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  • What is wrong with Paperclip+ImageMagick on Heroku?

    - by Yuri
    UPD class User < ActiveRecord::Base Paperclip.options[:swallow_stderr] = false has_attached_file :photo, :styles => { :square => "100%", :large => "100%" }, :convert_options => { :square => "-auto-orient -geometry 70X70#", :large => "-auto-orient -geometry X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' validates_attachment_size :photo, :less_than => 5.megabyte end Works great on local machine, but gives me an error on Heroku: There was an error processing the thumbnail for stream.20143 The thing is I want to auto-orient photos before resizing, so they resized properly. The only working variant now(thanks to jonnii) is resizing without auto-orient: ... as_attached_file :photo, :styles => { :square => "70X70#", :large => "X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' ... How to pass additional convert options to paperclip on Heroku?

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  • Problem with Mapping Linq-to-Sql on different Types

    - by csharpnoob
    Hi, maybe someone can help. I want to have on mapped Linq-Class different Datatype. This is working: private System.Nullable<short> _deleted = 1; [Column(Storage = "_deleted", Name = "deleted", DbType = "SmallInt", CanBeNull = true)] public System.Nullable<short> deleted { get { return this._deleted; } set { this._deleted = value; } } Sure thing. But no when i want to place some logic for boolean, like this: private System.Nullable<short> _deleted = 1; [Column(Storage = "_deleted", Name = "deleted", DbType = "SmallInt", CanBeNull = true)] public bool deleted { get { if (this._deleted == 1) { return true; } return false; } set { if(value == true) { this._deleted = (short)1; }else { this._deleted = (short)0; } } } I get always runtime error: [TypeLoadException: GenericArguments[2], "System.Nullable`1[System.Int16]", on 'System.Data.Linq.Mapping.PropertyAccessor+Accessor`3[T,V,V2]' violates the constraint of type parameter 'V2'.] I can't change the database to bit.. I need to have casting in mapping class.

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  • Creating a multi-step process with mysql and php

    - by Paul Atkins
    Hi, I am working on a script which allows users to create a stepped process. The steps will consist of sending visitors to urls where they will fill out a form then be directed to the next step the user has created. Each user can create as many steps as they wish and the url for each step will be unique. I am not sure if I am doing this in the correct/most efficient way so I have a few questions about this. Before I begin here is a simple version of my table structure: step_id user_id step_url step_order 1 1 example.com?step=1 1 2 2 test.com?step=1 1 3 1 example.com?step=3 2 A visitor will be directed to step_url: example.com?step=1 by user_id: 1 On this page there will be a form which contains a hidden field with the value of the step_id like this: <input type="hidden" name="step_id" value="1"> Once the visitor has filled out this form it will be processed by my script at a url similar to: http://mysite.com/form-process.php Once the form has been submitted I then need to direct the visitor to the next step my user has created. I would currently do this using code similar to this: SELECT step_url FROM table WHERE step_order='$current_step_order'+1 Here are my questions about this: Is this the best most efficient way to accomplish this? Or is there a better way? As the step_id column is auto increment...how would I increment the order column by 1 each time a user inserts a new step? Thanks for taking the time to read this. Paul

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  • Extracting files from merge module

    - by Mystagogue
    All I want is a command-line tool that can extract files from a merge module (.msm) onto disk. I'm trying msidb.exe and orca.exe The documentation for orca states: Many merge module options can be specified from the command line... Extracting Files from a Merge Module Orca supports three different methods for extracting files contained in a merge module. Orca can extract the individual CAB file, extract the files into a module tree and extract the files into a source image once it has been merged into a target database... Extracting Files To extract the individual files from a merge module, use the ... -x ... option on the command line, where is the desired path to the new directory tree. The specified path is used as the root path for the extracted files. All files are extracted from the CAB file embedded in the module and placed in the specified path. The directory layout for the extracted files is based on the directory tree of the merge module. It mostly sounds like exactly what I need. But when I try it, orca simply opens up an editor (with info on the msm I specified) and then does nothing. I've tried a variety of command lines, usually starting with this: orca -x theDirectory theModule.msm I use "theDirectory" as whatever empty folder I want. Like I said - it didn't do anything. Then I tried msidb, where a couple of attempts I've made look like this: msidb -d theModule.msm -w {storage} msidb -d theModule.msm -x {stream} In both cases, I don't know what to insert for {storage} or {stream} to make it happy - I don't know what those represent. Can someone explain what I'm doing wrong with the command line options? Is there any other tool that can do this?

