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  • using return values from a c# .net made component build as com+

    - by YvesR
    Hello, so far I made a component in C# .NET 4 and use System.EnterpriseServices to make it COM visible. I want to develop business methods in C#, but I still need to access them from classic ASP (vbscript). So far so good, everything works fine (exept function overloading :)). Now I made a test class to get more expirience with return code. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.EnterpriseServices; using System.Management; namespace iController { /// /// The tools class provides additional functions for general use in out of context to other classes of the iController. /// public class tools :ServicedComponent { #region publich methods public bool TestBoolean() { return true; } public string TestString() { return "this is a string"; } public int TestInteger() { return 32; } public double TestDouble() { return 32.32; } public float TestFloat() { float ret = 2 ^ 16; return ret; } public string[] TestArray() { string[] ret = {"0","1"}; return ret; } public int[][] TestJaggedArray() { int[][] jaggedArray = new int[3][]; jaggedArray[0] = new int[] { 1, 3, 5, 7, 9 }; jaggedArray[1] = new int[] { 0, 2, 4, 6 }; jaggedArray[2] = new int[] { 11, 22 }; return jaggedArray; } public Dictionary<string, string> TestDictionary() { Dictionary<string, string> ret = new Dictionary<string,string>(); ret.Add("test1","val1"); ret.Add("test2","val2"); return ret; } #endregion } } Then I just made a simple vbscript file to run it with cscript.exe for testing porpuse. Dim oTools : Set oTools = CreateObject("iController.tools") WScript.StdOut.WriteLine TypeName(oTools.TestBoolean()) & " - " & oTools.TestBoolean() WScript.StdOut.WriteLine TypeName(oTools.TestString()) & " - " & oTools.TestString() WScript.StdOut.WriteLine TypeName(oTools.TestInteger()) & " - " & oTools.TestInteger() WScript.StdOut.WriteLine TypeName(oTools.TestDouble()) & " - " & oTools.TestDouble() WScript.StdOut.WriteLine TypeName(oTools.TestFloat()) & " - " & oTools.TestFloat() test = oTools.TestArray() WScript.StdOut.WriteLine TypeName(test) WScript.StdOut.WriteLine UBound(test) For i = 0 To UBound(test) WScript.StdOut.WriteLine test(i) Next For Each item IN test WScript.StdOut.WriteLine item Next test = oTools.TestJaggedArray() WScript.StdOut.WriteLine TypeName(test) For Each item IN test WScript.StdOut.WriteLine test & " - " & test.Item(item) Next test = oTools.TestDictionary() WScript.StdOut.WriteLine TypeName(test) For Each item IN test WScript.StdOut.WriteLine test & " - " & test.Item(item) Next What works fine: string, int, foat, double When it comes to array, jaggedarray or dictionaries I get a type mismatch. VarType is 13 object for the dictionary e.g. but this dict seems to be different then the Scripting.Dictionary. I checked codeproject.com and stackoverflow all day and didn't find any hints exept some thread on stackoverflow where someone mentioned there is a need to created a IDispatch interface. So anyone ever had the same issue and can help me or give me some hints I can go on with?

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  • .NET Declarative Security: Why is SecurityAction.Deny impossible to work with?

    - by rally25rs
    I've been messing with this for about a day and a half now sifting through .NET reflector and MSDN docs, and can't figure anything out... As it stands in the .NET framework, you can demand that the current Principal belong to a role to be able to execute a method by marking a method like this: [PrincipalPermission(SecurityAction.Demand, Role = "CanEdit")] public void Save() { ... } I am working with an existing security model that already has a "ReadOnly" role defined, so I need to do exactly the opposite of above... block the Save() method if a user is in the "ReadOnly" role. No problem, right? just flip the SecurityAction to .Deny: [PrincipalPermission(SecurityAction.Deny, Role = "ReadOnly")] public void Save() { ... } Well, it turns out that this does nothing at all. The method still runs fine. It seems that the PrincipalPermissionAttribute defines: public override IPermission CreatePermission() But when the attribute is set to SecurityAction.Deny, this method is never called, so no IPermission object is ever created. Does anyone know of a way to get .Deny to work? I've been trying to make a custom secutiry attribute, but even that doesn't work. I tried to get tricky and do: public class MyPermissionAttribute : CodeAccessSecurityAttribute { private SecurityAction securityAction; public MyPermissionAttribute(SecurityAction action) : base(SecurityAction.Demand) { if (action != SecurityAction.Demand && action != SecurityAction.Deny) throw new ArgumentException("Unsupported SecurityAction. Only Demand and Deny are supported."); this.securityAction = action; } public override IPermission CreatePermission() { // do something based on the SecurityAction... } } Notice my attribute constructor always passes SecurityAction.Demand, which is the one action that would work previously. However, even in this case, the CreatePermission() method is still only called when the attribute is set to .Demand, and not .Deny! Maybe the runtime is actually checking the attribute instead of the SecurityAction passed to the CodeAccessSecurityAttribute constructor? I'm not sure what else to try here... anyone have any ideas? You wouldn't think it would be that hard to deny method access based on a role, instead of only demanding it. It really disturbed me that the default PrincipalPermission appears from within an IDE like it would be just fine doing a .Deny, and there is like a 1-liner in the MSDN docs that hint that it won't work. You would think the PrincipalPermissionAttribute constructor would throw an exception immediately if anything other that .Demand is specified, since that could create a big security hole! I never would have realized that .Deny does nothing at all if I hadn't been unit testing! Again, all this stems from having to deal with an existing security model that has a "ReadOnly" role that needs to be denied access, instead of doing it the other way around, where I cna just grant access to a role. Thanks for any help! Quick followup: I can actually make my custom attribute work by doing this: public class MyPermissionAttribute : CodeAccessSecurityAttribute { public SecurityAction SecurityAction { get; set; } public MyPermissionAttribute(SecurityAction action) : base(action) { } public override IPermission CreatePermission() { switch(this.SecurityAction) { ... } // check Demand or Deny } } And decorating the method: [MyPermission(SecurityAction.Demand, SecurityAction = SecurityAction.Deny, Role = "ReadOnly")] public void Save() { ... } But that is terribly ugly, since I'm specifying both Demand and Deny in the same attribute. But it does work... Another interesting note: My custom class extends CodeAccessSecurityAttribute, which in turn only extends SecurityAttribute. If I cnage my custom class to directly extend SecurityAttribute, then nothing at all works. So it seems the runtime is definately looking for only CodeAccessSecurityAttribute instances in the metadata, and does something funny with the SecurityAction specified, even if a custom constructor overrides it.

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  • Changing html <-> ajax <-> php/mysql to threaded approach

    - by Saif Bechan
    I have an application that needs to be updated real-time. There are various counters and other information that have to come from the database and the system needs to be up to date for the user. My approach now is just a normal ajax request every second to get the new values from the database. There is a JavaScript which loops every second getting the values trough ajax. This works fine but I think its very inefficient. The problem There is an ajax script that loops every second requesting data from php # On the server it has to load the PHP interpeter The PHP file has to get the data and format it correctly # PHP has to make a connection with the mysql database Work with the database(reads,never writes) Format the data so it can be send Send the data back to the browser # Close the database connection, and close the php interpeter Last the browser has to read these values and update the various html parts Now with this approach it has to load the interpreter and make a db connection every second. I was thinking of a way to make this more efficient, and maybe use a threaded approach to this. Threaded aprouch Do a post to the PHP when you enter the page and keep the connection alive In PHP only load the interpreter once, and make a connection to the DB ones Every second send an ajax response to the javascript listener The javascript listener than just changes values as the response from php arrives. I think this approach will be a great optimization to the server load and overall performance. But I can spot some weak point in the system and i need some help with these. Problems with the approach PHP execution time limit I don't think PHP is designed for such a setup. I know there is a time limit on php script execution. I don't know if an everlasting loop in PHP will cause any serious cpu/memory problems. Sending ajax request without breaking I don't know if it is possible to have just one ajax post action and have open and accepting data. user exists the page What will happen when the user exists the page and the PHP script is still going. Will it go on forever. security issues so far i can't think of any security issues. Almost every setup you use have some security issues. Maybe there are some with this solution I do not know of. Open to other solution I really want to change the setup as it is now and move to a threaded approach or better. If someone has a better approach to tackle this I definitely want to hear that. Maybe the usage of some other scripts is better suited for having an ongoing runtime. I only know php and java so any suggestions are welcome and I am willing to dig trough. I know there are things like perl, python etcetera that are used for this type of threaded but i don't know which one is best suited. When using other script If the best way is to go with other type of script like perl,python etcetera I do have some critera. The script has to be accessible via ajax post If it accepts some kind of json encode/decode it would be nice The script has to be able to access the session file This is essential because I need to know if the user is logged in The script has to be able to easily talk to MySQL All comments are welcome, and I hope this question is helpful to other also. Cheers!

