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  • Do we need to explicitly pass php.ini's location to php-fpm?

    - by F21
    I am seeing a strange issue where my php.ini is not used if I do not explicitly pass it to php-fpm when starting it. This is the upstart script I am using: start on (filesystem and net-device-up IFACE=lo) stop on runlevel [016] pre-start script mkdir -p /run/php end script expect fork respawn exec /usr/local/php/sbin/php-fpm --fpm-config /etc/php/php-fpm.conf If PHP is started with the above, my php.ini is never used, even though it is in Configuration File (php.ini) Path. This is the relevant part from phpinfo(): Configuration File (php.ini) Path /etc/php/ Loaded Configuration File (none) Scan this dir for additional .ini files (none) Additional .ini files parsed (none) If I modify the last line of the upstart script to point php-fpm to php.ini explicitly: exec /usr/local/php/sbin/php-fpm --fpm-config /etc/php/php-fpm.conf -c /etc/php/php.ini Then we see that the php.ini is loaded: Configuration File (php.ini) Path /etc/php/ Loaded Configuration File /etc/php/php.ini Scan this dir for additional .ini files (none) Additional .ini files parsed (none) Why is this the case? Is this a quirk in php-fpm? Minor update: This also seems to be a problem for php5-fpm installed using apt-get. I did a test install in a Ubuntu Server 12.04 virtual machine by running the following: sudo apt-get install nginx php5-fpm PHP-FPM and nginx were started after installation and everything seemed fine. I then uncommented php's settings in nginx's configuration and placed a test phpinfo() file to inspect PHP's settings. The relevant bits are: Configuration File (php.ini) Path /etc/php5/fpm Loaded Configuration File (none) Scan this dir for additional .ini files /etc/php5/fpm/conf.d Additional .ini files parsed /etc/php5/fpm/conf.d/10-pdo.ini I noted that no php.ini was loaded either. However, if I go to /etc/php5/fpm, I can see that a php.ini exists. I also checked the start up scripts for PHP-FPM and the -c parameter was not used to link the ini file to PHP. This can potentially be confusing for people who would expect php.ini to be loaded automatically by PHP-FPM.

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  • How to select table column names in a view and pass to controller in rails?

    - by zachd1_618
    So I am new to Rails, and OO programming in general. I have some grasp of the MVC architecture. My goal is to make a (nearly) completely dynamic plug-and-play plotting web server. I am fairly confused with params, forms, and select helpers. What I want to do is use Rails drop downs to basically pass parameters as strings to my controller, which will use the params to select certain column data from my database and plot it dynamically. I have the latter part of the task working, but I can't seem to pass values from my view to controller. For simplicity's sake, say my database schema looks like this: --------------Plot--------------- |____x____|____y1____|____y2____| | 1 | 1 | 1 | | 2 | 2 | 4 | | 3 | 3 | 9 | | 4 | 4 | 16 | | 5 | 5 | 25 | ... and in my Model, I have dynamic selector scopes that will let me select just certain columns of data: in Plot.rb class Plot < ActiveRecord::Base scope :select_var, lambda {|varname| select(varname)} scope :between_x, lambda {|x1,x2| where("x BETWEEN ? and ?","#{x1}","#{x2}")} So this way, I can call: irb>>@p1 = Plot.select_var(['x','y1']).between_x(1,3) and get in return a class where @p1.x and @p1.y1 are my only attributes, only for values between x=1 to x=4, which I dynamically plot. I want to start off in a view (plot/index), where I can dynamically select which variable names (table column names), and which rows from the database to fetch and plot. The problem is, most select helpers don't seem to work with columns in the database, only rows. So to select columns, I first get an array of column names that exist in my database with a function I wrote. Plots Controller def index d=Plot.first @tags = d.list_vars end So @tags = ['x','y1','y2'] Then in my plot/index.html.erb I try to use a drop down to select wich variables I send back to the controller. index.html.erb <%= select_tag( :variable, options_for_select(@plots.first.list_vars,:name,:multiple=>:true) )%> <%= button_to 'Plot now!', :controller =>"plots/plot_vars", :variable => params[:variable]%> Finally, in the controller again Plots controller ... def plot_vars @plot_data=Plot.select_vars([params[:variable]]) end The problem is everytime I try this (or one of a hundred variations thereof), the params[:variable] is nill. How can I use a drop down to pass a parameter with string variable names to the controller? Sorry its so long, I have been struggling with this for about a month now. :-( I think my biggest problem is that this setup doesn't really match the Rails architecture. I don't have "users" and "articles" as individual entities. I really have a data structure, not a data object. Trying to work with the structure in terms of data object speak is not necessarily the easiest thing to do I think. For background: My actual database has about 250 columns and a couple million rows, and they get changed and modified from time to time. I know I can make the database smarter, but its not worth it on my end. I work at a scientific institute where there are a ton of projects with databases just like this. Each one has a web developer that spends months setting up a web interface and their own janky plotting setups. I want to make this completely dynamic, as a plug-and-play solution so all you have to do is specify your database connection, and this rails setup will automatically show and plot which data you want in it. I am more of a sequential programmer and number cruncher, as are many people here. I think this project could be very helpful in the end, but its difficult to figure out for me right now.

