Search Results

Search found 14693 results on 588 pages for 'azure storage tables'.

Page 551/588 | < Previous Page | 547 548 549 550 551 552 553 554 555 556 557 558  | Next Page >

• stdio's remove() not always deleting on time.

  - by Kyte

  For a particular piece of homework, I'm implementing a basic data storage system using sequential files under standard C, which cannot load more than 1 record at a time. So, the basic part is creating a new file where the results of whatever we do with the original records are stored. The previous file's renamed, and a new one under the working name is created. The code's compiled with MinGW 5.1.6 on Windows 7. Problem is, this particular version of the code (I've got nearly-identical versions of this floating around my functions) doesn't always remove the old file, so the rename fails and hence the stored data gets wiped by the fopen(). FILE *archivo, *antiguo; remove("IndiceNecesidades.old"); // This randomly fails to work in time. rename("IndiceNecesidades.dat", "IndiceNecesidades.old"); // So rename() fails. antiguo = fopen("IndiceNecesidades.old", "rb"); // But apparently it still gets deleted, since this turns out null (and I never find the .old in my working folder after the program's done). archivo = fopen("IndiceNecesidades.dat", "wb"); // And here the data gets wiped. Basically, anytime the .old previously exists, there's a chance it's not removed in time for the rename() to take effect successfully. No possible name conflicts both internally and externally. The weird thing's that it's only with this particular file. Identical snippets except with the name changed to Necesidades.dat (which happen in 3 different functions) work perfectly fine. // I'm yet to see this snippet fail. FILE *antiguo, *archivo; remove("Necesidades.old"); rename("Necesidades.dat", "Necesidades.old"); antiguo = fopen("Necesidades.old", "rb"); archivo = fopen("Necesidades.dat", "wb"); Any ideas on why would this happen, and/or how can I ensure the remove() command has taken effect by the time rename() is executed? (I thought of just using a while loop to force call remove() again so long as fopen() returns a non-null pointer, but that sounds like begging for a crash due to overflowing the OS with delete requests or something.)

  Read the article

• WPF DataTemplateKey can not find ListBox key

  - by Ryan

  I am fairly new to WPF and am having trouble getting the DataTemplateKey to find my ListBox. <Window.Resources> <ControlTemplate x:Key="FocusTemplate" > <Rectangle Fill="Azure" Width="290" Height="55" /> </ControlTemplate> <Style x:Key="FocusStyle" TargetType="{x:Type Control}"> <Setter Property="Template" Value="{StaticResource FocusTemplate}"/> </Style> <Style TargetType="ListBoxItem"> <EventSetter Event="GotFocus" Handler="ListItem_GotFocus"></EventSetter> </Style> <DataTemplate DataType="{x:Type TextBlock}"> </DataTemplate> <DataTemplate x:Key="CustomListData" DataType="{x:Type ListBox}"> <Border BorderBrush="Black" BorderThickness="1" Margin="-2,0,0,-1"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Grid.RenderTransform> <!--<ScrollViewer x:Name="PART_ContentHost" />--> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="18" FocusVisualStyle="{StaticResource FocusStyle}" Name="editingBox" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" > <TextBox.Background> <LinearGradientBrush EndPoint="0,1" StartPoint="0,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform Angle="0" CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF2D4984"/> <GradientStop Color="#FF182D56" Offset="0.042"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </Border> </DataTemplate> <Style TargetType="{x:Type ListBox}"> <Setter Property="ItemTemplate" Value="{StaticResource CustomListData }" /> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" /> </Style> </Window.Resources> <Window.DataContext> <ObjectDataProvider ObjectType="{x:Type local:ImageLoader}" MethodName="LoadImages" /> </Window.DataContext> <ListBox ItemsSource="{Binding}" Width="320" Background="#FF021422" BorderBrush="#FF1C4B79"> <ListBox.Resources> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}">Transparent</SolidColorBrush> </ListBox.Resources> </ListBox> The following code will find a TextBlock var key = new System.Windows.DataTemplateKey(typeof(TextBlock)); var r = (DataTemplate)this.FindResource(key); However, when I change the type to ListBox, the key can not be found. What have I missed? Thanks Ryan

  Read the article

• Odd "Object reference not set to an instance of an object" involving xWinForms

  - by Kyle

  Hey, I've been trying to get the xWinForms 3.0 library (a library with forms support in xna) working with my C# XNA Game project but I keep getting the same problem. I add the reference to my project, put in the using statement, declare a formCollection variable and then I try to initialize it. whenever I run the project I get stopped on this line: formCollection = new FormCollection(this.Window, Services, ref graphics); it gives me the error: " System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object." Source="Microsoft.Xna.Framework" StackTrace: at Microsoft.Xna.Framework.Graphics.VertexShader..ctor(GraphicsDevice graphicsDevice, Byte[] shaderCode) at Microsoft.Xna.Framework.Graphics.SpriteBatch.ConstructPlatformData() at Microsoft.Xna.Framework.Graphics.SpriteBatch..ctor(GraphicsDevice graphicsDevice) at xWinFormsLib.FormCollection..ctor(GameWindow window, IServiceProvider services, GraphicsDeviceManager& graphics) at GameSolution.Game2.LoadContent() in C:\Users\Owner\Documents\School\Year 3\Winter\Soen 390\TeamWTF_3\SourceCode\GameSolution\GameSolution\Game2.cs:line 45 at Microsoft.Xna.Framework.Game.Initialize() at GameSolution.Game2.Initialize() in C:\Users\Owner\Documents\School\Year 3\Winter\Soen 390\TeamWTF_3\SourceCode\GameSolution\GameSolution\Game2.cs:line 37 at Microsoft.Xna.Framework.Game.Run() at GameSolution.Program.Main(String[] args) in C:\Users\Owner\Documents\School\Year 3\Winter\Soen 390\TeamWTF_3\SourceCode\GameSolution\GameSolution\Program.cs:line 14 InnerException: " In a project I downloaded that used the xWinForms, I put the following code in and it compiled and ran no error. but when I put it in my project I get the error. Am I making some stupid mistake about including dlls or something? I've been at this for hours and I can't seem to find anything that would cause this. using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; using Microsoft.Xna.Framework.Net; using Microsoft.Xna.Framework.Storage; using xWinFormsLib; namespace GameSolution { public class Game2 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; FormCollection formCollection; public Game2() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); formCollection = new FormCollection(this.Window, Services, ref graphics); } protected override void Update(GameTime gameTime) { base.Update(gameTime); } protected override void Draw(GameTime gameTime) { base.Draw(gameTime); } } } Any help would be greatly appreciated ._.

  Read the article

• Searches (and general querying) with HBase and/or Cassandra (best practices?)