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  • PROJECT HELP NEEDED. SOME BASIC CONCEPTS GREAT CONFUSION BECAUSE OF LACK OF PROPER MATERIAL PLEASE H

    - by user287745
    Task ATTENDENCE RECORDER AND MANAGEMENT SYSTEM IN DISTRIBUTED ENVIRONMENT ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Example implementation needed. a main server in each lab where the operator punches in the attendence of the student. =========================================================== scenerio:- a college, 10 departments, all departments have a computer lab with 60-100 computers, the computers within each lab are interconnected and all computers in any department have to dail to a particular number (THE NUMBER GIVEN BY THE COLLEGE INTERNET DEPARTMENT) to get connected to the internet. therefore safe to assume that there is a central location to which all the computers in the college are connected to. there is a 'students attendence portal' which can be accessed using internet explorer, students enter there id and get the particular attendence record regarding to the labs only. a description of the working is like:- 1) the user will select which department, which year has arrived to the lab 2) the selection will give the user a return of all the students name and there roll numbers belonging to that department; 'with a check box to "TICK MARK IF THE STUDENT IS PRESENT" ' 3) A SUBMIT BUTTON when pressed reads the 'id' of the checkbox to determine the "particular count number of the student" from that an id of the student is constructed and that id is inserted with a present. (there is also date and time and much more to normalize the db and to avoid conflicts and keep historic records etc but that you will have to assume) steps taken till this date:- ( please note we are not computer students, we are to select something of some other line as a project!, as you will read in my many post 'i" have designed small websites just out of liking. have never ever done any thing official to implement like this.) * have made the database fully normalized. * have made the website which does the functions required on the database. Testing :- deployed the db and site on a free aspspider server and it worked. tested from several computers. Now the problem please help thank youuuuuuuu a practical demonstration has to be done within the college network. no internet! we have been assigned a lab - 60 computers- to demonstrate. (please dont give replies as 60 computers only! is not a big deal one CPU can manage it. i know that; IT IS A HYPOTHETICAL SITUATION WHERE WE ASSUME THAT 60 IS NOT 60 BUT ITS LIKE 60,000 COMPUTERS) 1a) make a web server, yes iis and put files in www folder and configure server to run aspx files- although a link to a step by step guide will be appreciated)\ ? which version of windows should i ask for xp or win server 2000 something? 2a) make a database server. ( well yes install sql server 2005, okay but then what? just put the database file on a pc share it and append the connection string to the share? ) 3a) make the site accessible from the remaining computers ? http://localhost/sitename ? all users "being operators of the particular lab" have the right to edit, write or delete(in dispute), thereby any "users" who hate our program can make the database inconsistent by accessing te same record and doing different edits and then complaining? so how to prevent this? you know something like when the db table is being written to others can only read but not write.. one big confusion:- IN DISTRIBUTED ENVIRONMENT "how to implement this" where does "distributed environment" come in! meaning :- alright the labs are in different departments but the "database server will be one" the "web server will be one" so whats distributed!?

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  • jQuery / jqGrids / Submitting form data troubles...

    - by Kelso
    Ive been messing with jqgrids alot of the last couple days, and I have nearly everything the way I want it from the display, tabs with different grids, etc. Im wanting to make use of Modal for adding and editing elements on my grid. My problem that Im running into is this. I have my editurl:"editsu.php" set, if that file is renamed, on edit, i get a 404 in the modal.. great! However, with that file in place, nothing at all seems to happen. I even put a die("testing"); line at the top, so it sees the file, it just doesnt do anything with it. Below is the content. ........ the index page jQuery("#landings").jqGrid({ url:'server.php?tid=1', datatype: "json", colNames:['ID','Tower','Sector', 'Client', 'VLAN','IP','DLink','ULink','Service','Lines','Freq','Radio','Serial','Mac'], colModel:[ {name:'id', index:'id', width : 50, align: 'center', sortable:true,editable:true,editoptions:{size:10}}, {name:'tower', index:'tower', width : 85, align: 'center', sortable:true,editable:false,editoptions:{readonly:true,size:30}}, {name:'sector', index:'sector', width : 50, align: 'center',sortable:true,editable:true,editoptions:{readonly:true,size:20}}, {name:'customer',index:'customer', width : 175, align: 'left', editable:true,editoptions:{readonly:true,size:35}}, {name:'vlan', index:'vlan', width : 35, align: 'left',editable:true,editoptions:{size:10}}, {name:'suip', index:'suip', width : 65, align: 'left',editable:true,editoptions:{size:20}}, {name:'datadl',index:'datadl', width:55, editable: true,edittype:"select",editoptions:{value:"<? $qr = qquery("select * from datatypes"); while ($q = ffetch($qr)) {echo "$q[id]:$q[name];";}?>"}}, {name:'dataul', index:'dataul', width : 55, editable: true,edittype:"select",editoptions:{value:"<? $qr = qquery("select * from datatypes"); while ($q = ffetch($qr)) {echo "$q[id]:$q[name];";}?>"}}, {name:'servicetype', index:'servicetype', width : 85, editable: true,edittype:"select",editoptions:{value:"<? $qr = qquery("select * from servicetype"); while ($q = ffetch($qr)) {echo "$q[id]:$q[name];";}?>"}}, {name:'voicelines', index:'voicelines', width : 35, align: 'center',editable:true,editoptions:{size:30}}, {name:'freqname', index:'freqname', width : 35, editable: true,edittype:"select",editoptions:{value:"<? $qr = qquery("select * from freqband"); while ($q = ffetch($qr)) {echo "$q[id]:$q[name];";}?>"}}, {name:'radioname', index:'radioname', width : 120, editable: true,edittype:"select",editoptions:{value:"<? $qr = qquery("select * from radiotype"); while ($q = ffetch($qr)) {echo "$q[id]:$q[name];";}?>"}}, {name:'serial', index:'serial', width : 100, align: 'right',editable:true,editoptions:{size:20}}, {name:'mac', index:'mac', width : 120, align: 'right',editable:true,editoptions:{size:20}} ], rowNum:20, rowList:[30,50,70], pager: '#pagerl', sortname: 'sid', mtype: "GET", viewrecords: true, sortorder: "asc", altRows: true, caption:"Landings", editurl:"editsu.php", height:420 }); jQuery("#landings").jqGrid('navGrid','#pagerl',{edit:true,add:true,del:false,search:false},{height:400,reloadAfterSubmit:false},{height:400,reloadAfterSubmit:false},{reloadAfterSubmit:false},{}); now for the editsu.php file.. $operation = $_REQUEST['oper']; if ($operation == "edit") { qquery("UPDATE customers SET vlan = '".$_POST['vlan']."', datadl = '".$_POST['datadl']."', dataul = '".$_POST['dataul']."', servicetype = '".$_POST['servicetype']."', voicelines = '".$_POST['voicelines']."', freqname = '".$_POST['freqname']."', radioname = '".$_POST['radioname']."', serial = '".$_POST['serial']."', mac = '".$_POST['mac']."' WHERE id = '".$_POST['id']."'") or die(mysql_error()); } Im just having a hard time troubleshooting this to figure out where its getting hung up at. My next question after this would be to see if its possible to make it so when you click "add", that it auto inserts a row into the db with a couple variable predtermined and then bring up the modal window, but ill work on the first problem first. thanks!

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  • SDL side-scroller scrolls inconsistantly

    - by SDLFunTimes
    So I'm working on an upgrade from my previous project (that I posted here for code review) this time implementing a repeating background (like what is used on cartoons) so that SDL doesn't have to load really big images for a level. There's a strange inconsistency in the program, however: the first time the user scrolls all the way to the right 2 less panels are shown than is specified. Going backwards (left) the correct number of panels is shown (that is the panels repeat the number of times specified in the code). After that it appears that going right again (once all the way at the left) the correct number of panels is shown and same going backwards. Here's some selected code and here's a .zip of all my code constructor: Game::Game(SDL_Event* event, SDL_Surface* scr, int level_w, int w, int h, int bpp) { this->event = event; this->bpp = bpp; level_width = level_w; screen = scr; w_width = w; w_height = h; //load images and set rects background = format_surface("background.jpg"); person = format_surface("person.png"); background_rect_left = background->clip_rect; background_rect_right = background->clip_rect; current_background_piece = 1; //we are displaying the first clip rect_in_view = &background_rect_right; other_rect = &background_rect_left; person_rect = person->clip_rect; background_rect_left.x = 0; background_rect_left.y = 0; background_rect_right.x = background->w; background_rect_right.y = 0; person_rect.y = background_rect_left.h - person_rect.h; person_rect.x = 0; } and here's the move method which is probably causing all the trouble: void Game::move(SDLKey direction) { if(direction == SDLK_RIGHT) { if(move_screen(direction)) { if(!background_reached_right()) { //move background right background_rect_left.x += movement_increment; background_rect_right.x += movement_increment; if(rect_in_view->x >= 0) { //move the other rect in to fill the empty space SDL_Rect* temp; other_rect->x = -w_width + rect_in_view->x; temp = rect_in_view; rect_in_view = other_rect; other_rect = temp; current_background_piece++; std::cout << current_background_piece << std::endl; } if(background_overshoots_right()) { //sees if this next blit is past the surface //this is used only for re-aligning the rects when //the end of the screen is reached background_rect_left.x = 0; background_rect_right.x = w_width; } } } else { //move the person instead person_rect.x += movement_increment; if(get_person_right_side() > w_width) { //person went too far right person_rect.x = w_width - person_rect.w; } } } else if(direction == SDLK_LEFT) { if(move_screen(direction)) { if(!background_reached_left()) { //moves background left background_rect_left.x -= movement_increment; background_rect_right.x -= movement_increment; if(rect_in_view->x <= -w_width) { //swap the rect in view SDL_Rect* temp; rect_in_view->x = w_width; temp = rect_in_view; rect_in_view = other_rect; other_rect = temp; current_background_piece--; std::cout << current_background_piece << std::endl; } if(background_overshoots_left()) { background_rect_left.x = 0; background_rect_right.x = w_width; } } } else { //move the person instead person_rect.x -= movement_increment; if(person_rect.x < 0) { //person went too far left person_rect.x = 0; } } } } without the rest of the code this doesn't make too much sense. Since there is too much of it I'll upload it here for testing. Anyway does anyone know how I could fix this inconsistency?