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  • SQL Server slow in production environment

    - by Lieven Cardoen
    I have a weird problem in a customer's production environment. I can't give any details on the infrastructure, except that SQL server runs on a virtual server. The data, log and filestream file are on another storage server (data and filestream together and log on a separate server). In our local Test environment, there's one particular query that executes with these durations: first we clear the cache 300ms (First time it takes longer, but from then on it's cached.) 20ms 15ms 17ms In the customer's production environment, the SQL Server is more powerful, these are the durations (I didn't have the rights to clear the cache. Will try this tomorrow). 2500ms 2600ms 2400ms The servers in the customer's production environment are more powerful but they do have virtual servers (we don't). What could be the cause... Not enough memory? Fragmentation? Physical storage? How would you tackle this performance problem? EDIT: Some people have asked me if the data set is equal and it is. I restored their database on our environment. It's true that this was the first thing I looked at. (@Everyone: I added the edit because it will be the first thing that many will think off).

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  • How do you use asynchronous ORMs without huge callback chains?

    - by hornairs
    I'm using the relatively immature Joose Javascript ORM plugin (project page) to persist objects in an Appcelerator Titanium (company page) mobile project. Since it's client side storage, the application has to check to see if the database is initialized before starting up the ORM since it inspects the DB tables to construct the classes. My problem is that this sequence of operations (and if this one is like this, other things down the road) takes a lot of callbacks to complete. I have a lot of jumping around in the code that isn't apparent to a maintainer and results in some complex call graphs and whatnot. So, I ask these questions: How would you asynchronously initialize a database and populate it with seed data using an ORM that needs the schema to be correct to function? Do you have any general strategies or links for async/event driven programming and keeping the call graph simple and understandable? Do you have any suggestions for Javascript ORMs/meta object systems that work with HTML 5 as a storage engine and are hopefully framework agnostic? Am I just a big newb and should be able to work this out with ease? Thanks folks!

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  • What are good NoSQL and non-relational database solutions for audit/logging database

    - by Juha Syrjälä
    What would be suitable database for following? I am especially interested about your experiences with non-relational NoSQL systems. Are they any good for this kind of usage, which system you have used and would recommend, or should I go with normal relational database (DB2)? I need to gather audit trail/logging type information from bunch of sources to a centralized server where I could generate reports efficiently and examine what is happening in the system. Typically a audit/logging event would consist always of some mandatory fields, for example globally unique id (some how generated by program that generated this event) timestamp event type (i.e. user logged in, error happened etc) some information about source (server1, server2) Additionally the event could contain 0-N key-value pairs, where value might be up to few kilobytes of text. It must run on Linux server It should work with high amount of data (100GB for example) it should support some kind of efficient full text search It should allow concurrent reading and writing It should be flexible to add new event types and add/remove key-value pairs to new events. Flexible=no changes should be required to database schema, application generating the events can just add new event types/new fields as needed. it should be efficient to make queries against database. For reporting and exploring what happened. For example: How many events with type=X occurred in some time period. Get all events where field A has value Y. Get all events with type X and field A has value 1 and field B is not 2 and event occurred in last 24h

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  • jQuery not and classes

    - by Giles B
    Hi Guys, I have 2 anchor links (a.selector) and when one is clicked it has a class applied to it of 'active-arrow' and the click also removes the class of the same name from the other anchor as well as lowering the opacity to 0.2. I then want to have a fade effect when the user hovers over the anchor that doesn't have 'active-arrow' applied to it so that it goes to full opacity when mouseenters and back to 0.2 when mouseleaves. The problem im having is that both .not and :not don't seem to be working as expected, the hover effect works but if I click on the anchor whilst hovering the 'active-arrow' class is applied but when mouseleaves the opacity is faded down to 0.2 again even though the 'active-arrow' class is applied. Also the hover then doesn't work for the other a link which has had 'active-arrow' removed. Bit of a hard one to explain so heres some code that hopefully helps a bit. *//If a.selector doesn't have the class 'active-arrow' then run the hoverFade function* $("a.selector").not(".active-arrow").hoverFade(); //Functions for first element $('a.selector-1').click(function () { $('a.selector-2').removeClass('active-arrow'); //Remove background image from corresponding element $('ul#storage-items-2').fadeOut(1200).addClass('hide'); //Fade out then hide corresponding list $(this).addClass('active-arrow', 'fast'); //Add background image to current element $('ul#storage-items-1').removeClass('hide').fadeIn(1800); //Unhide and fade in the list $('a.selector-2').fadeTo(500, 0.2); //Fade corresponding element $(this).fadeTo(800, 1);//Fade this element to full opacity }); I only included the code for teh first anchor (a.selector-1) as the code for the second anchor is identical but just changes the class names to a.selector-2. Also the hoverFade function is in a seperate file so we can re-use it. jQuery.fn.hoverFade = function() { return this.each(function(){ $(this).hover( function () { $(this).fadeTo(500, 0.8); }, function () { $(this).fadeTo(500, 0.2); }); }); } Each anchor link fades in and fades out a UL as well. Any help is most appreciated Thanks Giles

