Search Results

Search found 5420 results on 217 pages for 'auxilliary storage'.

Page 206/217 | < Previous Page | 202 203 204 205 206 207 208 209 210 211 212 213  | Next Page >

  • SQL Server 2008: FileStream Insertion Failure w/ .NET 3.5SP1

    - by James Alexander
    I've configured a db w/ a FileStream group and have a table w/ File type on it. When attempting to insert a streamed file and after I create the table row, my query to read the filepath out and the buffer returns a null file path. I can't seem to figure out why though. Here is the table creation script: /****** Object: Table [dbo].[JobInstanceFile] Script Date: 03/22/2010 18:05:36 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[JobInstanceFile]( [JobInstanceFileId] [int] IDENTITY(1,1) NOT NULL, [JobInstanceId] [int] NOT NULL, [File] [varbinary](max) FILESTREAM NULL, [FileId] [uniqueidentifier] ROWGUIDCOL NOT NULL, [Created] [datetime] NOT NULL, CONSTRAINT [PK_JobInstanceFile] PRIMARY KEY CLUSTERED ( [JobInstanceFileId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] FILESTREAM_ON [JobInstanceFilesGroup], UNIQUE NONCLUSTERED ( [FileId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] FILESTREAM_ON [JobInstanceFilesGroup] GO SET ANSI_PADDING OFF GO ALTER TABLE [dbo].[JobInstanceFile] ADD DEFAULT (newid()) FOR [FileId] GO Here's my proc I call to create the row before streaming the file: /****** Object: StoredProcedure [dbo].[JobInstanceFileCreate] Script Date: 03/22/2010 18:06:23 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO create proc [dbo].[JobInstanceFileCreate] @JobInstanceId int, @Created datetime as insert into JobInstanceFile (JobInstanceId, FileId, Created) values (@JobInstanceId, newid(), @Created) select scope_identity() GO And lastly, here's the code I'm using: public int CreateJobInstanceFile(int jobInstanceId, string filePath) { using (var connection = new SqlConnection(ConfigurationManager.ConnectionStrings["ConsumerMarketingStoreFiles"].ConnectionString)) using (var fileStream = new FileStream(filePath, FileMode.Open)) { connection.Open(); var tran = connection.BeginTransaction(IsolationLevel.ReadCommitted); try { //create the JobInstanceFile instance var command = new SqlCommand("JobInstanceFileCreate", connection) { Transaction = tran }; command.CommandType = CommandType.StoredProcedure; command.Parameters.AddWithValue("@JobInstanceId", jobInstanceId); command.Parameters.AddWithValue("@Created", DateTime.Now); int jobInstanceFileId = Convert.ToInt32(command.ExecuteScalar()); //read out the filestream transaction context to stream the file for storage command.CommandText = "select [File].PathName(), GET_FILESTREAM_TRANSACTION_CONTEXT() from JobInstanceFile where JobInstanceFileId = @JobInstanceFileId"; command.CommandType = CommandType.Text; command.Parameters.AddWithValue("@JobInstanceFileId", jobInstanceFileId); using (SqlDataReader dr = command.ExecuteReader()) { dr.Read(); //get the file path we're writing out to string writePath = dr.GetString(0); using (var writeStream = new SqlFileStream(writePath, (byte[])dr.GetValue(1), FileAccess.ReadWrite)) { //copy from one stream to another byte[] bytes = new byte[65536]; int numBytes; while ((numBytes = fileStream.Read(bytes, 0, 65536)) 0) writeStream.Write(bytes, 0, numBytes); } } tran.Commit(); return jobInstanceFileId; } catch (Exception e) { tran.Rollback(); throw e; } } } Can someone please let me know what I'm doing wrong. In the code, the following expression is returning null for the file path and shouldn't be: //get the file path we're writing out to string writePath = dr.GetString(0); The server is different then the computer the code is running on but the necessary shares appear to be in order and I have also run the following: EXEC sp_configure filestream_access_level, 2 Any help would be greatly appreciated. Thanks!