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  • SQL SERVER – Fix: Error: 147 An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference

    - by pinaldave
    Everybody was beginner once and I always like to get involved in the questions from beginners. There is a big difference between the question from beginner and question from advanced user. I have noticed that if an advanced user gets an error, they usually need just a small hint to resolve the problem. However, when a beginner gets error he sometimes sits on the error for a long time as he/she has no idea about how to solve the problem as well have no idea regarding what is the capability of the product. I recently received a very novice level question. When I received the problem I quickly see how the user was stuck. When I replied him with the solution, he wrote a long email explaining how he was not able to solve the problem. He thanked multiple times in the email. This whole thing inspired me to write this quick blog post. I have modified the user’s question to match the code with AdventureWorks as well simplified so it contains the core content which I wanted to discuss. Problem Statement: Find all the details of SalesOrderHeaders for the latest ShipDate. He comes up with following T-SQL Query: SELECT * FROM [Sales].[SalesOrderHeader] WHERE ShipDate = MAX(ShipDate) GO When he executed above script it gave him following error: Msg 147, Level 15, State 1, Line 3 An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference. He was not able to resolve this problem, even though the solution was given in the query description itself. Due to lack of experience he came up with another version of above query based on the error message. SELECT * FROM [Sales].[SalesOrderHeader] HAVING ShipDate = MAX(ShipDate) GO When he ran above query it produced another error. Msg 8121, Level 16, State 1, Line 3 Column ‘Sales.SalesOrderHeader.ShipDate’ is invalid in the HAVING clause because it is not contained in either an aggregate function or the GROUP BY clause. What he wanted actually was the SalesOrderHeader all the Sales shipped on the last day. Based on the problem statement what the right solution is as following, which does not generate error. SELECT * FROM [Sales].[SalesOrderHeader] WHERE ShipDate = (SELECT MAX(ShipDate) FROM [Sales].[SalesOrderHeader]) Well, that’s it! Very simple. With SQL Server there are always multiple solution to a single problem. Is there any other solution available to the problem stated? Please share in the comment. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Error Messages, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Speaking at PASS 2012… Exciting and Scary… As usual…

    - by drsql
    I have been selected this year at the PASS Summit 2012 to do two sessions, and they are both going to be interesting. Pre-Con: Relational Database Design Workshop - Abstract Triggers: Born Evil or Misunderstood? - Abstract The pre-con session entitled Relational Database Design Workshop will be (at least) the third time I will have done this pre-con session, and I am pretty excited to take it to a bit larger scale. The one big change that I am forcing this time is a limit on the lecture time. Each...(read more)

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  • publishing asp.net website give "Object reference not set to an instance of an object." error