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  • Choosing random numbers efficiently

    - by Frederik Wordenskjold
    I have a method, which uses random samples to approximate a calculation. This method is called millions of times, so its very important that the process of choosing the random numbers is efficient. I'm not sure how fast javas Random().nextInt really are, but my program does not seem to benefit as much as I would like it too. When choosing the random numbers, I do the following (in semi pseudo-code): // Repeat this 300000 times Set set = new Set(); while(set.length != 5) set.add(randomNumber(MIN,MAX)); Now, this obviously has a bad worst-case running time, as the random-function in theory can add duplicated numbers for an eternity, thus staying in the while-loop forever. However, the numbers are chosen from {0..45}, so a duplicated value is for the most part unlikely. When I use the above method, its only 40% faster than my other method, which does not approximate, but yields the correct result. This is ran ~ 1 million times, so I was expecting this new method to be at least 50% faster. Do you have any suggestions for a faster method? Or maybe you know of a more efficient way of generation a set of random numbers.

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  • How to pass additional convert options to paperclip on Heroku?

    - by Yuri
    UPD class User < ActiveRecord::Base Paperclip.options[:swallow_stderr] = false has_attached_file :photo, :styles => { :square => "100%", :large => "100%" }, :convert_options => { :square => "-auto-orient -geometry 70X70#", :large => "-auto-orient -geometry X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' validates_attachment_size :photo, :less_than => 5.megabyte end Works great on local machine, but gives me an error on Heroku: There was an error processing the thumbnail for stream.20143 The thing is I want to auto-orient photos before resizing, so they resized properly. The only working variant now(thanks to jonnii) is resizing without auto-orient: ... as_attached_file :photo, :styles => { :square => "70X70#", :large => "X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' ... How to pass additional convert options to paperclip on Heroku?

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  • Migrating data from Plone to Liferay, or how could I retrieve information from Plone's Data.fs

    - by brandizzi
    Hello, all. I need to migrate data from a Plone-based portal to Liferay. Has anyone some idea on how to do it? Anyway, I am trying to retrieve data from Data.fs and store it in a representation easier to work, such as JSON. To do it, I need to know which objects I should get from Plone's Data.fs. I already got the Products.CMFPlone.Portal.PloneSite instance from the Data.fs, but I cannot get anything from it. I would like to get the PloneSite instance and do something like this: >>> import ZODB >>> from ZODB import FileStorage, DB >>> path = r"C:\Arquivos de programas\Plone\var\filestorage\Data.fs" >>> storage = FileStorage.FileStorage(path) >>> db = DB(storage) >>> conn = db.open() >>> root = conn.root() >>> app = root['Application'] >>> plone_site = app.getChildNodes()[13] # 13 would be index of PloneSite object >>> a = plone_site.get_articles() >>> for article in a: ... print "Title:", a.title ... print "Content:", a.content Title: <some title> Conent: <some content> Title: <some title> Conent: <some content> Of course, it did not need to be so straightforward. I just want some information about the structure of PloneSite and how to recover its data. Has anyone some idea? Thank you in advance!

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  • C#, Asp.net Uploading files to file server...

