Search Results

Search found 60932 results on 2438 pages for 'data operations'.

Page 642/2438 | < Previous Page | 638 639 640 641 642 643 644 645 646 647 648 649  | Next Page >

• how random is Math.random() in java across different jvms or different machines

  - by user881480

  I have a large distributed program across many different physical servers, each program spawns many threads, each thread use Math.random() in its operations to draw a piece from many common resource pools. The goal is to utilize the pools evenly across all operations. Sometimes, it doesn't appear so random by looking at a snapshot on a resource pool to see which pieces it's getting at that instant (it might actually be, but it's hard to measure and find out for sure). Is there something that's better than Math.random() and performs just as good (not much worse at least)?

  Read the article

• C# to php translator

  - by Ole Jak

  Is there a C# to php translator (capable of dealing with byte operations, TCPSockets)?

  Read the article

• Single console in eclipse for both Server and Client

  - by rits

  I am building a client server application using Java Sockets (in Windows XP). For that I need different consoles for both Client and Server(for Input and Output operations). But in eclipse both share a single console. Is there any plugin or some sort of cheat through which I can do this. After googling I got this, http://dev.eclipse.org/newslists/news.eclipse.newcomer/msg17138.html But, this seems to be only for write operations, not read operations. Also, I tried the following to launch application manually, but even this is not working........ package mypack; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import java.io.PrintStream; public class MySystem { public static void changeStream(String mainFile) throws IOException{ File temp = new File(".") ; String parentPath = temp.getCanonicalPath() ; System.out.println(parentPath); //creation of batch file starts here try{ File f = new File(parentPath + "\\a.bat") ; System.out.println("Created : " + f.createNewFile()); //f.deleteOnExit() ; FileOutputStream fos = new FileOutputStream(f) ; String str = "java " + mainFile ; String batchCommand="@echo off\n"+str+"\npause\nexit"; char arr[] = batchCommand.toCharArray() ; System.out.println(str) ; for(int i = 0 ; i < arr.length ; i++){ fos.write(arr[i]) ; } fos.close() ; } catch(Exception e){ } //creation of batch file ends here //execution of batch file starts here try{ Runtime r = Runtime.getRuntime() ; System.out.println(parentPath + "\\a.bat") ; Process p = r.exec(new String[]{"cmd","/k","start a.bat"},null,new File(parentPath)) ; OutputStream os = (OutputStream)p.getOutputStream() ; System.setOut( new PrintStream(os) ) ; System.out.println("Hello"); } catch(Exception e){ e.printStackTrace(); } //execution of batch file ends here } public static void main(String[] args) throws IOException { MySystem.changeStream("MySystem") ; } }

  Read the article

• IsAuthenticated is false! weird behaviour + review question

  - by Naor

  This is the login function (after I validate user name and password, I load user data into "user" variable and call Login function: public static void Login(IUser user) { HttpResponse Response = HttpContext.Current.Response; HttpRequest Request = HttpContext.Current.Request; FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1, user.UserId.ToString(), DateTime.Now, DateTime.Now.AddHours(12), false, UserResolver.Serialize(user)); HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, FormsAuthentication.Encrypt(ticket)); cookie.Path = FormsAuthentication.FormsCookiePath; Response.Cookies.Add(cookie); string redirectUrl = user.HomePage; Response.Redirect(redirectUrl, true); } UserResolver is the following class: public class UserResolver { public static IUser Current { get { IUser user = null; if (HttpContext.Current.User.Identity.IsAuthenticated) { FormsIdentity id = (FormsIdentity)HttpContext.Current.User.Identity; FormsAuthenticationTicket ticket = id.Ticket; user = Desrialize(ticket.UserData); } return user; } } public static string Serialize(IUser user) { StringBuilder data = new StringBuilder(); StringWriter w = new StringWriter(data); string type = user.GetType().ToString(); //w.Write(type.Length); w.WriteLine(user.GetType().ToString()); StringBuilder userData = new StringBuilder(); XmlSerializer serializer = new XmlSerializer(user.GetType()); serializer.Serialize(new StringWriter(userData), user); w.Write(userData.ToString()); w.Close(); return data.ToString(); } public static IUser Desrialize(string data) { StringReader r = new StringReader(data); string typeStr = r.ReadLine(); Type type=Type.GetType(typeStr); string userData = r.ReadToEnd(); XmlSerializer serializer = new XmlSerializer(type); return (IUser)serializer.Deserialize(new StringReader(userData)); } } And the global.asax implements the following: void Application_PostAuthenticateRequest(Object sender, EventArgs e) { IPrincipal p = HttpContext.Current.User; if (p.Identity.IsAuthenticated) { IUser user = UserResolver.Current; Role[] roles = user.GetUserRoles(); HttpContext.Current.User = Thread.CurrentPrincipal = new GenericPrincipal(p.Identity, Role.ToString(roles)); } } First question: Am I do it right? Second question - weird thing! The user variable I pass to Login has 4 members: UserName, Password, Name, Id. When UserResolver.Current executed, I got the user instance. I descided to change the user structure - I add an array of Warehouse object. Since that time, when UserResolver.Current executed (after Login), HttpContext.Current.User.Identity.IsAuthenticated was false and I couldn't get the user data. When I removed the Warehouse[] from user structure, it starts to be ok again and HttpContext.Current.User.Identity.IsAuthenticated become true after I Login. What is the reason to this weird behaviour?

