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  • dialog.show() crashes my application, why?

    - by user1739462
    I'm new in adroid. I like to do things when the color reach a value. I like (for example) show the alert if r is bigger than 30, but the application go in crash. Thank for very simple answares. public class MainActivity extends Activity { private AlertDialog dialog; private AlertDialog.Builder builder; private BackgroundColors view; public class BackgroundColors extends SurfaceView implements Runnable { public int grand=0; public int step=0; private boolean flip=true; private Thread thread; private boolean running; private SurfaceHolder holder; public BackgroundColors(Context context) { super(context); } Inside this loop while running is true. is impossible to show dialogs ?? public void run() { int r = 0; while (running){ if (holder.getSurface().isValid()){ Canvas canvas = holder.lockCanvas(); if (r > 250) r = 0; r += 10; if (r>30 && flip){ flip=false; // ********************************* dialog.show(); // ********************************* // CRASH !! } try { Thread.sleep(300); } catch(InterruptedException e) { e.printStackTrace(); } canvas.drawARGB(255, r, 255, 255); holder.unlockCanvasAndPost(canvas); } } } public void start() { running = true; thread = new Thread(this); holder = this.getHolder(); thread.start(); } public void stop() { running = false; boolean retry = true; while (retry){ try { thread.join(); retry = false; } catch(InterruptedException e) { retry = true; } } } public boolean onTouchEvent(MotionEvent e){ dialog.show(); return false; } protected void onSizeChanged(int xNew, int yNew, int xOld, int yOld){ super.onSizeChanged(xNew, yNew, xOld, yOld); grand = xNew; step =grand/15; } } public void onCreate(Bundle b) { super.onCreate(b); view = new BackgroundColors(this); this.setContentView(view); builder = new AlertDialog.Builder(this); builder.setMessage("ciao"); builder.setPositiveButton("OK", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { Log.d("Basic", "It worked"); } }); dialog = builder.create(); } public void onPause(){ super.onPause(); view.stop(); } public void onResume(){ super.onResume(); view.start(); } }

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  • Abstract class and an inheritor: is it possible to factorize .parent() here?

    - by fge
    Here are what I think are the relevant parts of the code of these two classes. First, TreePointer (original source here): public abstract class TreePointer<T extends TreeNode> implements Iterable<TokenResolver<T>> { //... /** * What this tree can see as a missing node (may be {@code null}) */ private final T missing; /** * The list of token resolvers */ protected final List<TokenResolver<T>> tokenResolvers; /** * Main protected constructor * * <p>This constructor makes an immutable copy of the list it receives as * an argument.</p> * * @param missing the representation of a missing node (may be null) * @param tokenResolvers the list of reference token resolvers */ protected TreePointer(final T missing, final List<TokenResolver<T>> tokenResolvers) { this.missing = missing; this.tokenResolvers = ImmutableList.copyOf(tokenResolvers); } /** * Alternate constructor * * <p>This is the same as calling {@link #TreePointer(TreeNode, List)} with * {@code null} as the missing node.</p> * * @param tokenResolvers the list of token resolvers */ protected TreePointer(final List<TokenResolver<T>> tokenResolvers) { this(null, tokenResolvers); } //... /** * Tell whether this pointer is empty * * @return true if the reference token list is empty */ public final boolean isEmpty() { return tokenResolvers.isEmpty(); } @Override public final Iterator<TokenResolver<T>> iterator() { return tokenResolvers.iterator(); } // .equals(), .hashCode(), .toString() follow } Then, JsonPointer, which contains this .parent() method which I'd like to factorize here (original source here: public final class JsonPointer extends TreePointer<JsonNode> { /** * The empty JSON Pointer */ private static final JsonPointer EMPTY = new JsonPointer(ImmutableList.<TokenResolver<JsonNode>>of()); /** * Return an empty JSON Pointer * * @return an empty, statically allocated JSON Pointer */ public static JsonPointer empty() { return EMPTY; } //... /** * Return the immediate parent of this JSON Pointer * * <p>The parent of the empty pointer is itself.</p> * * @return a new JSON Pointer representing the parent of the current one */ public JsonPointer parent() { final int size = tokenResolvers.size(); return size <= 1 ? EMPTY : new JsonPointer(tokenResolvers.subList(0, size - 1)); } // ... } As mentioned in the subject, the problem I have here is with JsonPointer's .parent() method. In fact, the logic behind this method applies to TreeNode all the same, and therefore to its future implementations. Except that I have to use a constructor, and of course such a constructor is implementation dependent :/ Is there a way to make that .parent() method available to each and every implementation of TreeNode or is it just a pipe dream?

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  • String.valueOf(int value) gives error [closed]

    - by Davidrd91
    I am trying to convert an int into a String so that I can put the String values into an SQLite Cursor. I've tried multiple syntax and methods but none seem to work for me. The Error occurs in MangaItemDB() while trying to convert any Int types aswell as the boolean. I've looked through several articles like this one but none works for me. Here's my code: public class MangaItem { private int _id; private String mangaName; private String mangaLink; private static String mangaAlpha; private static int mangaCount; private static int alphaCount; private boolean mangaComplete = false; public MangaItem MangaItemDB(int id, String mangaName, String mangaLink, String mangaAlpha, String mangaCount, String alphaCount, String mangaComplete) { MangaItem MangaItemDB = new MangaItem(); MangaItemDB._id = id; MangaItemDB.mangaName = mangaName; MangaItemDB.mangaLink = mangaLink; MangaItemDB.mangaAlpha = mangaAlpha; MangaItemDB.mangaCount = String.valueOf(int mangaCount); MangaItemDB.alphaCount = Integer.toString(getAlphaCount()); MangaItemDB.mangaComplete = String.valueOf(getMangaComplete()); return MangaItemDB; } public void incrementMangaCount() { mangaCount++; } public int getMangaCount() { return mangaCount; } public void incrementAlphaCount() { alphaCount++; } public int getAlphaCount() { return alphaCount; } public boolean setMangaComplete(boolean mangaComplete) { return true; } public boolean getMangaComplete() { return mangaComplete; } /** * @return the mangaName */ public String getMangaName() { return mangaName; } /** * @param mangaName the mangaName to set */ public void setMangaName(String mangaName) { this.mangaName = mangaName; } /** * @return the mangaLink */ public String getMangaLink() { return mangaLink; } /** * @param mangaLink the mangaLink to set */ public void setMangaLink(String mangaLink) { this.mangaLink = mangaLink; } /** * @return the mangaAlpha */ public String getMangaAlpha() { return mangaAlpha; } /** * @param mangaAlpha the mangaAlpha to set */ public void setMangaAlpha(String mangaAlpha) { this.mangaAlpha = mangaAlpha; } /** * @return the _id */ public int get_id() { return _id; } /** * @param _id the _id to set */ public void set_id(int _id) { this._id = _id; } } The lines : MangaItemDB.mangaCount = String.valueOf(mangaCount); MangaItemDB.alphaCount = Integer.toString(getAlphaCount()); MangaItemDB.mangaComplete = String.valueOf(getMangaComplete()); all give "Type mismatch: cannot convert from String to Int"

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  • Minecraft Style Chunk building problem

    - by David Torrey
    I'm having some problems with speed in my chunk engine. I timed it out, and in its current state it takes a total ~5 seconds per chunk to fill each face's list. I have a check to see if each face of a block is visible and if it is not visible, it skips it and moves on. I'm using a dictionary (unordered map) because it makes sense memorywise to just not have an entry if there is no block. I've tracked my problem down to testing if there is an entry, and accessing an entry if it does exist. If I remove the tests to see if there is an entry in the dictionary for an adjacent block, or if the block type itself is seethrough, it runs within about 2-4 milliseconds. so here's my question: Is there a faster way to check for an entry in a dictionary than .ContainsKey()? As an aside, I tried TryGetValue() and it doesn't really help with the speed that much. If I remove the ContainsKey() and keep the test where it does the IsSeeThrough for each block, it halves the time, but it's still about 2-3 seconds. It only drops to 2-4ms if I remove BOTH checks. Here is my code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Runtime.InteropServices; using OpenTK; using OpenTK.Graphics.OpenGL; using System.Drawing; namespace Anabelle_Lee { public enum BlockEnum { air = 0, dirt = 1, } [StructLayout(LayoutKind.Sequential,Pack=1)] public struct Coordinates<T1> { public T1 x; public T1 y; public T1 z; public override string ToString() { return "(" + x + "," + y + "," + z + ") : " + typeof(T1); } } public struct Sides<T1> { public T1 left; public T1 right; public T1 top; public T1 bottom; public T1 front; public T1 back; } public class Block { public int blockType; public bool SeeThrough() { switch (blockType) { case 0: return true; } return false ; } public override string ToString() { return ((BlockEnum)(blockType)).ToString(); } } class Chunk { private Dictionary<Coordinates<byte>, Block> mChunkData; //stores the block data private Sides<List<Coordinates<byte>>> mVBOVertexBuffer; private Sides<int> mVBOHandle; //private bool mIsChanged; private const byte mCHUNKSIZE = 16; public Chunk() { } public void InitializeChunk() { //create VBO references #if DEBUG Console.WriteLine ("Initializing Chunk"); #endif mChunkData = new Dictionary<Coordinates<byte> , Block>(); //mIsChanged = true; GL.GenBuffers(1, out mVBOHandle.left); GL.GenBuffers(1, out mVBOHandle.right); GL.GenBuffers(1, out mVBOHandle.top); GL.GenBuffers(1, out mVBOHandle.bottom); GL.GenBuffers(1, out mVBOHandle.front); GL.GenBuffers(1, out mVBOHandle.back); //make new list of vertexes for each face mVBOVertexBuffer.top = new List<Coordinates<byte>>(); mVBOVertexBuffer.bottom = new List<Coordinates<byte>>(); mVBOVertexBuffer.left = new List<Coordinates<byte>>(); mVBOVertexBuffer.right = new List<Coordinates<byte>>(); mVBOVertexBuffer.front = new List<Coordinates<byte>>(); mVBOVertexBuffer.back = new List<Coordinates<byte>>(); #if DEBUG Console.WriteLine("Chunk Initialized"); #endif } public void GenerateChunk() { #if DEBUG Console.WriteLine("Generating Chunk"); #endif for (byte i = 0; i < mCHUNKSIZE; i++) { for (byte j = 0; j < mCHUNKSIZE; j++) { for (byte k = 0; k < mCHUNKSIZE; k++) { Random blockLoc = new Random(); Coordinates<byte> randChunk = new Coordinates<byte> { x = i, y = j, z = k }; mChunkData.Add(randChunk, new Block()); mChunkData[randChunk].blockType = blockLoc.Next(0, 1); } } } #if DEBUG Console.WriteLine("Chunk Generated"); #endif } public void DeleteChunk() { //delete VBO references #if DEBUG Console.WriteLine("Deleting Chunk"); #endif GL.DeleteBuffers(1, ref mVBOHandle.left); GL.DeleteBuffers(1, ref mVBOHandle.right); GL.DeleteBuffers(1, ref mVBOHandle.top); GL.DeleteBuffers(1, ref mVBOHandle.bottom); GL.DeleteBuffers(1, ref mVBOHandle.front); GL.DeleteBuffers(1, ref mVBOHandle.back); //clear all vertex buffers ClearPolyLists(); #if DEBUG Console.WriteLine("Chunk Deleted"); #endif } public void UpdateChunk() { #if DEBUG Console.WriteLine("Updating Chunk"); #endif ClearPolyLists(); //prepare buffers //for every entry in mChunkData map foreach(KeyValuePair<Coordinates<byte>,Block> feBlockData in mChunkData) { Coordinates<byte> checkBlock = new Coordinates<byte> { x = feBlockData.Key.x, y = feBlockData.Key.y, z = feBlockData.Key.z }; //check for polygonson the left side of the cube if (checkBlock.x > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x - 1, checkBlock.y, checkBlock.z)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.left); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.left); } //check for polygons on the right side of the cube if (checkBlock.x < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x + 1, checkBlock.y, checkBlock.z)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.right); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.right); } if (checkBlock.y > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x, checkBlock.y - 1, checkBlock.z)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.bottom); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.bottom); } //check for polygons on the right side of the cube if (checkBlock.y < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x, checkBlock.y + 1, checkBlock.z)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.top); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.top); } if (checkBlock.z > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x, checkBlock.y, checkBlock.z - 1)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.back); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.back); } //check for polygons on the right side of the cube if (checkBlock.z < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x, checkBlock.y, checkBlock.z + 1)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.front); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.front); } } BuildBuffers(); #if DEBUG Console.WriteLine("Chunk Updated"); #endif } public void RenderChunk() { } public void LoadChunk() { #if DEBUG Console.WriteLine("Loading Chunk"); #endif #if DEBUG Console.WriteLine("Chunk Deleted"); #endif } public void SaveChunk() { #if DEBUG Console.WriteLine("Saving Chunk"); #endif #if DEBUG Console.WriteLine("Chunk Saved"); #endif } private bool IsVisible(int pX,int pY,int pZ) { Block testBlock; Coordinates<byte> checkBlock = new Coordinates<byte> { x = Convert.ToByte(pX), y = Convert.ToByte(pY), z = Convert.ToByte(pZ) }; if (mChunkData.TryGetValue(checkBlock,out testBlock )) //if data exists { if (testBlock.SeeThrough() == true) //if existing data is not seethrough { return true; } } return true; } private void AddPoly(byte pX, byte pY, byte pZ, int BufferSide) { //create temp array GL.BindBuffer(BufferTarget.ArrayBuffer, BufferSide); if (BufferSide == mVBOHandle.front) { //front face mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); } else if (BufferSide == mVBOHandle.right) { //back face mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.top) { //left face mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.bottom) { //right face mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); } else if (BufferSide == mVBOHandle.front) { //top face mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.back) { //bottom face mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ + 1) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ + 1) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ + 1) }); } } private void BuildBuffers() { #if DEBUG Console.WriteLine("Building Chunk Buffers"); #endif GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.front); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.front.Count), mVBOVertexBuffer.front.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.back); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.back.Count), mVBOVertexBuffer.back.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.left); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.left.Count), mVBOVertexBuffer.left.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.right); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.right.Count), mVBOVertexBuffer.right.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.top); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.top.Count), mVBOVertexBuffer.top.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.bottom); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.bottom.Count), mVBOVertexBuffer.bottom.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer,0); #if DEBUG Console.WriteLine("Chunk Buffers Built"); #endif } private void ClearPolyLists() { #if DEBUG Console.WriteLine("Clearing Polygon Lists"); #endif mVBOVertexBuffer.top.Clear(); mVBOVertexBuffer.bottom.Clear(); mVBOVertexBuffer.left.Clear(); mVBOVertexBuffer.right.Clear(); mVBOVertexBuffer.front.Clear(); mVBOVertexBuffer.back.Clear(); #if DEBUG Console.WriteLine("Polygon Lists Cleared"); #endif } }//END CLASS }//END NAMESPACE