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  • How should I clean up hung grandchild processes when an alarm trips in Perl?

    - by brian d foy
    I have a parallelized automation script which needs to call many other scripts, some of which hang because they (incorrectly) wait for standard input. That's not a big deal because I catch those with alarm. The trick is to shut down those hung grandchild processes when the child shuts down. I thought various incantations of SIGCHLD, waiting, and process groups could do the trick, but they all block and the grandchildren aren't reaped. My solution, which works, just doesn't seem like it is the right solution. I'm not especially interested in the Windows solution just yet, but I'll eventually need that too. Mine only works for Unix, which is fine for now. I wrote a small script that takes the number of simultaneous parallel children to run and the total number of forks: $ fork_bomb <parallel jobs> <number of forks> $ fork_bomb 8 500 This will probably hit the per-user process limit within a couple of minutes. Many solutions I've found just tell you to increase the per-user process limit, but I need this to run about 300,000 times, so that isn't going to work. Similarly, suggestions to re-exec and so on to clear the process table aren't what I need. I'd like to actually fix the problem instead of slapping duct tape over it. I crawl the process table looking for the child processes and shut down the hung processes individually in the SIGALRM handler, which needs to die because the rest of real code has no hope of success after that. The kludgey crawl through the process table doesn't bother me from a performance perspective, but I wouldn't mind not doing it: use Parallel::ForkManager; use Proc::ProcessTable; my $pm = Parallel::ForkManager->new( $ARGV[0] ); my $alarm_sub = sub { kill 9, map { $_->{pid} } grep { $_->{ppid} == $$ } @{ Proc::ProcessTable->new->table }; die "Alarm rang for $$!\n"; }; foreach ( 0 .. $ARGV[1] ) { print "."; print "\n" unless $count++ % 50; my $pid = $pm->start and next; local $SIG{ALRM} = $alarm_sub; eval { alarm( 2 ); system "$^X -le '<STDIN>'"; # this will hang alarm( 0 ); }; $pm->finish; } If you want to run out of processes, take out the kill. I thought that setting a process group would work so I could kill everything together, but that blocks: my $alarm_sub = sub { kill 9, -$$; # blocks here die "Alarm rang for $$!\n"; }; foreach ( 0 .. $ARGV[1] ) { print "."; print "\n" unless $count++ % 50; my $pid = $pm->start and next; setpgrp(0, 0); local $SIG{ALRM} = $alarm_sub; eval { alarm( 2 ); system "$^X -le '<STDIN>'"; # this will hang alarm( 0 ); }; $pm->finish; } The same thing with POSIX's setsid didn't work either, and I think that actually broke things in a different way since I'm not really daemonizing this. Curiously, Parallel::ForkManager's run_on_finish happens too late for the same clean-up code: the grandchildren are apparently already disassociated from the child processes at that point.

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  • Getting a Temporary Table Returned from from Dynamic SQL in SQL Server 05, and parsing

    - by gloomy.penguin
    So I was requested to make a few things.... (it is Monday morning and for some reason this whole thing is turning out to be really hard for me to explain so I am just going to try and post a lot of my code; sorry) First, I needed a table: CREATE TABLE TICKET_INFORMATION ( TICKET_INFO_ID INT IDENTITY(1,1) NOT NULL, TICKET_TYPE INT, TARGET_ID INT, TARGET_NAME VARCHAR(100), INFORMATION VARCHAR(MAX), TIME_STAMP DATETIME DEFAULT GETUTCDATE() ) -- insert this row for testing... INSERT INTO TICKET_INFORMATION (TICKET_TYPE, TARGET_ID, TARGET_NAME, INFORMATION) VALUES (1,1,'RT_ID','IF_ID,int=1&IF_ID,int=2&OTHER,varchar(10)=val,ue3&OTHER,varchar(10)=val,ue4') The Information column holds data that needs to be parsed into a table. This is where I am having problems. In the resulting table, Target_Name needs to become a column that holds Target_ID as a value for each row in the resulting table. The string that needs to be parsed is in this format: @var_name1,@var_datatype1=@var_value1&@var_name2,@var_datatype2=@var_value2&@var_name3,@var_datatype3=@var_value3 And what I ultimately need as a result (in a table or table variable): RT_ID IF_ID OTHER 1 1 val,ue3 1 2 val,ue3 1 1 val,ue4 1 2 val,ue4 And I need to be able to join on the result. Initially, I was just going to make this a function that returns a table variable but for some reason I can't figure out how to get it into an actual table variable. Whatever parses the string needs to be able to be used directly in queries so I don't think a stored procedure is really the right thing to be using. This is the code that parses the Information string... it returns in a temporary table. -- create/empty temp table for var_name, var_type and var_value fields if OBJECT_ID('tempdb..#temp') is not null drop table #temp create table #temp (row int identity(1,1), var_name varchar(max), var_type varchar(30), var_value varchar(max)) -- just setting stuff up declare @target_name varchar(max), @target_id varchar(max), @info varchar(max) set @target_name = (select target_name from ticket_information where ticket_info_id = 1) set @target_id = (select target_id from ticket_information where ticket_info_id = 1) set @info = (select information from ticket_information where ticket_info_id = 1) --print @info -- some of these variables are re-used later declare @col_type varchar(20), @query varchar(max), @select as varchar(max) set @query = 'select ' + @target_id + ' as ' + @target_name + ' into #target; ' set @select = 'select * into ##global_temp from #target' declare @var_name varchar(100), @var_type varchar(100), @var_value varchar(100) declare @comma_pos int, @equal_pos int, @amp_pos int set @comma_pos = 1 set @equal_pos = 1 set @amp_pos = 0 -- while loop to parse the string into a table while @amp_pos < len(@info) begin -- get new comma position set @comma_pos = charindex(',',@info,@amp_pos+1) -- get new equal position set @equal_pos = charindex('=',@info,@amp_pos+1) -- set stuff that is going into the table set @var_name = substring(@info,@amp_pos+1,@comma_pos-@amp_pos-1) set @var_type = substring(@info,@comma_pos+1,@equal_pos-@comma_pos-1) -- get new ampersand position set @amp_pos = charindex('&',@info,@amp_pos+1) if @amp_pos=0 or @amp_pos<@equal_pos set @amp_pos = len(@info)+1 -- set last variable for insert into table set @var_value = substring(@info,@equal_pos+1,@amp_pos-@equal_pos-1) -- put stuff into the temp table insert into #temp (var_name, var_type, var_value) values (@var_name, @var_type, @var_value) -- is this a new field? if ((select count(*) from #temp where var_name = (@var_name)) = 1) begin set @query = @query + ' create table #' + @var_name + '_temp (' + @var_name + ' ' + @var_type + '); ' set @select = @select + ', #' + @var_name + '_temp ' end set @query = @query + ' insert into #' + @var_name + '_temp values (''' + @var_value + '''); ' end if OBJECT_ID('tempdb..##global_temp') is not null drop table ##global_temp exec (@query + @select) --select @query --select @select select * from ##global_temp Okay. So, the result I want and need is now in ##global_temp. How do I put all of that into something that can be returned from a function (or something)? Or can I get something more useful returned from the exec statement? In the end, the results of the parsed string need to be in a table that can be joined on and used... Ideally this would have been a view but I guess it can't with all the processing that needs to be done on that information string. Ideas? Thanks!

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  • A methology that allows for a single Java code base covering many different versions?

    - by Thorbjørn Ravn Andersen
    I work in a small shop where we have a LOT of legacy Cobol code and where a methology has been adopted to allow us to minimize forking and branching as much as possible. For a given release we have three levels: CORE - bottom layer, this code is common to all releases GROUP - optional code common to several customers. CUSTOMER - optional code specific for a single customer. When a program is needed, it is first searched for in CUSTOMER, then in GROUP and finally in CORE. A given application for us invokes many programs which all are looked for in this sequence (think exe files and PATH under Windows). We also have Java programs interacting with this legacy code, and as the core-group-customer lookup mehchanism does not lend it self easily to Java it has tended to grow in a CVS branch for each customer, requiring much too much maintainance. The Java part and the backend part tend to be developed in parallel. I have been assigned to figure out a way to make the two worlds meet. Essentially we want a Java enviornment which allows us to have a single code base with sources for each release, where we easily can select a group and a customer and work with the application as it goes for that customer, and then easily switch to another codeset and THAT customer. I was thinking of perhaps a scenario with an Eclipse project for each core, customer, and group and then use Project Sets to select those we need for a given scenario. The problem I cannot get my head about, is how we would create robust code in the CORE projects which will work regardless of which group and customer is selected. A Factory class which knows which sub class of a passed Class object to invoke instead of each and every new? Others must have had similar code base management problems. Anybody with experiences to share? EDIT: The conclusion to this problem above has been that CVS needs to be replaced with a source code management system better suited for dealing with many branches concurrently and the migration of source from one component to the other while keeping history. Inspired by the recent migration by slf4j and logback we are currently looking at git as it handles branches very well. We've considered subversion and mercurial too but git appears to be better for single location, multibranched projects. I've asked about Perforce in another question, but my personal inclination is towards open source solutions for something as crucial as this. EDIT: After some more pondering, we've found that our actual pain point is that we use branches in CVS, and that branches in CVS are the easiest to work with if you branch ALL files! The revised conclusion is that we can do this with CVS alone, by switching to a forest of java projects, each corresponding to one of the levels above, and use the Eclipse build paths to tie them together so each CUSTOMER version pulls in the appropriate GROUP and CORE project. We still want to switch to a better versioning system but this is so important a decision so we want to delay it as much as possible. EDIT: I now have a proof-of-concept implementation of the CORE-GROUP-CUSTOMER concept using Google Guice 2.0 - the @ImplementedBy tag is just what we need. I wonder what everybody else does? Using if's all over the place? EDIT: Now I also need this functionality for web applications. Guice was until the JSR-330 is in place. Anybody with versioning experience? EDIT: JSR-330/299 is now in place with the JEE6 reference implementation Weld based on JBoss Seam and I have reimplemented the proof-of-concept with Weld and can see that if we use @Alternative along with ... in beans.xml we can get the behaviour we desire. I.e. provide a new implementation for a given functionality in CORE without changing a bit in the CORE jars. Initial reading up on the Servlet 3.0 specification indicates that it may support the same functionality for web application resources (not code). We will now do initial testing on the real application.