    Read the article

  • Bazaar newbie question about repository structures

    - by esc1729
    I want to use Bazaar on Windows XP for web-development and related tasks. Most of the files are edited locally and then transferred via FTP to the server. Just now the repository sits on my local workstation. Later on it should be shared locally with some co-workers. Perhaps we will use a local Linux server as a centralized repository, but this structure is not decided for now. But first I need to understand the impacts of the different repository setups, which I do not at all. Using Bazaar-Explorer on Windows XP I’ve created a ‘shared tree repository’ from the option list of the init-dialogue in some location dev-filter/. Bazaar Explorer tells me: Created repository with treeless branches at F:/bzr.local/dev-filter Created branch at F:/bzr.local/dev-filter/trunk Created working tree at F:/bzr.local/dev-filter/work OK so far. Now I move a bunch of files into the work directory and add and commit them as Rev 1 ‘Start Revision’. Then I work on some of these files and commit them again as Rev 2. Here my confusion starts. Shouldn’t both revisions go into the trunk? The trunk is still empty, beside the .bzr directory which only holds some management information. If I delete my working directory, which I have tried during these first experiments, everything is gone. There’s obviously no hidden storage of those files. OK. Perhaps I need to push it into the trunk? This does not work either. Entering the work/ directory and initializing the ‘push’ to the trunk, Bazaar-Explorer tells me No new revisions to push. So what? This looks like a severe conceptual misunderstanding about what should happen on my side. Edit, 2010-02-03: Some conclusions What I learned meanwhile is this: I think I should switch to the command line until I really understand what’s going on, at least for creating the repositories and branches. Bazaar Explorer introduces a new level of abstraction which I only can handle if I understand the level beneath One of the secrets of working with Bazaar at least for me is to understand those .bzr directories, their particular properties and states when created with ‘bzr init’, ‘bzr init-repository’, ‘bzr branch’ etc. in all their variants and how they are plumped together. While there’s a whole chapter of ‘Organizing your workspace’ in the Bazaar User Guide, it’s more or less workflow oriented. The manual contains a lot of directory structures for the given examples. What I would prefer beside this and have not (or only rudimentary) found so far is some graphical representation of those ‘Lego like’ .bzr building blocks which create the linking of all the parts. So I started to invent some simple notation while working through the examples and looking into the .bzr directories to document what information is stored there, where does it come from, how and to what is it linked, is it complete or shared, etc. Erich Schreiber

    Read the article

  • print a linear linked list into a table

    - by user1796970
    I am attempting to print some values i have stored into a LLL into a readable table. The data i have stored is the following : DEBBIE STARR F 3 W 1000.00 JOAN JACOBUS F 9 W 925.00 DAVID RENN M 3 H 4.75 ALBERT CAHANA M 3 H 18.75 DOUGLAS SHEER M 5 W 250.00 SHARI BUCHMAN F 9 W 325.00 SARA JONES F 1 H 7.50 RICKY MOFSEN M 6 H 12.50 JEAN BRENNAN F 6 H 5.40 JAMIE MICHAELS F 8 W 150.00 i have stored each firstname, lastname, gender, tenure, payrate, and salary into their own List. And would like to be able to print them out in the same format that they are viewed on the text file i read them in from. i have messed around with a few methods that allow me to traverse and print the Lists, but i end up with ugly output. . . here is my code for the storage of the text file and the format i would like to print out: public class Payroll { private LineWriter lw; private ObjectList output; ListNode input; private ObjectList firstname, lastname, gender, tenure, rate, salary; public Payroll(LineWriter lw) { this.lw = lw; this.firstname = new ObjectList(); this.lastname = new ObjectList(); this.gender = new ObjectList(); this.tenure = new ObjectList(); this.rate = new ObjectList(); this.salary = new ObjectList(); this.output = new ObjectList(); this.input = new ListNode(); } public void readfile() { File file = new File("payfile.txt"); try{ Scanner scanner = new Scanner(file); while(scanner.hasNextLine()) { String line = scanner.nextLine(); Scanner lineScanner = new Scanner(line); lineScanner.useDelimiter("\\s+"); while(lineScanner.hasNext()) { firstname.insert1(lineScanner.next()); lastname.insert1(lineScanner.next()); gender.insert1(lineScanner.next()); tenure.insert1(lineScanner.next()); rate.insert1(lineScanner.next()); salary.insert1(lineScanner.next()); } } }catch(FileNotFoundException e) {e.printStackTrace();} } public void printer(LineWriter lw) { String msg = " FirstName " + " LastName " + " Gender " + " Tenure " + " Pay Rate " + " Salary "; output.insert1(msg); System.out.println(output.getFirst()); System.out.println(" " + firstname.getFirst() + " " + lastname.getFirst() + "\t" + gender.getFirst() + "\t" + tenure.getFirst() + "\t" + rate.getFirst() + "\t" + salary.getFirst()); } }

