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• best practices question: How to save a collection of images and a java object in a single file? File

  - by Richard

  Hi all, I am making a java program that has a collection of flash-card like objects. I store the objects in a jtree composed of defaultmutabletreenodes. Each node has a user object attached to it with has a few string/native data type parameters. However, i also want each of these objects to have an image (typical formats, jpg, png etc). I would like to be able to store all of this information, including the images and the tree data to the disk in a single file so the file can be transferred between users and the entire tree, including the images and parameters for each object, can be reconstructed. I had not approached a problem like this before so I was not sure what the best practices were. I found XLMEncoder (http://java.sun.com/j2se/1.4.2/docs/api/java/beans/XMLEncoder.html) to be a very effective way of storing my tree and the native data type information. However I couldn't figure out how to save the image data itself inside of the XML file, and I'm not sure it is possible since the data is binary (so restricted characters would be invalid). My next thought was to associate a hash string instead of an image within each user object, and then gzip together all of the images, with the hash strings as the names and the XMLencoded tree in the same compmressed file. That seemed really contrived though. Does anyone know a good approach for this type of issue? THanks! Thanks!

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• Use Shakespeare-text and external file

  - by Adam

  How can I convert the below example to use an external file instead of the embedded lazy text quasi quotes? {-# LANGUAGE QuasiQuotes, OverloadedStrings #-} import Text.Shakespeare.Text import qualified Data.Text.Lazy.IO as TLIO import Data.Text (Text) import Control.Monad (forM_) data Item = Item { itemName :: Text , itemQty :: Int } items :: [Item] items = [ Item "apples" 5 , Item "bananas" 10 ] main :: IO () main = forM_ items $ \item -> TLIO.putStrLn [lt|You have #{show $ itemQty item} #{itemName item}.|] This is from the yesod online book.

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• How is fseek() implemented in the filesystem?

  - by pajton

  This is not a pure programming question, however it impacts the performance of programs using fseek(), hence it is important to know how it works. A little disclaimer so that it doesn't get closed. I am wondering how efficient it is to insert data in the middle of the file. Supposing I have a file with 1MB data and then I insert something at the 512KB offset. How efficient would that be compared to appending my data at the end of the file? Just to make the example complete lets say I want to insert 16KB of data. I understand the answer varies depending on the filesystem, however I assume that the techniques used in common filesystems are quite similar and I just want to get the right notion of it.

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• javascript error: variable is not defined

  - by Hristo

  to is not defined [Break on this error] setTimeout('updateChat(from, to)', 1); I'm getting this error... I'm using Firebug to test and this comes up in the Console. The error corresponds to line 71 of chat.js and the whole function that wraps this line is: function updateChat(from, to) { $.ajax({ type: "POST", url: "process.php", data: { 'function': 'getFromDB', 'from': from, 'to': to }, dataType: "json", cache: false, success: function(data) { if (data.text != null) { for (var i = 0; i < data.text.length; i++) { $('#chat-box').append($("<p>"+ data.text[i] +"</p>")); } document.getElementById('chat-box').scrollTop = document.getElementById('chat-box').scrollHeight; } instanse = false; state = data.state; setTimeout('updateChat(from, to)', 1); // gives error }, }); } This links to process.php with function call getFromDB and the code for that is: case ('getFromDB'): // get the sender and receiver user IDs from their user names $from = mysql_real_escape_string($_POST['from']); $query = "SELECT `user_id` FROM `Users` WHERE `user_name` = '$from' LIMIT 1"; $result = mysql_query($query) or die(mysql_error()); $row = mysql_fetch_assoc($result); $fromID = $row['user_id']; $to = mysql_real_escape_string($_POST['to']); $query = "SELECT `user_id` FROM `Users` WHERE `user_name` = '$to' LIMIT 1"; $result = mysql_query($query) or die(mysql_error()); $row = mysql_fetch_assoc($result); $toID = $row['user_id']; $query = "SELECT * FROM `Messages` WHERE `from_id` = '$fromID' AND `to_id` = '$toID' LIMIT 1"; $result = mysql_query($query); while($row = mysql_fetch_assoc($result)) { $text[] = $line = $row['message']; $log['text'] = $text; } break; So I'm confused with the line that is giving the error. setTimeout('updateChat(from,to)',1); aren't the parameters to updateChat the same parameters that came into the function? Or are they being pulled in from somewhere else and I have to define to and from else where? Any ideas how to fix this error? Thanks, Hristo