  Read the article

• python, wrapping class returning the average of the wrapped members

  - by João Portela

  The title isn't very clear but I'll try to explain. Having this class: class Wrapped(object): def method_a(self): # do some operations return n def method_b(self): # also do some operations return n I wan't to have a class that performs the same way as this one: class Wrapper(object): def __init__(self): self.ws = [Wrapped(1),Wrapped(2),Wrapped(3)] def method_a(self): results=[Wrapped.method_a(w) for w in self.ws] sum_ = sum(results,0.0) average = sum_/len(self.ws) return average def method_b(self): results=[Wrapped.method_b(w) for w in self.ws] sum_ = sum(results,0.0) average = sum_/len(self.ws) return average obviously this is not the actual problem at hand (it is not only two methods), and this code is also incomplete (only included the minimum to explain the problem). So, what i am looking for is a way to obtain this behavior. Meaning, whichever method is called in the wrapper class, call that method for all the Wrapped class objects and return the average of their results. Can it be done? how? Thanks in advance. ps-didn't know which tags to include...

  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

• How to get `gcc` to generate `bts` instruction for x86-64 from standard C?

  - by Norman Ramsey

  Inspired by a recent question, I'd like to know if anyone knows how to get gcc to generate the x86-64 bts instruction (bit test and set) on the Linux x86-64 platforms, without resorting to inline assembly or to nonstandard compiler intrinsics. Related questions: Why doesn't gcc do this for a simple |= operation were the right-hand side has exactly 1 bit set? How to get bts using compiler intrinsics or the asm directive Portability is more important to me than bts, so I won't use and asm directive, and if there's another solution, I prefer not to use compiler instrinsics. EDIT: The C source language does not support atomic operations, so I'm not particularly interested in getting atomic test-and-set (even though that's the original reason for test-and-set to exist in the first place). If I want something atomic I know I have no chance of doing it with standard C source: it has to be an intrinsic, a library function, or inline assembly. (I have implemented atomic operations in compilers that support multiple threads.)