  - by alexeypro

  I have User model object with quite few fields (properties, if you wish) in it. Say "firstname", "lastname", "city" and "year-of-birth". Each user also gets "unique id". I want to be able to search by them. How do I do that properly? How to do that at all? My understanding (will work for pretty much any key-value storage -- first goes key, then value) u:123456789 = serialized_json_object ("u" as a simple prefix for user's keys, 123456789 is "unique id"). Now, thinking that I want to be able to search by firstname and lastname, I can save in: f:Steve = u:384734807,u:2398248764,u:23276263 f:Alex = u:12324355,u:121324334 so key is "f" - which is prefix for firstnames, and "Steve" is actual firstname. For "u:Steve" we save as value all user id's who are "Steve's". That makes every search very-very easy. Querying by few fields (properties) -- say by firstname (i.e. "Steve") and lastname (i.e. "l:Anything") is still easy - first get list of user ids from "f:Steve", then list from "l:Anything", find crossing user ids, an here you go. Problems (and there are quite a few): Saving, updating, deleting user is a pain. It has to be atomic and consistent operation. Also, if we have size of value limited to some value - then we are in (potential) trouble. And really not of an answer here. Only zipping the list of user ids? Not too cool, though. What id we want to add new field to search by. Eventually. Say by "city". We certainly can do the same way "c:Los Angeles" = ..., "c:Chicago" = ..., but if we didn't foresee all those "search choices" from the very beginning, then we will have to be able to create some night job or something to go by all existing User records and update those "c:CITY" for them... Quite a big job! Problems with locking. User "u:123" updates his name "Alex", and user "u:456" updates his name "Alex". They both have to update "f:Alex" with their id's. That means either we get into overwriting problem, or one update will wait for another (and imaging if there are many of them?!). What's the best way of doing that? Keeping in mind that I want to search by many fields? P.S. Please, the question is about HBase/Cassandra/NoSQL/Key-Value storages. Please please - no advices to use MySQL and "read about" SELECTs; and worry about scaling problems "later". There is a reason why I asked MY question exactly the way I did. :-)

  Read the article

• When is #include <new> library required in C++?

  - by Czarak

  Hi, According to this reference entry for operator new ( http://www.cplusplus.com/reference/std/new/operator%20new/ ) : Global dynamic storage operator functions are special in the standard library: All three versions of operator new are declared in the global namespace, not in the std namespace. The first and second versions are implicitly declared in every translation unit of a C++ program: The header does not need to be included for them to be present. This seems to me to imply that the third version of operator new (placement new) is not implicitly declared in every translation unit of a C++ program and the header <new> does need to be included for it to be present. Is that correct? If so, how is it that using both g++ and MS VC++ Express compilers it seems I can compile code using the third version of new without #include <new> in my source code? Also, the MSDN Standard C++ Library reference entry on operator new gives some example code for the three forms of operator new which contains the #include <new> statement, however the example seems to compile and run just the same for me without this include? // new_op_new.cpp // compile with: /EHsc #include<new> #include<iostream> using namespace std; class MyClass { public: MyClass( ) { cout << "Construction MyClass." << this << endl; }; ~MyClass( ) { imember = 0; cout << "Destructing MyClass." << this << endl; }; int imember; }; int main( ) { // The first form of new delete MyClass* fPtr = new MyClass; delete fPtr; // The second form of new delete char x[sizeof( MyClass )]; MyClass* fPtr2 = new( &x[0] ) MyClass; fPtr2 -> ~MyClass(); cout << "The address of x[0] is : " << ( void* )&x[0] << endl; // The third form of new delete MyClass* fPtr3 = new( nothrow ) MyClass; delete fPtr3; } Could anyone shed some light on this and when and why you might need to #include <new> - maybe some example code that will not compile without #include <new> ? Thanks.

  Read the article

• Help choosing authentication method

  - by Dima

  I need to choose an authentication method for an application installed and integrated in customers environment. There are two types of environments - windows and linux/unix. Application is user based, no web stuff, pure Java. The requirement is to authenticate users which will use my application against customer provided user base. Meaning, customer installs my app, but uses his own users to grant or deny access to my app. Typical, right? I have three options to consider and I need to pick up the one which would be a) the most flexible to cover most common modern environments and b) would take least effort while stay robust and standard. Option (1) - Authenticate locally managing user credentials in some local storage, e.g. file. Customer would then add his users to my application and it will then check the passwords. Simple, clumsy but would work. Customers would have to punch every user they want to grant access to my app using some UI we will have to provide. Lots of work for me, headache to the customer. Option (2) - Use LDAP authentication. Customers would tell my app where to look for users and I will walk their directory resolving names into user names and trying to bind with found password. This is better approach IMO, but more fragile because I will have to walk an unknown directory structure and who knows if this will be permitted everywhere. Would be harder to test since there are many LDAP implementation out there, last thing I want is drowning in this voodoo. Option(3) - Use plain Kerberos authentication. Customers would tell my app what realm (domain) and which KDC (key distribution center) to use. In ideal world these two parameters would be all I need to set while customers could use their own administration tools to configure domain and kdc. My application would simply delegate user credentials to this third party (using JAAS or Spring security) and consider success when third party is happy with them. I personally prefer #3, but not sure what surprises I might face. Would this cover windows and *nix systems entirely? Is there another option to consider?

  Read the article

• Program execution stop at scanf???

  - by Mohit Deshpande

  main.c (with all the headers like stdio, stdlib, etc): int main() { int input; while(1) { printf("\n"); printf("\n1. Add new node"); printf("\n2. Delete existing node"); printf("\n3. Print all data"); printf("\n4. Exit"); printf("Enter your option -> "); scanf("%d", &input); string key = ""; string tempKey = ""; string tempValue = ""; Node newNode; Node temp; switch (input) { case 1: printf("\nEnter a key: "); scanf("%s", tempKey); printf("\nEnter a value: "); scanf("%s", tempValue); //execution ternimates here newNode.key = tempKey; newNode.value = tempValue; AddNode(newNode); break; case 2: printf("\nEnter the key of the node: "); scanf("%s", key); temp = GetNode(key); DeleteNode(temp); break; case 3: printf("\n"); PrintAllNodes(); break; case 4: exit(0); break; default: printf("\nWrong option chosen!\n"); break; } } return 0; } storage.h: #ifndef DATABASEIO_H_ #define DATABASEIO_H_ //typedefs typedef char *string; /* * main struct with key, value, * and pointer to next struct * Also typedefs Node and NodePtr */ typedef struct Node { string key; string value; struct Node *next; } Node, *NodePtr; //Function Prototypes void AddNode(Node node); void DeleteNode(Node node); Node GetNode(string key); void PrintAllNodes(); #endif /* DATABASEIO_H_ */ I am using Eclipse CDT, and when I enter 1, then I enter a key. Then the console says . I used gdb and got this error: Program received signal SIGSEGV, Segmentation fault. 0x00177024 in _IO_vfscanf () from /lib/tls/i686/cmov/libc.so.6 Any ideas why?

  Read the article

• android zxing intentintegrator

  - by cristi _b

  I've written the following code that works fine if you decide to scan a QR code (using zxing) and store it in private storage but in case you decide to cancel scanning, it crashes and the file previously stored content disappears. I think it might be a design error, not sure why. Below is relevant code ... /** * menu generation */ @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.menu, menu); return true; } /** * menu handling */ @Override public boolean onOptionsItemSelected(MenuItem item) { Context context = getApplicationContext(); Toast toast = Toast.makeText(context, "", Toast.LENGTH_LONG); toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0); switch (item.getItemId()) { case R.id.qrScan: IntentIntegrator integrator = new IntentIntegrator(this); integrator.initiateScan(); return true; case R.id.qrReset: File dir = getFilesDir(); File file = new File(dir, qrCodeFile); boolean deleted = file.delete(); return true; case R.id.appClose: this.finish(); return true; default: return super.onOptionsItemSelected(item); } } ... public void onActivityResult(int requestCode, int resultCode, Intent intent) { IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent); Context context = getApplicationContext(); Toast toast = Toast.makeText(context, "", Toast.LENGTH_SHORT); if (scanResult != null) { FileOutputStream fos = null; CharSequence text = scanResult.getContents(); try { fos = openFileOutput(qrCodeFile, Context.MODE_PRIVATE); try { fos.write(text.toString().getBytes()); fos.close(); toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0); toast.setText("Code saved"); toast.show(); } catch (IOException ex) { toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0); toast.setText("Invalid code"); toast.show(); Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex); } } catch (FileNotFoundException ex) { toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0); toast.setText("Error while saving"); toast.show(); Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex); } } else { toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0); toast.setText("Invalid code"); toast.show(); } }

  Read the article

• Recursive N-way merge/diff algorithm for directory trees?