    - by Johan
    Good day I am using VS 2008 I am getting fed up with this error. I have search all over the web and tried every possible suggestion to this error I could find. 1. delete app_code, build, add files back, publish. (did not work) 2. delete temporary asp.net files (did not work) in the end I even tried the command line and get the following stacktrace. error ASPRUNTIME: Object reference not set to an instance of an object. [NullReferenceException]: Object reference not set to an instance of an object. at System.Web.Compilation.BuildManager.CopyPrecompiledFile(VirtualFile vfile, String destPhysicalPath) at System.Web.Compilation.BuildManager.CopyStaticFilesRecursive(VirtualDirect ory sourceVdir, String destPhysicalDir, Boolean topLevel) at System.Web.Compilation.BuildManager.CopyStaticFilesRecursive(VirtualDirect ory sourceVdir, String destPhysicalDir, Boolean topLevel) at System.Web.Compilation.BuildManager.CopyStaticFilesRecursive(VirtualDirect ory sourceVdir, String destPhysicalDir, Boolean topLevel) at System.Web.Compilation.BuildManager.PrecompileAppInternal(VirtualPath star tingVirtualDir) at System.Web.Compilation.BuildManager.PrecompileApp(VirtualPath startingVirt ualDir) at System.Web.Compilation.BuildManager.PrecompileApp(ClientBuildManagerCallba ck callback) at System.Web.Compilation.BuildManagerHost.PrecompileApp(ClientBuildManagerCa llback callback) at System.Web.Compilation.BuildManagerHost.PrecompileApp(ClientBuildManagerCa llback callback) at System.Web.Compilation.ClientBuildManager.PrecompileApplication(ClientBuil dManagerCallback callback, Boolean forceCleanBuild) at System.Web.Compilation.ClientBuildManager.PrecompileApplication(ClientBuil dManagerCallback callback) at System.Web.Compilation.Precompiler.Main(String[] args) I used the following command line: aspnet_compiler.exe -p d:\code\websites\brokerweb -v / d:\code\websites\published -f -c -errorstack -u Please help as I cannot publish this site at all at present and it worked fine for quite a long time now before this stupid error. Regards Johan

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  • WPF binding to ComboBox SelectedItem when reference not in ItemsSource.

    - by juharr
    I'm binding the PageMediaSize collection of a PrintQueue to the ItemSource of a ComboBox (This works fine). Then I'm binding the SelectedItem of the ComboBox to the DefaultPrintTicket.PageMediaSize of the PrintQueue. While this will set the selected value to the DefaultPrintTicket.PageMediaSize just fine it does not set the initially selected value of the ComboBox to the initial value of DefaultPrintTicket.PageMediaSize This is because the DefaultPrintTicket.PageMediaSize reference does not match any of the references in the collection. However I don't want it to compare the objects by reference, but instead by value, but PageMediaSize does not override Equals (and I have no control over it). What I'd really like to do is setup a IComparable for the ComboBox to use, but I don't see any way to do that. I've tried to use a Converter, but I would need more than the value and I couldn't figured out how to pass the collection to the ConverterProperty. Any ideas on how to handle this problem. Here's my xaml <ComboBox x:Name="PaperSizeComboBox" ItemsSource="{Binding ElementName=PrintersComboBox, Path=SelectedItem, Converter={StaticResource printQueueToPageSizesConverter}}" SelectedItem="{Binding ElementName=PrintersComboBox, Path=SelectedItem.DefaultPrintTicket.PageMediaSize}" DisplayMemberPath="PageMediaSizeName" Height="22" Margin="120,76,15,0" VerticalAlignment="Top"/> And the code for the converter that gets the PageMediaSize collection public class PrintQueueToPageSizesConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { return value == null ? null : ((PrintQueue)value).GetPrintCapabilities().PageMediaSizeCapability; } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { throw new NotImplementedException(); } }

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  • How to pass SAFEARRAY of UDTs to unmaged code from C#.

    - by themilan
    I also used VT_RECORD. But didn't got success in passing safearray of UDTs. [ComVisible(true)] [StructLayout(LayoutKind.Sequential)] public class MY_CLASS { [MarshalAs(UnmanagedType.U4)] public Int32 width; [MarshalAs(UnmanagedType.U4)] public Int32 height; }; [DllImport("mydll.dll")] public static extern Int32 GetTypes( [In, Out][MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_RECORD, SafeArrayUserDefinedSubType = typeof(MY_CLASS))]MY_CLASS[] myClass, [In, Out][MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_RECORD, SafeArrayUserDefinedSubType = typeof(Guid))]Guid[] guids ); If i communicate with my unmanaged code without 1st parameter, Then there is no error in passing "guids" parameter to unmanaged code. I also able to cast elements of obtained SAFEARRAY at unmanaged side to GUID type. But If i tried to pass my UDT class MY_CLASS to unmanaged code with SAFEARRAY then it fails on managed code. (as above code snippet) It shows exception "An unhandled exception of type 'System.Runtime.InteropServices.SafeArrayTypeMismatchException' occurred in myapp.exe" "Additional information: Specified array was not of the expected type." Plz help me in such a situation to pass SAFEARRAY of UDTs to unmaged code.