  Read the article

• C# problem with two threads and hardware access

  - by mack369

  I'm creating an application which communicates with the device via FT2232H USB/RS232 converter. For communication I'm using FTD2XX_NET.dll library from FTDI website. I'm using two threads: first thread continuously reads data from the device the second thread is the main thread of the Windows Form Application I've got a problem when I'm trying to write any data to the device while the receiver's thread is running. The main thread simply hangs up on ftdiDevice.Write function. I tried to synchronize both threads so that only one thread can use Read/Write function at the same time, but it didn't help. Below code responsible for the communication. Note that following functions are methods of FtdiPort class. Receiver's thread private void receiverLoop() { if (this.DataReceivedHandler == null) { throw new BackendException("dataReceived delegate is not set"); } FTDI.FT_STATUS ftStatus = FTDI.FT_STATUS.FT_OK; byte[] readBytes = new byte[this.ReadBufferSize]; while (true) { lock (FtdiPort.threadLocker) { UInt32 numBytesRead = 0; ftStatus = ftdiDevice.Read(readBytes, this.ReadBufferSize, ref numBytesRead); if (ftStatus == FTDI.FT_STATUS.FT_OK) { this.DataReceivedHandler(readBytes, numBytesRead); } else { Trace.WriteLine(String.Format("Couldn't read data from ftdi: status {0}", ftStatus)); Thread.Sleep(10); } } Thread.Sleep(this.RXThreadDelay); } } Write function called from main thread public void Write(byte[] data, int length) { if (this.IsOpened) { uint i = 0; lock (FtdiPort.threadLocker) { this.ftdiDevice.Write(data, length, ref i); } Thread.Sleep(1); if (i != (int)length) { throw new BackendException("Couldnt send all data"); } } else { throw new BackendException("Port is closed"); } } Object used to synchronize two threads static Object threadLocker = new Object(); Method that starts the receiver's thread private void startReceiver() { if (this.DataReceivedHandler == null) { return; } if (this.IsOpened == false) { throw new BackendException("Trying to start listening for raw data while disconnected"); } this.receiverThread = new Thread(this.receiverLoop); //this.receiverThread.Name = "protocolListener"; this.receiverThread.IsBackground = true; this.receiverThread.Start(); } The ftdiDevice.Write function doesn't hang up if I comment following line: ftStatus = ftdiDevice.Read(readBytes, this.ReadBufferSize, ref numBytesRead);

  Read the article

• Parallel.For maintain input list order on output list

  - by romeozor

  I'd like some input on keeping the order of a list during heavy-duty operations that I decided to try to do in a parallel manner to see if it boosts performance. (It did!) I came up with a solution, but since this was my first attempt at anything parallel, I'd need someone to slap my hands if I did something very stupid. There's a query that returns a list of card owners, sorted by name, then by date of birth. This needs to be rendered in a table on a web page (ASP.Net WebForms). The original coder decided he would construct the table cell-by-cell (TableCell), add them to rows (TableRow), then each row to the table. So no GridView, allegedly its performance is bad, but the performance was very poor regardless :). The database query returns in no time, the most time is spent on looping through the results and adding table cells etc. I made the following method to maintain the original order of the list: private TableRow[] ComposeRows(List<CardHolder> queryResult) { int queryElementsCount = queryResult.Count(); // array with the query's size var rowArray = new TableRow[queryElementsCount]; Parallel.For(0, queryElementsCount, i => { var row = new TableRow(); var cell = new TableCell(); // various operations, including simple ones such as: cell.Text = queryResult[i].Name; row.Cells.Add(cell); // here I'm adding the current item to it's original index // to maintain order in the output list rowArray[i] = row; }); return rowArray; } So as you can see, because I'm returning a very different type of data (List<CardHolder> -> TableRow[]), I can't just simply omit the ordering from the original query to do it after the operations. Also, I also thought it would be a good idea to Dispose() the objects at the end of each loop, because the query can return a huge list and letting cell and row objects pile up in the heap could impact performance.(?) How badly did I do? Does anyone have a better solution in case mine is flawed?

  Read the article

• Another C datatypes question

  - by b-gen-jack-o-neill

  Hello. Well, I completely get the most basic datatypes of C, like short, int, long, float, to be exact, all numerical types.These types are needed to be known perform right operations with right numbers. For example to use FPU to add two float numbers. So the compiler must know what the type is. But, when it comes to characters I am little bit off. I know that basic C datatype char is there for ASCII characters coding. But what I don´t know is, why you even need another datatype for characters. Why could not you just use 1 byte integer value to store ASCII character. If you call printf, you apecify the datatype in the call, so you could say to printf that the integer represents ASCII character. I dont know how cout resolves datatype, but I guess you could just specify it somehow. Another thing is, when you want to use Unicode, you must use datatype wchar. But, what if I would like to use some another, for example ISO, or Windows coding instead of UTF? Becouse wchar codes characters as UTF-16 or UTF-32 (I read its compiler specific). And, what if I would want to use for example some imaginary new 8 byte text coding? What datatype should I use for it? I am actually pretty confused of this, becouse I always expected that if I want to use UTF-32 instead of ASCII, I just tell compiler "get UTF-32 value of the character I typed and save it into 4 char field." I thought that text coding is to be dealt with by the end, print function for example. That I just need to specify the coding for the compiler to use, since Windows doesent use ASCII in win32 apps, I guess C compiler must convert the char I typed to ASCII from whatever the type is that windows sends to the C editor. And the last thing is, what if I want to use for example 25 Byte integer for some high math operations? C has no specify-yourself datatype. Yes, I know that this would be difficult since all the math operations would need to be changed, becouse CPU can not add 25 Bytes numbers together. But is there a way to do it? Or is there some math library for it? What if I want to compute Pi to 1000000000000000 digits? :) I know my question is pretty long, but I just wanted to explain my thoughts the best I can in English, since its not my native language it is difficult. And I believe there is simple answer to my question(s), something I missed that explains everything. I read lot about text coding, C tutorials, but nothing about his. Thank you for your time.