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  • Building a &ldquo;real&rdquo; extension for Expression Blend

    - by Timmy Kokke
    .Last time I showed you how to get started building extensions for Expression Blend. Lets build a useful extension this time and go a bit deeper into Blend. Source of project  => here Compiled dll => here (extract into /extensions folder of Expression Blend)   The Extension When working on large Xaml files in Blend it’s often hard to find a specific control in the "Objects and Timeline Pane”. An extension that searches the active document and presents all elements that satisfy the query would be helpful. When the user starts typing a search query a search will be performed and the results are shown in the list. After the user selects an item in the results list, the control in the "Objects and Timeline Pane” will be selected. Below is a sketch of what it is going to look like. The Solution Create a new WPF User Control project as shown in the earlier tutorial in the Configuring the extension project section, but name it AdvancedSearch this time. Delete the default UserControl1.Xaml to clear the solution (a new user control will be added later thought, but adding a user control is easier then renaming one). Create the main entry point of the addin by adding a new class to the solution and naming this  AdvancedSearchPackage. Add a reference to Microsoft.Expression.Extensibility and to System.ComponentModel.Composition . Implement the IPackage interface and add the Export attribute from the MEF to the definition. While you’re at it. Add references to Microsoft.Expression.DesignSurface, Microsoft.Expression.FrameWork and Microsoft.Expression.Markup. These will be used later. The Load method from the IPackage interface is going to create a ViewModel to bind to from the UI. Add another class to the solution and name this AdvancedSearchViewModel. This class needs to implement the INotifyPropertyChanged interface to enable notifications to the view.  Add a constructor to the class that takes an IServices interface as a parameter. Create a new instance of the AdvancedSearchViewModel in the load method in the AdvanceSearchPackage class. The AdvancedSearchPackage class should looks like this now:   using System.ComponentModel.Composition; using Microsoft.Expression.Extensibility;   namespace AdvancedSearch { [Export(typeof(IPackage))] public class AdvancedSearchPackage:IPackage {   public void Load(IServices services) { new AdvancedSearchViewModel(services); }   public void Unload() { } } }   Add a new UserControl to the project and name this AdvancedSearchView. The View will be created by the ViewModel, which will pass itself to the constructor of the view. Change the constructor of the View to take a AdvancedSearchViewModel object as a parameter. Add a private field to store the ViewModel and set this field in the constructor. Point the DataContext of the view to the ViewModel. The View will look something like this now:   namespace AdvancedSearch { public partial class AdvancedSearchView:UserControl { private readonly AdvancedSearchViewModel _advancedSearchViewModel;   public AdvancedSearchView(AdvancedSearchViewModel advancedSearchViewModel) { _advancedSearchViewModel = advancedSearchViewModel; InitializeComponent(); this.DataContext = _advancedSearchViewModel; } } }   The View is going to be created in the constructor of the ViewModel and stored in a read only property.   public FrameworkElement View { get; private set; }   public AdvancedSearchViewModel(IServices services) { _services = services; View = new AdvancedSearchView(this); } The last thing the solution needs before we’ll wire things up is a new class, PossibleNode. This class will be used later to store the search results. The solution should look like this now:   Adding UI to the UI The extension should build and run now, although nothing is showing up in Blend yet. To enable the user to perform a search query add a TextBox and a ListBox to the AdvancedSearchView.xaml file. I’ve set the rows of the grid too to make them look a little better. Add the TextChanged event to the TextBox and the SelectionChanged event to the ListBox, we’ll need those later on. <Grid> <Grid.RowDefinitions> <RowDefinition Height="32" /> <RowDefinition Height="*" /> </Grid.RowDefinitions> <TextBox TextChanged="SearchQueryTextChanged" HorizontalAlignment="Stretch" Margin="4" Name="SearchQuery" VerticalAlignment="Stretch" /> <ListBox SelectionChanged="SearchResultSelectionChanged" HorizontalAlignment="Stretch" Margin="4" Name="SearchResult" VerticalAlignment="Stretch" Grid.Row="1" /> </Grid>   This will create a user interface like: To make the View show up in Blend it has to be registered with the WindowService. The GetService<T> method is used to get services from Blend, which are your entry points into Blend.When writing extensions you will encounter this method very often. In this case we’re asking for an IWindowService interface. The IWindowService interface serves events for changing windows and themes, is used for adding or removing resources and is used for registering and unregistering Palettes. All panes in Blend are palettes and are registered thru the RegisterPalette method. The first parameter passed to this method is a string containing a unique ID for the palette. This ID can be used to get access to the palette later. The second parameter is the View. The third parameter is a title for the pane. This title is shown when the pane is visible. It is also shown in the window menu of Blend. The last parameter is a KeyBinding. I have chosen Ctrl+Shift+F to call the Advanced Search pane. This value is also shown in the window menu of Blend.   services.GetService<IWindowService>().RegisterPalette( "AdvancedSearch", viewModel.View, "Advanced Search", new KeyBinding { Key = Key.F, Modifiers = ModifierKeys.Control | ModifierKeys.Shift } );   You can compiler and run now. After Blend starts you can hit Ctrl+Shift+F or go the windows menu to call the advanced search extension. Searching for controls The search has to be cleared on every change of the active document. The DocumentServices fires an event every time a new document is opened, a document is closed or another document view is selected. Add the following line to the constructor of the ViewModel to handle the ActiveDocumentChanged event:   _services.GetService<IDocumentService>().ActiveDocumentChanged += ActiveDocumentChanged;   And implement the ActiveDocumentChanged method:   private void ActiveDocumentChanged(object sender, DocumentChangedEventArgs e) { }   To get to the contents of the document we first need to get access to the “Objects and Timeline” pane. This pane is registered in the PaletteRegistry in the same way as this extension has registered itself. The palettes are accessible thru an associative array. All you need to provide is the Identifier of the palette you want. The Id of the “Objects and Timeline” pane is “Designer_TimelinePane”. I’ve included a list of the other default panes at the bottom of this article. Each palette has a Content property which can be cast to the type of the pane.   var timelinePane = (TimelinePane)_services.GetService<IWindowService>() .PaletteRegistry["Designer_TimelinePane"] .Content;   Add a private field to the top of the AdvancedSearchViewModel class to store the active SceneViewModel. The SceneViewModel is needed to set the current selection and to get the little icons for the type of control.   private SceneViewModel _activeSceneViewModel;   When the active SceneViewModel changes, the ActiveSceneViewModel is stored in this field. The list of possible nodes is cleared and an PropertyChanged event is fired for this list to notify the UI to clear the list. This will make the eventhandler look like this: private void ActiveDocumentChanged(object sender, DocumentChangedEventArgs e) { var timelinePane = (TimelinePane)_services.GetService<IWindowService>() .PaletteRegistry["Designer_TimelinePane"].Content;   _activeSceneViewModel = timelinePane.ActiveSceneViewModel; PossibleNodes = new List<PossibleNode>(); InvokePropertyChanged("PossibleNodes"); } The PossibleNode class used to store information about the controls found by the search. It’s a dumb data class with only 3 properties, the name of the control, the SceneNode and a brush used for the little icon. The SceneNode is the base class for every possible object you can create in Blend, like Brushes, Controls, Annotations, ResourceDictionaries and VisualStates. The entire PossibleNode class looks like this:   using System.Windows.Media; using Microsoft.Expression.DesignSurface.ViewModel;   namespace AdvancedSearch { public class PossibleNode { public string Name { get; set; } public SceneNode SceneNode { get; set; } public DrawingBrush IconBrush { get; set; } } }   Add these two methods to the AdvancedSearchViewModel class:   public void Search(string searchText) { } public void SelectElement(PossibleNode node){ }   Both these methods are going to be called from the view. The Search method performs the search and updates the PossibleNodes list.  The controls in the active document can be accessed thru TimeLineItemsManager class. This class contains a read only collection of TimeLineItems. By using a Linq query the possible nodes are selected and placed in the PossibleNodes list.   var timelineItemManager = new TimelineItemManager(_activeSceneViewModel); PossibleNodes = new List<PossibleNode>( (from d in timelineItemManager.ItemList where d.DisplayName.ToLowerInvariant().StartsWith( searchText.ToLowerInvariant()) select new PossibleNode() { IconBrush = d.IconBrush, SceneNode = d.SceneNode, Name = d.DisplayName }).ToList() ); InvokePropertyChanged(InternalConst.PossibleNodes);   The Select method is pretty straight forward. It contains two lines.The first to clear the selection. Otherwise the selected element would be added to the current selection. The second line selects the nodes. It is given a new array with the node to be selected.   _activeSceneViewModel.ClearSelections(); _activeSceneViewModel.SelectNodes(new[] { node.SceneNode });   The last thing that needs to be done is to wire the whole thing to the View. The two event handlers just call the Search and SelectElement methods on the ViewModel.   private void SearchQueryTextChanged(object sender, TextChangedEventArgs e) { _advancedSearchViewModel.Search(SearchQuery.Text); }   private void SearchResultSelectionChanged(object sender, SelectionChangedEventArgs e) { if(e.AddedItems.Count>0) { _advancedSearchViewModel.SelectElement(e.AddedItems[0] as PossibleNode); } }   The Listbox has to be bound to the PossibleNodes list and a simple DataTemplate is added to show the selection. The IconWithOverlay control can be found in the Microsoft.Expression.DesignSurface.UserInterface.Timeline.UI namespace in the Microsoft.Expression.DesignSurface assembly. The ListBox should look something like:   <ListBox SelectionChanged="SearchResultSelectionChanged" HorizontalAlignment="Stretch" Margin="4" Name="SearchResult" VerticalAlignment="Stretch" Grid.Row="1" ItemsSource="{Binding PossibleNodes}"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <tlui:IconWithOverlay Margin="2,0,10,0" Width="12" Height="12" SourceBrush="{Binding Path=IconBrush, Mode=OneWay}" /> <TextBlock Text="{Binding Name}"/> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox>   Compile and run. Inside Blend the extension could look something like below. What’s Next When you’ve got the extension running. Try placing breakpoints in the code and see what else is in there. There’s a lot to explore and build extension on. I personally would love an extension to search for resources. Last but not least, you can download the source of project here.  If you have any questions let me know. If you just want to use this extension, you can download the compiled dll here. Just extract the . zip into the /extensions folder of Expression Blend. Notes Target framework I ran into some issues when using the .NET Framework 4 Client Profile as a target framework. I got some strange error saying certain obvious namespaces could not be found, Microsoft.Expression in my case. If you run into something like this, try setting the target framework to .NET Framework 4 instead of the client version.   Identifiers of default panes Identifier Type Title Designer_TimelinePane TimelinePane Objects and Timeline Designer_ToolPane ToolPane Tools Designer_ProjectPane ProjectPane Projects Designer_DataPane DataPane Data Designer_ResourcePane ResourcePane Resources Designer_PropertyInspector PropertyInspector Properties Designer_TriggersPane TriggersPane Triggers Interaction_Skin SkinView States Designer_AssetPane AssetPane Assets Interaction_Parts PartsPane Parts Designer_ResultsPane ResultsPane Results