  - by BobMcGee

  What algorithms or Java libraries are available to do N-way, recursive diff/merge of directories? I need to be able to generate a list of folder trees that have many identical files, and have subdirectories with many similar files. I want to be able to use 2-way merge operations to quickly remove as much redundancy as possible. Goals: Find pairs of directories that have many similar files between them. Generate short list of directory pairs that can be synchronized with 2-way merge to eliminate duplicates Should operate recursively (there may be nested duplicates of higher-level directories) Run time and storage should be O(n log n) in numbers of directories and files Should be able to use an embedded DB or page to disk for processing more files than fit in memory (100,000+). Optional: generate an ancestry and change-set between folders Optional: sort the merge operations by how many duplicates they can elliminate I know how to use hashes to find duplicate files in roughly O(n) space, but I'm at a loss for how to go from this to finding partially overlapping sets between folders and their children. EDIT: some clarification The tricky part is the difference between "exact same" contents (otherwise hashing file hashes would work) and "similar" (which will not). Basically, I want to feed this algorithm at a set of directories and have it return a set of 2-way merge operations I can perform in order to reduce duplicates as much as possible with as few conflicts possible. It's effectively constructing an ancestry tree showing which folders are derived from each other. The end goal is to let me incorporate a bunch of different folders into one common tree. For example, I may have a folder holding programming projects, and then copy some of its contents to another computer to work on it. Then I might back up and intermediate version to flash drive. Except I may have 8 or 10 different versions, with slightly different organizational structures or folder names. I need to be able to merge them one step at a time, so I can chose how to incorporate changes at each step of the way. This is actually more or less what I intend to do with my utility (bring together a bunch of scattered backups from different points in time). I figure if I can do it right I may as well release it as a small open source util. I think the same tricks might be useful for comparing XML trees though.

  Read the article

• Why is cell phone software still so primitive?

  - by Tomislav Nakic-Alfirevic

  I don't do mobile development, but it strikes me as odd that features like this aren't available by default on most phones: full text search: searches all address book contents, messages, anything else being a plus better call management: e.g. a rotating audio call log, meaning you always have the last N calls recorded for your listening pleasure later (your little girl just said her first "da-da" while you were on a business trip, you had a telephone job interview, you received complex instructions to do something etc.) bluetooth remote control (like e.g. anyRemote, but available by default on a bluetooth phone) no multitasking capabilities worth mentioning and in general no e.g. weekly software updates, making the phone much more usable (even if it had to be done over USB, rather than over the network). I'm sure I was dumbfounded by the lack or design of other features as well, but they don't come to mind right now. To clarify, I'm not talking about smartphones here: my plain, 2-year old phone has a CPU an order of magnitude faster than my first PC, about as much storage space and it's ridiculous how bad (slow, unwieldy) the software is and it's not one phone or one manufacturer. What keeps the (to me) obvious software functionality vacuum on a capable hardware platform from being filled up? Edit: I believe a clarification on the multitasking point might be beneficial. I'll use my phone as an example, although the point is much more general. The phone can multitask and in fact does: you can listen to music and do something else at the same time. On the other hand, the way the software has been designed makes multitasking next to useless. (Ditto with the external touch screen: it can take touch commands, but only one application makes use of it, and only with 3 commands.) To take the multitasking example to the extreme, if I plug my phone into my laptop and it registers as an external disk, it doesn't allow any kind of operation: messages, calling, calendar, everything out of reach, although I can receive a call. No "battery life" issue there: it's charging while connected. BTW, another example of design below the current state of the art: I don't see a phone on the horizon which will remember where in an audio or video file you were when you stopped listening/watching it last time (podcasts are a good use case). Simplistic rewind/fast forward functionality only aggravates the problem.

  Read the article

• How to implement Xml Serialization with inherited classes in C#

  - by liorafar

  I have two classes : base class name Component and inheritd class named DBComponent [Serializable] public class Component { private string name = string.Empty; private string description = string.Empty; } [Serializable] public class DBComponent : Component { private List<string> spFiles = new List<string>(); // Storage Procedure Files [XmlArrayItem("SPFile", typeof(string))] [XmlArray("SPFiles")] public List<string> SPFiles { get { return spFiles; } set { spFiles = value; } } public DBComponent(string name, string description) : base(name, description) { } } [Serializable] public class ComponentsCollection { private static ComponentsCollection instance = null; private List<Component> components = new List<Component>(); public List<Component> Components { get { return components; } set { components = value; } } public static ComponentsCollection GetInstance() { if (ccuInstance == null) { lock (lockObject) { if (instance == null) PopulateComponents(); } } return instance; } private static void PopulateComponents() { instance = new CCUniverse(); XmlSerializer xs = new XmlSerializer(instance.GetType()); instance = xs.Deserialize(XmlReader.Create("Components.xml")) as ComponentsCollection; } } } I want read\write from a Xml file. I know that I need to implement the Serialization for DBComponent class otherwise it will not read it.But i cannot find any simple article for that. all the articles that I found were too complex for this simple scenario. The Xml file looks like this: <?xml version="1.0" encoding="utf-8" ?> <ComponentsCollection> <Components> <DBComponent Name="Tenant Historical Database" Description="Tenant Historical Database"> <SPFiles> <SPFile>Setup\TenantHistoricalSP.sql</SPFile> </SPFiles> </DBComponent> <Component Name="Agent" Description="Desktop Agent" /> </Components> </ComponentsCollection> Can someone please give me a simple example of how to read this kind of xml file and what should be implemented ? Thanks Lior

  Read the article

• NullPointerException using datanucleus-json with S3

  - by Matt

  I'm using datanucleus 3.2.7 from Maven, trying to use the Amazon S3 JPA provider. I can successfully write data into S3, but querying either by using "SELECT u FROM User u" or "SELECT u FROM User u WHERE id = :id" causes a NullPointerException to be thrown. Using the RDBMS provider, everything works perfectly. Is there something I'm doing wrong? Main.java EntityManagerFactory factory = Persistence.createEntityManagerFactory("MyUnit"); EntityManager entityManager = factory.createEntityManager(); Query query = entityManager.createQuery("SELECT u FROM User u", User.class); List<User> users = query.getResultList(); // Null pointer exception here for(User u:users) System.out.println(u); User.java package test; import javax.persistence.*; @Entity @Table(name = "User") public class User { @Id public String id; public String name; public User(String id, String name) { this.id = id; this.name = name; } public String toString() { return id+" : "+name; } } persistence.xml <?xml version="1.0" encoding="UTF-8" ?> <persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0"> <persistence-unit name="MyUnit"> <class>test.User</class> <exclude-unlisted-classes /> <properties> <properties> <property name="datanucleus.ConnectionURL" value="amazons3:http://s3.amazonaws.com/" /> <property name="datanucleus.ConnectionUserName" value="xxxxx" /> <property name="datanucleus.ConnectionPassword" value="xxxxx" /> <property name="datanucleus.cloud.storage.bucket" value="my-bucket" /> </properties> <property name="datanucleus.autoCreateSchema" value="true" /> </properties> </persistence-unit> </persistence> Exception java.lang.NullPointerException at org.datanucleus.NucleusContext.isClassWithIdentityCacheable(NucleusContext.java:1840) at org.datanucleus.ExecutionContextImpl.getObjectFromLevel2Cache(ExecutionContextImpl.java:5287) at org.datanucleus.ExecutionContextImpl.getObjectFromCache(ExecutionContextImpl.java:5191) at org.datanucleus.ExecutionContextImpl.findObject(ExecutionContextImpl.java:3137) at org.datanucleus.store.json.CloudStoragePersistenceHandler.getObjectsOfCandidateType(CloudStoragePersistenceHandler.java:367) at org.datanucleus.store.json.query.JPQLQuery.performExecute(JPQLQuery.java:94) at org.datanucleus.store.query.Query.executeQuery(Query.java:1786) at org.datanucleus.store.query.Query.executeWithMap(Query.java:1690) at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:194) at test.Main.main(Main.java:16)