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  • Thread Synchronisation 101

    - by taspeotis
    Previously I've written some very simple multithreaded code, and I've always been aware that at any time there could be a context switch right in the middle of what I'm doing, so I've always guarded access the shared variables through a CCriticalSection class that enters the critical section on construction and leaves it on destruction. I know this is fairly aggressive and I enter and leave critical sections quite frequently and sometimes egregiously (e.g. at the start of a function when I could put the CCriticalSection inside a tighter code block) but my code doesn't crash and it runs fast enough. At work my multithreaded code needs to be a tighter, only locking/synchronising at the lowest level needed. At work I was trying to debug some multithreaded code, and I came across this: EnterCriticalSection(&m_Crit4); m_bSomeVariable = true; LeaveCriticalSection(&m_Crit4); Now, m_bSomeVariable is a Win32 BOOL (not volatile), which as far as I know is defined to be an int, and on x86 reading and writing these values is a single instruction, and since context switches occur on an instruction boundary then there's no need for synchronising this operation with a critical section. I did some more research online to see whether this operation did not need synchronisation, and I came up with two scenarios it did: The CPU implements out of order execution or the second thread is running on a different core and the updated value is not written into RAM for the other core to see; and The int is not 4-byte aligned. I believe number 1 can be solved using the "volatile" keyword. In VS2005 and later the C++ compiler surrounds access to this variable using memory barriers, ensuring that the variable is always completely written/read to the main system memory before using it. Number 2 I cannot verify, I don't know why the byte alignment would make a difference. I don't know the x86 instruction set, but does mov need to be given a 4-byte aligned address? If not do you need to use a combination of instructions? That would introduce the problem. So... QUESTION 1: Does using the "volatile" keyword (implicity using memory barriers and hinting to the compiler not to optimise this code) absolve a programmer from the need to synchronise a 4-byte/8-byte on x86/x64 variable between read/write operations? QUESTION 2: Is there the explicit requirement that the variable be 4-byte/8-byte aligned? I did some more digging into our code and the variables defined in the class: class CExample { private: CRITICAL_SECTION m_Crit1; // Protects variable a CRITICAL_SECTION m_Crit2; // Protects variable b CRITICAL_SECTION m_Crit3; // Protects variable c CRITICAL_SECTION m_Crit4; // Protects variable d // ... }; Now, to me this seems excessive. I thought critical sections synchronised threads between a process, so if you've got one you can enter it and no other thread in that process can execute. There is no need for a critical section for each variable you want to protect, if you're in a critical section then nothing else can interrupt you. I think the only thing that can change the variables from outside a critical section is if the process shares a memory page with another process (can you do that?) and the other process starts to change the values. Mutexes would also help here, named mutexes are shared across processes, or only processes of the same name? QUESTION 3: Is my analysis of critical sections correct, and should this code be rewritten to use mutexes? I have had a look at other synchronisation objects (semaphores and spinlocks), are they better suited here? QUESTION 4: Where are critical sections/mutexes/semaphores/spinlocks best suited? That is, which synchronisation problem should they be applied to. Is there a vast performance penalty for choosing one over the other? And while we're on it, I read that spinlocks should not be used in a single-core multithreaded environment, only a multi-core multithreaded environment. So, QUESTION 5: Is this wrong, or if not, why is it right? Thanks in advance for any responses :)

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  • How to reduce Entity Framework 4 query compile time?

    - by Rup
    Summary: We're having problems with EF4 query compilation times of 12+ seconds. Cached queries will only get us so far; are there any ways we can actually reduce the compilation time? Is there anything we might be doing wrong we can look for? Thanks! We have an EF4 model which is exposed over the WCF services. For each of our entity types we expose a method to fetch and return the whole entity for display / edit including a number of referenced child objects. For one particular entity we have to .Include() 31 tables / sub-tables to return all relevant data. Unfortunately this makes the EF query compilation prohibitively slow: it takes 12-15 seconds to compile and builds a 7,800-line, 300K query. This is the back-end of a web UI which will need to be snappier than that. Is there anything we can do to improve this? We can CompiledQuery.Compile this - that doesn't do any work until first use and so helps the second and subsequent executions but our customer is nervous that the first usage shouldn't be slow either. Similarly if the IIS app pool hosting the web service gets recycled we'll lose the cached plan, although we can increase lifetimes to minimise this. Also I can't see a way to precompile this ahead of time and / or to serialise out the EF compiled query cache (short of reflection tricks). The CompiledQuery object only contains a GUID reference into the cache so it's the cache we really care about. (Writing this out it occurs to me I can kick off something in the background from app_startup to execute all queries to get them compiled - is that safe?) However even if we do solve that problem, we build up our search queries dynamically with LINQ-to-Entities clauses based on which parameters we're searching on: I don't think the SQL generator does a good enough job that we can move all that logic into the SQL layer so I don't think we can pre-compile our search queries. This is less serious because the search data results use fewer tables and so it's only 3-4 seconds compile not 12-15 but the customer thinks that still won't really be acceptable to end-users. So we really need to reduce the query compilation time somehow. Any ideas? Profiling points to ELinqQueryState.GetExecutionPlan as the place to start and I have attempted to step into that but without the real .NET 4 source available I couldn't get very far, and the source generated by Reflector won't let me step into some functions or set breakpoints in them. The project was upgraded from .NET 3.5 so I have tried regenerating the EDMX from scratch in EF4 in case there was something wrong with it but that didn't help. I have tried the EFProf utility advertised here but it doesn't look like it would help with this. My large query crashes its data collector anyway. I have run the generated query through SQL performance tuning and it already has 100% index usage. I can't see anything wrong with the database that would cause the query generator problems. Is there something O(n^2) in the execution plan compiler - is breaking this down into blocks of separate data loads rather than all 32 tables at once likely to help? Setting EF to lazy-load didn't help. I've bought the pre-release O'Reilly Julie Lerman EF4 book but I can't find anything in there to help beyond 'compile your queries'. I don't understand why it's taking 12-15 seconds to generate a single select across 32 tables so I'm optimistic there's some scope for improvement! Thanks for any suggestions! We're running against SQL Server 2008 in case that matters and XP / 7 / server 2008 R2 using RTM VS2010.

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  • Win32 window capture with BitBlt not displaying border

    - by user292533
    I have written some c++ code to capture a window to a .bmp file. BITMAPFILEHEADER get_bitmap_file_header(int width, int height) { BITMAPFILEHEADER hdr; memset(&hdr, 0, sizeof(BITMAPFILEHEADER)); hdr.bfType = ((WORD) ('M' << 8) | 'B'); // is always "BM" hdr.bfSize = 0;//sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + (width * height * sizeof(int)); hdr.bfReserved1 = 0; hdr.bfReserved2 = 0; hdr.bfOffBits = (DWORD)(sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER)); return hdr; } BITMAPINFO get_bitmap_info(int width, int height) { BITMAPINFO bmi; memset(&bmi.bmiHeader, 0, sizeof(BITMAPINFOHEADER)); //initialize bitmap header bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); bmi.bmiHeader.biWidth = width; bmi.bmiHeader.biHeight = height; bmi.bmiHeader.biPlanes = 1; bmi.bmiHeader.biBitCount = 4 * 8; bmi.bmiHeader.biCompression = BI_RGB; bmi.bmiHeader.biSizeImage = width * height * 4; return bmi; } void get_bitmap_from_window(HWND hWnd, int * imageBuff) { HDC hDC = GetWindowDC(hWnd); SIZE size = get_window_size(hWnd); HDC hMemDC = CreateCompatibleDC(hDC); RECT r; HBITMAP hBitmap = CreateCompatibleBitmap(hDC, size.cx, size.cy); HBITMAP hOld = (HBITMAP)SelectObject(hMemDC, hBitmap); BitBlt(hMemDC, 0, 0, size.cx, size.cy, hDC, 0, 0, SRCCOPY); //PrintWindow(hWnd, hMemDC, 0); BITMAPINFO bmi = get_bitmap_info(size.cx, size.cy); GetDIBits(hMemDC, hBitmap, 0, size.cy, imageBuff, &bmi, DIB_RGB_COLORS); SelectObject(hMemDC, hOld); DeleteDC(hMemDC); ReleaseDC(NULL, hDC); } void save_image(HWND hWnd, char * name) { int * buff; RECT r; SIZE size; GetWindowRect(hWnd, &r); size.cx = r.right-r.left; size.cy = r.bottom-r.top; buff = (int*)malloc(size.cx * size.cy * sizeof(int)); get_bitmap_from_window(hWnd, buff); BITMAPINFO bmi = get_bitmap_info(size.cx, size.cy); BITMAPFILEHEADER hdr = get_bitmap_file_header(size.cx, size.cy); FILE * fout = fopen(name, "w"); fwrite(&hdr, 1, sizeof(BITMAPFILEHEADER), fout); fwrite(&bmi.bmiHeader, 1, sizeof(BITMAPINFOHEADER), fout); fwrite(buff, 1, size.cx * size.cy * sizeof(int), fout); fflush(fout); fclose(fout); free(buff); } It works find under XP, but under Vista the border of the window is transparent. Using PrintWindow solves the problem, but is unacceptable for performance reasons. Is there a performant code change, or a setting that can be changed to make the border non-transparent?