  Read the article

• Tricky Big-O complexity

  - by timeNomad

  public void foo (int n, int m) { int i = m; while (i > 100) i = i/3; for (int k=i ; k>=0; k--) { for (int j=1; j<n; j*=2) System.out.print(k + "\t" + j); System.out.println(); } } I figured the complexity would be O(logn). That is as a product of the inner loop, the outer loop -- will never be executed more than 100 times, so it can be omitted. What I'm not sure about is the while clause, should it be incorporated into the Big-O complexity? For very large i values it could make an impact, or arithmetic operations, doesn't matter on what scale, count as basic operations and can be omitted?

  Read the article

• Mongomapper - unit testing with shoulda on rails 2.3.5

  - by egarcia

  I'm trying to implement shoulda unit tests on a rails 2.3.5 app using mongomapper. So far I've: Configured a rails app that uses mongomapper (the app works) Added shoulda to my gems, and installed it with rake gems:install Added config.frameworks -= [ :active_record, :active_resource ] to config/environment.rb so ActiveRecord isn't used. My models look like this: class Account include MongoMapper::Document key :name, String, :required => true key :description, String key :company_id, ObjectId key :_type, String belongs_to :company many :operations end My test for that model is this one: class AccountTest < Test::Unit::TestCase should_belong_to :company should_have_many :operations should_validate_presence_of :name end It fails on the first should_belong_to: ./test/unit/account_test.rb:3: undefined method `should_belong_to' for AccountTest:Class (NoMethodError) Any ideas why this doesn't work? Should I try something different from shoulda? I must point out that this is the first time I try to use shoulda, and I'm pretty new to testing itself.

  Read the article

• Undo/Redo Support for Table Changes in WPF RichTextBox

  - by Jeff

  As part of an editor project, I need to add functionality to the WPF RichTextBox control to allow the user to perform operations on a table. One of those operations is to apply a new width value to one or more columns of the table. I have a function that is applying a new Width value to the TableColumn objects in question, and the table is resizing itself nicely. However, I've noticed that the column-width change operation does not seem to be added to the undo stack. In other words, if a user types something, then changes a column width, then selects undo, the RichTextBox control undoes the user's typing. Undo and redo don't seem to be picking up the property change on the TableColumn object. Is there some way to make this operation occur in a way that it actually is undoable/redoable?

  Read the article

• Java Mail timeout & connectiontimeout handling

  - by Gnanam

  Hi, I'm using JavaMail to send email requests to an SMTP server. I would like to set both "mail.smtp.connectiontimeout" and "mail.smtp.timeout" properties within my code. Programmatically, I want to catch both when timeout and/or connectiontimeout operations are reached in Java and handle things accordingly. Handling in the sense, I need to retry the same email once again the next time. How do I handle this in Java/JavaMail? Is it possible to catch & handle this timeout operations?

  Read the article

• Preview result of update/insert query whithout comitting changes to database in MySQL?

  - by Camsoft

  I am writing a script to import CSV files into existing tables within my database. I decided to do the insert/update operations myself using PHP and INSERT/UPDATE statements, and not use MySQL's LOAD INFILE command, I have good reasons for this. What I would like to do is emulate the insert/update operations and display the results to the user, and then give them the option of confirming that this is OK, and then committing the changes to the database. I'm using InnoDB database engine with support for transactions. Not sure if this helps but was thinking down the line of insert/update, query data, display to user, then either commit or rollback transaction? Any advise would be appreciated.