  Read the article

• NSLinguisticTagger on the contents of an NSTextStorage- crashing bug

  - by Remy Porter

  I'm trying to use an NSLinguisticTagger to monitor the contents of an NSTextStorage and provide some contextual information based on what the user types. To that end, I have an OverlayManager object, which wires up this relationship: -(void) setView:(NSTextView*) view { _view = view; _layout = view.layoutManager; _storage = view.layoutManager.textStorage; //get the TextStorage from the view [_tagger setString:_storage.string]; //pull the string out, this grabs the mutable version [self registerForNotificationsOn:self->_storage]; //subscribe to the willProcessEditing notification } When an edit occurs, I make sure to trap it and notify the tagger (and yes, I know I'm being annoyingly inconsistent with member access, I'm rusty on Obj-C, I'll fix it later): - (void) textStorageWillProcessEditing:(NSNotification*) notification{ if ([self->_storage editedMask] & NSTextStorageEditedCharacters) { NSRange editedRange = [self->_storage editedRange]; NSUInteger delta = [self->_storage changeInLength]; [_tagger stringEditedInRange:editedRange changeInLength:delta]; //should notify the tagger of the changes [self highlightEdits:self]; } } The highlightEdits message delegates the job out to a pool of "Overlay" objects. Each contains a block of code similar to this: [tagger enumerateTagsInRange:range scheme:NSLinguisticTagSchemeLexicalClass options:0 usingBlock:^(NSString *tag, NSRange tokenRange, NSRange sentenceRange, BOOL *stop) { if (tag == PartOfSpeech) { [self applyHighlightToRange:tokenRange onStorage:storage]; } }]; And that's where the problem is- the enumerateTagsInRange method crashes out with a message: 2014-06-04 10:07:19.692 WritersEditor[40191:303] NSMutableRLEArray replaceObjectsInRange:withObject:length:: Out of bounds This problem doesn't occur if I don't link to the mutable copy of the underlying string and instead do a [[_storage string] copy], but obviously I don't want to copy the entire backing store every time I want to do tagging. This all should be happening in the main run loop, so I don't think this is a threading issue. The NSRange I'm enumerating tags on exists both in the NSTextStorage and in the NSLinguisticTagger's view of the string. It's not even the fact that the applyHighlightToRange call adds attributes to the string, because it crashes before even reaching that line. I attempted to build a test case around the problem, but can't replicate it in those situations: - (void) testEdit { NSAttributedString* str = [[NSMutableAttributedString alloc] initWithString:@"Quickly, this is a test."]; text = [[NSTextStorage alloc] initWithAttributedString:str]; NSArray* schemes = [NSLinguisticTagger availableTagSchemesForLanguage:@"en"]; tagger = [[NSLinguisticTagger alloc] initWithTagSchemes:schemes options:0]; [tagger setString:[text string]]; [text beginEditing]; [[text mutableString] appendString:@"T"]; NSRange edited = [text editedRange]; NSUInteger length = [text changeInLength]; [text endEditing]; [tagger stringEditedInRange:edited changeInLength:length]; [tagger enumerateTagsInRange:edited scheme:NSLinguisticTagSchemeLexicalClass options:0 usingBlock:^(NSString *tag, NSRange tokenRange, NSRange sentenceRange, BOOL *stop) { //doesn't matter, this should crash }]; } That code doesn't crash.

  Read the article

• Deterministic key serialization

  - by Mike Boers

  I'm writing a mapping class which uses SQLite as the storage backend. I am currently allowing only basestring keys but it would be nice if I could use a couple more types hopefully up to anything that is hashable (ie. same requirements as the builtin dict). To that end I would like to derive a deterministic serialization scheme. Ideally, I would like to know if any implementation/protocol combination of pickle is deterministic for hashable objects (e.g. can only use cPickle with protocol 0). I noticed that pickle and cPickle do not match: >>> import pickle >>> import cPickle >>> def dumps(x): ... print repr(pickle.dumps(x)) ... print repr(cPickle.dumps(x)) ... >>> dumps(1) 'I1\n.' 'I1\n.' >>> dumps('hello') "S'hello'\np0\n." "S'hello'\np1\n." >>> dumps((1, 2, 'hello')) "(I1\nI2\nS'hello'\np0\ntp1\n." "(I1\nI2\nS'hello'\np1\ntp2\n." Another option is to use repr to dump and ast.literal_eval to load. This would only be valid for builtin hashable types. I have written a function to determine if a given key would survive this process (it is rather conservative on the types it allows): def is_reprable_key(key): return type(key) in (int, str, unicode) or (type(key) == tuple and all( is_reprable_key(x) for x in key)) The question for this method is if repr itself is deterministic for the types that I have allowed here. I believe this would not survive the 2/3 version barrier due to the change in str/unicode literals. This also would not work for integers where 2**32 - 1 < x < 2**64 jumping between 32 and 64 bit platforms. Are there any other conditions (ie. do strings serialize differently under different conditions)? (If this all fails miserably then I can store the hash of the key along with the pickle of both the key and value, then iterate across rows that have a matching hash looking for one that unpickles to the expected key, but that really does complicate a few other things and I would rather not do it.) Any insights?

  Read the article

• Issues declaring already existing NSMutableArray in new class

  - by Graeme

  I have a class (DataImporter) which has the code to download an RSS feed. I also have a view and separate class (TableView) which displays the data in a UITableView and starts the parsing process, storing parsed information in an NSMutableArray (items) which is located in the (TableView) subclass. Now I wish to add a UIMapView which displays the items in the (items) NSMutableArray. Herein lies the issue - I need to somehow get the data from the (items) NSMutableArray into the new (mapView) subclass which I'm struggling with - and I preferably don't want to have to create a new class to download the data again for the mapView class when it already is in the applications memory. Is there a way I can transfer the information from the NSMutableArray (items) class to the (mapView) class (i.e. how do I declare the NSMutableArray in the (mapView) class)? Here's a overview of how the system works: App opened Data downloaded (using DataImporter class) when (TableView) viewDidLoad runs Data stored in NSMutableArray accessible by the (TableView) class And from here I need to access and declare the array from a new (mapView) class. Any help greatly appreciated, thanks. Code for viewDidLoad MapKit: Data *data = nil; NSString *ilocation = [data locations]; NSString *ilocation2 = @"New Zealand"; NSString *inewlString; inewlString = [ilocation stringByAppendingString:ilocation2]; NSLog(@"inewlString=%@",inewlString); if(forwardGeocoder == nil) { forwardGeocoder = [[BSForwardGeocoder alloc] initWithDelegate:self]; } // Forward geocode! [forwardGeocoder findLocation: inewlString]; Code for parsing data into original NSMutable Array: - (void)beginParsing { NSLog(@"Parsing has begun"); //self.navigationItem.rightBarButtonItem.enabled = NO; // Allocate the array for song storage, or empty the results of previous parses if (incidents == nil) { NSLog(@"Grabbing array"); self.datas = [NSMutableArray array]; } else { [datas removeAllObjects]; [self.tableView reloadData]; } // Create the parser, set its delegate, and start it. self.parser = [[DataImporter alloc] init]; parser.delegate = self; [parser start]; }

  Read the article

• Asp.net Mvc - Kigg: Maintain User object in HttpContext.Items between requests.