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  • Can the STREAM and GUPS (single CPU) benchmark use non-local memory in NUMA machine

    - by osgx
    Hello I want to run some tests from HPCC, STREAM and GUPS. They will test memory bandwidth, latency, and throughput (in term of random accesses). Can I start Single CPU test STREAM or Single CPU GUPS on NUMA node with memory interleaving enabled? (Is it allowed by the rules of HPCC - High Performance Computing Challenge?) Usage of non-local memory can increase GUPS results, because it will increase 2- or 4- fold the number of memory banks, available for random accesses. (GUPS typically limited by nonideal memory-subsystem and by slow memory bank opening/closing. With more banks it can do update to one bank, while the other banks are opening/closing.) Thanks. UPDATE: (you may nor reorder the memory accesses that the program makes). But can compiler reorder loops nesting? E.g. hpcc/RandomAccess.c /* Perform updates to main table. The scalar equivalent is: * * u64Int ran; * ran = 1; * for (i=0; i<NUPDATE; i++) { * ran = (ran << 1) ^ (((s64Int) ran < 0) ? POLY : 0); * table[ran & (TableSize-1)] ^= stable[ran >> (64-LSTSIZE)]; * } */ for (j=0; j<128; j++) ran[j] = starts ((NUPDATE/128) * j); for (i=0; i<NUPDATE/128; i++) { /* #pragma ivdep */ for (j=0; j<128; j++) { ran[j] = (ran[j] << 1) ^ ((s64Int) ran[j] < 0 ? POLY : 0); Table[ran[j] & (TableSize-1)] ^= stable[ran[j] >> (64-LSTSIZE)]; } } The main loop here is for (i=0; i<NUPDATE/128; i++) { and the nested loop is for (j=0; j<128; j++) {. Using 'loop interchange' optimization, compiler can convert this code to for (j=0; j<128; j++) { for (i=0; i<NUPDATE/128; i++) { ran[j] = (ran[j] << 1) ^ ((s64Int) ran[j] < 0 ? POLY : 0); Table[ran[j] & (TableSize-1)] ^= stable[ran[j] >> (64-LSTSIZE)]; } } It can be done because this loop nest is perfect loop nest. Is such optimization prohibited by rules of HPCC?

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  • TripleDES in Perl/PHP/ColdFusion

    - by Seidr
    Recently a problem arose regarding hooking up an API with a payment processor who were requesting a string to be encrypted to be used as a token, using the TripleDES standard. Our Applications run using ColdFusion, which has an Encrypt tag - that supports TripleDES - however the result we were getting back was not what the payment processor expected. First of all, here is the resulting token the payment processor were expecting. AYOF+kRtg239Mnyc8QIarw== And below is the snippet of ColdFusion we were using, and the resulting string. <!--- Coldfusion Crypt (here be monsters) ---> <cfset theKey="123412341234123412341234"> <cfset theString = "username=test123"> <cfset strEncodedEnc = Encrypt(theString, theKey, "DESEDE", "Base64")> <!--- resulting string(strEncodedEnc): tc/Jb7E9w+HpU2Yvn5dA7ILGmyNTQM0h ---> As you can see, this was not returning the string we were hoping for. Seeking a solution, we ditched ColdFusion for this process and attempted to reproduce the token in PHP. Now I'm aware that various languages implement encryption in different ways - for example in the past managing encryption between a C# application and PHP back-end, I've had to play about with padding in order to get the two to talk, but my experience has been that PHP generally behaves when it comes to encryption standards. Anyway, on to the PHP source we tried, and the resulting string. /* PHP Circus (here be Elephants) */ $theKey="123412341234123412341234"; $theString="username=test123"; $strEncodedEnc=base64_encode(mcrypt_ecb (MCRYPT_3DES, $theKey, $theString, MCRYPT_ENCRYPT)); /* resulting string(strEncodedEnc): sfiSu4mVggia8Ysw98x0uw== */ As you can plainly see, we've got another string that differs from both the string expected by the payment processor AND the one produced by ColdFusion. Cue head-against-wall integration techniques. After many to-and-fro communications with the payment processor (lots and lots of reps stating 'we can't help with coding issues, you must be doing it incorrectly, read the manual') we were finally escalated to someone with more than a couple of brain-cells to rub together, who was able to step back and actually look at and diagnose the issue. He agreed, our CF and PHP attempts were not resulting in the correct string. After a quick search, he also agreed that it was not neccesarily our source, but rather how the two languages implemented their vision of the TripleDES standard. Coming into the office this morning, we were met by an email with a snippet of source code, in Perl. This is was the code they were directly using on their end to produce the expected token. #!/usr/bin/perl # Perl Crypt Calamity (here be...something) use strict; use CGI; use MIME::Base64; use Crypt::TripleDES; my $cgi = CGI->new(); my $param = $cgi->Vars(); $param->{key} = "123412341234123412341234"; $param->{string} = "username=test123"; my $des = Crypt::TripleDES->new(); my $enc = $des->encrypt3($param->{string}, $param->{key}); $enc = encode_base64($enc); $enc =~ s/\n//gs; # resulting string (enc): AYOF+kRtg239Mnyc8QIarw== So, there we have it. Three languages, three implementations of what they quote in the documentation as TripleDES Standard Encryption, and three totally different resulting strings. My question is, from your experience of these three languages and their implementations of the TripleDES algorithm, have you been able to get any two of them to give the same response, and if so what tweaks to the code did you have to make in order to come to the result? I understand this is a very drawn out question, but I wanted to give clear and precise setting for each stage of testing that we had to perform. I'll also be performing some more investigatory work on this subject later, and will post any findings that I come up with to this question, so that others may avoid this headache.

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  • Paging, sorting and filtering in a stored procedure (SQL Server)

    - by Fruitbat
    I was looking at different ways of writing a stored procedure to return a "page" of data. This was for use with the asp ObjectDataSource, but it could be considered a more general problem. The requirement is to return a subset of the data based on the usual paging paremeters, startPageIndex and maximumRows, but also a sortBy parameter to allow the data to be sorted. Also there are some parameters passed in to filter the data on various conditions. One common way to do this seems to be something like this: [Method 1] ;WITH stuff AS ( SELECT CASE WHEN @SortBy = 'Name' THEN ROW_NUMBER() OVER (ORDER BY Name) WHEN @SortBy = 'Name DESC' THEN ROW_NUMBER() OVER (ORDER BY Name DESC) WHEN @SortBy = ... ELSE ROW_NUMBER() OVER (ORDER BY whatever) END AS Row, ., ., ., FROM Table1 INNER JOIN Table2 ... LEFT JOIN Table3 ... WHERE ... (lots of things to check) ) SELECT * FROM stuff WHERE (Row > @startRowIndex) AND (Row <= @startRowIndex + @maximumRows OR @maximumRows <= 0) ORDER BY Row One problem with this is that it doesn't give the total count and generally we need another stored procedure for that. This second stored procedure has to replicate the parameter list and the complex WHERE clause. Not nice. One solution is to append an extra column to the final select list, (SELECT COUNT(*) FROM stuff) AS TotalRows. This gives us the total but repeats it for every row in the result set, which is not ideal. [Method 2] An interesting alternative is given here (http://www.4guysfromrolla.com/articles/032206-1.aspx) using dynamic SQL. He reckons that the performance is better because the CASE statement in the first solution drags things down. Fair enough, and this solution makes it easy to get the totalRows and slap it into an output parameter. But I hate coding dynamic SQL. All that 'bit of SQL ' + STR(@parm1) +' bit more SQL' gubbins. [Method 3] The only way I can find to get what I want, without repeating code which would have to be synchronised, and keeping things reasonably readable is to go back to the "old way" of using a table variable: DECLARE @stuff TABLE (Row INT, ...) INSERT INTO @stuff SELECT CASE WHEN @SortBy = 'Name' THEN ROW_NUMBER() OVER (ORDER BY Name) WHEN @SortBy = 'Name DESC' THEN ROW_NUMBER() OVER (ORDER BY Name DESC) WHEN @SortBy = ... ELSE ROW_NUMBER() OVER (ORDER BY whatever) END AS Row, ., ., ., FROM Table1 INNER JOIN Table2 ... LEFT JOIN Table3 ... WHERE ... (lots of things to check) SELECT * FROM stuff WHERE (Row > @startRowIndex) AND (Row <= @startRowIndex + @maximumRows OR @maximumRows <= 0) ORDER BY Row (Or a similar method using an IDENTITY column on the table variable). Here I can just add a SELECT COUNT on the table variable to get the totalRows and put it into an output parameter. I did some tests and with a fairly simple version of the query (no sortBy and no filter), method 1 seems to come up on top (almost twice as quick as the other 2). Then I decided to test probably I needed the complexity and I needed the SQL to be in stored procedures. With this I get method 1 taking nearly twice as long as the other 2 methods. Which seems strange. Is there any good reason why I shouldn't spurn CTEs and stick with method 3? UPDATE - 15 March 2012 I tried adapting Method 1 to dump the page from the CTE into a temporary table so that I could extract the TotalRows and then select just the relevant columns for the resultset. This seemed to add significantly to the time (more than I expected). I should add that I'm running this on a laptop with SQL Server Express 2008 (all that I have available) but still the comparison should be valid. I looked again at the dynamic SQL method. It turns out I wasn't really doing it properly (just concatenating strings together). I set it up as in the documentation for sp_executesql (with a parameter description string and parameter list) and it's much more readable. Also this method runs fastest in my environment. Why that should be still baffles me, but I guess the answer is hinted at in Hogan's comment.