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  • How do I pass a lot of parameters to views in Django?

    - by Mark
    I'm very new to Django and I'm trying to build an application to present my data in tables and charts. Till now my learning process went very smooth, but now I'm a bit stuck. My pageview retrieves large amounts of data from a database and puts it in the context. The template then generates different html-tables. So far so good. Now I want to add different charts to the template. I manage to do this by defining <img src=".../> tags. The Matplotlib chart is generate in my chartview an returned via: response=HttpResponse(content_type='image/png') canvas.print_png(response) return response Now I have different questions: the data is retrieved twice from the database. Once in the pageview to render the tables, and again in the chartview for making the charts. What is the best way to pass the data, already in the context of the page to the chartview? I need a lot of charts, each with different datasets. I could make a chartview for each chart, but probably there is a better way. How do I pass the different dataset names to the chartview? Some charts have 20 datasets, so I don't think that passing these dataset parameters via the url (like: <imgm src="chart/dataset1/dataset2/.../dataset20/chart.png />) is the right way. Any advice?

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  • Using Directives, Namespace and Assembly Reference - all jumbled up with StyleCop!

    - by Jack
    I like to adhere to StyleCop's formatting rules to make code nice and clear, but I've recently had a problem with one of its warnings: All using directives must be placed inside of the namespace. My problem is that I have using directives, an assembly reference (for mocking file deletion), and a namespace to juggle in one of my test classes: using System; using System.IO; using Microsoft.Moles.Framework; using Microsoft.VisualStudio.TestTools.UnitTesting; [assembly: MoledType(typeof(System.IO.File))] namespace MyNamespace { //Some Code } The above allows tests to be run fine - but StyleCop complains about the using directives not being inside the namespace. Putting the usings inside the namespace gives the error that "MoledType" is not recognised. Putting both the usings and the assembly reference inside the namespace gives the error 'assembly' is not a valid attribute location for this declaration. Valid attribute locations for this declaration are 'type'. All attributes in this block will be ignored. It seems I've tried every layout I can but to no avail - either the solution won't build, the mocking won't work or StyleCop complains! Does anyone know a way to set these out so that everything's happy? Or am I going to have to ignore the StyleCop warning in this case?

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  • How do I reference an unsigned assembly from a VSTO Word Doc project?

    - by Gishu
    I created a new project in VS2008. Project type Visual C# > Office > 2007 > Word 2007 Document Added some code.. got Word to do a few jumps through some custom hoops.. all fine. Now I need to reference another assembly (CopyLocal as false) which is not signed. So I add the project reference. Now the project will not build complaining error MSB3188: Assembly 'X.dll' must be strong signed in order to be marked as a prerequisite. The error code page is concise (now accustomed to this) Been googling and reading posts ever since.. No Luck. How do I get around this ? Or is the hidden commandment that all references (for VSTO?) must be strong named / signed. I cannot sign 'X.dll' and be done with it because it is a binary that I don't control also it depends on another bunch of unsigned dlls.. can't set off a chain sign reaction. Update: Solved the build issue by turning CopyLocal=True. But this meant dumping the referenced X.DLL and all its dependencies into the bin\debug folder... Ughh! Tried creating a subfolder called bin\debug\refExecs and referencing X.dll CopyLocal=false from there. The error message was back.

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  • jQuery HOW TO?? pass additional parameters to success callback for $.ajax call ?

    - by dotnetgeek
    Hello jQuery Ninjas! I am trying, in vain it seems, to be able to pass additional parameters back to the success callback method that I have created for a successful ajax call. A little background. I have a page with a number of dynamically created textbox / selectbox pairs. Each pair having a dynamically assigned unique name such as name="unique-pair-1_txt-url" and name="unique-pair-1_selectBox" then the second pair has the same but the prefix is different. In an effort to reuse code, I have crafted the callback to take the data and a reference to the selectbox. However when the callback is fired the reference to the selectbox comes back as 'undefined'. I read here that it should be doable. I have even tried taking advantage of the 'context' option but still nothing. Here is the script block that I am trying to use: <script type="text/javascript" language="javascript"> $j = jQuery.noConflict(); function getImages(urlValue, selectBox) { $j.ajax({ type: "GET", url: $j(urlValue).val(), dataType: "jsonp", context: selectBox, success:function(data){ loadImagesInSelect(data, $j(this)) } , error:function (xhr, ajaxOptions, thrownError) { alert(xhr.status); alert(thrownError); } }); } function loadImagesInSelect(data, selectBox) { //var select = $j('[name=single_input.<?cs var:op_unique_name ?>.selImageList]'); var select = selectBox; select.empty(); $j(data).each(function() { var theValue = $j(this)[0]["@value"]; var theId = $j(this)[0]["@name"]; select.append("<option value='" + theId + "'>" + theValue + "</option>"); }); select.children(":first").attr("selected", true); } From what I have read, I feel I am close but I just cant put my finger on the missing link. Please help in your typical ninja stealthy ways. TIA