  - by Pickels

  Hallo, first I want to say that I hope this doesn't look like I am lazy but I have some trouble understanding a piece of code from the following project. http://kigg.codeplex.com/ I was going through the source code and I noticed something that would be usefull for my own little project I am making. In their BaseController they have the following code: private static readonly Type CurrentUserKey = typeof(IUser); public IUser CurrentUser { get { if (!string.IsNullOrEmpty(CurrentUserName)) { IUser user = HttpContext.Items[CurrentUserKey] as IUser; if (user == null) { user = AccountRepository.FindByClaim(CurrentUserName); if (user != null) { HttpContext.Items[CurrentUserKey] = user; } } return user; } return null; } } This isn't an exact copy of the code I adjusted it a little to my needs. This part of the code I still understand. They store their IUser in HttpContext.Items. I guess they do it so that they don't have to call the database eachtime they need the User object. The part that I don't understand is how they maintain this object in between requests. If I understand correctly the HttpContext.Items is a per request cache storage. So after some more digging I found the following code. internal static IDictionary<UnityPerWebRequestLifetimeManager, object> GetInstances(HttpContextBase httpContext) { IDictionary<UnityPerWebRequestLifetimeManager, object> instances; if (httpContext.Items.Contains(Key)) { instances = (IDictionary<UnityPerWebRequestLifetimeManager, object>) httpContext.Items[Key]; } else { lock (httpContext.Items) { if (httpContext.Items.Contains(Key)) { instances = (IDictionary<UnityPerWebRequestLifetimeManager, object>) httpContext.Items[Key]; } else { instances = new Dictionary<UnityPerWebRequestLifetimeManager, object>(); httpContext.Items.Add(Key, instances); } } } return instances; } This is the part where some magic happens that I don't understand. I think they use Unity to do some dependency injection on each request? In my project I am using Ninject and I am wondering how I can get the same result. I guess InRequestScope in Ninject is the same as UnityPerWebRequestLifetimeManager? I am also wondering which class/method they are binding to which interface? Since the HttpContext.Items get destroyed each request how do they prevent losing their user object? Anyway it's kinda a long question so I am gradefull for any push in the right direction. Kind regards, Pickels

  Read the article

• ASP.NET MVC 4/Web API Single Page App for Mobile Devices ... Needs Authentication

  - by lmttag

  We have developed an ASP.NET MVC 4/Web API single page, mobile website (also using jQuery Mobile) that is intended to be accessed only from mobile devices (e.g., iPads, iPhones, Android tables and phones, etc.), not desktop browsers. This mobile website will be hosted internally, like an intranet site. However, since we’re accessing it from mobile devices, we can’t use Windows authentication. We still need to know which user (and their role) is logging in to the mobile website app. We tried simply using ASP.NET’s forms authentication and membership provider, but couldn’t get it working exactly the way we wanted. What we need is for the user to be prompted for a user name and password only on the first time they access the site on their mobile device. After they enter a correct user name and password and have been authenticated once, each subsequent time they access the site they should just go right in. They shouldn’t have to re-enter their credentials (i.e., something needs to be saved locally to each device to identify the user after the first time). This is where we had troubles. Everything worked as expected the first time. That is, the user was prompted to enter a user name and password, and, after doing that, was authenticated and allowed into the site. The problem is every time after the browser was closed on the mobile device, the device and user were not know and the user had to re-enter user name and password. We tried lots of things too. We tried setting persistent cookies in JavaScript. No good. The cookies weren’t there to be read the second time. We tried manually setting persistent cookies from ASP.NET. No good. We, of course, used FormsAuthentication.SetAuthCookie(model.UserName, true); as part of the form authentication framework. No good. We tried using HTML5 local storage. No good. No matter what we tried, if the user was on a mobile device, they would have to log in every single time. (Note: we’ve tried on an iPad and iPhone running both iOS 5.1 and 6.0, with Safari configure to allow cookies, and we’ve tried on Android 2.3.4.) Is there some trick to getting a scenario like this working? Or, do we have to write some sort of custom authentication mechanism? If so, how? And, what? Or, should we use something like claims-based authentication and WIF? Or??? Any help is appreciated. Thanks!

  Read the article

• Difference between Cloud and Virtualization

  - by Akash Kava

  Ops: This does not belong to ServerFault because it focuses on Programing Architecture. I have following questions regarding differences between Cloud and Virtualization.. How Cloud is different then Virtualization? Currently I tried to find out pricing of Rackspace, Amazone and all similar cloud providers, I found that our current 6 dedicated servers came cheaper then their pricing. So how one can claim cloud is cheaper? Is it cheaper only in comparison of normal hosting? We re organized our infrastructure in virtual environment to reduce or configuration overhead at time of failure, we did not have to rewrite any peice of code that is already written for earlier setup. So moving to virtualization does not require any re programming. But cloud is absoltely different and it will require entire reprogramming right? Is it really worth to recode when our current IT costs are 3-4 times lower then cloud hosting including raid backups and all sort of clustering for high availability? New programming architecture means new overheads of training staff, new methods of testing and new deployment schemes, does it justify over "on demand resource usage" words of cloud? We are having current development architecture with simple Server side ASP.NET WebServices with no local context and on client side Flex/Silverlight which offers pretty good REST architecture and its highly scalable. How does cloud differs from REST model of deployment? On storage, SQL Server or MySQL offers pretty good replication and high availibility then what is advantage in cloud? Data guarantee, one of our vendor hosting some other customer's app on cloud (one of most used), lost Entire Hard Disk (the virtual) and entire module in first 6 months. Second provider said its your duty to take backup, fine I agree, but no provider gives SLA for data guarantee, they give 99% uptime. However in most business apps, uptime is less important then data integrity. In our 10 years of dedicated hosting experience we had only one hard disk crash. This makes me little skeptical to go for cloud and loosing control over data. And I feel its just a big marketing buzz to sell virtulization in different form. Size of data, currently all providers charge very heavy for large data, if you are hosting only below 100GB cloud can be good alternative, but I think virtual servers and dedicated servers above 100GB to few TBs are still cheaper. Why would want to pay so high on cloud when there is no data guarentee as well as it doesnt say anything about redundancy. (I wish SO had something for spell check for Internet Explorer, sorry for wrong spellings in my post)