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  • jScrollPane jEditable DOM problems

    - by Kyle Lafkoff
    Hello world, I am having a funky problem. See (this link won't disappear): www.skitzo.org/~el/bugjeditable.png for the firebug output screenshot. Here's my code. I run getJSON() to fetch the info from the PHP which pulls from DB and I fill a div with the result. I have jScrollPane and jEditable so a user can scroll down and click to edit any of the content. It works sometimes and then it doesn't work which makes me wonder if the browser is not interpreting the code properly or if I am misunderstanding fundamental DOM concepts here.... Here is a live current version of the code: http://www.musedates.com/testing.php $().ready(function() { $('#pane1').jScrollPane(); $('#tab_journal').tabs(); $('#tab2').load("/journal_new.php"); var i=0; var row = ''; var k, v, dt; $.getJSON("/ajax.php?j=22", function(data) { row = '<p>'; while(i<data.length) { $.each(data[i], function(k, v) { if (k == 'subject') { row += '<div style="font-size:1.5em; color:#000000;"><div class="editable" style="width:705px;" id="title-'+data[i].id+'">'+v+'</div></div>posted: '+dt+'<br />'; } else if (k == 'dt') { dt = v; } else if (k == 'msg') { row += '<div class="editableMsg" style="width:705px; height:40px;" id="msg-'+data[i].id+'">'+v+'</div></p>'; } }); i++; } $('#pane1').append(row).jScrollPane({scrollbarWidth:10, scrollbarMargin:10, showArrows:true}); }); $('.editable').livequery(function () { $('.editable').editable("/savejournal.php", { submitdata : function() { }, tooltip : 'Click to edit', indicator : '<img src="/UI/images/indicator.gif">', cancel : 'Cancel', submit : 'OK' }); $('.editableMsg').editable("/savejournal.php", { submitdata : function() { }, tooltip: 'Click to edit', indicator : '<img src="/UI/images/indicator.gif">', cancel : 'Cancel', submit : 'OK', type : 'textarea' }); $(".editable,.editableMsg").mouseover(function() { $(this).css('background-color', '#FDD017'); }); $(".editable,.editableMsg").mouseout(function() { $(this).css('background-color', '#fff'); }); }); }); And then the HTML: <div id="tab_container" style="margin:0px 0px 2px 8px;"> <ul id="tab_journal"> <li><a href="#tab1"><span>View / Edit</span></a></li> <li><a href="#tab2"><span>New Entry</span></a></li> </ul> </div> <div id="tab1" style="margin:0px 0px 0px 8px;"> <div id="pane1" class="scroll-pane super-wide"></div> </div> <div id="tab2" style="margin:0px 0px 0px 8px; width:700px;"></div> Thanks world.

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  • Need Help Setting Transparent Image to Clipboard

    - by AMissico
    I need help setting a transparent image to the clipboard. I keep getting "handle is invalid". Following is the specific code with the complete working project at ftp://missico.net/ImageVisualizer.zip. This is an image Debug Visualizer class library, but I made to run as executable for testing. (Note that window is a toolbox window and show in taskbar is set to false.) I was tired of having to perform a screen capture on the toolbox window, open with an image editor, and then deleting the background added due to the screen capture. So I thought I would quickly put the transparent image onto the clipboard. Well, the problem is...no transparency support for Clipboard.SetImage. Google to the rescue...not quite. This is what I have so far pulled from a number of sources. See the code for the main reference. My problem is the "invalid handle" when using CF_DIBV5. I imagine the problem is related to BITMAPV5HEADER and CreateDIBitmap. Any help from you GDI/GDI+ Wizards would be greatly appreciated. public static void SetClipboardData(Bitmap bitmap, IntPtr hDC) { const uint SRCCOPY = 0x00CC0020; const int CF_DIBV5 = 17; const int CF_BITMAP = 2; //'reference //'http://social.msdn.microsoft.com/Forums/en-US/winforms/thread/816a35f6-9530-442b-9647-e856602cc0e2 IntPtr memDC = CreateCompatibleDC(hDC); IntPtr memBM = CreateCompatibleBitmap(hDC, bitmap.Width, bitmap.Height); SelectObject(memDC, memBM); using (Graphics g = Graphics.FromImage(bitmap)) { IntPtr hBitmapDC = g.GetHdc(); IntPtr hBitmap = bitmap.GetHbitmap(); SelectObject(hBitmapDC, hBitmap); BitBlt(memDC, 0, 0, bitmap.Width, bitmap.Height, hBitmapDC, 0, 0, SRCCOPY); if (!OpenClipboard(IntPtr.Zero)) { throw new System.Runtime.InteropServices.ExternalException("Could not open Clipboard", new Win32Exception()); } if (!EmptyClipboard()) { throw new System.Runtime.InteropServices.ExternalException("Unable to empty Clipboard", new Win32Exception()); } //IntPtr hClipboard = SetClipboardData(CF_BITMAP, memBM); //works but image is not transparent //all my attempts result in SetClipboardData returning hClipboard = IntPtr.Zero IntPtr hClipboard = SetClipboardData(CF_DIBV5, memBM); //because if (hClipboard == IntPtr.Zero) { // InnerException: System.ComponentModel.Win32Exception // Message="The handle is invalid" // ErrorCode=-2147467259 // NativeErrorCode=6 // InnerException: throw new System.Runtime.InteropServices.ExternalException("Could not put data on Clipboard", new Win32Exception()); } if (!CloseClipboard()) { throw new System.Runtime.InteropServices.ExternalException("Could not close Clipboard", new Win32Exception()); } g.ReleaseHdc(hBitmapDC); } } private void __copyMenuItem_Click(object sender, EventArgs e) { //'Applications that I have verified can paste the clipboard custom data format PNG are: //' Word 2003 //' Excel 2003 using (Graphics g = __pictureBox.CreateGraphics()) { IntPtr hDC = g.GetHdc(); MemoryStream ms = new MemoryStream(); __pictureBox.Image.Save(ms, ImageFormat.Png); ms.Seek(0, SeekOrigin.Begin); Image imag = Image.FromStream(ms); // Derive BitMap object using Image instance, so that you can avoid the issue //"a graphics object cannot be created from an image that has an indexed pixel format" Bitmap img = new Bitmap(new Bitmap(imag)); SetClipboardData(img, hDC); g.ReleaseHdc(); } }

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  • Clear data at serial port in Linux in C?

    - by ipkiss
    Hello guys, I am testing the sending and receiving programs with the code as The main() function is below: include include include include include include include "read_write.h" int fd; int initport(int fd) { struct termios options; // Get the current options for the port... tcgetattr(fd, &options); // Set the baud rates to 19200... cfsetispeed(&options, B9600); cfsetospeed(&options, B9600); // Enable the receiver and set local mode... options.c_cflag |= (CLOCAL | CREAD); options.c_cflag &= ~PARENB; options.c_cflag &= ~CSTOPB; options.c_cflag &= ~CSIZE; options.c_cflag |= CS8; // Set the new options for the port... tcsetattr(fd, TCSANOW, &options); return 1; } int main(int argc, char **argv) { fd = open("/dev/pts/2", O_RDWR | O_NOCTTY | O_NDELAY); if (fd == -1) { perror("open_port: Unable to open /dev/pts/1 - "); return 1; } else { fcntl(fd, F_SETFL, 0); } printf("baud=%d\n", getbaud(fd)); initport(fd); printf("baud=%d\n", getbaud(fd)); char sCmd[254]; sCmd[0] = 0x41; sCmd[1] = 0x42; sCmd[2] = 0x43; sCmd[3] = 0x00; if (!writeport(fd, sCmd)) { printf("write failed\n"); close(fd); return 1; } printf("written:%s\n", sCmd); usleep(500000); char sResult[254]; fcntl(fd, F_SETFL, FNDELAY); if (!readport(fd,sResult)) { printf("read failed\n"); close(fd); return 1; } printf("readport=%s\n", sResult); close(fd); return 0; } read_write.h: #include <stdio.h> /* Standard input/output definitions */ include /* String function definitions */ include /* UNIX standard function definitions */ include /* File control definitions */ include /* Error number definitions */ include /* POSIX terminal control definitions */ int writeport(int fd, char *chars) { int len = strlen(chars); chars[len] = 0x0d; // stick a after the command chars[len+1] = 0x00; // terminate the string properly int n = write(fd, chars, strlen(chars)); if (n < 0) { fputs("write failed!\n", stderr); return 0; } return 1; } int readport(int fd, char *result) { int iIn = read(fd, result, 254); result[iIn-1] = 0x00; if (iIn < 0) { if (errno == EAGAIN) { printf("SERIAL EAGAIN ERROR\n"); return 0; } else { printf("SERIAL read error %d %s\n", errno, strerror(errno)); return 0; } } return 1; } and got the issue: In order to test with serial port, I used the socat (https://help.ubuntu.com/community/VirtualSerialPort ) to create a pair serial ports on Linux and test my program with these port. The first time the program sends the data and the program receives data is ok. However, if I read again or even re-write the new data into the serial port, the return data is always null until I stop the virtual serial port and start it again, then the write and read data is ok, but still, only one time. (In the real case, the sending part will be done by another device, I am just taking care of the reading data from the serial port. I wrote both parts just to test my reading code.) Does anyone have any ideas? Thanks a lot.