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  • How to simulate inner join on very large files in java (without running out of memory)

    - by Constantin
    I am trying to simulate SQL joins using java and very large text files (INNER, RIGHT OUTER and LEFT OUTER). The files have already been sorted using an external sort routine. The issue I have is I am trying to find the most efficient way to deal with the INNER join part of the algorithm. Right now I am using two Lists to store the lines that have the same key and iterate through the set of lines in the right file once for every line in the left file (provided the keys still match). In other words, the join key is not unique in each file so would need to account for the Cartesian product situations ... left_01, 1 left_02, 1 right_01, 1 right_02, 1 right_03, 1 left_01 joins to right_01 using key 1 left_01 joins to right_02 using key 1 left_01 joins to right_03 using key 1 left_02 joins to right_01 using key 1 left_02 joins to right_02 using key 1 left_02 joins to right_03 using key 1 My concern is one of memory. I will run out of memory if i use the approach below but still want the inner join part to work fairly quickly. What is the best approach to deal with the INNER join part keeping in mind that these files may potentially be huge public class Joiner { private void join(BufferedReader left, BufferedReader right, BufferedWriter output) throws Throwable { BufferedReader _left = left; BufferedReader _right = right; BufferedWriter _output = output; Record _leftRecord; Record _rightRecord; _leftRecord = read(_left); _rightRecord = read(_right); while( _leftRecord != null && _rightRecord != null ) { if( _leftRecord.getKey() < _rightRecord.getKey() ) { write(_output, _leftRecord, null); _leftRecord = read(_left); } else if( _leftRecord.getKey() > _rightRecord.getKey() ) { write(_output, null, _rightRecord); _rightRecord = read(_right); } else { List<Record> leftList = new ArrayList<Record>(); List<Record> rightList = new ArrayList<Record>(); _leftRecord = readRecords(leftList, _leftRecord, _left); _rightRecord = readRecords(rightList, _rightRecord, _right); for( Record equalKeyLeftRecord : leftList ){ for( Record equalKeyRightRecord : rightList ){ write(_output, equalKeyLeftRecord, equalKeyRightRecord); } } } } if( _leftRecord != null ) { write(_output, _leftRecord, null); _leftRecord = read(_left); while(_leftRecord != null) { write(_output, _leftRecord, null); _leftRecord = read(_left); } } else { if( _rightRecord != null ) { write(_output, null, _rightRecord); _rightRecord = read(_right); while(_rightRecord != null) { write(_output, null, _rightRecord); _rightRecord = read(_right); } } } _left.close(); _right.close(); _output.flush(); _output.close(); } private Record read(BufferedReader reader) throws Throwable { Record record = null; String data = reader.readLine(); if( data != null ) { record = new Record(data.split("\t")); } return record; } private Record readRecords(List<Record> list, Record record, BufferedReader reader) throws Throwable { int key = record.getKey(); list.add(record); record = read(reader); while( record != null && record.getKey() == key) { list.add(record); record = read(reader); } return record; } private void write(BufferedWriter writer, Record left, Record right) throws Throwable { String leftKey = (left == null ? "null" : Integer.toString(left.getKey())); String leftData = (left == null ? "null" : left.getData()); String rightKey = (right == null ? "null" : Integer.toString(right.getKey())); String rightData = (right == null ? "null" : right.getData()); writer.write("[" + leftKey + "][" + leftData + "][" + rightKey + "][" + rightData + "]\n"); } public static void main(String[] args) { try { BufferedReader leftReader = new BufferedReader(new FileReader("LEFT.DAT")); BufferedReader rightReader = new BufferedReader(new FileReader("RIGHT.DAT")); BufferedWriter output = new BufferedWriter(new FileWriter("OUTPUT.DAT")); Joiner joiner = new Joiner(); joiner.join(leftReader, rightReader, output); } catch (Throwable e) { e.printStackTrace(); } } } After applying the ideas from the proposed answer, I changed the loop to this private void join(RandomAccessFile left, RandomAccessFile right, BufferedWriter output) throws Throwable { long _pointer = 0; RandomAccessFile _left = left; RandomAccessFile _right = right; BufferedWriter _output = output; Record _leftRecord; Record _rightRecord; _leftRecord = read(_left); _rightRecord = read(_right); while( _leftRecord != null && _rightRecord != null ) { if( _leftRecord.getKey() < _rightRecord.getKey() ) { write(_output, _leftRecord, null); _leftRecord = read(_left); } else if( _leftRecord.getKey() > _rightRecord.getKey() ) { write(_output, null, _rightRecord); _pointer = _right.getFilePointer(); _rightRecord = read(_right); } else { long _tempPointer = 0; int key = _leftRecord.getKey(); while( _leftRecord != null && _leftRecord.getKey() == key ) { _right.seek(_pointer); _rightRecord = read(_right); while( _rightRecord != null && _rightRecord.getKey() == key ) { write(_output, _leftRecord, _rightRecord ); _tempPointer = _right.getFilePointer(); _rightRecord = read(_right); } _leftRecord = read(_left); } _pointer = _tempPointer; } } if( _leftRecord != null ) { write(_output, _leftRecord, null); _leftRecord = read(_left); while(_leftRecord != null) { write(_output, _leftRecord, null); _leftRecord = read(_left); } } else { if( _rightRecord != null ) { write(_output, null, _rightRecord); _rightRecord = read(_right); while(_rightRecord != null) { write(_output, null, _rightRecord); _rightRecord = read(_right); } } } _left.close(); _right.close(); _output.flush(); _output.close(); } UPDATE While this approach worked, it was terribly slow and so I have modified this to create files as buffers and this works very well. Here is the update ... private long getMaxBufferedLines(File file) throws Throwable { long freeBytes = Runtime.getRuntime().freeMemory() / 2; return (freeBytes / (file.length() / getLineCount(file))); } private void join(File left, File right, File output, JoinType joinType) throws Throwable { BufferedReader leftFile = new BufferedReader(new FileReader(left)); BufferedReader rightFile = new BufferedReader(new FileReader(right)); BufferedWriter outputFile = new BufferedWriter(new FileWriter(output)); long maxBufferedLines = getMaxBufferedLines(right); Record leftRecord; Record rightRecord; leftRecord = read(leftFile); rightRecord = read(rightFile); while( leftRecord != null && rightRecord != null ) { if( leftRecord.getKey().compareTo(rightRecord.getKey()) < 0) { if( joinType == JoinType.LeftOuterJoin || joinType == JoinType.LeftExclusiveJoin || joinType == JoinType.FullExclusiveJoin || joinType == JoinType.FullOuterJoin ) { write(outputFile, leftRecord, null); } leftRecord = read(leftFile); } else if( leftRecord.getKey().compareTo(rightRecord.getKey()) > 0 ) { if( joinType == JoinType.RightOuterJoin || joinType == JoinType.RightExclusiveJoin || joinType == JoinType.FullExclusiveJoin || joinType == JoinType.FullOuterJoin ) { write(outputFile, null, rightRecord); } rightRecord = read(rightFile); } else if( leftRecord.getKey().compareTo(rightRecord.getKey()) == 0 ) { String key = leftRecord.getKey(); List<File> rightRecordFileList = new ArrayList<File>(); List<Record> rightRecordList = new ArrayList<Record>(); rightRecordList.add(rightRecord); rightRecord = consume(key, rightFile, rightRecordList, rightRecordFileList, maxBufferedLines); while( leftRecord != null && leftRecord.getKey().compareTo(key) == 0 ) { processRightRecords(outputFile, leftRecord, rightRecordFileList, rightRecordList, joinType); leftRecord = read(leftFile); } // need a dispose for deleting files in list } else { throw new Exception("DATA IS NOT SORTED"); } } if( leftRecord != null ) { if( joinType == JoinType.LeftOuterJoin || joinType == JoinType.LeftExclusiveJoin || joinType == JoinType.FullExclusiveJoin || joinType == JoinType.FullOuterJoin ) { write(outputFile, leftRecord, null); } leftRecord = read(leftFile); while(leftRecord != null) { if( joinType == JoinType.LeftOuterJoin || joinType == JoinType.LeftExclusiveJoin || joinType == JoinType.FullExclusiveJoin || joinType == JoinType.FullOuterJoin ) { write(outputFile, leftRecord, null); } leftRecord = read(leftFile); } } else { if( rightRecord != null ) { if( joinType == JoinType.RightOuterJoin || joinType == JoinType.RightExclusiveJoin || joinType == JoinType.FullExclusiveJoin || joinType == JoinType.FullOuterJoin ) { write(outputFile, null, rightRecord); } rightRecord = read(rightFile); while(rightRecord != null) { if( joinType == JoinType.RightOuterJoin || joinType == JoinType.RightExclusiveJoin || joinType == JoinType.FullExclusiveJoin || joinType == JoinType.FullOuterJoin ) { write(outputFile, null, rightRecord); } rightRecord = read(rightFile); } } } leftFile.close(); rightFile.close(); outputFile.flush(); outputFile.close(); } public void processRightRecords(BufferedWriter outputFile, Record leftRecord, List<File> rightFiles, List<Record> rightRecords, JoinType joinType) throws Throwable { for(File rightFile : rightFiles) { BufferedReader rightReader = new BufferedReader(new FileReader(rightFile)); Record rightRecord = read(rightReader); while(rightRecord != null){ if( joinType == JoinType.LeftOuterJoin || joinType == JoinType.RightOuterJoin || joinType == JoinType.FullOuterJoin || joinType == JoinType.InnerJoin ) { write(outputFile, leftRecord, rightRecord); } rightRecord = read(rightReader); } rightReader.close(); } for(Record rightRecord : rightRecords) { if( joinType == JoinType.LeftOuterJoin || joinType == JoinType.RightOuterJoin || joinType == JoinType.FullOuterJoin || joinType == JoinType.InnerJoin ) { write(outputFile, leftRecord, rightRecord); } } } /** * consume all records having key (either to a single list or multiple files) each file will * store a buffer full of data. The right record returned represents the outside flow (key is * already positioned to next one or null) so we can't use this record in below while loop or * within this block in general when comparing current key. The trick is to keep consuming * from a List. When it becomes empty, re-fill it from the next file until all files have * been consumed (and the last node in the list is read). The next outside iteration will be * ready to be processed (either it will be null or it points to the next biggest key * @throws Throwable * */ private Record consume(String key, BufferedReader reader, List<Record> records, List<File> files, long bufferMaxRecordLines ) throws Throwable { boolean processComplete = false; Record record = records.get(records.size() - 1); while(!processComplete){ long recordCount = records.size(); if( record.getKey().compareTo(key) == 0 ){ record = read(reader); while( record != null && record.getKey().compareTo(key) == 0 && recordCount < bufferMaxRecordLines ) { records.add(record); recordCount++; record = read(reader); } } processComplete = true; // if record is null, we are done if( record != null ) { // if the key has changed, we are done if( record.getKey().compareTo(key) == 0 ) { // Same key means we have exhausted the buffer. // Dump entire buffer into a file. The list of file // pointers will keep track of the files ... processComplete = false; dumpBufferToFile(records, files); records.clear(); records.add(record); } } } return record; } /** * Dump all records in List of Record objects to a file. Then, add that * file to List of File objects * * NEED TO PLACE A LIMIT ON NUMBER OF FILE POINTERS (check size of file list) * * @param records * @param files * @throws Throwable */ private void dumpBufferToFile(List<Record> records, List<File> files) throws Throwable { String prefix = "joiner_" + files.size() + 1; String suffix = ".dat"; File file = File.createTempFile(prefix, suffix, new File("cache")); BufferedWriter writer = new BufferedWriter(new FileWriter(file)); for( Record record : records ) { writer.write( record.dump() ); } files.add(file); writer.flush(); writer.close(); }