    Read the article

  • NSXMLParser Memory Allocation Efficiency for the iPhone

    - by Staros
    Hello, I've recently been playing with code for an iPhone app to parse XML. Sticking to Cocoa, I decided to go with the NSXMLParser class. The app will be responsible for parsing 10,000+ "computers", all which contain 6 other strings of information. For my test, I've verified that the XML is around 900k-1MB in size. My data model is to keep each computer in an NSDictionary hashed by a unique identifier. Each computer is also represented by a NSDictionary with the information. So at the end of the day, I end up with a NSDictionary containing 10k other NSDictionaries. The problem I'm running into isn't about leaking memory or efficient data structure storage. When my parser is done, the total amount of allocated objects only does go up by about 1MB. The problem is that while the NSXMLParser is running, my object allocation is jumping up as much as 13MB. I could understand 2 (one for the object I'm creating and one for the raw NSData) plus a little room to work, but 13 seems a bit high. I can't imaging that NSXMLParser is that inefficient. Thoughts? Code... The code to start parsing... NSXMLParser *parser = [[NSXMLParser alloc] initWithData: data]; [parser setDelegate:dictParser]; [parser parse]; output = [[dictParser returnDictionary] retain]; [parser release]; [dictParser release]; And the parser's delegate code... -(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict { if(mutableString) { [mutableString release]; mutableString = nil; } mutableString = [[NSMutableString alloc] init]; } -(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { if(self.mutableString) { [self.mutableString appendString:string]; } } -(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { if([elementName isEqualToString:@"size"]){ //The initial key, tells me how many computers returnDictionary = [[NSMutableDictionary alloc] initWithCapacity:[mutableString intValue]]; } if([elementName isEqualToString:hashBy]){ //The unique identifier if(mutableDictionary){ [mutableDictionary release]; mutableDictionary = nil; } mutableDictionary = [[NSMutableDictionary alloc] initWithCapacity:6]; [returnDictionary setObject:[NSDictionary dictionaryWithDictionary:mutableDictionary] forKey:[NSMutableString stringWithString:mutableString]]; } if([fields containsObject:elementName]){ //Any of the elements from a single computer that I am looking for [mutableDictionary setObject:mutableString forKey:elementName]; } } Everything initialized and released correctly. Again, I'm not getting errors or leaking. Just inefficient. Thanks for any thoughts!

    Read the article

  • NoHostAvailableException With Cassandra & DataStax Java Driver If Large ResultSet

    - by hughj
    The setup: 2-node Cassandra 1.2.6 cluster replicas=2 very large CQL3 table with no secondary index Rowkey is a UUID.randomUUID().toString() read consistency set to ONE Using DataStax java driver 1.0 The request: Attempting to do a table scan by "SELECT some-col from schema.table LIMIT nnn;" The fail: Once I go beyond a certain nnn LIMIT, I start to get NoHostAvailableExceptions from the driver. It reads like this: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /10.181.13.239 ([/10.181.13.239] Unexpected exception triggered)) at com.datastax.driver.core.exceptions.NoHostAvailableException.copy(NoHostAvailableException.java:64) at com.datastax.driver.core.ResultSetFuture.extractCauseFromExecutionException(ResultSetFuture.java:214) at com.datastax.driver.core.ResultSetFuture.getUninterruptibly(ResultSetFuture.java:169) at com.jpmc.es.rtm.storage.impl.EventExtract.main(EventExtract.java:36) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120) Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /10.181.13.239 ([/10.181.13.239] Unexpected exception triggered)) at com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:98) at com.datastax.driver.core.RequestHandler$1.run(RequestHandler.java:165) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) Given: This is probably not the most enlightened thing to do to a large table with millions of rows, but this is how I learn what not to do, so I would really appreciate someone who could volunteer how this kind of error can be debugged. For example, when this happens, there are no indications that the nodes in the cluster ever had an issue with the request (there is nothing in the logs on either node that indicate any timeout or failure). Also, I enabled the trace on the driver, which gives you some nice autotrace (ala Oracle) info as long as the query succeeds. But in this case, the driver blows a NoHostAvailableException and no ExecutionInfo is available, so tracing has not provided any benefit in this case. I also find it interesting that this does not seem to be recorded as a timeout (my JMX consoles tell me no timeouts have occurred). So, I am left not understanding WHERE the failure is actually occurring. I am left with the idea that it is the driver that is having a problem, but I don't know how to debug it (and I would really like to). I have read several posts from folks that state that query'g for resultSets 10000 rows is probably not a good idea, and I am willing to accept this, but I would like to understand what is causing the exception and where the exception is happening. FWIW, I also tried bumping the timeout properties in the cassandra.yaml, but this made no difference whatsoever. I welcome any suggestions, anecdotes, insults, or monetary contributions for my registration in the house of moron-developers. Regards!!