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• select2: "text is undefined" when getting json using ajax

  - by user3046715

  I'm having an issue when getting json results back to select2. My json does not return a result that has a "text" field so need to format the result so that select2 accepts "Name". This code works if the text field in the json is set to "text" but in this case, I cannot change the formatting of the json result (code outside my control). $("#e1").select2({ formatNoMatches: function(term) {return term +" does not match any items." }, ajax: { // instead of writing the function to execute the request we use Select2's convenient helper url: "localhost:1111/Items.json", dataType: 'jsonp', cache: true, quietMillis: 200, data: function (term, page) { return { q: term, // search term p: page, s: 15 }; }, results: function (data, page) { // parse the results into the format expected by Select2. var numPages = Math.ceil(data.total / 15); return {results: data.Data, numPages: numPages}; } } }); I have looked into the documentation and found some statements you can put into the results such as text: 'Name', but I am still getting "text is undefined". Thanks for any help.

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• Grabbing all <a> tags in a specific div and displaying them

  - by Taylor Swyter

  So I'v got a small problem with my portfolio site (you can see it at here) When you click on a portfolio piece, a top section opens up to reveal the details (Title, year, role, description) as well as the photos. I'v been able to get each project to replace all the text data, but I can't seem to get the images to load into the thumbnails. I have been able to get the last image i'm looking for in all of the images on the site, but not display each photo for each project. Here's the HTML i'm working with: <section id="details"> <div class="pagewrapper"> <section id="main-img"> <article id="big-img"> <img src="" alt="big-img" /> </article> <article class="small-img-container"> <a href="#"><img src="#" alt="smallimg" class="small-img" /></a> </article> </section> <section id="description"> <h3></h3> <h4></h4> <h5></h5> <p></p> </section> </div> <div class="clear"></div> </section> <section id="portfolio"> <div class="pagewrapper"> <h2 class="sectionTitle">Portfolio</h2> <div class="thumb"> <a class="small" href="#" title="David Lockwood Music" data-year="2010" data-role="Sole Wordpress Developer" data-description="David Lockwood is a musician and an educator based in New Hampshire who came to me needing a website for his musical career. I fully developed his site using Wordpress as a CMS, creating a custom template based on the design by Jeremiah Louf. Jeremiah and I worked together on the website's UX design."><img src="images_original/davidcover.png" alt="thumb" /> <div class="hide"> <a href="images/davidlockwood/homepage.png" ></a> <a href="images/davidlockwood/blog.png"></a> <a href="images/davidlockwood/shows.png"></a> <a href="images/davidlockwood/bio.png"></a> <a href="images/davidlockwood/photos.png"></a> </div> <h3>David Lockwood Music</h3> <div class="clear"></div> </a> </div><!--thumb--> and here's the jQuery: $(document).ready(function(){ var proj = {}; $('.thumb a').click(function() { $('#details').slideDown(1000); $('.hide a').each(function() { proj.img = $(this).attr("href"); $('.small-img-container img').attr('src',proj.img); }); alert("the image is " + proj.img);//is it getting the image URLS? proj.title = $(this).attr("title"); proj.year = $(this).attr("data-year"); proj.role = $(this).attr("data-role"); proj.description = $(this).attr("data-description"); $('#description h3').text(proj.title); $('#description h4').text(proj.year); $('#description h5').text(proj.role); $('#description p').text(proj.description); }); }); Anyone have any idea how I grab just the images for the specific project, display them all as thumbnails and then make those thumbnail clickable to see the bigger image? Thanks!

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• Python's cPickle deserialization from PHP?