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  • Branding Support for TopComponents

    - by Geertjan
    In yesterday's blog entry, you saw how a menu item can be created, in this case with the label "Brand", especially for Java classes that extend TopComponent: And, as you can see here, it's not about the name of the class, i.e., not because the class above is named "BlaTopComponent" because below the "Brand" men item is also available for the class named "Bla": Both the files BlaTopComponent.java and Bla.java have the "Brand" menu item available, because both extend the "org.openide.windows.TopComponent"  class, as shown yesterday. Now we continue by creating a new JPanel, with checkboxes for each part of a TopComponent that we consider to be brandable. In my case, this is the end result, at deployment, when the Brand menu item is clicked for the Bla class: When the user (who, in this case, is a developer) clicks OK, a constructor is created and the related client properties are added, depending on which of the checkboxes are clicked: public Bla() {     putClientProperty(TopComponent.PROP_SLIDING_DISABLED, false);     putClientProperty(TopComponent.PROP_UNDOCKING_DISABLED, true);     putClientProperty(TopComponent.PROP_MAXIMIZATION_DISABLED, false);     putClientProperty(TopComponent.PROP_CLOSING_DISABLED, true);     putClientProperty(TopComponent.PROP_DRAGGING_DISABLED, false); } At this point, no check is done to see whether a constructor already exists, nor whether the client properties are already available. That's for an upcoming blog entry! Right now, the constructor is always created, regardless of whether it already exists, and the client properties are always added. The key to all this is the 'actionPeformed' of the TopComponent, which was left empty yesterday. We start by creating a JDialog from the JPanel and we retrieve the selected state of the checkboxes defined in the JPanel: @Override public void actionPerformed(ActionEvent ev) {     String msg = dobj.getName() + " Branding";     final BrandTopComponentPanel brandTopComponentPanel = new BrandTopComponentPanel();     dd = new DialogDescriptor(brandTopComponentPanel, msg, true, new ActionListener() {         @Override         public void actionPerformed(ActionEvent e) {             Object result = dd.getValue();             if (DialogDescriptor.OK_OPTION == result) {                 isClosing = brandTopComponentPanel.getClosingCheckBox().isSelected();                 isDragging = brandTopComponentPanel.getDraggingCheckBox().isSelected();                 isMaximization = brandTopComponentPanel.getMaximizationCheckBox().isSelected();                 isSliding = brandTopComponentPanel.getSlidingCheckBox().isSelected();                 isUndocking = brandTopComponentPanel.getUndockingCheckBox().isSelected();                 JavaSource javaSource = JavaSource.forFileObject(dobj.getPrimaryFile());                 try {                     javaSource.runUserActionTask(new ScanTask(javaSource), true);                 } catch (IOException ex) {                     Exceptions.printStackTrace(ex);                 }             }         }     });     DialogDisplayer.getDefault().createDialog(dd).setVisible(true); } Then we start a scan process, which introduces the branding. We're already doing a scan process for identifying whether a class is a TopComponent. So, let's combine those two scans, branching out based on which one we're doing: private class ScanTask implements Task<CompilationController> {     private BrandTopComponentAction action = null;     private JavaSource js = null;     private ScanTask(JavaSource js) {         this.js = js;     }     private ScanTask(BrandTopComponentAction action) {         this.action = action;     }     @Override     public void run(final CompilationController info) throws Exception {         info.toPhase(Phase.ELEMENTS_RESOLVED);         if (action != null) {             new EnableIfTopComponentScanner(info, action).scan(                     info.getCompilationUnit(), null);         } else {             introduceBranding();         }     }     private void introduceBranding() throws IOException {         CancellableTask task = new CancellableTask<WorkingCopy>() {             @Override             public void run(WorkingCopy workingCopy) throws IOException {                 workingCopy.toPhase(Phase.RESOLVED);                 CompilationUnitTree cut = workingCopy.getCompilationUnit();                 TreeMaker treeMaker = workingCopy.getTreeMaker();                 for (Tree typeDecl : cut.getTypeDecls()) {                     if (Tree.Kind.CLASS == typeDecl.getKind()) {                         ClassTree clazz = (ClassTree) typeDecl;                         ModifiersTree methodModifiers = treeMaker.Modifiers(Collections.<Modifier>singleton(Modifier.PUBLIC));                         MethodTree newMethod =                                 treeMaker.Method(methodModifiers,                                 "<init>",                                 treeMaker.PrimitiveType(TypeKind.VOID),                                 Collections.<TypeParameterTree>emptyList(),                                 Collections.EMPTY_LIST,                                 Collections.<ExpressionTree>emptyList(),                                 "{ putClientProperty(TopComponent.PROP_SLIDING_DISABLED, " + isSliding + ");\n"+                                 "  putClientProperty(TopComponent.PROP_UNDOCKING_DISABLED, " + isUndocking + ");\n"+                                 "  putClientProperty(TopComponent.PROP_MAXIMIZATION_DISABLED, " + isMaximization + ");\n"+                                 "  putClientProperty(TopComponent.PROP_CLOSING_DISABLED, " + isClosing + ");\n"+                                 "  putClientProperty(TopComponent.PROP_DRAGGING_DISABLED, " + isDragging + "); }\n",                                 null);                         ClassTree modifiedClazz = treeMaker.addClassMember(clazz, newMethod);                         workingCopy.rewrite(clazz, modifiedClazz);                     }                 }             }             @Override             public void cancel() {             }         };         ModificationResult result = js.runModificationTask(task);         result.commit();     } } private static class EnableIfTopComponentScanner extends TreePathScanner<Void, Void> {     private CompilationInfo info;     private final AbstractAction action;     public EnableIfTopComponentScanner(CompilationInfo info, AbstractAction action) {         this.info = info;         this.action = action;     }     @Override     public Void visitClass(ClassTree t, Void v) {         Element el = info.getTrees().getElement(getCurrentPath());         if (el != null) {             TypeElement te = (TypeElement) el;             if (te.getSuperclass().toString().equals("org.openide.windows.TopComponent")) {                 action.setEnabled(true);             } else {                 action.setEnabled(false);             }         }         return null;     } }

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  • apache Client Certificate Authentication errors: Certificate Verification: Error (18): self signed certificate

    - by decoy
    So I have been following instructions on setting up Client Certificate Authentication in Apache2 w/ mod_ssl. This is solely for the purpose of testing an application against CAA, not for any sort of production use. So far I've followed http://www.impetus.us/~rjmooney/projects/misc/clientcertauth.html for advice on generating my CA, server, and client encryption information. I've put all three of them into /etc/ssl/ca/private. I've setup the following additional directives in my default_ssl site file: <IfModule mod_ssl.c> <VirtualHost _default_:443> ... SSLEngine on SSLCertificateFile /etc/ssl/ca/private/server.crt SSLCertificateKeyFile /etc/ssl/ca/private/server.key SSLVerifyClient require SSLVerifyDepth 2 SSLCACertificatePath /etc/ssl/ca/private SSLCACertificateFile /etc/ssl/ca/private/ca.crt <Location /> SSLRequireSSL SSLVerifyClient require SSLVerifyDepth 2 </Location> <FilesMatch "\.(cgi|shtml|phtml|php)$"> SSLOptions +StdEnvVars </FilesMatch> <Directory /usr/lib/cgi-bin> SSLOptions +StdEnvVars </Directory> ... </VirtualHost> </IfModule> I've install the p12 file into Chrome, but when I go to visit https://localhost, I get the following errors Chrome: Error 107 (net::ERR_SSL_PROTOCOL_ERROR): SSL protocol error. Apache: Certificate Verification: Error (18): self signed certificate If I had to guess, one of my directives is not setup right to load and verify the p12 w/ my self created CA. But I can't for the life of me figure out what it is. Would anyone have more experience here who could point me in the right direction?

