; struct jpeg_error_mgr jerr; /* this is a pointer to one row of image data */ JSAMPROW row_pointer[1]; FILE *outfile = fopen( filename, "wb" ); if ( !outfile ) { printf("Error opening output jpeg file %s\n!", filename ); return -1; } cinfo.err = jpeg_std_error( &jerr ); jpeg_create_compress(&cinfo); jpeg_stdio_dest(&cinfo, outfile); /* Setting the parameters of the output file here */ cinfo.image_width = width; cinfo.image_height = height; cinfo.input_components = bytes_per_pixel; cinfo.in_color_space = color_space; /* default compression parameters, we shouldn't be worried about these */ jpeg_set_defaults( &cinfo ); /* Now do the compression .. */ jpeg_start_compress( &cinfo, TRUE ); /* like reading a file, this time write one row at a time */ while( cinfo.next_scanline < cinfo.image_height ) { row_pointer[0] = &raw_image[ cinfo.next_scanline * cinfo.image_width * cinfo.input_components]; jpeg_write_scanlines( &cinfo, row_pointer, 1 ); } /* similar to read file, clean up after we're done compressing */ jpeg_finish_compress( &cinfo ); jpeg_destroy_compress( &cinfo ); fclose( outfile ); /* success code is 1! */ return 1; } I would actually need to write the jpeg compressed image just to memory buffer, without saving it to a file, to save time. Could somebody give me an example how to do it? I have been searching the web for a while but the documentation is very rare if any and examples are also difficult to come by.

  Read the article

• C : files manipulation Can't figure out how to simplify this code with files manipulation.

  - by Bon_chan

  Hey guys, I have been working on this code but I can't find out what is wrong. This program does compile and run but it ends up having a fatal error. I have a file called myFile.txt, with the following content : James------ 07.50 Anthony--- 17.00 And here is the code : int main() { int n =2, valueTest=0,count=0; FILE* file = NULL; float temp= 00.00f, average= 00.00f, flTen = 10.00f; float *totalNote = (float*)malloc(n*sizeof(float)); int position = 0; char selectionNote[5+1], nameBuffer[10+1], noteBuffer[5+1]; file = fopen("c:\\myFile.txt","r"); fseek(file,10,SEEK_SET); while(valueTest<2) { fscanf(file,"%5s",&selectionNote); temp = atof(selectionNote); totalNote[position]= temp; position++; valeurTest++; } for(int counter=0;counter<2;counter++) { average += totalNote[counter]; } printf("The total is : %f \n",average); rewind(file); printf("here is the one with less than 10.00 :\n"); while(count<2) { fscanf(file,"%10s",&nameBuffer); fseek(file,10,SEEK_SET); fscanf(file,"%5s",&noteBuffer); temp = atof(noteBuffer); if(temp<flTen) { printf("%s who has %f\n",nameBuffer,temp); } fseek(file,1,SEEK_SET); count++; } fclose(file); } I am pretty new to c and find it more difficult than c# or java. And I woud like to get some suggestions to help me to get better. I think this code could be simplier. Do you think the same ?

  Read the article

• Jquery drag /drop and clone

  - by Sajeev

  Hi I need to achive this .. I have a set of droppable items ( basically I am droping designs on a apparel ) and I am dropping a clone.. If I don't like the dropped object (designs) - I want to delete that by doing something like hidden . But I am unable to do that. Please help me.. here is the code var clone; $(document).ready(function(){ $(".items").draggable({helper: 'clone',cursor: 'hand'}); $(".droparea").droppable({ accept: ".items", hoverClass: 'dropareahover', tolerance: 'pointer', drop: function(ev, ui) { var dropElemId = ui.draggable.attr("id"); var dropElem = ui.draggable.html(); clone = $(dropElem).clone(); // clone it and hold onto the jquery object clone.id="newId"; clone.css("position", "absolute"); clone.css("top", ui.absolutePosition.top); clone.css("left", ui.absolutePosition.left); clone.draggable({ containment: 'parent' ,cursor: 'crosshair'}); $(this).append(clone); alert("done dragging "); /lets assume I have a delete button when I click that clone should dissapear so that I can drop another design - but the following code has no effect //and the item is still visible , how to make it dissapear ? $('#newId').css("visibility","hidden"); } }); });

  Read the article

• Blackberry (Java) - Can't get KeyListener to work

  - by paullb

  I am trying to get the KeyListener working for Blackberry, but none of the Dialogs pop up indicating that a key has been pressed (see code below, each action has a dialog popup in them). Any ideas on what i might be doing wrong? public class CityInfo extends UiApplication implements KeyListener { static CityInfo application; public static void main(String[] args) { //create a new instance of the application //and start the application on the event thread application.enterEventDispatcher(); } public CityInfo() { //display a new screen application = new CityInfo(); pushScreen(new WorkflowDisplayScreen()); this.addKeyListener(this); } public boolean keyChar(char arg0, int arg1, int arg2) { // TODO Auto-generated method stub Dialog.alert("key pressed : " + arg0); return true; } public boolean keyDown(int keycode, int time) { // TODO Auto-generated method stub Dialog.alert("keyDown : " + keycode); return false; } public boolean keyRepeat(int keycode, int time) { // TODO Auto-generated method stub Dialog.alert("keyRepeat : " + keycode); return false; } public boolean keyStatus(int keycode, int time) { // TODO Auto-generated method stub Dialog.alert("keyStatus : " + keycode); return false; } public boolean keyUp(int keycode, int time) { Dialog.alert("keyUp : " + keycode); // TODO Auto-generated method stub return false; } } I also tried implementing keyChar on the MainScreen class but that did not yield any results either.

  Read the article

• User to kernel mode big picture?

  - by fsdfa

  I've to implement a char device, a LKM. I know some basics about OS, but I feel I don't have the big picture. In a C programm, when I call a syscall what I think it happens is that the CPU is changed to ring0, then goes to the syscall vector and jumps to a kernel memmory space function that handle it. (I think that it does int 0x80 and in eax is the offset of the syscall vector, not sure). Then, I'm in the syscall itself, but I guess that for the kernel is the same process that was before, only that it is in kernel mode, I mean the current PCB is the process that called the syscall. So far... so good?, correct me if something is wrong. Others questions... how can I write/read in process memory?. If in the syscall handler I refer to address, say, 0xbfffffff. What it means that address? physical one? Some virtual kernel one?

  Read the article

< Previous Page | 352 353 354 355 356 357 358 359 360 361 362 363  | Next Page >