  Read the article

• Inserting contact with android and querying the result uri returns no entries

  - by th0m4d

  Im developing an application which is dealing with the android contacts API. I implemented methods to insert, update and query contacts. So far everything worked (writing and reading contacts). At one point in my project Im experiencing a strange behaviour. I insert a contact using batch mode. I receive the URI to the RawContact. I do this in a background thread. // use batchmode for contact insertion ArrayList ops = new ArrayList(); int rawContactInsertIndex = ops.size(); // create rawContact ops.add(ContentProviderOperation.newInsert(RawContacts.CONTENT_URI) .withValue(RawContacts.ACCOUNT_TYPE, ConstantsContract.ACCOUNT_TYPE) .withValue(RawContacts.ACCOUNT_NAME, accountName).build()); ops.add(createInsertOperation().withValueBackReference(Data.RAW_CONTACT_ID, rawContactInsertIndex) .withValue(Data.MIMETYPE, StructuredName.CONTENT_ITEM_TYPE) .withValue(StructuredName.DISPLAY_NAME, displayName).withValue(StructuredName.GIVEN_NAME, firstName) .withValue(StructuredName.FAMILY_NAME, lastName).build()); //other data values... ContentProviderResult[] results = context.getContentResolver().applyBatch(ContactsContract.AUTHORITY, ops); if (results.length 0) { result = results[0]; } Then i request and store the lookup uri RawContacts.getContactLookupUri(this.getContentResolver(), myContantRawContactUri); I am able to query the contact using the rawContactUri directly after inserting it (in the same thread). The lookup uri returns null. Uri rawContactUri = appUser.getRawContactUri(ctx); if (rawContactUri == null) { return null; } String lastPathSegment = rawContactUri.getLastPathSegment(); long rawContactId = Long.decode(lastPathSegment); if (rawContactUri != null) { contact = readContactWithID(rawContactId, ContactsContract.Data.RAW_CONTACT_ID); In a different place in the project I want to query the contact i inserted by the stored lookup uri or raw contact uri. Both return no rows from the content provider. I tried it in the main thread and in another background thread. ctx.getContentResolver().query(ContactsContract.Data.CONTENT_URI, null, ContactsContract.Data.RAW_CONTACT_ID + " = ? AND " + ContactsContract.Data.MIMETYPE + " = ?", new String[] { contactID + "", ContactsContract.CommonDataKinds.StructuredName.CONTENT_ITEM_TYPE }, null); My first thought was that it could be related to the context.getContentResolver(). But the android documentation states, that the ContentResolver objects scope is the application's package, so you have on ContentResolver for the whole app. Am I right? What am I doing wrong? Why does the same rawContactUri return the contact at one place and does not on another place? And why do I get a lookup uri from a raw contact, which is not working at all?

  Read the article

• Efficiency of Java code with primitive types

  - by super89

  Hello! I want to ask which piece of code is more efficient in Java? Code 1: void f() { for(int i = 0 ; i < 99999;i++) { for(int j = 0 ; j < 99999;j++) { //Some operations } } } Code 2: void f() { int i,j; for(i = 0 ; i < 99999;i++) { for(j = 0 ; j < 99999;j++) { //Some operations } } } My teacher said that second is better, but I can't agree that opinion.

  Read the article

• How do I create a downscaled copy of an FBO in OpenGL?

  - by Jasper Bekkers

  Hi, In order to speed up some post-processing shaders I'm using, I need to perform these operations on a framebuffer that is smaller in size than the actual window (about 1/4th or more). Most of the effects I want to optimize are simple blurring operations that could be replaced (for a large part) by smaller kernel and bilinear filtering. Thus, I need to create a copy of the current FBO into another one. However, I couldn't find anything, that works, on how to do this. I've tried using glBlitframebufferEXT and rendering a fullscreen quad into the other framebuffer, but both paths result in a black texture as output. How do I go about solving this problem?

  Read the article

• building a web application in eclipse

  - by Noona

  As a concluding assignment for the technologies taught in a data management course, we have to write a web application using the technologies taught throughout the course, this mostly includes xhtml, css, JSP, servelets, JDBC, AJAX, webservices. the project will eventually be deployed using tomcat. we are given the option of choosing the technologies that we see fit. since this is my first time developing a web application I am having some uncertainties about where to start, so for example now I am writing the object classes that will be used in the database and implementing the operations that will be performed on the database, but I am not sure about how to make these operations available to a client through the website, I mean I think I have to write a servlet through which I can extract the request parameters and set the response accordingly, but I would still like a more specific overview of what I am going to do, so if someone can link me to a tutorial with an example that makes use of these technologies while illustrating the stages of the design so that I can see how all these things are linked together in a web project. thanks