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  • What code smell best describes this code?

    - by Paul Stovell
    Suppose you have this code in a class: private DataContext _context; public Customer[] GetCustomers() { GetContext(); return _context.Customers.ToArray(); } public Order[] GetOrders() { GetContext(); return _context.Customers.ToArray(); } // For the sake of this example, a new DataContext is *required* // for every public method call private void GetContext() { if (_context != null) { _context.Dispose(); } _context = new DataContext(); } This code isn't thread-safe - if two calls to GetOrders/GetCustomers are made at the same time from different threads, they may end up using the same context, or the context could be disposed while being used. Even if this bug didn't exist, however, it still "smells" like bad code. A much better design would be for GetContext to always return a new instance of DataContext and to get rid of the private field, and to dispose of the instance when done. Changing from an inappropriate private field to a local variable feels like a better solution. I've looked over the code smell lists and can't find one that describes this. In the past I've thought of it as temporal coupling, but the Wikipedia description suggests that's not the term: Temporal coupling When two actions are bundled together into one module just because they happen to occur at the same time. This page discusses temporal coupling, but the example is the public API of a class, while my question is about the internal design. Does this smell have a name? Or is it simply "buggy code"?

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  • Understanding LINQ to SQL (11) Performance

    - by Dixin
    [LINQ via C# series] LINQ to SQL has a lot of great features like strong typing query compilation deferred execution declarative paradigm etc., which are very productive. Of course, these cannot be free, and one price is the performance. O/R mapping overhead Because LINQ to SQL is based on O/R mapping, one obvious overhead is, data changing usually requires data retrieving:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { Product product = database.Products.Single(item => item.ProductID == id); // SELECT... product.UnitPrice = unitPrice; // UPDATE... database.SubmitChanges(); } } Before updating an entity, that entity has to be retrieved by an extra SELECT query. This is slower than direct data update via ADO.NET:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (SqlConnection connection = new SqlConnection( "Data Source=localhost;Initial Catalog=Northwind;Integrated Security=True")) using (SqlCommand command = new SqlCommand( @"UPDATE [dbo].[Products] SET [UnitPrice] = @UnitPrice WHERE [ProductID] = @ProductID", connection)) { command.Parameters.Add("@ProductID", SqlDbType.Int).Value = id; command.Parameters.Add("@UnitPrice", SqlDbType.Money).Value = unitPrice; connection.Open(); command.Transaction = connection.BeginTransaction(); command.ExecuteNonQuery(); // UPDATE... command.Transaction.Commit(); } } The above imperative code specifies the “how to do” details with better performance. For the same reason, some articles from Internet insist that, when updating data via LINQ to SQL, the above declarative code should be replaced by:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.ExecuteCommand( "UPDATE [dbo].[Products] SET [UnitPrice] = {0} WHERE [ProductID] = {1}", id, unitPrice); } } Or just create a stored procedure:CREATE PROCEDURE [dbo].[UpdateProductUnitPrice] ( @ProductID INT, @UnitPrice MONEY ) AS BEGIN BEGIN TRANSACTION UPDATE [dbo].[Products] SET [UnitPrice] = @UnitPrice WHERE [ProductID] = @ProductID COMMIT TRANSACTION END and map it as a method of NorthwindDataContext (explained in this post):private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.UpdateProductUnitPrice(id, unitPrice); } } As a normal trade off for O/R mapping, a decision has to be made between performance overhead and programming productivity according to the case. In a developer’s perspective, if O/R mapping is chosen, I consistently choose the declarative LINQ code, unless this kind of overhead is unacceptable. Data retrieving overhead After talking about the O/R mapping specific issue. Now look into the LINQ to SQL specific issues, for example, performance in the data retrieving process. The previous post has explained that the SQL translating and executing is complex. Actually, the LINQ to SQL pipeline is similar to the compiler pipeline. It consists of about 15 steps to translate an C# expression tree to SQL statement, which can be categorized as: Convert: Invoke SqlProvider.BuildQuery() to convert the tree of Expression nodes into a tree of SqlNode nodes; Bind: Used visitor pattern to figure out the meanings of names according to the mapping info, like a property for a column, etc.; Flatten: Figure out the hierarchy of the query; Rewrite: for SQL Server 2000, if needed Reduce: Remove the unnecessary information from the tree. Parameterize Format: Generate the SQL statement string; Parameterize: Figure out the parameters, for example, a reference to a local variable should be a parameter in SQL; Materialize: Executes the reader and convert the result back into typed objects. So for each data retrieving, even for data retrieving which looks simple: private static Product[] RetrieveProducts(int productId) { using (NorthwindDataContext database = new NorthwindDataContext()) { return database.Products.Where(product => product.ProductID == productId) .ToArray(); } } LINQ to SQL goes through above steps to translate and execute the query. Fortunately, there is a built-in way to cache the translated query. Compiled query When such a LINQ to SQL query is executed repeatedly, The CompiledQuery can be used to translate query for one time, and execute for multiple times:internal static class CompiledQueries { private static readonly Func<NorthwindDataContext, int, Product[]> _retrieveProducts = CompiledQuery.Compile((NorthwindDataContext database, int productId) => database.Products.Where(product => product.ProductID == productId).ToArray()); internal static Product[] RetrieveProducts( this NorthwindDataContext database, int productId) { return _retrieveProducts(database, productId); } } The new version of RetrieveProducts() gets better performance, because only when _retrieveProducts is first time invoked, it internally invokes SqlProvider.Compile() to translate the query expression. And it also uses lock to make sure translating once in multi-threading scenarios. Static SQL / stored procedures without translating Another way to avoid the translating overhead is to use static SQL or stored procedures, just as the above examples. Because this is a functional programming series, this article not dive into. For the details, Scott Guthrie already has some excellent articles: LINQ to SQL (Part 6: Retrieving Data Using Stored Procedures) LINQ to SQL (Part 7: Updating our Database using Stored Procedures) LINQ to SQL (Part 8: Executing Custom SQL Expressions) Data changing overhead By looking into the data updating process, it also needs a lot of work: Begins transaction Processes the changes (ChangeProcessor) Walks through the objects to identify the changes Determines the order of the changes Executes the changings LINQ queries may be needed to execute the changings, like the first example in this article, an object needs to be retrieved before changed, then the above whole process of data retrieving will be went through If there is user customization, it will be executed, for example, a table’s INSERT / UPDATE / DELETE can be customized in the O/R designer It is important to keep these overhead in mind. Bulk deleting / updating Another thing to be aware is the bulk deleting:private static void DeleteProducts(int categoryId) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.Products.DeleteAllOnSubmit( database.Products.Where(product => product.CategoryID == categoryId)); database.SubmitChanges(); } } The expected SQL should be like:BEGIN TRANSACTION exec sp_executesql N'DELETE FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0',N'@p0 int',@p0=9 COMMIT TRANSACTION Hoverer, as fore mentioned, the actual SQL is to retrieving the entities, and then delete them one by one:-- Retrieves the entities to be deleted: exec sp_executesql N'SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0',N'@p0 int',@p0=9 -- Deletes the retrieved entities one by one: BEGIN TRANSACTION exec sp_executesql N'DELETE FROM [dbo].[Products] WHERE ([ProductID] = @p0) AND ([ProductName] = @p1) AND ([SupplierID] IS NULL) AND ([CategoryID] = @p2) AND ([QuantityPerUnit] IS NULL) AND ([UnitPrice] = @p3) AND ([UnitsInStock] = @p4) AND ([UnitsOnOrder] = @p5) AND ([ReorderLevel] = @p6) AND (NOT ([Discontinued] = 1))',N'@p0 int,@p1 nvarchar(4000),@p2 int,@p3 money,@p4 smallint,@p5 smallint,@p6 smallint',@p0=78,@p1=N'Optimus Prime',@p2=9,@p3=$0.0000,@p4=0,@p5=0,@p6=0 exec sp_executesql N'DELETE FROM [dbo].[Products] WHERE ([ProductID] = @p0) AND ([ProductName] = @p1) AND ([SupplierID] IS NULL) AND ([CategoryID] = @p2) AND ([QuantityPerUnit] IS NULL) AND ([UnitPrice] = @p3) AND ([UnitsInStock] = @p4) AND ([UnitsOnOrder] = @p5) AND ([ReorderLevel] = @p6) AND (NOT ([Discontinued] = 1))',N'@p0 int,@p1 nvarchar(4000),@p2 int,@p3 money,@p4 smallint,@p5 smallint,@p6 smallint',@p0=79,@p1=N'Bumble Bee',@p2=9,@p3=$0.0000,@p4=0,@p5=0,@p6=0 -- ... COMMIT TRANSACTION And the same to the bulk updating. This is really not effective and need to be aware. Here is already some solutions from the Internet, like this one. The idea is wrap the above SELECT statement into a INNER JOIN:exec sp_executesql N'DELETE [dbo].[Products] FROM [dbo].[Products] AS [j0] INNER JOIN ( SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0) AS [j1] ON ([j0].[ProductID] = [j1].[[Products])', -- The Primary Key N'@p0 int',@p0=9 Query plan overhead The last thing is about the SQL Server query plan. Before .NET 4.0, LINQ to SQL has an issue (not sure if it is a bug). LINQ to SQL internally uses ADO.NET, but it does not set the SqlParameter.Size for a variable-length argument, like argument of NVARCHAR type, etc. So for two queries with the same SQL but different argument length:using (NorthwindDataContext database = new NorthwindDataContext()) { database.Products.Where(product => product.ProductName == "A") .Select(product => product.ProductID).ToArray(); // The same SQL and argument type, different argument length. database.Products.Where(product => product.ProductName == "AA") .Select(product => product.ProductID).ToArray(); } Pay attention to the argument length in the translated SQL:exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(1)',@p0=N'A' exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(2)',@p0=N'AA' Here is the overhead: The first query’s query plan cache is not reused by the second one:SELECT sys.syscacheobjects.cacheobjtype, sys.dm_exec_cached_plans.usecounts, sys.syscacheobjects.[sql] FROM sys.syscacheobjects INNER JOIN sys.dm_exec_cached_plans ON sys.syscacheobjects.bucketid = sys.dm_exec_cached_plans.bucketid; They actually use different query plans. Again, pay attention to the argument length in the [sql] column (@p0 nvarchar(2) / @p0 nvarchar(1)). Fortunately, in .NET 4.0 this is fixed:internal static class SqlTypeSystem { private abstract class ProviderBase : TypeSystemProvider { protected int? GetLargestDeclarableSize(SqlType declaredType) { SqlDbType sqlDbType = declaredType.SqlDbType; if (sqlDbType <= SqlDbType.Image) { switch (sqlDbType) { case SqlDbType.Binary: case SqlDbType.Image: return 8000; } return null; } if (sqlDbType == SqlDbType.NVarChar) { return 4000; // Max length for NVARCHAR. } if (sqlDbType != SqlDbType.VarChar) { return null; } return 8000; } } } In this above example, the translated SQL becomes:exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(4000)',@p0=N'A' exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(4000)',@p0=N'AA' So that they reuses the same query plan cache: Now the [usecounts] column is 2.