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  • C#/.Net Error: MySql.Data Object reference not set to an instance of an object.

    - by Simon
    Hello, I get this exception on my Windows 7 64bit in application running in VS 2008 express. I am using Connector/Net 6.2.2.0: Message: Object reference not set to an instance of an object. Source: MySql.Data in MySql.Data.MySqlClient.NativeDriver.GetResult(Int32& affectedRow, Int32& insertedId) Stack trace: in MySql.Data.MySqlClient.Driver.GetResult(Int32 statementId, Int32& affectedRows, Int32& insertedId) in MySql.Data.MySqlClient.Driver.NextResult(Int32 statementId) in MySql.Data.MySqlClient.MySqlDataReader.NextResult() in MySql.Data.MySqlClient.MySqlDataReader.Close() in MySql.Data.MySqlClient.MySqlConnection.Close() in MySql.Data.MySqlClient.MySqlConnection.Dispose(Boolean disposing) in System.ComponentModel.Component.Finalize() No inner exception. This exception is unhalted and the debugger dont point on any code line. It just say "Object reference not set to an instance of an object. MySql.Data" This error is really hard to repeat. On my Windows XP 32bit is all ok. Could it be error in 64bit Windows 7? Thank you very much for your answers. Regards, simon

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  • How to pass filename to StandardInput (Process) in C#?

    - by Cosmo
    Hello Guys! I'm using the native windows application spamc.exe (SpamAssassin - sawin32) from command line as follows: C:\SpamAssassin\spamc.exe -R < C:\email.eml Now I'd like to call this process from C#: Process p = new Process(); p.StartInfo.UseShellExecute = false; p.StartInfo.RedirectStandardOutput = true; p.StartInfo.RedirectStandardInput = true; p.StartInfo.FileName = @"C:\SpamAssassin\spamc.exe"; p.StartInfo.Arguments = @"-R"; p.Start(); p.StandardInput.Write(@"C:\email.eml"); p.StandardInput.Close(); Console.Write(p.StandardOutput.ReadToEnd()); p.WaitForExit(); p.Close(); The above code just passes the filename as string to spamc.exe (not the content of the file). However, this one works: Process p = new Process(); p.StartInfo.UseShellExecute = false; p.StartInfo.RedirectStandardOutput = true; p.StartInfo.RedirectStandardInput = true; p.StartInfo.FileName = @"C:\SpamAssassin\spamc.exe"; p.StartInfo.Arguments = @"-R"; p.Start(); StreamReader sr = new StreamReader(@"C:\email.eml"); string msg = sr.ReadToEnd(); sr.Close(); p.StandardInput.Write(msg); p.StandardInput.Close(); Console.Write(p.StandardOutput.ReadToEnd()); p.WaitForExit(); p.Close(); Could someone point me out why it's working if I read the file and pass the content to spamc, but doesn't work if I just pass the filename as I'd do in windows command line?

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  • How can I get the mapi system stub dll to pass extended mapi calls to my dll?

    - by Bogatyr
    For various reasons (questioning the reasons is not helpful to me), I'd like to implement my own extended mapi dll for windows xp. I have a skeleton dll now, just a few entrypoints exist for testing, but the system mapi stub (c:\windows\system32\mapi32.dll, I've checked that it's identical to mapistub.dll) will not pass through calls to my dll, while it happily passes the same calls through to MS Outlook's msmapi32.dll, (MAPIInitialize, MAPILoginEx are two such calls). There's some secret handshake between the stub and the extended mapi dll wherein the stub checks that "yup, it's an extended mapi dll": maybe it's the presence of some additional entrypoints I haven't implemented yet, maybe it's the return value from some function, I don't know. I've tried tracing a sample app I wrote that calls MAPIInitialize with STraceNT and ProcessMonitor but that didn't show anything obvious. Tracing has shown that indeed the stub loads my dll, but then finds the secret sauce is missing apparently, and returns an error code instead of calling my dll's function. What more could be needed for calling MAPIInitialize than the presence of MAPIInitialize in my dll's exports table? GetProcAddress says it's there. What I'd like to know is how to minimally extend my skeleton extended mapi dll so that the stub mapi dll will pass through extended mapi calls to my dll. What's the secret sauce? I'd rather not spend a painful week in msvc reverse engineering the stub behavior.