    Read the article

  • Creating thousands of records in Rails

    - by willCosgrove
    Let me set the stage: My application deals with gift cards. When we create cards they have to have a unique string that the user can use to redeem it with. So when someone orders our gift cards, like a retailer, we need to make a lot of new card objects and store them in the DB. With that in mind, I'm trying to see how quickly I can have my application generate 100,000 Cards. Database expert, I am not, so I need someone to explain this little phenomena: When I create 1000 Cards, it takes 5 seconds. When I create 100,000 cards it should take 500 seconds right? Now I know what you're wanting to see, the card creation method I'm using, because the first assumption would be that it's getting slower because it's checking the uniqueness of a bunch of cards, more as it goes along. But I can show you my rake task desc "Creates cards for a retailer" task :order_cards, [:number_of_cards, :value, :retailer_name] => :environment do |t, args| t = Time.now puts "Searching for retailer" @retailer = Retailer.find_by_name(args[:retailer_name]) puts "Retailer found" puts "Generating codes" value = args[:value].to_i number_of_cards = args[:number_of_cards].to_i codes = [] top_off_codes(codes, number_of_cards) while codes != codes.uniq codes.uniq! top_off_codes(codes, number_of_cards) end stored_codes = Card.all.collect do |c| c.code end while codes != (codes - stored_codes) codes -= stored_codes top_off_codes(codes, number_of_cards) end puts "Codes are unique and generated" puts "Creating bundle" @bundle = @retailer.bundles.create!(:value => value) puts "Bundle created" puts "Creating cards" @bundle.transaction do codes.each do |code| @bundle.cards.create!(:code => code) end end puts "Cards generated in #{Time.now - t}s" end def top_off_codes(codes, intended_number) (intended_number - codes.size).times do codes << ReadableRandom.get(CODE_LENGTH) end end I'm using a gem called readable_random for the unique code. So if you read through all of that code, you'll see that it does all of it's uniqueness testing before it ever starts creating cards. It also writes status updates to the screen while it's running, and it always sits for a while at creating. Meanwhile it flies through the uniqueness tests. So my question to the stackoverflow community is: Why is my database slowing down as I add more cards? Why is this not a linear function in regards to time per card? I'm sure the answer is simple and I'm just a moron who knows nothing about data storage. And if anyone has any suggestions, how would you optimize this method, and how fast do you think you could get it to create 100,000 cards? (When I plotted out my times on a graph and did a quick curve fit to get my line formula, I calculated how long it would take to create 100,000 cards with my current code and it says 5.5 hours. That maybe completely wrong, I'm not sure. But if it stays on the line I curve fitted, it would be right around there.)

    Read the article

  • 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

  • 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

  • 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

  • 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

  • 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

  • DB Design Pattern - Many to many classification / categorised tagging.

    - by Robin Day
    I have an existing database design that stores Job Vacancies. The "Vacancy" table has a number of fixed fields across all clients, such as "Title", "Description", "Salary range". There is an EAV design for "Custom" fields that the Clients can setup themselves, such as, "Manager Name", "Working Hours". The field names are stored in a "ClientText" table and the data stored in a "VacancyClientText" table with VacancyId, ClientTextId and Value. Lastly there is a many to many EAV design for custom tagging / categorising the vacancies with things such as Locations/Offices the vacancy is in, a list of skills required. This is stored as a "ClientCategory" table listing the types of tag, "Locations, Skills", a "ClientCategoryItem" table listing the valid values for each Category, e.g., "London,Paris,New York,Rome", "C#,VB,PHP,Python". Finally there is a "VacancyClientCategoryItem" table with VacancyId and ClientCategoryItemId for each of the selected items for the vacancy. There are no limits to the number of custom fields or custom categories that the client can add. I am now designing a new system that is very similar to the existing system, however, I have the ability to restrict the number of custom fields a Client can have and it's being built from scratch so I have no legacy issues to deal with. For the Custom Fields my solution is simple, I have 5 additional columns on the Vacancy Table called CustomField1-5. This removes one of the EAV designs. It is with the tagging / categorising design that I am struggling. If I limit a client to having 5 categories / types of tag. Should I create 5 tables listing the possible values "CustomCategoryItems1-5" and then an additional 5 many to many tables "VacancyCustomCategoryItem1-5" This would result in 10 tables performing the same storage as the three tables in the existing system. Also, should (heaven forbid) the requirements change in that I need 6 custom categories rather than 5 then this will result in a lot of code change. Therefore, can anyone suggest any DB Design Patterns that would be more suitable to storing such data. I'm happy to stick with the EAV approach, however, the existing system has come across all the usual performance issues and complex queries associated with such a design. Any advice / suggestions are much appreciated. The DBMS system used is SQL Server 2005, however, 2008 is an option if required for any particular pattern.

    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

< Previous Page | 202 203 204 205 206 207 208 209 210 211 212 213  | Next Page >