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  • Can a wifi AP act as a client, and a server at the same time?

    - by nbolton
    I feel this is SF worthy (as opposed to SU) as I go into a bit of detail on gateways/routing. Here's my ideal setup (if possible) -- there is a wifi network (lets call it bob's) with which I want access to, but I have a few other computers on my network which I want to keep behind a firewall. So I was thinking of buying a wireless access point so that I could set it up to connect to bob's network from the AP, and then from my server, connect to the AP via ethernet. So that's the first bit. Second part is that I want to have my own private wifi network off the back of this; can I then tell the AP to serve a new network called foobar. When I say private network, I mean that my server is actually a Debian linux install with routing configured (and I also do some QoS stuff on, etc). So ideally, I'd like all the clients on the private network to be behind the server in terms of routing. However, if the private clients connect to the server via wifi, then aren't they exposed to the "public" network? That is, if someone is savvy enough to scan for my IP range. Also, to do routing I'd need to connect two ethernet cables between the server and the AP (because you can't do routing/QoS on virtual devices) -- which isn't a problem really; but I'm not sure whether the AP will allow me to separate the public and private LANs. Or, as well as the AP, am I better getting a wifi-to-ethernet adapter for the server? I could use a wifi usb, but this can be tricky to set up on headless linux; plus the signal strength is a bit lousy. If this question is a bit vague/spurious in places, please comment and I will explain in more detail.

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  • Using dnsmasq for accessing multiple nameservers assigned by DHCP

    - by Ash
    At my work desktop running openSUSE 11.4, I have a local network which gets its address, domain (work.site) and nameservers (10.100.1.1, 10.100.1.2) info through DHCP - which get written into /etc/resolv.conf I get to access the internet using the work network, and these 2 nameservers end up returning the entries for any public domain name lookups on the internet. I also have a private VPN that I end up connecting. The nameserver (10.111.1.1) and domain (private.site) are rarely bound to change for this network, but currently they're pushed by the openVPN client into networkmanager, and which also gets merged with the existing /etc/resolv.conf My resolv.conf ultimately ends up looking like this: search private.site work.site nameserver 127.0.0.1 nameserver 10.111.1.1 nameserver 10.100.1.1 As you can see the 2nd nameserver from my work network was pushed out because of the max 3 entry limitations. It is fine still, but would be a problem if that nameserver goes down for maintenance or something. So I found out that dnsmasq could help me here, and hence I setup dnsmasq just as a local DNS resolver without any DHCP support. So right now this is my /etc/dnsmasq.conf: resolv-file=/etc/resolv.conf server=/private.site/10.111.1.1 server=/1.111.10.in-addr.arpa/10.111.1.1 listen-address=127.0.0.1 bind-interfaces log-queries I've made dnsmasq get the list of nameservers from /etc/resolv.conf since NetworkManager seems to be updating this list correctly (for a max of 3 nameservers). I'm able to resolve the host names in both the networks correctly. So these are the questions I have: Is there a way I can make either NetworkManager or dhclient write out the list of nameservers somewhere else which I can make dnsmasq use as resolv-file ? How do I make dnsmasq use certain nameservers as the default for all queries ? Right now I notice that lookups for public domains on the internet are usually sent to both the nameservers - the one on work.site as well as private.site. It would be good if I can limit this only to work.site.

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  • My New BDD Style

    - by Liam McLennan
    I have made a change to my code-based BDD style. I start with a scenario such as: Pre-Editing * Given I am a book editor * And some chapters are locked and some are not * When I view the list of chapters for editing * Then I should see some chapters are editable and are not locked * And I should see some chapters are not editable and are locked and I implement it using a modified SpecUnit base class as: [Concern("Chapter Editing")] public class when_pre_editing_a_chapter : BaseSpec { private User i; // other context variables protected override void Given() { i_am_a_book_editor(); some_chapters_are_locked_and_some_are_not(); } protected override void Do() { i_view_the_list_of_chapters_for_editing(); } private void i_am_a_book_editor() { i = new UserBuilder().WithUsername("me").WithRole(UserRole.BookEditor).Build(); } private void some_chapters_are_locked_and_some_are_not() { } private void i_view_the_list_of_chapters_for_editing() { } [Observation] public void should_see_some_chapters_are_editable_and_are_not_locked() { } [Observation] public void should_see_some_chapters_are_not_editable_and_are_locked() { } } and the output from the specunit report tool is: Chapter Editing specifications    1 context, 2 specifications Chapter Editing, when pre editing a chapter    2 specifications should see some chapters are editable and are not locked should see some chapters are not editable and are locked The intent is to provide a clear mapping from story –> scenarios –> bdd tests.

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  • Avoiding new operator in JavaScript -- the better way

    - by greengit
    Warning: This is a long post. Let's keep it simple. I want to avoid having to prefix the new operator every time I call a constructor in JavaScript. This is because I tend to forget it, and my code screws up badly. The simple way around this is this... function Make(x) { if ( !(this instanceof arguments.callee) ) return new arguments.callee(x); // do your stuff... } But, I need this to accept variable no. of arguments, like this... m1 = Make(); m2 = Make(1,2,3); m3 = Make('apple', 'banana'); The first immediate solution seems to be the 'apply' method like this... function Make() { if ( !(this instanceof arguments.callee) ) return new arguments.callee.apply(null, arguments); // do your stuff } This is WRONG however -- the new object is passed to the apply method and NOT to our constructor arguments.callee. Now, I've come up with three solutions. My simple question is: which one seems best. Or, if you have a better method, tell it. First – use eval() to dynamically create JavaScript code that calls the constructor. function Make(/* ... */) { if ( !(this instanceof arguments.callee) ) { // collect all the arguments var arr = []; for ( var i = 0; arguments[i]; i++ ) arr.push( 'arguments[' + i + ']' ); // create code var code = 'new arguments.callee(' + arr.join(',') + ');'; // call it return eval( code ); } // do your stuff with variable arguments... } Second – Every object has __proto__ property which is a 'secret' link to its prototype object. Fortunately this property is writable. function Make(/* ... */) { var obj = {}; // do your stuff on 'obj' just like you'd do on 'this' // use the variable arguments here // now do the __proto__ magic // by 'mutating' obj to make it a different object obj.__proto__ = arguments.callee.prototype; // must return obj return obj; } Third – This is something similar to second solution. function Make(/* ... */) { // we'll set '_construct' outside var obj = new arguments.callee._construct(); // now do your stuff on 'obj' just like you'd do on 'this' // use the variable arguments here // you have to return obj return obj; } // now first set the _construct property to an empty function Make._construct = function() {}; // and then mutate the prototype of _construct Make._construct.prototype = Make.prototype; eval solution seems clumsy and comes with all the problems of "evil eval". __proto__ solution is non-standard and the "Great Browser of mIsERY" doesn't honor it. The third solution seems overly complicated. But with all the above three solutions, we can do something like this, that we can't otherwise... m1 = Make(); m2 = Make(1,2,3); m3 = Make('apple', 'banana'); m1 instanceof Make; // true m2 instanceof Make; // true m3 instanceof Make; // true Make.prototype.fire = function() { // ... }; m1.fire(); m2.fire(); m3.fire(); So effectively the above solutions give us "true" constructors that accept variable no. of arguments and don't require new. What's your take on this. -- UPDATE -- Some have said "just throw an error". My response is: we are doing a heavy app with 10+ constructors and I think it'd be far more wieldy if every constructor could "smartly" handle that mistake without throwing error messages on the console.

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  • Can I use my existing SSL certificates on a new server with Plesk?

    - by Wil
    We are migrating to a Virtual Private Server running on Ubuntu 8.04 LTS and with a Plesk configuration panel. We have some valid SSL certificates on the old server, which I would like to use on the new configuration. I have the CSR, private key, certificate and CA-certificate. I cannot find a way to change the CSR and private key in the Plesk configuration panel. Anyone know, if this is possible and how?

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  • Importing GPG Key

    - by Bodo
    I have problems importing my GPG-Keys into my new installation of debian. I exportet the private-key a few years ago. Now I am trying to get everything running under a new debian. I tried to do gpg --allow-secret-key-import --import private-key.asc But I only get this: gpg: Keine gültigen OpenPGP-Daten gefunden. gpg: Anzahl insgesamt bearbeiteter Schlüssel: 0 which translates to: gpg: No valid OpenPGP-Data found gpg: Number of processed Keys : 0 The file looks correct and starts with --BEGIN PGP PRIVATE KEY BLOCK----- Version: GnuPG v1.4.9 (GNU/Linux) and ends with -----END PGP PRIVATE KEY BLOCK----- what could be wrong?

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  • Retrieving an RSA key from a running instance of Apache?

    - by Nathan Osman
    I created an RSA keypair for an SSL certificate and stored the private key in /etc/ssl/private/server.key. Unfortunately this was the only copy of the private key that I had. Then I accidentally overwrote the file on disk (yes, I know). Apache is still running and still serving SSL requests, leading me to believe that there may be hope in recovering the private key. (Perhaps there is a symbolic link somewhere in /proc or something?) This server is running Ubuntu 12.04 LTS.

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  • C#: Why Decorate When You Can Intercept