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  • How do I pass a lot of parameters to views in Dango?

    - by Mark
    I'm very new to Django and I'm trying to build an application to present my data in tables and charts. Till now my learning process went very smooth, but now I'm a bit stuck. My pageview retrieves large amounts of data from a database and puts it in the context. The template then generates different html-tables. So far so good. Now I want to add different charts to the template. I manage to do this by defining <img src=".../> tags. The Matplotlib chart is generate in my chartview an returned via: response=HttpResponse(content_type='image/png') canvas.print_png(response) return response Now I have different questions: the data is retrieved twice from the database. Once in the pageview to render the tables, and again in the chartview for making the charts. What is the best way to pass the data, already in the context of the page to the chartview? I need a lot of charts, each with different datasets. I could make a chartview for each chart, but probably there is a better way. How do I pass the different dataset names to the chartview? Some charts have 20 datasets, so I don't think that passing these dataset parameters via the url (like: <imgm src="chart/dataset1/dataset2/.../dataset20/chart.png />) is the right way. Any advice?

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  • How do I pass a LuaTable between two Lua states using LuaInterface?

    - by user316675
    I've been trying to pass a LuaTable class between two Lua states, like so: LuaManager L1 = new Lua(); LuaManager L2 = new Lua(); LuaTable table = L1.DoString("return {apple = 25}")[0]; L2["tbl"] = table; double results = L2.DoString("return tbl[\"apple\"]")[0]; Assert.AreEqual(25.0, results); The above test fails; I receive a return value of nil. Using the Immediate Window confirms that "table" is a non-null object, and that table["apple"] returns 25; it's something that's being lost in translation to L2. Interestingly, when the object is loaded back into the same state, the test works, like so: //Succeeds LuaManager lua = new Lua(); LuaTable table = lua.DoString("return {apple = 25}")[0]; lua["tbl"] = table; double results = lua.DoString("return tbl[\"apple\"]")[0]; Assert.AreEqual(25.0, results); How can I safely pass the LuaTables without hassles? Thanks in advance!

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  • How to pass multiple different records (not class due to delphi limitations) to a function?

    - by mingo
    Hi to all. I have a number of records I cannot convert to classes due to Delphi limitation (all of them uses class operators to implement comparisons). But I have to pass to store them in a class not knowing which record type I'm using. Something like this: type R1 = record begin x :Mytype; class operator Equal(a,b:R1) end; type R2 = record begin y :Mytype; class operator Equal(a,b:R2) end; type Rn = record begin z :Mytype; class operator Equal(a,b:Rn) end; type TC = class begin x : TObject; y : Mytype; function payload (n:TObject) end; function TC.payload(n:TObject) begin x := n; end; program: c : TC; x : R1; y : R2; ... c := TC.Create(): n:=TOBject(x); c.payload(n); Now, Delphi do not accept typecast from record to TObject, and I cannot make them classes due to Delphi limitation. Anyone knows a way to pass different records to a function and recognize their type when needed, as we do with class: if x is TMyClass then TMyClass(x) ... ???

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  • Function parameters evaluation order: is undefined behaviour if we pass reference?

    - by bolov
    This is undefined behaviour: void feedMeValue(int x, int a) { cout << x << " " << a << endl; } int main() { int a = 2; int &ra = a; feedMeValue(ra = 3, a); return 0; } because depending on what parameter gets evaluated first we could call (3, 2) or (3, 3). However this: void feedMeReference(int x, int const &ref) { cout << x << " " << ref << endl; } int main() { int a = 2; int &ra = a; feedMeReference(ra = 3, a); return 0; } will always output 3 3 since the second parameter is a reference and all parameters have been evaluated before the function call, so even if the second parameter is evaluated before of after ra = 3, the function received a reference to a wich will have a value of 2 or 3 at the time of the evaluation, but will always have the value 3 at the time of the function call. Is the second example UB? It is important to know because the compiler is free to do anything if he detects undefined behaviour, even if I know it would always yield the same results. *Note: I think that feedMeReference(a = 3, a) is the exact same situation as feedMeReference(ra = 3, a). However it seems not everybody agrees, in the addition to having 2 completely different answers.