  Read the article

• PDF Report generation

  - by IniTech

  EDIT : I completed this project using ABCpdf. For anyone interested, I love this product and their support is A+. Everything I listed as a 'Con' for the HTML - PDF solution was easily doable in ABCpdf. I've been charged with creating a data driven pdf report. After reviewing the plethora of options, I have narrowed it down to 2. I need you all to to help me decide, or offer alternatives I haven't considered. Here are the requirements: 100% Data driven Eventually PDF (a stop in HTML is fine, so long as it is converted) Can be run with multiple sets of data (the layout is always the same, the data is variable) Contains normal analysis-style copy (saved in DB with html markup) Contains tables (data for tables is generated at run-time) Header/Page # on each page Table of Contents .NET (VB or C#) Done quickly Now, because of the fact that the report is going to be generated with multiple sets of data, I don't think a stamped pdf template will work since I won't know how long or how many pages a certain piece of the report could require. So, I think my best options are: Programmatic creation using an iText-like solution. Generate in HTML and convert to PDF using a third-party application (ABCPdf is the tool I have played with so far) Both solutions have their pro's and con's. Programmatic solution: Pros: Flexible Easy page numbering/page header/table of contents Free Cons: Time consuming (to write a layer on top of iText to do what I need and keep maintainable) Since the copy is already stored in the db with html markup, I would have to parse through the data before I place it into the pdf, ensuring I don't have to break the paragraph into chunks so I can apply bold, italic, underline, etc. to specific phrases. This seems like a huge PITA, and I hope I am wrong about that assumption. HTML - PDF Pros: Easy to generate from db (no parsing necessary) Many tools for conversion Uses technology I am already familiar with Built-in "Print Preview" - not a req, but nice Cons: (Edited after project completion. All of my assumptions were incorrect and ABCpdf is awesome) 1. Almost impossible to generate page headers - Not True 2. Very difficult to generate page numbers Not True 3. Nearly impossible to generate table of contents Not True 4. (Cross-browser support isn't a con; Since its internal, I can dictate what browser to use) 5. Conversion tool quirks - may not convert exactly as rendered in browser Not True 6. Overall, I think it would be very hard to format the HTML exactly as I would want it to appear/convert to PDF. Not True That's it - I need the communitys help in deciding which way I should go. I might be wrong about some of my Pro/Con assumptions. If I am, please tell me. All thoughts and suggestions are welcome and appreciated. Thanks

  Read the article

• Problem determining how to order F# types due to circular references

  - by James Black

  I have some types that extend a common type, and these are my models. I then have DAO types for each model type for CRUD operations. I now have a need for a function that will allow me to find an id given any model type, so I created a new type for some miscellaneous functions. The problem is that I don't know how to order these types. Currently I have models before dao, but I somehow need DAOMisc before CityDAO and CityDAO before DAOMisc, which isn't possible. The simple approach would be to put this function in each DAO, referring to just the types that can come before it, so, State comes before City as State has a foreign key relationship with City, so the miscellaneous function would be very short. But, this just strikes me as wrong, so I am not certain how to best approach this. Here is my miscellaneous type, where BaseType is a common type for all my models. type DAOMisc = member internal self.FindIdByType item = match(item:BaseType) with | :? StateType as i -> let a = (StateDAO()).Retrieve i a.Head.Id | :? CityType as i -> let a = (CityDAO()).Retrieve i a.Head.Id | _ -> -1 Here is one dao type. CommonDAO actually has the code for the CRUD operations, but that is not important here. type CityDAO() = inherit CommonDAO<CityType>("city", ["name"; "state_id"], (fun(reader) -> [ while reader.Read() do let s = new CityType() s.Id <- reader.GetInt32 0 s.Name <- reader.GetString 1 s.StateName <- reader.GetString 3 ]), list.Empty ) This is my model type: type CityType() = inherit BaseType() let mutable name = "" let mutable stateName = "" member this.Name with get() = name and set restnameval=name <- restnameval member this.StateName with get() = stateName and set stateidval=stateName <- stateidval override this.ToSqlValuesList = [this.Name;] override this.ToFKValuesList = [StateType(Name=this.StateName);] The purpose for this FindIdByType function is that I want to find the id for a foreign key relationship, so I can set the value in my model and then have the CRUD functions do the operations with all the correct information. So, City needs the id for the state name, so I would get the state name, put it into the state type, then call this function to get the id for that state, so my city insert will also include the id for the foreign key. This seems to be the best approach, in a very generic way to handle inserts, which is the current problem I am trying to solve.