    - by Imcl
    Using the link below, I wrote a code for my application. I am not able to get it right though, Please refer the link and help me ot with it... http://stackoverflow.com/questions/263518/c-uploading-files-to-file-server The following is my code:- protected void Button1_Click(object sender, EventArgs e) { filePath = FileUpload1.FileName; try { WebClient client = new WebClient(); NetworkCredential nc = new NetworkCredential(uName, password); Uri addy = new Uri("\\\\192.168.1.3\\upload\\"); client.Credentials = nc; byte[] arrReturn = client.UploadFile(addy, filePath); arrReturn = client.UploadFile(addy, filePath); Console.WriteLine(arrReturn.ToString()); } catch (Exception ex) { Console.WriteLine(ex.Message); } } I also used:- File.Copy(filePath, "\\192.168.1.3\upload\"); The following line doesnt execute... byte[] arrReturn = client.UploadFile(addy, filePath); tried changing it to:- byte[] arrReturn = client.UploadFile("\\192.168.1.3\upload\", filePath); IT still doesnt work...Any solution to it?? I basically want to transfer a file from the client to the file storage server without actually loggin into the server so that the client cannot access the storage location on the server directly...

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  • What's are the best readings to start using WPF instead of WinForms?

    - by Ivan
    Keeping in mind what CannibalSmith once said - "All the answers are saying "WPF is different". That's a huge understatement. You not only have to learn lots of new stuff - you must forget everything you've learned from Forms. It's a completely new way of doing UI." .. and having many years of experience with visual Windows desktop applications development (VB6, Borland C++ Builder VCL, WinForms) (which is hard to forget), how do I quickly move to developing to say well-formed WPF applications with Visual Studio? I don't need boozy-woozy graphics to give my app look and feel of a Hollywood blockbuster or a million dollar pyjamas. I always loved tidiness of standard Windows common controls and UI design guidelines, end even more I enjoyed them under Vista Glass Aero Graphite sauce. I am perfectly satisfied with WinForms but I want to my applications to be built of the most efficient and up-to-date standard technologies and architectured according to the most efficient and flexible patterns of today and tomorrow, leveraging interface-based integration and functionality reuse and to take all advantages of modern hardware and APIs to maximize performance, usability, reliability, maintainability, extensibility, etc. I very much like the idea of separating view, logic and data, letting a view to take all advantages of the platform (may it run as a web browser applet on a thin client or as a desktop application on a PC with a latest GPU), letting logic be reused, parallelized and seamlessly evolve, storing data in a well structured format in a right place. But... while moving from VB6 to Borland C++ Builder was very easy (no books/tutorials needed to turn it on and start working) (assuming I already knew C++), moving from BCB to WinForms was the same seamless, it does not seem any obvious to me how to do with WPF. So how do I best convert myself from a WinForms developer into a right-way thinking and doing WPF developer?

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  • "Work stealing" vs. "Work shrugging (tm)"?

    - by John
    Why is it that I can find lots of information on "work stealing" and nothing on a "work shrugging(tm)" as a load-balancing strategy? I am surprised because work-stealing seems to me to have an inherent weakness when implementating efficient fine-grained load-balancing. Vis:- Relying on consumer processors to implement distribution (by actively stealing) begs the question of what these processors do when they find no work? None of the work-stealing references and implementations I have come across so far address this issue satisfactorarily for me. They either:- 1) Manage not to disclose what they do with idle processors! [Cilk] (?anyone know?) 2) Have all idle processors sleep and wake periodically and scatter messages to the four winds to see if any work has arrived [e.g. JAWS] (= way too latent & inefficient for me). 3) Assume that it is acceptable to have processors "spinning" looking for work ( = non-starter for me!) Unless anyone thinks there is a solution for this I will move on to consider a "Work Shrugging(tm)" strategy. Having the task-producing processor distribute excess load seems to me inherently capable of a much more efficient implementation. However a quick google didn't show up anything under the heading of "Work Shrugging" so any pointers to prior-art would be welcome. tx Tags I would have added if I was allowed to [work-stealing]

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  • Replacing a Namespace with XSLT