  Read the article

• Rewrite code from Threads to AnyEvent

  - by user1779868

  I wrote a code: use LWP::UserAgent; use HTTP::Cookies; use threads; use threads::shared; $| = 1; $threads = 50; my @urls : shared = loadf('url.txt'); my @thread_list = (); $thread_list[$_] = threads->create(\&thread) for 0 .. $threads - 1; $_->join for @thread_list; thread(); sub thread { my ($web, $ck) = browser(); while(1) { my $url = shift @urls; if(!$url) { last; } $code = $web->get($url)->code; print "[+] $url - code: $code\n"; if($code == 200) { open F, ">>200.txt"; print F $url."\n"; close F; } elsif($code == 301) { open F, ">>301.txt"; print F $url."\n"; close F; } else { open F, ">>else.txt"; print F "$url code - $code\n"; close F; } } } sub loadf { open (F, "<".$_[0]) or erroropen($_[0]); chomp(my @data = <F>); close F; return @data; } sub browser { my $web = new LWP::UserAgent; my $ck = new HTTP::Cookies; $web->cookie_jar($ck); $web->agent('Opera/9.80 (Windows 7; U; en) Presto/2.9.168 Version/11.50'); $web->timeout(5); return $web, $ck; } After its working for some time physical storage is full. Can u help me to re-write it with AnyEvent. I tried but my code didn't work. I read that it will help me to safe some memory. Thanks a lot to any helpers.

  Read the article

• Is there a way to efficiently yield every file in a directory containing millions of files?

  - by Josh Smeaton

  I'm aware of os.listdir, but as far as I can gather, that gets all the filenames in a directory into memory, and then returns the list. What I want, is a way to yield a filename, work on it, and then yield the next one, without reading them all into memory. Is there any way to do this? I worry about the case where filenames change, new files are added, and files are deleted using such a method. Some iterators prevent you from modifying the collection during iteration, essentially by taking a snapshot of the state of the collection at the beginning, and comparing that state on each move operation. If there is an iterator capable of yielding filenames from a path, does it raise an error if there are filesystem changes (add, remove, rename files within the iterated directory) which modify the collection? There could potentially be a few cases that could cause the iterator to fail, and it all depends on how the iterator maintains state. Using S.Lotts example: filea.txt fileb.txt filec.txt Iterator yields filea.txt. During processing, filea.txt is renamed to filey.txt and fileb.txt is renamed to filez.txt. When the iterator attempts to get the next file, if it were to use the filename filea.txt to find it's current position in order to find the next file and filea.txt is not there, what would happen? It may not be able to recover it's position in the collection. Similarly, if the iterator were to fetch fileb.txt when yielding filea.txt, it could look up the position of fileb.txt, fail, and produce an error. If the iterator instead was able to somehow maintain an index dir.get_file(0), then maintaining positional state would not be affected, but some files could be missed, as their indexes could be moved to an index 'behind' the iterator. This is all theoretical of course, since there appears to be no built-in (python) way of iterating over the files in a directory. There are some great answers below, however, that solve the problem by using queues and notifications. Edit: The OS of concern is Redhat. My use case is this: Process A is continuously writing files to a storage location. Process B (the one I'm writing), will be iterating over these files, doing some processing based on the filename, and moving the files to another location. Edit: Definition of valid: Adjective 1. Well grounded or justifiable, pertinent. (Sorry S.Lott, I couldn't resist). I've edited the paragraph in question above.

  Read the article

• sys.path() and PYTHONPATH issues

  - by Justin

  I've been learning Python, I'm working in 2.7.3, and I'm trying to understand import statements. The documentation says that when you attempt to import a module, the interpreter will first search for one of the built-in modules. What is meant by a built-in module? Then, the documentation says that the interpreter searches in the directories listed by sys.path, and that sys.path is initialized from these sources: the directory containing the input script (or the current directory). PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH). the installation-dependent default. Here is a sample output of a sys.path command from my computer using python in command-line mode: (I deleted a few so that it wouldn't be huge) ['', '/usr/lib/python2.7', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PIL', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/ubuntuone-couch', '/usr/lib/python2.7/dist-packages/ubuntuone-storage-protocol'] Now, I'm assuming that the '' path refers to the directory containing the 'script', and so I figured the rest of them would be coming from my PYTHONPATH environmental variable. However, when I go to the terminal and type env, PYTHONPATH doesn't exist as an environmental variable. I also tried import os then os.environ, but I get the same output. Do I really not have a PYTHONPATH environmental variable? I don't believe I ever specifically defined a PYTHONPATH environmental variable, but I assumed that when I installed new packages they automatically altered that environment variable. If I don't have a PYTHONPATH, how is my sys.path getting populated? If I download new packages, how does Python know where to look for them if I don't have this PYTHONPATH variable? How do environment variables work? From what I understand, environment variables are specific to the process for which they are set, however, if I open multiple terminal windows and run env, they all display a number of identical variables, for example, PATH. I know there file locations for persistent environment variables, for example /etc/environment, which contains my PATH variable. Is it possible to tell where a persistent environment variable is stored? What is the recommended location for storing new persistent environment variables? How do environment variables actually work with say, the Python interpreter? The Python interpreter looks for PYTHONPATH, but how does it work at the nitty-gritty level?

  Read the article

• Android: How to properly exit application when inconsistent condition is unavoidable?

  - by Bevor

  First of all I already read about all this discussion that it isn't a good idea to manually exit an Android application. But in my case it seems to be needed. I have an AsyncTask which does a lof of operations in background. That means downloading data, saving it to local storage and preparing it for usage in application. It could happen that there is no internet connection or something different happens. For all that cases I have an Exception handling which returns the result. And if there is an exception, the application is unusable so I need to exit it. My question is, do I have to do some unregistration unloading or unbinding tasks or something when I exit the application by code or is System.exit(0) ok? I do all this in an AsyncTask, see my example: public class InitializationTask extends AsyncTask<Void, Void, InitializationResult> { private ProcessController processController = new ProcessController(); private ProgressDialog progressDialog; private Activity mainActivity; public InitializationTask(Activity mainActivity) { this.mainActivity = mainActivity; } @Override protected void onPreExecute() { super.onPreExecute(); progressDialog = new ProgressDialog(mainActivity); progressDialog.setMessage("Die Daten werden aufbereitet.\nBitte warten..."); progressDialog.setIndeterminate(true); //means that the "loading amount" is not measured. progressDialog.setCancelable(false); progressDialog.show(); }; @Override protected InitializationResult doInBackground(Void... params) { return processController.initializeData(); } @Override protected void onPostExecute(InitializationResult result) { super.onPostExecute(result); progressDialog.dismiss(); if (!result.isValid()) { AlertDialog.Builder dialog = new AlertDialog.Builder(mainActivity); dialog.setTitle("Initialisierungsfehler"); dialog.setMessage(result.getReason()); dialog.setPositiveButton("Ok", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.cancel(); //TODO cancel application System.exit(0); } }); dialog.show(); } } }