    - by James Michael Hare
    We've all heard of the old Decorator Design Pattern (here) or used it at one time or another either directly or indirectly.  A decorator is a class that wraps a given abstract class or interface and presents the same (or a superset) public interface but "decorated" with additional functionality.   As a really simplistic example, consider the System.IO.BufferedStream, it itself is a descendent of System.IO.Stream and wraps the given stream with buffering logic while still presenting System.IO.Stream's public interface:   1: Stream buffStream = new BufferedStream(rawStream); Now, let's take a look at a custom-code example.  Let's say that we have a class in our data access layer that retrieves a list of products from a database:  1: // a class that handles our CRUD operations for products 2: public class ProductDao 3: { 4: ... 5:  6: // a method that would retrieve all available products 7: public IEnumerable<Product> GetAvailableProducts() 8: { 9: var results = new List<Product>(); 10:  11: // must create the connection 12: using (var con = _factory.CreateConnection()) 13: { 14: con.ConnectionString = _productsConnectionString; 15: con.Open(); 16:  17: // create the command 18: using (var cmd = _factory.CreateCommand()) 19: { 20: cmd.Connection = con; 21: cmd.CommandText = _getAllProductsStoredProc; 22: cmd.CommandType = CommandType.StoredProcedure; 23:  24: // get a reader and pass back all results 25: using (var reader = cmd.ExecuteReader()) 26: { 27: while(reader.Read()) 28: { 29: results.Add(new Product 30: { 31: Name = reader["product_name"].ToString(), 32: ... 33: }); 34: } 35: } 36: } 37: }            38:  39: return results; 40: } 41: } Yes, you could use EF or any myriad other choices for this sort of thing, but the germaine point is that you have some operation that takes a non-trivial amount of time.  What if, during the production day I notice that my application is performing slowly and I want to see how much of that slowness is in the query versus my code.  Well, I could easily wrap the logic block in a System.Diagnostics.Stopwatch and log the results to log4net or other logging flavor of choice: 1:     // a class that handles our CRUD operations for products 2:     public class ProductDao 3:     { 4:         private static readonly ILog _log = LogManager.GetLogger(typeof(ProductDao)); 5:         ... 6:         7:         // a method that would retrieve all available products 8:         public IEnumerable<Product> GetAvailableProducts() 9:         { 10:             var results = new List<Product>(); 11:             var timer = Stopwatch.StartNew(); 12:             13:             // must create the connection 14:             using (var con = _factory.CreateConnection()) 15:             { 16:                 con.ConnectionString = _productsConnectionString; 17:                 18:                 // and all that other DB code... 19:                 ... 20:             } 21:             22:             timer.Stop(); 23:             24:             if (timer.ElapsedMilliseconds > 5000) 25:             { 26:                 _log.WarnFormat("Long query in GetAvailableProducts() took {0} ms", 27:                     timer.ElapsedMillseconds); 28:             } 29:             30:             return results; 31:         } 32:     } In my eye, this is very ugly.  It violates Single Responsibility Principle (SRP), which says that a class should only ever have one responsibility, where responsibility is often defined as a reason to change.  This class (and in particular this method) has two reasons to change: If the method of retrieving products changes. If the method of logging changes. Well, we could “simplify” this using the Decorator Design Pattern (here).  If we followed the pattern to the letter, we'd need to create a base decorator that implements the DAOs public interface and forwards to the wrapped instance.  So let's assume we break out the ProductDAO interface into IProductDAO using your refactoring tool of choice (Resharper is great for this). Now, ProductDao will implement IProductDao and get rid of all logging logic: 1:     public class ProductDao : IProductDao 2:     { 3:         // this reverts back to original version except for the interface added 4:     } 5:  And we create the base Decorator that also implements the interface and forwards all calls: 1:     public class ProductDaoDecorator : IProductDao 2:     { 3:         private readonly IProductDao _wrappedDao; 4:         5:         // constructor takes the dao to wrap 6:         public ProductDaoDecorator(IProductDao wrappedDao) 7:         { 8:             _wrappedDao = wrappedDao; 9:         } 10:         11:         ... 12:         13:         // and then all methods just forward their calls 14:         public IEnumerable<Product> GetAvailableProducts() 15:         { 16:             return _wrappedDao.GetAvailableProducts(); 17:         } 18:     } This defines our base decorator, then we can create decorators that add items of interest, and for any methods we don't decorate, we'll get the default behavior which just forwards the call to the wrapper in the base decorator: 1:     public class TimedThresholdProductDaoDecorator : ProductDaoDecorator 2:     { 3:         private static readonly ILog _log = LogManager.GetLogger(typeof(TimedThresholdProductDaoDecorator)); 4:         5:         public TimedThresholdProductDaoDecorator(IProductDao wrappedDao) : 6:             base(wrappedDao) 7:         { 8:         } 9:         10:         ... 11:         12:         public IEnumerable<Product> GetAvailableProducts() 13:         { 14:             var timer = Stopwatch.StartNew(); 15:             16:             var results = _wrapped.GetAvailableProducts(); 17:             18:             timer.Stop(); 19:             20:             if (timer.ElapsedMilliseconds > 5000) 21:             { 22:                 _log.WarnFormat("Long query in GetAvailableProducts() took {0} ms", 23:                     timer.ElapsedMillseconds); 24:             } 25:             26:             return results; 27:         } 28:     } Well, it's a bit better.  Now the logging is in its own class, and the database logic is in its own class.  But we've essentially multiplied the number of classes.  We now have 3 classes and one interface!  Now if you want to do that same logging decorating on all your DAOs, imagine the code bloat!  Sure, you can simplify and avoid creating the base decorator, or chuck it all and just inherit directly.  But regardless all of these have the problem of tying the logging logic into the code itself. Enter the Interceptors.  Things like this to me are a perfect example of when it's good to write an Interceptor using your class library of choice.  Sure, you could design your own perfectly generic decorator with delegates and all that, but personally I'm a big fan of Castle's Dynamic Proxy (here) which is actually used by many projects including Moq. What DynamicProxy allows you to do is intercept calls into any object by wrapping it with a proxy on the fly that intercepts the method and allows you to add functionality.  Essentially, the code would now look like this using DynamicProxy: 1: // Note: I like hiding DynamicProxy behind the scenes so users 2: // don't have to explicitly add reference to Castle's libraries. 3: public static class TimeThresholdInterceptor 4: { 5: // Our logging handle 6: private static readonly ILog _log = LogManager.GetLogger(typeof(TimeThresholdInterceptor)); 7:  8: // Handle to Castle's proxy generator 9: private static readonly ProxyGenerator _generator = new ProxyGenerator(); 10:  11: // generic form for those who prefer it 12: public static object Create<TInterface>(object target, TimeSpan threshold) 13: { 14: return Create(typeof(TInterface), target, threshold); 15: } 16:  17: // Form that uses type instead 18: public static object Create(Type interfaceType, object target, TimeSpan threshold) 19: { 20: return _generator.CreateInterfaceProxyWithTarget(interfaceType, target, 21: new TimedThreshold(threshold, level)); 22: } 23:  24: // The interceptor that is created to intercept the interface calls. 25: // Hidden as a private inner class so not exposing Castle libraries. 26: private class TimedThreshold : IInterceptor 27: { 28: // The threshold as a positive timespan that triggers a log message. 29: private readonly TimeSpan _threshold; 30:  31: // interceptor constructor 32: public TimedThreshold(TimeSpan threshold) 33: { 34: _threshold = threshold; 35: } 36:  37: // Intercept functor for each method invokation 38: public void Intercept(IInvocation invocation) 39: { 40: // time the method invocation 41: var timer = Stopwatch.StartNew(); 42:  43: // the Castle magic that tells the method to go ahead 44: invocation.Proceed(); 45:  46: timer.Stop(); 47:  48: // check if threshold is exceeded 49: if (timer.Elapsed > _threshold) 50: { 51: _log.WarnFormat("Long execution in {0} took {1} ms", 52: invocation.Method.Name, 53: timer.ElapsedMillseconds); 54: } 55: } 56: } 57: } Yes, it's a bit longer, but notice that: This class ONLY deals with logging long method calls, no DAO interface leftovers. This class can be used to time ANY class that has an interface or virtual methods. Personally, I like to wrap and hide the usage of DynamicProxy and IInterceptor so that anyone who uses this class doesn't need to know to add a Castle library reference.  As far as they are concerned, they're using my interceptor.  If I change to a new library if a better one comes along, they're insulated. Now, all we have to do to use this is to tell it to wrap our ProductDao and it does the rest: 1: // wraps a new ProductDao with a timing interceptor with a threshold of 5 seconds 2: IProductDao dao = TimeThresholdInterceptor.Create<IProductDao>(new ProductDao(), 5000); Automatic decoration of all methods!  You can even refine the proxy so that it only intercepts certain methods. This is ideal for so many things.  These are just some of the interceptors we've dreamed up and use: Log parameters and returns of methods to XML for auditing. Block invocations to methods and return default value (stubbing). Throw exception if certain methods are called (good for blocking access to deprecated methods). Log entrance and exit of a method and the duration. Log a message if a method takes more than a given time threshold to execute. Whether you use DynamicProxy or some other technology, I hope you see the benefits this adds.  Does it completely eliminate all need for the Decorator pattern?  No, there may still be cases where you want to decorate a particular class with functionality that doesn't apply to the world at large. But for all those cases where you are using Decorator to add functionality that's truly generic.  I strongly suggest you give this a try!

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  • Need help trouble shooting Https webserver error - SSL Handshake failed

    - by DerNalia
    I followed this guide: http://hints.macworld.com/article.php?story=20041129143420344 Here is my virtual host definition <VirtualHost *:443> SSLEngine on SSLProxyEngine On RequestHeader set Front-End-Https "On" CacheDisable * SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL DocumentRoot "/Users/me/projects/myproject/public" ServerName ssl.mydomain.com ServerAlias *.ssl.mydomain.com SSLCertificateKeyFile "/private/etc/apache2/certs/webserver.nopass.key" SSLCertificateFile "/private/etc/apache2/certs/newcert.pem" SSLCACertificateFile "/private/etc/apache2/certs/demoCA/cacert.pem" SSLCARevocationPath "/private/etc/apache2/certs/demoCA/crl" ErrorLog "/Users/me/Desktop/ssl.log" ProxyPass / https://localhost:3002/ ProxyPassReverse / https://localhost:3002 ProxyPreserveHost on </VirtualHost> And when I try connecting to the sevre viov the web browser, I get this error: [Thu Feb 02 16:50:40 2012] [error] (502)Unknown error: 502: proxy: pass request body failed to 127.0.0.1:3002 (localhost) [Thu Feb 02 16:50:40 2012] [error] [client 96.11.81.39] proxy: Error during SSL Handshake with remote server returned by /session/new [Thu Feb 02 16:50:40 2012] [error] proxy: pass request body failed to 127.0.0.1:3002 (localhost) from 96.11.81.39 () how do I debug / fix this?

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  • WSDL-world vs CLR-world – some differences