  Read the article

• How to do the processing and keep GUI refreshed using databinding?

  - by macias

  History of the problem This is continuation of my previous question How to start a thread to keep GUI refreshed? but since Jon shed new light on the problem, I would have to completely rewrite original question, which would make that topic unreadable. So, new, very specific question. The problem Two pieces: CPU hungry heavy-weight processing as a library (back-end) WPF GUI with databinding which serves as monitor for the processing (front-end) Current situation -- library sends so many notifications about data changes that despite it works within its own thread it completely jams WPF data binding mechanism, and in result not only monitoring the data does not work (it is not refreshed) but entire GUI is frozen while processing the data. The aim -- well-designed, polished way to keep GUI up to date -- I am not saying it should display the data immediately (it can skip some changes even), but it cannot freeze while doing computation. Example This is simplified example, but it shows the problem. XAML part: <StackPanel Orientation="Vertical"> <Button Click="Button_Click">Start</Button> <TextBlock Text="{Binding Path=Counter}"/> </StackPanel> C# part (please NOTE this is one piece code, but there are two sections of it): public partial class MainWindow : Window,INotifyPropertyChanged { // GUI part public MainWindow() { InitializeComponent(); DataContext = this; } private void Button_Click(object sender, RoutedEventArgs e) { var thread = new Thread(doProcessing); thread.IsBackground = true; thread.Start(); } // this is non-GUI part -- do not mess with GUI here public event PropertyChangedEventHandler PropertyChanged; public void OnPropertyChanged(string property_name) { if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(property_name)); } long counter; public long Counter { get { return counter; } set { if (counter != value) { counter = value; OnPropertyChanged("Counter"); } } } void doProcessing() { var tmp = 10000.0; for (Counter = 0; Counter < 10000000; ++Counter) { if (Counter % 2 == 0) tmp = Math.Sqrt(tmp); else tmp = Math.Pow(tmp, 2.0); } } } Known workarounds (Please do not repost them as answers) Those two first are based on Jon ideas: pass GUI dispatcher to library and use it for sending notifications -- why it is ugly? because it could be no GUI at all give up with data binding COMPLETELY (one widget with databinding is enough for jamming), and instead check from time to time data and update the GUI manually -- well, I didn't learn WPF just to give up with it now ;-) and this is mine, it is ugly, but simplicity of it kills -- before sending notification freeze a thread -- Thread.Sleep(1) -- to let the potential receiver "breathe" -- it works, it is minimalistic, it is ugly though, and it ALWAYS slows down computation even if no GUI is there So... I am all ears for real solutions, not some tricks.

  Read the article

• Coolstack MySQL Crash Unable to Restart

  - by rayblasdel

  Environment: Solaris 10 This mysql server has been up and running for 6 months now. Today all of a sudden it crashed. When typing 'mysql' as user it gives the error MYSQL" Error 2002 (HY000): Can't Connect to Local MySQL server though socket '/tmp/mysql.sock' The server try to open mysql, it stays open for 9-10 seconds and restarts the process. Below are the application logs. Application-database-mysql_mysql-csk.log [ May 30 22:37:52 Enabled. ] [ May 30 22:37:58 Rereading configuration. ] [ May 30 22:37:59 Executing start method ("/opt/coolstack/lib/svc/method/svc-cskmysql start") ] /opt/coolstack/mysql/bin/mysqld_safe --user=mysql --datadir=/dbpool1/data --pid-file=/dbpool1/data/database.soliaonline.com.pid [ May 30 22:37:59 Method "start" exited with status 0 ] [ May 30 22:38:13 Stopping because all processes in service exited. ] [ May 30 22:38:13 Executing stop method ("/opt/coolstack/lib/svc/method/svc-cskmysql stop") ] [ May 30 22:38:13 Method "stop" exited with status 0 ] [ May 30 22:38:13 Executing start method ("/opt/coolstack/lib/svc/method/svc-cskmysql start") ] /opt/coolstack/mysql/bin/mysqld_safe --user=mysql --datadir=/dbpool1/data --pid-file=/dbpool1/data/database.soliaonline.com.pid [ May 30 22:38:13 Method "start" exited with status 0 ] [ May 30 22:38:25 Stopping because all processes in service exited. ] [ May 30 22:38:25 Executing stop method ("/opt/coolstack/lib/svc/method/svc-cskmysql stop") ] [ May 30 22:38:25 Method "stop" exited with status 0 ] I am hoping someone might have run into this before and might know how to fix it. The following is an excerpt from the MySQL Error log 100530 22:44:03 mysqld_safe mysqld from pid file /dbpool1/data/database.soliaonline.com.pid ended 100530 22:44:04 mysqld_safe Starting mysqld daemon with databases from /dbpool1/data InnoDB: Log scan progressed past the checkpoint lsn 32 727170612 100530 22:44:13 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... InnoDB: Doing recovery: scanned up to log sequence number 32 727200901 100530 22:44:14 InnoDB: Starting an apply batch of log records to the database... InnoDB: Progress in percents: 100530 22:44:14 - mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=209715200 read_buffer_size=1048576 max_used_connections=0 max_threads=10000 threads_connected=0 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 31024253 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. enter code here