  Read the article

• IntentService android download and return file to Activity

  - by Andrew G

  I have a fairly tricky situation that I'm trying to determine the best design for. The basics are this: I'm designing a messaging system with a similar interface to email. When a user clicks a message that has an attachment, an activity is spawned that shows the text of that message along with a paper clip signaling that there is an additional attachment. At this point, I begin preloading the attachment so that when the user clicks on it - it loads more quickly. currently, when the user clicks the attachment, it prompts with a loading dialog until the download is complete at which point it loads a separate attachment viewer activity, passing in the bmp byte array. I don't ever want to save attachments to persistent storage. The difficulty I have is in supporting rotation as well as home button presses etc. The download is currently done with a thread and handler setup. Instead of this, I'd like the flow to be the following: User loads message as before, preloading begins of attachment as before (invisible to user). When the user clicks on the attachment link, the attachment viewer activity is spawned right away. If the download was done, the image is displayed. If not, a dialog is shown in THIS activity until it is done and can be displayed. Note that ideally the download never restarts or else I've wasted cycles on the preload. Obviously I need some persistent background process that is able to keep downloading and is able to call back to arbitrarily bonded Activities. It seems like the IntentService almost fits my needs as it does its work in a background thread and has the Service (non UI) lifecycle. However, will it work for my other needs? I notice that common implementations for what I want to do get a Messenger from the caller Activity so that a Message object can be sent back to a Handler in the caller's thread. This is all well and good but what happens in my case when the caller Activity is Stopped or Destroyed and the currently active Activity (the attachment viewer) is showing? Is there some way to dynamically bind a new Activity to a running IntentService so that I can send a Message back to the new Activity? The other question is on the Message object. Can I send arbitrarily large data back in this package? For instance, rather than send back that "The file was downloaded", I need to send back the byte array of the downloaded file itself since I never want to write it to disk (and yes this needs to be the case). Any advice on achieving the behavior I want is greatly appreciated. I've not been working with Android for that long and I often get confused with how to best handle asynchronous processes over the course of the Activity lifecycle especially when it comes to orientation changes and home button presses...

  Read the article

• Multi-tenant ASP.NET MVC – Introduction

  - by zowens

  I’ve read a few different blogs that talk about multi-tenancy and how to resolve some of the issues surrounding multi-tenancy. What I’ve come to realize is that these implementations overcomplicate the issues and give only a muddy implementation! I’ve seen some really illogical code out there. I have recently been building a multi-tenancy framework for internal use at eagleenvision.net. Through this process, I’ve realized a few different techniques to make building multi-tenant applications actually quite easy. I will be posting a few different entries over the issue and my personal implementation. In this first post, I will discuss what multi-tenancy means and how my implementation will be structured.   So what’s the problem? Here’s the deal. Multi-tenancy is basically a technique of code-reuse of web application code. A multi-tenant application is an application that runs a single instance for multiple clients. Here the “client” is different URL bindings on IIS using ASP.NET MVC. The problem with different instances of the, essentially, same application is that you have to spin up different instances of ASP.NET. As the number of running instances of ASP.NET grows, so does the memory footprint of IIS. Stack Exchange shifted its architecture to multi-tenancy March. As the blog post explains, multi-tenancy saves cost in terms of memory utilization and physical disc storage. If you use the same code base for many applications, multi-tenancy just makes sense. You’ll reduce the amount of work it takes to synchronize the site implementations and you’ll thank your lucky stars later for choosing to use one application for multiple sites. Multi-tenancy allows the freedom of extensibility while relying on some pre-built code.   You’d think this would be simple. I have actually seen a real lack of reference material on the subject in terms of ASP.NET MVC. This is somewhat surprising given the number of users of ASP.NET MVC. However, I will certainly fill the void ;). Implementing a multi-tenant application takes a little thinking. It’s not straight-forward because the possibilities of implementation are endless. I have yet to see a great implementation of a multi-tenant MVC application. The only one that comes close to what I have in mind is Rob Ashton’s implementation (all the entries are listed on this page). There’s some really nasty code in there… something I’d really like to avoid. He has also written a library (MvcEx) that attempts to aid multi-tenant development. This code is even worse, in my honest opinion. Once I start seeing Reflection.Emit, I have to assume the worst :) In all seriousness, if his implementation makes sense to you, use it! It’s a fine implementation that should be given a look. At least look at the code. I will reference MvcEx going forward as a comparison to my implementation. I will explain why my approach differs from MvcEx and how it is better or worse (hopefully better).   Core Goals of my Multi-Tenant Implementation The first, and foremost, goal is to use Inversion of Control containers to my advantage. As you will see throughout this series, I pass around containers quite frequently and rely on their use heavily. I will be using StructureMap in my implementation. However, you could probably use your favorite IoC tool instead. <RANT> However, please don’t be stupid and abstract your IoC tool. Each IoC is powerful and by abstracting the capabilities, you’re doing yourself a real disservice. Who in the world swaps out IoC tools…? No one!</RANT> (It had to be said.) I will outline some of the goodness of StructureMap as we go along. This is really an invaluable tool in my tool belt and simple to use in my multi-tenant implementation. The second core goal is to represent a tenant as easily as possible. Just as a dependency container will be a first-class citizen, so will a tenant. This allows us to easily extend and use tenants. This will also allow different ways of “plugging in” tenants into your application. In my implementation, there will be a single dependency container for a single tenant. This will enable isolation of the dependencies of the tenant. The third goal is to use composition as a means to delegate “core” functions out to the tenant. More on this later.   Features In MvcExt, “Modules” are a code element of the infrastructure. I have simplified this concept and have named this “Features”. A feature is a simple element of an application. Controllers can be specified to have a feature and actions can have “sub features”. Each tenant can select features it needs and the other features will be hidden to the tenant’s users. My implementation doesn’t require something to be a feature. A controller can be common to all tenants. For example, (as you will see) I have a “Content” controller that will return the CSS, Javascript and Images for a tenant. This is common logic to all tenants and shouldn’t be hidden or considered a “feature”; Content is a core component.   Up next My next post will be all about the code. I will reveal some of the foundation to the way I do multi-tenancy. I will have posts dedicated to Foundation, Controllers, Views, Caching, Content and how to setup the tenants. Each post will be in-depth about the issues and implementation details, while adhering to my core goals outlined in this post. As always, comment with questions of DM me on twitter or send me an email.