    - by er4z0r
    Hi I want to work around a 'bug' in certain RSS-feeds, which use an incorrect namespace for the mediaRSS module. I tried to do it by manipulating the DOM programmatically, but using XSLT seems more flexible to me. Example: <media:thumbnail xmlns:media="http://search.yahoo.com/mrss" url="http://www.suedkurier.de/storage/pic/dpa/infoline/brennpunkte/4311018_0_merkelxI_24280028_original.large-4-3-800-199-0-3131-2202.jpg" /> <media:thumbnail url="http://www.suedkurier.de/storage/pic/dpa/infoline/brennpunkte/4311018_0_merkelxI_24280028_original.large-4-3-800-199-0-3131-2202.jpg" /> Where the namespace must be http://search.yahoo.com/mrss/ (mind the slash). This is my stylesheet: <?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="//*[namespace-uri()='http://search.yahoo.com/mrss']"> <xsl:element name="{local-name()}" namespace="http://search.yahoo.com/mrss/" > <xsl:apply-templates select="@*|*|text()" /> </xsl:element> </xsl:template> </xsl:stylesheet> Unfortunately the result of the transformation is an invalid XML and my RSS-Parser (ROME Library) does not parse the feed anymore: java.lang.IllegalStateException: Root element not set at org.jdom.Document.getRootElement(Document.java:218) at com.sun.syndication.io.impl.RSS090Parser.isMyType(RSS090Parser.java:58) at com.sun.syndication.io.impl.FeedParsers.getParserFor(FeedParsers.java:72) at com.sun.syndication.io.WireFeedInput.build(WireFeedInput.java:273) at com.sun.syndication.io.WireFeedInput.build(WireFeedInput.java:251) ... 8 more What is wrong with my stylesheet?

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  • InsertOnSubmit - NullReferenceException

    - by Jackie Chou
    I have 2 Model AccountEntity [Table(Name = "Account")] public class AccountEntity { [Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)] public int id { get; set; } [Column(CanBeNull = false, Name = "email")] public string email { get; set; } [Column(CanBeNull = false, Name = "pwd")] public string pwd { get; set; } [Column(CanBeNull = false, Name = "row_guid")] public Guid guid { get; set; } private EntitySet<DetailsEntity> details_id { get; set; } [Association(Storage = "details_id", OtherKey = "id", ThisKey = "id")] public ICollection<DetailsEntity> detailsCollection { get; set; } } DetailsEntity [Table(Name = "Details")] public class DetailsEntity { public DetailsEntity(AccountEntity a) { this.Account = a; } [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "int")] public int id { get; set; } private EntityRef<AccountEntity> _account = new EntityRef<AccountEntity>(); [Association(IsForeignKey = true, Storage = "_account", ThisKey = "id")] public AccountEntity Account { get; set; } } Main using (Database db = new Database()) { AccountEntity a = new AccountEntity(); a.email = "hahaha"; a.pwd = "13212312"; a.guid = Guid.NewGuid(); db.Account.InsertOnSubmit(a); db.SubmitChanges(); } that has relationhip AccountEntity <- DetailsEntity (1-n) when i'm trying to insert a record exception throws NullReferenceException cause: by EntitySet null please help me make it insert

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  • Specifying ASP.NET MVC attributes for auto-generated data models

    - by Lyubomyr Shaydariv
    Hello to everyone. I'm very new to ASP.NET MVC (as well as ASP.NET in general), and going to gain some knowledge for this technology, so I'm sorry I can ask some trivial questions. I have installed ASP.NET MVC 3 RC1 and I'm trying to do the following. Let's consider that I have a model that's completely auto-generated from a table using the "LINQ to SQL Classes" template in VS2010. The template generates 3 files (two .cs files and one .layout file respectively), and the generated partial class is expected to be used as an MVC model. Let's also consider, a single DB column, that's mapped into the model, may look like this: [global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_Name", DbType = "VarChar(128)")] public string Name { get { return this._Name; } set { if ( (this._Name != value) ) { // ... generated stuff goes here } } } The ASP.NET MVC engine also provides a beautiful declarative way to specify some additional stuff, like RequiredAttribute, DisplayNameAttribute and other nice attributes. But since the mapped model is a purely auto-genereated model, I've realized that I should not change the model manually, and specify the fields like: [Required] [DisplayName("Project name")] [StringLength(128)] [global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_Name", DbType = "VarChar(128)")] public string Name { ... though this approach works perfectly... until I change the model in the DBML-designer removing the ASP.NET MVC attributes automatically. So, how do I specify ASP.NET MVC attributes for the DBML models and their fields safely? Thanks in advance, and Merry Christmas.