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  • Select number of rows for each group where two column values makes one group

    - by Fábio Antunes
    I have a two select statements joined by UNION ALL. In the first statement a where clause gathers only rows that have been shown previously to the user. The second statement gathers all rows that haven't been shown to the user, therefore I end up with the viewed results first and non-viewed results after. Of course this could simply be achieved with the same select statement using a simple ORDER BY, however the reason for two separate selects is simple after you realize what I hope to accomplish. Consider the following structure and data. +----+------+-----+--------+------+ | id | from | to | viewed | data | +----+------+-----+--------+------+ | 1 | 1 | 10 | true | .... | | 2 | 10 | 1 | true | .... | | 3 | 1 | 10 | true | .... | | 4 | 6 | 8 | true | .... | | 5 | 1 | 10 | true | .... | | 6 | 10 | 1 | true | .... | | 7 | 8 | 6 | true | .... | | 8 | 10 | 1 | true | .... | | 9 | 6 | 8 | true | .... | | 10 | 2 | 3 | true | .... | | 11 | 1 | 10 | true | .... | | 12 | 8 | 6 | true | .... | | 13 | 10 | 1 | false | .... | | 14 | 1 | 10 | false | .... | | 15 | 6 | 8 | false | .... | | 16 | 10 | 1 | false | .... | | 17 | 8 | 6 | false | .... | | 18 | 3 | 2 | false | .... | +----+------+-----+--------+------+ Basically I wish all non viewed rows to be selected by the statement, that is accomplished by checking weather the viewed column is true or false, pretty simple and straightforward, nothing to worry here. However when it comes to the rows already viewed, meaning the column viewed is TRUE, for those records I only want 3 rows to be returned for each group. The appropriate result in this instance should be the 3 most recent rows of each group. +----+------+-----+--------+------+ | id | from | to | viewed | data | +----+------+-----+--------+------+ | 6 | 10 | 1 | true | .... | | 7 | 8 | 6 | true | .... | | 8 | 10 | 1 | true | .... | | 9 | 6 | 8 | true | .... | | 10 | 2 | 3 | true | .... | | 11 | 1 | 10 | true | .... | | 12 | 8 | 6 | true | .... | +----+------+-----+--------+------+ As you see from the ideal result set we have three groups. Therefore the desired query for the viewed results should show a maximum of 3 rows for each grouping it finds. In this case these groupings were 10 with 1 and 8 with 6, both which had three rows to be shown, while the other group 2 with 3 only had one row to be shown. Please note that where from = x and to = y, makes the same grouping as if it was from = y and to = x. Therefore considering the first grouping (10 with 1), from = 10 and to = 1 is the same group if it was from = 1 and to = 10. However there are plenty of groups in the whole table that I only wish the 3 most recent of each to be returned in the select statement, and thats my problem, I not sure how that can be accomplished in the most efficient way possible considering the table will have hundreds if not thousands of records at some point. Thanks for your help. Note: The columns id, from, to and viewed are indexed, that should help with performance. PS: I'm unsure on how to name this question exactly, if you have a better idea, be my guest and edit the title.

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  • random generator to obtain data from array not displaying

    - by Yang Jie Domodomo
    I know theres a better solution using arc4random (it's on my to-try-out-function list), but I wanted to try out using the rand() and stand(time(NULL)) function first. I've created a NSMutableArray and chuck it with 5 data. Testing out how many number it has was fine. But when I tried to use the button function to load the object it return me with object <sampleData: 0x9a2f0e0> - (IBAction)generateNumber:(id)sender { srand(time(NULL)); NSInteger number =rand()% ds.count ; label.text = [NSString stringWithFormat:@"object %@", [ds objectAtIndex:number] ]; NSLog(@"%@",label.text); } While I feel the main cause is the method itself, I've paste the rest of the code below just incase i made any error somewhere. ViewController.h #import <UIKit/UIKit.h> #import "sampleData.h" #import "sampleDataDAO.h" @interface ViewController : UIViewController @property (weak, nonatomic) IBOutlet UILabel *label; @property (weak, nonatomic) IBOutlet UIButton *onHitMePressed; - (IBAction)generateNumber:(id)sender; @property(nonatomic, strong) sampleDataDAO *daoDS; @property(nonatomic, strong) NSMutableArray *ds; @end ViewController.m #import "ViewController.h" @interface ViewController () @end @implementation ViewController @synthesize label; @synthesize onHitMePressed; @synthesize daoDS,ds; - (void)viewDidLoad { [super viewDidLoad]; daoDS = [[sampleDataDAO alloc] init]; self.ds = daoDS.PopulateDataSource; // Do any additional setup after loading the view, typically from a nib. } - (void)viewDidUnload { [self setLabel:nil]; [self setOnHitMePressed:nil]; [super viewDidUnload]; // Release any retained subviews of the main view. } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } - (IBAction)generateNumber:(id)sender { srand(time(NULL)); NSInteger number =rand()% ds.count ; label.text = [NSString stringWithFormat:@"object %@", [ds objectAtIndex:number] ]; NSLog(@"%@",label.text); } @end sampleData.h #import <Foundation/Foundation.h> @interface sampleData : NSObject @property (strong,nonatomic) NSString * object; @end sampleData.m #import "sampleData.h" @implementation sampleData @synthesize object; @end sampleDataDAO.h #import <Foundation/Foundation.h> #import "sampleData.h" @interface sampleDataDAO : NSObject @property(strong,nonatomic)NSMutableArray*someDataArray; -(NSMutableArray *)PopulateDataSource; @end sampleDataDAO.m #import "sampleDataDAO.h" @implementation sampleDataDAO @synthesize someDataArray; -(NSMutableArray *)PopulateDataSource { someDataArray = [[NSMutableArray alloc]init]; sampleData * myData = [[sampleData alloc]init]; myData.object= @"object 1"; [someDataArray addObject:myData]; myData=nil; myData = [[sampleData alloc] init]; myData.object= @"object 2"; [someDataArray addObject:myData]; myData=nil; myData = [[sampleData alloc] init]; myData.object= @"object 3"; [someDataArray addObject:myData]; myData=nil; myData = [[sampleData alloc] init]; myData.object= @"object 4"; [someDataArray addObject:myData]; myData=nil; myData = [[sampleData alloc] init]; myData.object= @"object 5"; [someDataArray addObject:myData]; myData=nil; return someDataArray; } @end

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  • CSG operations on implicit surfaces with marching cubes

    - by Mads Elvheim
    I render isosurfaces with marching cubes, (or perhaps marching squares as this is 2D) and I want to do set operations like set difference, intersection and union. I thought this was easy to implement, by simply choosing between two vertex scalars from two different implicit surfaces, but it is not. For my initial testing, I tried with two spheres, and the set operation difference. i.e A - B. One sphere is moving and the other one is stationary. Here's the approach I tried when picking vertex scalars and when classifying corner vertices as inside or outside. The code is written in C++. OpenGL is used for rendering, but that's not important. Normal rendering without any CSG operations does give the expected result. void march(const vec2& cmin, //min x and y for the grid cell const vec2& cmax, //max x and y for the grid cell std::vector<vec2>& tri, float iso, float (*cmp1)(const vec2&), //distance from stationary sphere float (*cmp2)(const vec2&) //distance from moving sphere ) { unsigned int squareindex = 0; float scalar[4]; vec2 verts[8]; /* initial setup of the grid cell */ verts[0] = vec2(cmax.x, cmax.y); verts[2] = vec2(cmin.x, cmax.y); verts[4] = vec2(cmin.x, cmin.y); verts[6] = vec2(cmax.x, cmin.y); float s1,s2; /********************************** ********For-loop of interest****** *******Set difference between **** *******two implicit surfaces****** **********************************/ for(int i=0,j=0; i<4; ++i, j+=2){ s1 = cmp1(verts[j]); s2 = cmp2(verts[j]); if((s1 < iso)){ //if inside sphere1 if((s2 < iso)){ //if inside sphere2 scalar[i] = s2; //then set the scalar to the moving sphere } else { scalar[i] = s1; //only inside sphere1 squareindex |= (1<<i); //mark as inside } } else { scalar[i] = s1; //inside neither sphere } } if(squareindex == 0) return; /* Usual interpolation between edge points to compute the new intersection points */ verts[1] = mix(iso, verts[0], verts[2], scalar[0], scalar[1]); verts[3] = mix(iso, verts[2], verts[4], scalar[1], scalar[2]); verts[5] = mix(iso, verts[4], verts[6], scalar[2], scalar[3]); verts[7] = mix(iso, verts[6], verts[0], scalar[3], scalar[0]); for(int i=0; i<10; ++i){ //10 = maxmimum 3 triangles, + one end token int index = triTable[squareindex][i]; //look up our indices for triangulation if(index == -1) break; tri.push_back(verts[index]); } } This gives me weird jaggies: It looks like the CSG operation is done without interpolation. It just "discards" the whole triangle. Do I need to interpolate in some other way, or combine the vertex scalar values? I'd love some help with this. A full testcase can be downloaded HERE

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  • Rendering a view to a string in MVC, then redirecting -- workarounds?