  Read the article

• CodePlex Daily Summary for Saturday, March 06, 2010

  CodePlex Daily Summary for Saturday, March 06, 2010New ProjectsAgr.CQRS: Agr.CQRS is a C# framework for DDD applications that use the Command Query Responsibility Segregation pattern (CQRS) and Event Sourcing. BigDays 2010: Big>Days 2010BizTalk - Controlled Admin: Hi .NET folks, I am planning to start project on a Controlled BizTalk Admin tool. This tool will be useful for the organizations which have "Sh...Blacklist of Providers: Blacklist of Providers - the application for department of warehouse logistics (warehouse) at firms.Career Vector: A job board software.Chargify Demo: This is a sample website for ChargifyConceptual: Concept description and animationEric Hexter: My publicly available source code and examplesFluentNHibernate.Search: A Fluent NHibernate.Search mapping interface for NHibernate provider implementation of Lucene.NET.FreelancePlanner: FreelancePlanner is a project tracking tool for freelance translators.HTMLx - JavaScript on the Server for .NET: HTMLx is a set of libraries based on ASP.NET engine to provide JavaScript programmability on the server side. It allows Web developers to use JavaS...IronMSBuild: IronMSBuild is a custom MSBuild Task, which allows you to execute IronRuby scripts. // have to provide some examples LINQ To Blippr: LINQ to Blippr is an open source LINQ Provider for the micro-reviewing service Blippr. LINQ to Blippr makes it easier and more efficent for develo...Luk@sh's HTML Parser: library that simplifies parsing of the HTML documents, for .NETMeta Choons: Unsure as yet but will be a kind of discogs type site but different..NetWork2: NetWork2Regular Expression Chooser: Simple gui for choosing the regular expressions that have become more than simple.See.Sharper: Hopefully useful C# extensions.SharePoint 2010 Toggle User Interface: Toggle the SharePoint 2010 user interface between the new SharePoint 2010 user interface and SharePoint 2007 user interface.Silverlight DiscussionBoard for SharePoint: This is a sharepoint 3.0 webpart that uses a silverlight treeview to display metadata about sharepoint discussions anduses the html bridge to show...Simple Sales Tracking CRM API Wrapper: The Simple Sales Tracking API Wrapper, enables easy extention development and integration with the hosted service at http://www.simplesalestracking...Syntax4Word: A syntax addin for word 2007.TortoiseHg installer builder: TortoiseHg and Mercurial installer builder for Windowsunbinder: Model un binding for route value dictionariesWindows Workflow Foundation on Codeplex: This site has previews of Workflow features which are released out of band for the purposes of adoption and feedback.XNA RSM Render State Manager: Render state management idea for XNA games. Enables isolation between draw calls whilst reducing DX9 SetRenderState calls to the minimum.New ReleasesAgr.CQRS: Sourcecode package: Agr.CQRS is a C# framework for DDD applications that use the Command Query Responsibility Segregation pattern (CQRS) and Event Sourcing. This dow...Book Cataloger: Preview 0.1.6a: New Features: Export to Word 2007 Bibliography format Dictionary list editors for Binding, Condition Improvements: Stability improved Content ...Braintree Client Library: Braintree-1.1.2: Includes minor enhancements to CreditCard and ValidationErrors to support upcoming example application.CassiniDev - Cassini 3.5 Developers Edition: CassiniDev v3.5.0.5: For usage see Readme.htm in download. New in CassiniDev v3.5.0.5 Reintroduced the Lib project and signed all Implemented the CassiniSqlFixture -...Composure: Calcium-64420-VS2010rc1.NET4.SL3: This is a simple conversion of Calcium (rev 64420) built in VS2010 RC1 against .NET4 and Silverlight 3. No source files were changed and ALL test...Composure: MS AJAX Library (46266) for VS2010 RC1 .NET4: This is a quick port of Microsoft's AJAX Library (rev 46266) for Visual Studio 2010 RC1 built against .NET 4.0. Since this conversion was thrown t...Composure: MS Web Test Lightweight for VS2010 RC1 .NET4: A simple conversion of Microsoft's Web Test Lightweight for Visual Studio 2010 RC1 .NET 4.0. This is part of a larger "special request" conversion...CoNatural Components: CoNatural Components 1.5: Supporting new data types: Added support for binary data types -> binary, varbinary, etc maps to byte[] Now supporting SQL Server 2008 new types ...Extensia: Extensia 2010-03-05: Extensia is a very large list of extension methods and a few helper types. Some extension methods are not practical (e.g. slow) whilst others are....Fluent Assertions: Fluent Assertions release 1.1: In this release, we've worked hard to add some important missing features that we really needed, and also improve resiliance against illegal argume...Fluent Ribbon Control Suite: Fluent Ribbon Control Suite 1.0 RC: Fluent Ribbon Control Suite 1.0 (Release Candidate)Includes: Fluent.dll (with .pdb and .xml, debug and release version) Showcase Application Sa...FluentNHibernate.Search: 0.1 Beta: First beta versionFolderSize: FolderSize.Win32.1.0.7.0: FolderSize.Win32.1.0.6.0 A simple utility intended to be used to scan harddrives for the folders that take most place and display this to the user...Free Silverlight & WPF Chart Control - Visifire: Silverlight and WPF Step Line Chart: Hi, With this release Visifire introduces Step Line Chart. This release also contains fix for the following issues: * In WPF, if AnimatedUpd...Html to OpenXml: HtmlToOpenXml 1.0: The dll library to include in your project. The dll is signed for GAC support. Compiled with .Net 3.5, Dependencies on System.Drawing.dll and Docu...Line Counter: 1.5.1: The Line Counter is a tool to calculate lines of your code files. The tool was written in .NET 2.0. Line Counter 1.5.1 Added outline icons and lin...Lokad Cloud - .NET O/C mapper (object to cloud) for Windows Azure: Lokad.Cloud v1.0.662.1: You can get the most recent release directly from the build server at http://build.lokad.com/distrib/Lokad.Cloud/Lost in Translation: LostInTranslation v0.2: Alpha release: function complete but not UX complete.MDownloader: MDownloader-0.15.7.56349: Supported large file resumption. Fixed minor bugs.Mini C# Lab: Mini CSharp Lab Ver 1.4: The primary new feature of Ver 1.4 is batch mode! Now you can run Mini C# Lab program as a scheduled task, no UI interactivity is needed. Here ar...Mobile Store: First drop: First droppatterns & practices SharePoint Guidance: SPG2010 Drop6: SharePoint Guidance Drop Notes Microsoft patterns and practices ****************************************** ***************************************...Picasa Downloader: PicasaDownloader (41446): Changelog: Replaced some exception messages by a Summary dialog shown after downloading if there have been problems. Corrected the Portable vers...Pod Thrower: Version 1: This is the first release, I'm sure there are bugs, the tool is fully functional and I'm using it currently.PowerShell Provider BizTalk: BizTalkFactory PowerShell Provider - 1.1-snapshot: This release constitutes the latest development snapshot for the Provider. Please, leave feedback and use the Issue Tracker to help improve this pr...Resharper Settings Manager: RSM 1.2.1: This is a bug fix release. Changes Fixed plug-in crash when shared settings file was modified externally.Reusable Library Demo: Reusable Library Demo v1.0.2: A demonstration of reusable abstractions for enterprise application developerSharePoint 2010 Toggle User Interface: SharePoint Toggle User Interface: Release 1.0.0.0Starter Kit Mytrip.Mvc.Entity: Mytrip.Mvc.Entity(net3.5 MySQL) 1.0 Beta: MySQL VS 2008 EF Membership UserManager FileManager Localization Captcha ClientValidation Theme CrossBrowserTortoiseHg: TortoiseHg 1.0: http://bitbucket.org/tortoisehg/stable/wiki/ReleaseNotes Please backup your user Mercurial.ini file and then uninstall any 0.9.X release before in...Visual Studio 2010 and Team Foundation Server 2010 VM Factory: Rangers Virtualization Guidance: Rangers Virtualization Guidance Focused guidance on creating a Rangers base image manually and introduction of PowerShell scripts to automate many ...Visual Studio DSite: Advanced Email Program (Visual Basic 2008): This email program can send email to any one using your email username and email credentials. The email program can also attatch attactments to you...WPF ShaderEffect Generator: WPF ShaderEffect Generator 1.6: Several improvements and bug fixes have gone into the comment parsing code for the registers. The plug-in should now correctly pay attention to th...WSDLGenerator: WSDLGenerator 0.0.0.3: - Fixed SharePoint generated *.wsdl.aspx file - Added commandline option -wsdl which does only generate the wsdl file.Most Popular ProjectsMetaSharpRawrWBFS ManagerAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)ASP.NETLiveUpload to FacebookMicrosoft SQL Server Community & SamplesMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsBlogEngine.NETjQuery Library for SharePoint Web Servicespatterns & practices – Enterprise LibraryIonics Isapi Rewrite FilterFluent AssertionsComposureDiffPlex - a .NET Diff Generator

  Read the article

< Previous Page | 547 548 549 550 551 552 553 554 555 556 557 558  | Next Page >