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  • including tk.h and tcl.h in c program

    - by user362075
    hi, i am working on an ubuntu system. My aim is to basically make an IDE in C language using GUI tools from TCL/TK. I installed tcl 8.4, tk8.4, tcl8.4-dev, tk8.4-dev and have the tk.h and tcl.h headers file in my system. But, when I am running a basic hello world program it's showing a hell lot of errors. include "tk.h" include "stdio.h" void hello() { puts("Hello C++/Tk!"); } int main(int, char *argv[]) { init(argv[0]); button(".b") -text("Say Hello") -command(hello); pack(".b") -padx(20) -pady(6); } Some of the errors are tkDecls.h:644: error: expected declaration specifiers before ‘EXTERN’ /usr/include/libio.h:488: error: expected ‘)’ before ‘*’ token In file included from tk.h:1559, from new1.c:1: tkDecls.h:1196: error: storage class specified for parameter ‘TkStubs’ tkDecls.h:1201: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘attribute’ before ‘*’ token /usr/include/stdio.h:145: error: storage class specified for parameter ‘stdin’ tk.h:1273: error: declaration for parameter ‘Tk_PhotoHandle’ but no such parameter Can anyone please tell me how can I rectify these errors? Please help...

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  • including tk.h and tcl.h in c program

    - by user362075
    hi, i am working on an ubuntu system. My aim is to basically make an IDE in C language using GUI tools from TCL/TK. I installed tcl 8.4, tk8.4, tcl8.4-dev, tk8.4-dev and have the tk.h and tcl.h headers file in my system. But, when I am running a basic hello world program it's showing a hell lot of errors. include "tk.h" include "stdio.h" void hello() { puts("Hello C++/Tk!"); } int main(int, char *argv[]) { init(argv[0]); button(".b") -text("Say Hello") -command(hello); pack(".b") -padx(20) -pady(6); } Some of the errors are tkDecls.h:644: error: expected declaration specifiers before ‘EXTERN’ /usr/include/libio.h:488: error: expected ‘)’ before ‘*’ token In file included from tk.h:1559, from new1.c:1: tkDecls.h:1196: error: storage class specified for parameter ‘TkStubs’ tkDecls.h:1201: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘attribute’ before ‘*’ token /usr/include/stdio.h:145: error: storage class specified for parameter ‘stdin’ tk.h:1273: error: declaration for parameter ‘Tk_PhotoHandle’ but no such parameter Can anyone please tell me how can I rectify these errors? Please help...

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  • C++ .NET DLL vs C# Managed Code ? (File Encrypting AES-128+XTS)

    - by Ranhiru
    I need to create a Windows Mobile Application (WinMo 6.x - C#) which is used to encrypt/decrypt files. However it is my duty to write the encryption algorithm which is AES-128 along with XTS as the mode of operation. RijndaelManaged just doesn't cut it :( Very much slower than DES and 3DES CryptoServiceProviders :O I know it all depends on how good I am at writing the algorithm in the most efficient way. (And yes I my self have to write it from scratch but i can take a look @ other implementations) Nevertheless, does writing a C++ .NET DLL to create the encryption/decryption algorithm + all the file handling and using it from C# have a significant performance advantage OVER writing the encryption algorithm + file handling in completely managed C# code? If I use C++ .NET to create the encryption algorithm, should I use MFC Smart Device DLL or ATL? What is the difference and is there any impact on which one I choose? And can i just add a reference to the C++ DLL from C# or should I use P/Invoke? I am fairly competent with C# than C++ but performance plays a major role as I have convinced my lecturers that AES is a very efficient cryptographic algorithm for resource constrained devices. Thanx a bunch :)

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  • How to keep only duplicates efficiently?

    - by Marc Eaddy
    Given an STL vector, I'd like an algorithm that outputs only the duplicates in sorted order, e.g., INPUT : { 4, 4, 1, 2, 3, 2, 3 } OUTPUT: { 2, 3, 4 } The algorithm is trivial, but the goal is to make it as efficient as std::unique(). My naive implementation modifies the container in-place: My naive implementation: void keep_duplicates(vector<int>* pv) { // Sort (in-place) so we can find duplicates in linear time sort(pv->begin(), pv->end()); vector<int>::iterator it_start = pv->begin(); while (it_start != pv->end()) { size_t nKeep = 0; // Find the next different element vector<int>::iterator it_stop = it_start + 1; while (it_stop != pv->end() && *it_start == *it_stop) { nKeep = 1; // This gets set redundantly ++it_stop; } // If the element is a duplicate, keep only the first one (nKeep=1). // Otherwise, the element is not duplicated so erase it (nKeep=0). it_start = pv->erase(it_start + nKeep, it_stop); } } If you can make this more efficient, elegant, or general, please let me know. For example, a custom sorting algorithm, or copy elements in the 2nd loop to eliminate the erase() call.