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  • Is there a way to increase the efficiency of shared_ptr by storing the reference count inside the co

    - by BillyONeal
    Hello everyone :) This is becoming a common pattern in my code, for when I need to manage an object that needs to be noncopyable because either A. it is "heavy" or B. it is an operating system resource, such as a critical section: class Resource; class Implementation : public boost::noncopyable { friend class Resource; HANDLE someData; Implementation(HANDLE input) : someData(input) {}; void SomeMethodThatActsOnHandle() { //Do stuff }; public: ~Implementation() { FreeHandle(someData) }; }; class Resource { boost::shared_ptr<Implementation> impl; public: Resource(int argA) explicit { HANDLE handle = SomeLegacyCApiThatMakesSomething(argA); if (handle == INVALID_HANDLE_VALUE) throw SomeTypeOfException(); impl.reset(new Implementation(handle)); }; void SomeMethodThatActsOnTheResource() { impl->SomeMethodThatActsOnTheHandle(); }; }; This way, shared_ptr takes care of the reference counting headaches, allowing Resource to be copyable, even though the underlying handle should only be closed once all references to it are destroyed. However, it seems like we could save the overhead of allocating shared_ptr's reference counts and such separately if we could move that data inside Implementation somehow, like boost's intrusive containers do. If this is making the premature optimization hackles nag some people, I actually agree that I don't need this for my current project. But I'm curious if it is possible.

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  • C#. How to pass message from unsafe callback to managed code?

    - by maxima120
    Is there a simple example of how to pass messages from unsafe callback to managed code? I have a proprietary dll which receives some messages packed in structs and all is coming to a callback function. The example of usage is as follows but it calls unsafe code too. I want to pass the messages into my application which is all managed code. *P.S. I have no experience in interop or unsafe code. I used to develop in C++ 8 yrs ago but remember very little from that nightmarish times :) P.P.S. The application is loaded as hell, the original devs claim it processes 2mil messages per sec.. I need a most efficient solution.* static unsafe int OnCoreCallback(IntPtr pSys, IntPtr pMsg) { // Alias structure pointers to the pointers passed in. CoreSystem* pCoreSys = (CoreSystem*)pSys; CoreMessage* pCoreMsg = (CoreMessage*)pMsg; // message handler function. if (pCoreMsg->MessageType == Core.MSG_STATUS) OnCoreStatus(pCoreSys, pCoreMsg); // Continue running return (int)Core.CALLBACKRETURN_CONTINUE; } Thank you.

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  • Drupal 6: getting particular fields from Node Reference types...

    - by artmania
    Hi friends, I'm a drupal newbie... <?php print $node->field_date[0]['view']; ?> I can get the custom created CCK fields' value and display in tpl.php files as above... that's fine. my question is how can I get the Node reference fields' in-fields? for example, I have an event content type, and I have defined Node Reference for Location (title, address, img, etc.). When I write the code below, it displays all location content; <?php print $node->field_location[0]['view']; ?> but I need to get only address field from this location content type. sth like below would be great :D but not working; <?php print $node->field_location[0]['field_address']['view']; ?> so how can get that? appreciate helps so much! thanks a lot!

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  • Should I pass a SqlDataReader by reference or not when passing it out to multiple threads.