  Read the article

• C++ Virtual Constructor, without clone()

  - by Julien L.

  I want to perform "deep copies" of an STL container of pointers to polymorphic classes. I know about the Prototype design pattern, implemented by means of the Virtual Ctor Idiom, as explained in the C++ FAQ Lite, Item 20.8. It is simple and straightforward: struct ABC // Abstract Base Class { virtual ~ABC() {} virtual ABC * clone() = 0; }; struct D1 : public ABC { virtual D1 * clone() { return new D1( *this ); } // Covariant Return Type }; A deep copy is then: for( i = 0; i < oldVector.size(); ++i ) newVector.push_back( oldVector[i]->clone() ); Drawbacks As Andrei Alexandrescu states it: The clone() implementation must follow the same pattern in all derived classes; in spite of its repetitive structure, there is no reasonable way to automate defining the clone() member function (beyond macros, that is). Moreover, clients of ABC can possibly do something bad. (I mean, nothing prevents clients to do something bad, so, it will happen.) Better design? My question is: is there another way to make an abstract base class clonable without requiring derived classes to write clone-related code? (Helper class? Templates?) Following is my context. Hopefully, it will help understanding my question. I am designing a class hierarchy to perform operations on a class Image: struct ImgOp { virtual ~ImgOp() {} bool run( Image & ) = 0; }; Image operations are user-defined: clients of the class hierarchy will implement their own classes derived from ImgOp: struct CheckImageSize : public ImgOp { std::size_t w, h; bool run( Image &i ) { return w==i.width() && h==i.height(); } }; struct CheckImageResolution; struct RotateImage; ... Multiple operations can be performed sequentially on an image: bool do_operations( std::vector< ImgOp* > v, Image &i ) { std::for_each( v.begin(), v.end(), /* bind2nd(mem_fun(&ImgOp::run), i ...) don't remember syntax */ ); } int main( ... ) { std::vector< ImgOp* > v; v.push_back( new CheckImageSize ); v.push_back( new CheckImageResolution ); v.push_back( new RotateImage ); Image i; do_operations( v, i ); } If there are multiple images, the set can be split and shared over several threads. To ensure "thread-safety", each thread must have its own copy of all operation objects contained in v -- v becomes a prototype to be deep copied in each thread.

  Read the article

• Java Conversion of byte[] into a srting and then back to a byte[]

  - by Sid

  I am working on a proxy server. I am getting data in byte[] which i convert into a string to perform certain operations. Now when i convert this new string back into a byte [] it causes unkonw problems. So mainly its like i need to know how to correctly convert a byte[] into a string and then back into a byte[] again. I tried to just convert the byte[] to string and then back to byte[] again (to make sure thats its not my operations that are causing problems). So its like: // where reply is a byte[] String str= new String(reply,0, bytesRead); streamToClient.write(str.getBytes(), 0, bytesRead); is not equivalent to streamToClient.write(reply, 0, bytesRead); my proxy works fine when i just send the byte[] without any conversion but when i convert it from byte[] to a string and then back to a byte[] its causes problems. can some one please help? =]

  Read the article

< Previous Page | 638 639 640 641 642 643 644 645 646 647 648 649  | Next Page >