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  • Database migration pattern for Java?

    - by Eno
    Im working on some database migration code in Java. Im also using a factory pattern so I can use different kinds of databases. And each kind of database im using implements a common interface. What I would like to do is have a migration check that is internal to the class and runs some database schema update code automatically. The actual update is pretty straight forward (I check schema version in a table and compare against a constant in my app to decide whether to migrate or not and between which versions of schema). To make this automatic I was thinking the test should live inside (or be called from) the constructor. OK, fair enough, that's simple enough. My problem is that I dont want the test to run every single time I instantiate a database object (it runs a query so having it run on every construction is not efficient). So maybe this should be a class static method? I guess my question is, what is a good design pattern for this type of problem? There ought to be a clean way to ensure the migration test runs only once OR is super-efficient.

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  • To have an Integer pointing to 3 ordered lists in Java

    - by Masi
    Which datastructure would you use in the place of X to have efficient merges, sorts and additions as described below? #1 Possible solution: one HashMap to X -datastructure Having a HashMap pointing from fileID to some datastructure linking word, wordCount and wordID may be a good solution. However, I have not found a way to implement it. I am not allowed to use Postgres or any similar tool to keep my data neutralized. I want to have efficient merges, sorts and additions according to fileID, wordID or wordCount for the type below. I have the type Words which has th field fileID that points to a list of words and to relating pieces of information: The Type class Words =================================== fileID: int [list of words] : ArrayList [list of wordCounts] : ArrayList [list of wordIDs] : ArrayList Example of the data in fileID word wordCount wordID instance1 of words 1 He 123 1111 1 llo 321 2 instance2 of words 2 Van 213 666 2 cou 777 932 Example of needed merge fileID wordID fileID wordID 1 2 1 3 wordID=2 2 2 ========> 1 2 2 3 2 2 I cannot see any usage of set-operations such as intersections here because order is needed. Having about three HashMaps makes sorting difficult: from word to wordID in a given fileID from wordID to fileID from wordID to wordCount in a given fileID

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  • dynamically horizontal scalable key value store

    - by Zubair
    Hi, Is there a key value store that will give me the following: Allow me to simply add and remove nodes and will redstribute the data automatically Allow me to remove nodes and still have 2 extra data nodes to provide redundancy Allow me to store text or images up to 1GB in size Can store small size data up to 100TB of data Fast (so will allow queries to be performed on top of it) Make all this transparent to the client Works on Ubuntu/FreeBSD or Mac Free or open source I basically want something I can use a "single", and not have to worry about having memcached, a db, and several storage components so yes, I do want a database "silver bullet" you could say. Thanks Zubair Answers so far: MogileFS on top of BackBlaze - As far as I can see this is just a filesystem, and after some research it only seems to be appropriate for large image files Tokyo Tyrant - Needs lightcloud. This doesn't auto scale as you add new nodes. I did look into this and it seems it is very fast for queries which fit onto a single node though Riak - This is one I am looking into myself, but I don't have any results yet Amazon S3 - Is anyone using this as their sole persistance layer in production? From what I have seen it seems to be used for storage of images as complex queries are too expensive @shaman suggested Cassandra - definitely one I am looking into So far it seems that there is no database or key value store that fulfills the criteria I mentioned, not even after offering a bounty of 100 points did the question get answered!

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  • How to search inbox using zend mail

    - by Bob Cavezza
    The following is a function from zend_mail_protocol_imap. i read that to search emails, I would want to override it using zend_mail_storage_imap (which is what I'm using now to grab email from gmail). I copy and pasted the following function into zend_mail_storage_imap, but I'm having issues with the params. I can't find documentation on what to use for the array $params. I initially thought it was the search term before reading it more thoroughly. I'm out of ideas. Here's the function... /** * do a search request * * This method is currently marked as internal as the API might change and is not * safe if you don't take precautions. * * @internal * @return array message ids */ public function search(array $params) { $response = $this->requestAndResponse('SEARCH', $params); if (!$response) { return $response; } foreach ($response as $ids) { if ($ids[0] == 'SEARCH') { array_shift($ids); return $ids; } } return array(); } Initially I thought this would do the trick... $storage = new Zend_Mail_Storage_Imap($imap); $searchresults = $storage->search('search term'); But nope, I need to send the info in an array. Any ideas?

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