    - by James S
    Hi -- I can't render a view to a string and then redirect, despite this answer from Feb (after version 1.0, I think) that claims it's possible. I thought I was doing something wrong, and then I read this answer from Haack in July that claims it's not possible. If somebody has it working and can help me get it working, that's great (and I'll post code, errors). However, I'm now at the point of needing workarounds. There are a few, but nothing ideal. Has anybody solved this, or have any comments on my ideas? This is to render email. While I can surely send the email outside of the web request (store info in a db and get it later), there are many types of emails and I don't want to store the template data (user object, a few other LINQ objects) in a db to let it get rendered later. I could create a simpler, serializable POCO and save that in the db, but why? ... I just want rendered text! I can create a new RedirectToAction object that checks if the headers have been sent (can't figure out how to do this -- try/catch?) and, if so, builds out a simple page with a meta redirect, a javascript redirect, and also a "click here" link. Within my controller, I can remember if I've rendered an email and, if so, manually do #2 by displaying a view. I can manually send the redirect headers before any potential email rendering. Then, rather than using the MVC infrastructure to redirecttoaction, I just call result.end. This seems easiest, but really messy. Anything else? EDIT: I've tried Dan's code (very similar to the code from Jan/Feb that I've already tried) and I'm still getting the same error. The only substantial difference I can see is that his example uses a view while I use a partial view. I'll try testing this later with a view. Here's what I've got: Controller public ActionResult Certifications(string email_intro) { //a lot of stuff ViewData["users"] = users; if (isPost()) { //create the viewmodel var view_model = new ViewModels.Emails.Certifications.Open(userContext) { emailIntro = email_intro }; //i've tried stopping this after just one iteration, in case the problem is due to calling it multiple times foreach (var user in users) { if (user.Email_Address.IsValidEmailAddress()) { //add more stuff to the view model specific to this user view_model.user = user; view_model.certification302Summary.subProcessesOwner = new SubProcess_Certifications(RecordUpdating.Role.Owner, null, null, user.User_ID, repository); //more here.... //if i comment out the next line, everything works ok SendEmail(view_model, this.ControllerContext); } } return RedirectToAction("Certifications"); } return View(); } SendEmail() public static void SendEmail(ViewModels.Emails.Certifications.Open model, ControllerContext context) { var vd = context.Controller.ViewData; vd["model"] = model; var renderer = new CustomRenderers(); //i fixed an error in your code here var text = renderer.RenderViewToString3(context, "~/Views/Emails/Certifications/Open.ascx", "", vd, null); var a = text; } CustomRenderers public class CustomRenderers { public virtual string RenderViewToString3(ControllerContext controllerContext, string viewPath, string masterPath, ViewDataDictionary viewData, TempDataDictionary tempData) { //copy/paste of dan's code } } Error [HttpException (0x80004005): Cannot redirect after HTTP headers have been sent.] System.Web.HttpResponse.Redirect(String url, Boolean endResponse) +8707691 Thanks, James

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  • Soft keyboard "del" key fails in EditText on Gallery widget

    - by droidful
    Hi, I am developing an application in Eclipse build ID 20090920-1017 using android SDK 2.2 and testing on a Google Nexus One. For the purposes of the tests below I am using the IME "Android keyboard" on a non-rooted phone. I have an EditText widget which exhibits some very strange behavior. I can type text, and then press the "del" key to delete that text; but after I enter a 'space' character, the "del" key will no longer remove characters before that space character. An example speaks a thousand words, so consider the following two incredibly simple applications... Example 1: An EditText in a LinearLayout widget: package com.example.linear.edit; import android.app.Activity; import android.os.Bundle; import android.view.ViewGroup.LayoutParams; import android.widget.EditText; import android.widget.Gallery; import android.widget.LinearLayout; public class LinearEdit extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(getApplicationContext()); layout.setLayoutParams(new Gallery.LayoutParams(Gallery.LayoutParams.MATCH_PARENT, Gallery.LayoutParams.MATCH_PARENT)); EditText edit = new EditText(getApplicationContext()); layout.addView(edit, new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); setContentView(layout); } } Run the above application, enter text "edit example", then press the "del" key several times until the entire sentence is deleted. Everything Works fine. Now consider example 2: An EditText in a Gallery widget: package com.example.gallery.edit; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.widget.ArrayAdapter; import android.widget.EditText; import android.widget.Gallery; import android.widget.LinearLayout; public class GalleryEdit extends Activity { private final String[] galleryData = {"string1", "string2", "string3"}; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Gallery gallery = new Gallery(getApplicationContext()); gallery.setAdapter(new ArrayAdapter(getApplicationContext(), android.R.layout.simple_list_item_1, galleryData) { @Override public View getView(int position, View convertView, ViewGroup parent) { LinearLayout layout = new LinearLayout(getApplicationContext()); layout.setLayoutParams(new Gallery.LayoutParams(Gallery.LayoutParams.MATCH_PARENT, Gallery.LayoutParams.MATCH_PARENT)); EditText edit = new EditText(getApplicationContext()); layout.addView(edit, new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); return layout; } }); setContentView(gallery); } } Run the above application, enter text "edit example", then press the "del" key several times. If you are getting the same problem as me then you will find that you can't deleted past the 'space' character. All is not well. If anyone could shed some light on this issue I would be most appreciative. Regards

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  • Looking for a better design: A readonly in-memory cache mechanism

    - by Dylan Lin
    Hi all, I have a Category entity (class), which has zero or one parent Category and many child Categories -- it's a tree structure. The Category data is stored in a RDBMS, so for better performance, I want to load all categories and cache them in memory while launching the applicaiton. Our system can have plugins, and we allow the plugin authors to access the Category Tree, but they should not modify the cached items and the tree(I think a non-readonly design might cause some subtle bugs in this senario), only the system knows when and how to refresh the tree. Here are some demo codes: public interface ITreeNode<T> where T : ITreeNode<T> { // No setter T Parent { get; } IEnumerable<T> ChildNodes { get; } } // This class is generated by O/R Mapping tool (e.g. Entity Framework) public class Category : EntityObject { public string Name { get; set; } } // Because Category is not stateless, so I create a cleaner view class for Category. // And this class is the Node Type of the Category Tree public class CategoryView : ITreeNode<CategoryView> { public string Name { get; private set; } #region ITreeNode Memebers public CategoryView Parent { get; private set; } private List<CategoryView> _childNodes; public IEnumerable<CategoryView> ChildNodes { return _childNodes; } #endregion public static CategoryView CreateFrom(Category category) { // here I can set the CategoryView.Name property } } So far so good. However, I want to make ITreeNode interface reuseable, and for some other types, the tree should not be readonly. We are not able to do this with the above readonly ITreeNode, so I want the ITreeNode to be like this: public interface ITreeNode<T> { // has setter T Parent { get; set; } // use ICollection<T> instead of IEnumerable<T> ICollection<T> ChildNodes { get; } } But if we make the ITreeNode writable, then we cannot make the Category Tree readonly, it's not good. So I think if we can do like this: public interface ITreeNode<T> { T Parent { get; } IEnumerable<T> ChildNodes { get; } } public interface IWritableTreeNode<T> : ITreeNode<T> { new T Parent { get; set; } new ICollection<T> ChildNodes { get; } } Is this good or bad? Are there some better designs? Thanks a lot! :)

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  • Overriding Object.Equals() instance method in C#; now Code Analysis / FxCop warning CA2218: "should

    - by Chris W. Rea
    I've got a complex class in my C# project on which I want to be able to do equality tests. It is not a trivial class; it contains a variety of scalar properties as well as references to other objects and collections (e.g. IDictionary). For what it's worth, my class is sealed. To enable a performance optimization elsewhere in my system (an optimization that avoids a costly network round-trip), I need to be able to compare instances of these objects to each other for equality – other than the built-in reference equality – and so I'm overriding the Object.Equals() instance method. However, now that I've done that, Visual Studio 2008's Code Analysis a.k.a. FxCop, which I keep enabled by default, is raising the following warning: warning : CA2218 : Microsoft.Usage : Since 'MySuperDuperClass' redefines Equals, it should also redefine GetHashCode. I think I understand the rationale for this warning: If I am going to be using such objects as the key in a collection, the hash code is important. i.e. see this question. However, I am not going to be using these objects as the key in a collection. Ever. Feeling justified to suppress the warning, I looked up code CA2218 in the MSDN documentation to get the full name of the warning so I could apply a SuppressMessage attribute to my class as follows: [SuppressMessage("Microsoft.Naming", "CA2218:OverrideGetHashCodeOnOverridingEquals", Justification="This class is not to be used as key in a hashtable.")] However, while reading further, I noticed the following: How to Fix Violations To fix a violation of this rule, provide an implementation of GetHashCode. For a pair of objects of the same type, you must ensure that the implementation returns the same value if your implementation of Equals returns true for the pair. When to Suppress Warnings ----- Do not suppress a warning from this rule. [arrow & emphasis mine] So, I'd like to know: Why shouldn't I suppress this warning as I was planning to? Doesn't my case warrant suppression? I don't want to code up an implementation of GetHashCode() for this object that will never get called, since my object will never be the key in a collection. If I wanted to be pedantic, instead of suppressing, would it be more reasonable for me to override GetHashCode() with an implementation that throws a NotImplementedException? Update: I just looked this subject up again in Bill Wagner's good book Effective C#, and he states in "Item 10: Understand the Pitfalls of GetHashCode()": If you're defining a type that won't ever be used as the key in a container, this won't matter. Types that represent window controls, web page controls, or database connections are unlikely to be used as keys in a collection. In those cases, do nothing. All reference types will have a hash code that is correct, even if it is very inefficient. [...] In most types that you create, the best approach is to avoid the existence of GetHashCode() entirely. ... that's where I originally got this idea that I need not be concerned about GetHashCode() always.

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