    - by nmarun
    A change in mindset is required when switching between a typical CLR application and a web service application. There are some things in a CLR environment that just don’t add-up in a WSDL arena (and vice-versa). I’m listing some of them here. When I say WSDL-world, I’m mostly talking with respect to a WCF Service and / or a Web Service. No (direct) Method Overloading: You definitely can have overloaded methods in a, say, Console application, but when it comes to a WCF / Web Services application, you need to adorn these overloaded methods with a special attribute so the service knows which specific method to invoke. When you’re working with WCF, use the Name property of the OperationContract attribute to provide unique names. 1: [OperationContract(Name = "AddInt")] 2: int Add(int arg1, int arg2); 3:  4: [OperationContract(Name = "AddDouble")] 5: double Add(double arg1, double arg2); By default, the proxy generates the code for this as: 1: [System.ServiceModel.OperationContractAttribute( 2: Action="http://tempuri.org/ILearnWcfService/AddInt", 3: ReplyAction="http://tempuri.org/ILearnWcfService/AddIntResponse")] 4: int AddInt(int arg1, int arg2); 5: 6: [System.ServiceModel.OperationContractAttribute( 7: Action="http://tempuri.org/ILearnWcfServiceExtend/AddDouble", 8: ReplyAction="http://tempuri.org/ILearnWcfServiceExtend/AddDoubleResponse")] 9: double AddDouble(double arg1, double arg2); With Web Services though the story is slightly different. Even after setting the MessageName property of the WebMethod attribute, the proxy does not change the name of the method, but only the underlying soap message changes. 1: [WebMethod] 2: public string HelloGalaxy() 3: { 4: return "Hello Milky Way!"; 5: } 6:  7: [WebMethod(MessageName = "HelloAnyGalaxy")] 8: public string HelloGalaxy(string galaxyName) 9: { 10: return string.Format("Hello {0}!", galaxyName); 11: } The one thing you need to remember is to set the WebServiceBinding accordingly. 1: [WebServiceBinding(ConformsTo = WsiProfiles.None)] The proxy is: 1: [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://tempuri.org/HelloGalaxy", 2: RequestNamespace="http://tempuri.org/", 3: ResponseNamespace="http://tempuri.org/", 4: Use=System.Web.Services.Description.SoapBindingUse.Literal, 5: ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)] 6: public string HelloGalaxy() 7:  8: [System.Web.Services.WebMethodAttribute(MessageName="HelloGalaxy1")] 9: [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://tempuri.org/HelloAnyGalaxy", 10: RequestElementName="HelloAnyGalaxy", 11: RequestNamespace="http://tempuri.org/", 12: ResponseElementName="HelloAnyGalaxyResponse", 13: ResponseNamespace="http://tempuri.org/", 14: Use=System.Web.Services.Description.SoapBindingUse.Literal, 15: ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)] 16: [return: System.Xml.Serialization.XmlElementAttribute("HelloAnyGalaxyResult")] 17: public string HelloGalaxy(string galaxyName) 18:  You see the calling method name is the same in the proxy, however the soap message that gets generated is different. Using interchangeable data types: See details on this here. Type visibility: In a CLR-based application, if you mark a field as private, well we all know, it’s ‘private’. Coming to a WSDL side of things, in a Web Service, private fields and web methods will not get generated in the proxy. In WCF however, all your operation contracts will be public as they get implemented from an interface. Even in case your ServiceContract interface is declared internal/private, you will see it as a public interface in the proxy. This is because type visibility is a CLR concept and has no bearing on WCF. Also if a private field has the [DataMember] attribute in a data contract, it will get emitted in the proxy class as a public property for the very same reason. 1: [DataContract] 2: public struct Person 3: { 4: [DataMember] 5: private int _x; 6:  7: [DataMember] 8: public int Id { get; set; } 9:  10: [DataMember] 11: public string FirstName { get; set; } 12:  13: [DataMember] 14: public string Header { get; set; } 15: } 16: } See the ‘_x’ field is a private member with the [DataMember] attribute, but the proxy class shows as below: 1: [System.Runtime.Serialization.DataMemberAttribute()] 2: public int _x { 3: get { 4: return this._xField; 5: } 6: set { 7: if ((this._xField.Equals(value) != true)) { 8: this._xField = value; 9: this.RaisePropertyChanged("_x"); 10: } 11: } 12: } Passing derived types to web methods / operation contracts: Once again, in a CLR application, I can have a derived class be passed as a parameter where a base class is expected. I have the following set up for my WCF service. 1: [DataContract] 2: public class Employee 3: { 4: [DataMember(Name = "Id")] 5: public int EmployeeId { get; set; } 6:  7: [DataMember(Name="FirstName")] 8: public string FName { get; set; } 9:  10: [DataMember] 11: public string Header { get; set; } 12: } 13:  14: [DataContract] 15: public class Manager : Employee 16: { 17: [DataMember] 18: private int _x; 19: } 20:  21: // service contract 22: [OperationContract] 23: Manager SaveManager(Employee employee); 24:  25: // in my calling code 26: Manager manager = new Manager {_x = 1, FirstName = "abc"}; 27: manager = LearnWcfServiceClient.SaveManager(manager); The above will throw an exception saying: In short, this is saying, that a Manager type was found where an Employee type was expected! Hierarchy flattening of interfaces in WCF: See details on this here. In CLR world, you’ll see the entire hierarchy as is. That’s another difference. Using ref parameters: * can use ref for parameters, but operation contract should not be one-way (gives an error when you do an update service reference)   => bad programming; create a return object that is composed of everything you need! This one kind of stumped me. Not sure why I tried this, but you can pass parameters prefixed with ref keyword* (* terms and conditions apply). The main issue is this, how would we know the changes that were made to a ‘ref’ input parameter are returned back from the service and updated to the local variable? Turns out both Web Services and WCF make this tracking happen by passing the input parameter in the response soap. This way when the deserializer does its magic, it maps all the elements of the response xml thereby updating our local variable. Here’s what I’m talking about. 1: [WebMethod(MessageName = "HelloAnyGalaxy")] 2: public string HelloGalaxy(ref string galaxyName) 3: { 4: string output = string.Format("Hello {0}", galaxyName); 5: if (galaxyName == "Andromeda") 6: { 7: galaxyName = string.Format("{0} (2.5 million light-years away)", galaxyName); 8: } 9: return output; 10: } This is how the request and response look like in soapUI. As I said above, the behavior is quite similar for WCF as well. But the catch comes when you have a one-way web methods / operation contracts. If you have an operation contract whose return type is void, is marked one-way and that has ref parameters then you’ll get an error message when you try to reference such a service. 1: [OperationContract(Name = "Sum", IsOneWay = true)] 2: void Sum(ref double arg1, ref double arg2); 3:  4: public void Sum(ref double arg1, ref double arg2) 5: { 6: arg1 += arg2; 7: } This is what I got when I did an update to my service reference: Makes sense, because a OneWay operation is… one-way – there’s no returning from this operation. You can also have a one-way web method: 1: [SoapDocumentMethod(OneWay = true)] 2: [WebMethod(MessageName = "HelloAnyGalaxy")] 3: public void HelloGalaxy(ref string galaxyName) This will throw an exception message similar to the one above when you try to update your web service reference. In the CLR space, there’s no such concept of a ‘one-way’ street! Yes, there’s void, but you very well can have ref parameters returned through such a method. Just a point here; although the ref/out concept sounds cool, it’s generally is a code-smell. The better approach is to always return an object that is composed of everything you need returned from a method. These are some of the differences that we need to bear when dealing with services that are different from our daily ‘CLR’ life.

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  • deploy ssh key from master to minion via salt pillars

    - by user180041
    I have two ssh keys that I'm trying to deploy to one of my minions.But I cant seem to get it to deploy.It errors out....Here is the init.sls in pillars.... /xxx/yyy/zzz/id_rsa: file.managed: - source: salt://private/id_rsa /xxx/yyy/zz/id_rsa.pub: file.managed: - source: salt://private/id_rsa.pub here is my init.sls states..... ssh: file.managed: - name: {{pillar['private']}} ...... I must be doing something wrong (obviously)... not sure what.. .any suggestions??

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  • Why does httpd handle requests for wrong hostnames in SSL mode?

    - by Manuel
    I have an SSL-enabled virtual host for my sites at example.com:10443 Listen 10443 <VirtualHost _default_:10443> ServerName example.com:10443 ServerAdmin [email protected] ErrorLog "/var/log/httpd/error_log" TransferLog "/var/log/httpd/access_log" SSLEngine on SSLProtocol all -SSLv2 SSLCipherSuite HIGH:MEDIUM:!aNULL:!MD5 SSLCertificateFile "/etc/ssl/private/example.com.crt" SSLCertificateKeyFile "/etc/ssl/private/example.com.key" SSLCertificateChainFile "/etc/ssl/private/sub.class1.server.ca.pem" SSLCACertificateFile "/etc/ssl/private/StartCom.pem" </VirtualHost> Browsing to https://example.com:10443/ works as expected. However, also browsing to https://subdomain.example.com:10443/ (with DNS set) shows me the same pages (after SSL certificate warning). I would have expected the directive ServerName example.com:10443 to reject all connection attempts to other server names. How can I tell the virtual host not to serve requests for URLs other than the top-level one?

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  • Why does Farseer 2.x store temporaries as members and not on the stack? (.NET)

    - by Andrew Russell
    UPDATE: This question refers to Farseer 2.x. The newer 3.x doesn't seem to do this. I'm using Farseer Physics Engine quite extensively at the moment, and I've noticed that it seems to store a lot of temporary value types as members of the class, and not on the stack as one might expect. Here is an example from the Body class: private Vector2 _worldPositionTemp = Vector2.Zero; private Matrix _bodyMatrixTemp = Matrix.Identity; private Matrix _rotationMatrixTemp = Matrix.Identity; private Matrix _translationMatrixTemp = Matrix.Identity; public void GetBodyMatrix(out Matrix bodyMatrix) { Matrix.CreateTranslation(position.X, position.Y, 0, out _translationMatrixTemp); Matrix.CreateRotationZ(rotation, out _rotationMatrixTemp); Matrix.Multiply(ref _rotationMatrixTemp, ref _translationMatrixTemp, out bodyMatrix); } public Vector2 GetWorldPosition(Vector2 localPosition) { GetBodyMatrix(out _bodyMatrixTemp); Vector2.Transform(ref localPosition, ref _bodyMatrixTemp, out _worldPositionTemp); return _worldPositionTemp; } It looks like its a by-hand performance optimisation. But I don't see how this could possibly help performance? (If anything I think it would hurt by making objects much larger).

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  • Configure Courier IMAP to deliver mail to multiple hostnames

    - by vy32
    I have a courier IMAP server running on a private server at dreamhost. The private server's hostname is psxxxx.dreamhostps.com. I also have CNAME for the private server, call it mydomain.com. I want to send email to [email protected] and have it delivered to [email protected]. Right now the Courer server on the private server is bouncing the mail. On other mail servers there is a file into which you put all of the names that the host responds to. The names are all synonyms for the host's name, so user@ are equivillent. How do I configure Courer to treat multiple hostnames as synonyms for its host name? Thank you.

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  • Some Original Expressions

    - by Phil Factor
    Guest Editorial for Simple-Talk newsletterIn a guest editorial for the Simple-Talk Newsletter, Phil Factor wonders if we are still likely to find some more novel and unexpected ways of using the newer features of Transact SQL: or maybe in some features that have always been there! There can be a great deal of fun to be had in trying out recent features of SQL Expressions to see if  they provide new functionality.  It is surprisingly rare to find things that couldn’t be done before, but in a different   and more cumbersome way; but it is great to experiment or to read of someone else making that discovery.  One such recent feature is the ‘table value constructor’, or ‘VALUES constructor’, that managed to get into SQL Server 2008 from Standard SQL.  This allows you to create derived tables of up to 1000 rows neatly within select statements that consist of  lists of row values.  E.g. SELECT Old_Welsh, number FROM (VALUES ('Un',1),('Dou',2),('Tri',3),('Petuar',4),('Pimp',5),('Chwech',6),('Seith',7),('Wyth',8),('Nau',9),('Dec',10)) AS WelshWordsToTen (Old_Welsh, number) These values can be expressions that return single values, including, surprisingly, subqueries. You can use this device to create views, or in the USING clause of a MERGE statement. Joe Celko covered  this here and here.  It can become extraordinarily handy to use once one gets into the way of thinking in these terms, and I’ve rewritten a lot of routines to use the constructor, but the old way of using UNION can be used the same way, but is a little slower and more long-winded. The use of scalar SQL subqueries as an expression in a VALUES constructor, and then applied to a MERGE, has got me thinking. It looks very clever, but what use could one put it to? I haven’t seen anything yet that couldn’t be done almost as  simply in SQL Server 2000, but I’m hopeful that someone will come up with a way of solving a tricky problem, just in the same way that a freak of the XML syntax forever made the in-line  production of delimited lists from an expression easy, or that a weird XML pirouette could do an elegant  pivot-table rotation. It is in this sort of experimentation where the community of users can make a real contribution. The dissemination of techniques such as the Number, or Tally table, or the unconventional ways that the UPDATE statement can be used, has been rapid due to articles and blogs. However, there is plenty to be done to explore some of the less obvious features of Transact SQL. Even some of the features introduced into SQL Server 2000 are hardly well-known. Certain operations on data are still awkward to perform in Transact SQL, but we mustn’t, I think, be too ready to state that certain things can only be done in the application layer, or using a CLR routine. With the vast array of features in the product, and with the tools that surround it, I feel that there is generally a way of getting tricky things done. Or should we just stick to our lasts and push anything difficult out into procedural code? I’d love to know your views.

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