    - by deroby
    Hi all, being new to c# I've run into this 'conundrum' when passing around a SqlDataReader between different threads. Without going into too much detail, the idea is to have a main thread fetching data from the database (a large recordset) and then have a helper-task run through this record by record and doing some stuff based upon the contents of this. There is no feedback to the recordset, it simply wades through until no records are left. This works fine, but given the nature of the job at hand it should be possible to have this job spread over different threads (CPUs) to maximize throughput (the order of execution is of no significance). The question then becomes, when I pass this recordset in a SqlDataReader, do I have to use ref or not ? It kind of boils down to the question : if I pass the object around without specifying ref, won't it create new copies in memory and have records processed n times ? Or, don't I risk having the record-position being moved forward while not all fields have been fully read yet ? The latter seems more like a 'data racing' issue and probably is covered by the lock()ing mechanism (or not?). My initial take on the problem was that it doesn't really hurt passing the variable using ref, yet as a colleague put it : "you only need ref when you're doing something wrong" =) Additionally using ref restricts me from applying a Using() construction too which isn't very nice either. I thus create a "basic" project that tackles the same approach but without the ref notation. Tests so far show that it works flawlessly on a Core2Duo (2cpu) using any number of threads, yet I'm still a bit wary... What do you experts think about this ? Use ref or not ? You can find the test-project here as it seems I can't upload it to this question directly ?!? ps: it's just a test-project and I'm new to c#, so please be gentle on me when breaking down the code =P

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  • Dataset holds a table called "Table", not the table I pass in?

    - by dotnetdev
    Hi, I have the code below: string SQL = "select * from " + TableName; using (DS = new DataSet()) using (SqlDataAdapter adapter = new SqlDataAdapter()) using (SqlConnection sqlconn = new SqlConnection(connectionStringBuilder.ToString())) using (SqlCommand objCommand = new SqlCommand(SQL, sqlconn)) { sqlconn.Open(); adapter.SelectCommand = objCommand; adapter.Fill(DS); } System.Windows.Forms.MessageBox.Show(DS.Tables[0].TableName); return DS; However, every time I run this code, the dataset (DS) is filled with one table called "Table". It does not represent the table name I pass in as the parameter TableName and this parameter does not get mutated so I don't know where the name Table comes from. I'd expect the table to be the same as the tableName parameter I pass in? Any idea why this is not so? EDIT: Important fact: This code needs to return a dataset because I use the dataRelation object in another method, which is dependent on this, and without using a dataset, that method throws an exception. The code for that method is: DataRelation PartToIntersection = new DataRelation("XYZ", this.LoadDataToTable(tableName).Tables[tableName].Columns[0], // Treating the PartStat table as the parent - .N this.LoadDataToTable("PartProducts").Tables["PartProducts"].Columns[0]); // 1 // PartsProducts (intersection) to ProductMaterial DataRelation ProductMaterialToIntersection = new DataRelation("", ds.Tables["ProductMaterial"].Columns[0], ds.Tables["PartsProducts"].Columns[1]); Thanks

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  • Strict pointer aliasing: is access through a 'volatile' pointer/reference a solution?

    - by doublep
    On the heels of a specific problem, a self-answer and comments to it, I'd like to understand if it is a proper solution, workaround/hack or just plain wrong. Specifically, I rewrote code: T x = ...; if (*reinterpret_cast <int*> (&x) == 0) ... As: T x = ...; if (*reinterpret_cast <volatile int*> (&x) == 0) ... with a volatile qualifier to the pointer. Let's just assume that treating T as int in my situation makes sense. Does this accessing through a volatile reference solve pointer aliasing problem? For a reference, from specification: [ Note: volatile is a hint to the implementation to avoid aggressive optimization involving the object because the value of the object might be changed by means undetectable by an implementation. See 1.9 for detailed semantics. In general, the semantics of volatile are intended to be the same in C++ as they are in C. — end note ] EDIT: The above code did solve my problem at least on GCC 4.5.

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  • Is this reference or code in mistake or bug?

    - by mikezang
    I copied some text from NSDate Reference as below, please check Return Value, it is said the format will be in YYYY-MM-DD HH:MM:SS ±HHMM, but I got as below in my app, so the reference is mistake? or code in mistake? Saturday, January 1, 2011 12:00:00 AM Japan Standard Time or 2011?1?1????0?00?00? ????? descriptionWithLocale: Returns a string representation of the receiver using the given locale. - (NSString *)descriptionWithLocale:(id)locale Parameters locale An NSLocale object. If you pass nil, NSDate formats the date in the same way as the description method. On Mac OS X v10.4 and earlier, this parameter was an NSDictionary object. If you pass in an NSDictionary object on Mac OS X v10.5, NSDate uses the default user locale—the same as if you passed in [NSLocale currentLocale]. Return Value A string representation of the receiver, using the given locale, or if the locale argument is nil, in the international format YYYY-MM-DD HH:MM:SS ±HHMM, where ±HHMM represents the time zone offset in hours and minutes from GMT (for example, “2001-03-24 10:45:32 +0600”)

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