  - by Ciantic

  Hi! I have to deserialize a dictionary in PHP that was serialized using cPickle in Python. In this specific case I probably could just regexp the wanted information, but is there a better way? Any extensions for PHP that would allow me to deserialize more natively the whole dictionary? Apparently it is serialized in Python like this: import cPickle as pickle data = { 'user_id' : 5 } pickled = pickle.dumps(data) print pickled Contents of such serialization cannot be pasted easily to here, because it contains binary data.

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• How to get JTree expanded?

  - by Dzmitry Zhaleznichenka

  I have a wizard with several screens where user has to fill his/her details for further processing. At the second screen I have a radio group with three radio buttons that enable additional elements. To proceed, user has to choose one of them. When user selects third button, single-selection JTree filled in with data enables and user has to select an option from it. Then user has to press "Next" to get to next screen. The option he\she had selected is stored as a TreePath. So far so good. My problem is the following. If the user wants to come back from the following screen to the screen with a JTree, I want to provide him\her with the JTree expanded to the option that had been selected and to highlight the option. However, whatsoever I try to do for that (any combinations of expandPath, scrollPathToVisible, addSelectionPath, makeVisible) always provides me with a collapsed tree. I try to expand both leaves and nodes. My code looks like this: rbProcessJTree.setSelected(isProcessJTree()); if (null != getSelectedTablePath()){ trTables.addSelectionPath(getSelectedTablePath()); trTables.expandPath(getSelectedTablePath()); trTables.scrollPathToVisible(getSelectedTablePath()); } When setSelected() is called, state change listener is invoked that enables JTree. The model is loaded during the form initialization. Each time I switch between screens, I save the input data from previous screen and dispose it. Then, when I need to open previous screen back, I save data from the following screen, dispose it, load data to this screen and show it. So each time the screen is generating from scratch. Could you please explain, what sequence of operations has to be done to get JTree expanded in a newly created form,with data model loaded and selection path provided?

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• PHP - Find a string in file then show it's line number

  - by xZero

  I have an application which needs to open the file, then find string in it, and print a line number where is string found. For example, file example.txt contains few hashes: APLF2J51 1a79a4d60de6718e8e5b326e338ae533 EEQJE2YX 66b375b08fc869632935c9e6a9c7f8da O87IGF8R c458fb5edb84c54f4dc42804622aa0c5 APLF2J51 B7TSW1ZE 1e9eea56686511e9052e6578b56ae018 EEQJE2YX affb23b07576b88d1e9fea50719fb3b7 So, I want to PHP search for "1e9eea56686511e9052e6578b56ae018" and print out its line number, in this case 4. Please note that there are will not be multiple hashes in file. I found a few codes over Internet, but none seem to work. I tried this one: <?PHP $string = "1e9eea56686511e9052e6578b56ae018"; $data = file_get_contents("example.txt"); $data = explode("\n", $data); for ($line = 0; $line < count($data); $line++) { if (strpos($data[$line], $string) >= 0) { die("String $string found at line number: $line"); } } ?> It just says that string is found at line 0.... Which is not correct.... Final application is much more complex than that... After it founds line number, it should replace string which something else, and save changes to file, then goes further processing.... Thanks in advance :)

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• replace NA in an R vector with adjacent values

  - by pssguy

  I have a dataframe which has merged player and team data for soccer seasons So for a particular player in a specific season I have data like df <- data.frame(team=c(NA,"CRP",NA,"CRP","CRP",NA), player=c(NA,"Ed",NA,"Ed","Ed",NA), playerGame= c(NA,1,NA,2,3,NA), teamGame =c(1,2,3,4,5,6)) Where the NA's indicate that the player did not appear in that specific team game How would I most efficiently replace the team and player NA's with "CRP" and "Ed" respectively and have a plGame output of, in this instance, 0,1,1,2,3,3

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• question about JSON

  - by Rawhi

  Hi, If I have in my db a table called User with name, Id, age fields and I want to get these data and put it in a var as a JSON serialize, then I want to send it to javascript page to reform it as I want . I need to know how to put these data in a var as a JSON, how to read the data in the javascript file (how to deal with each one. for example : array[name]) !!!? which thing is more better to deal with these data in asp.net code then send it in the javascript or to send it to the javascript and then to deal with !!? thank u :D

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• javasrcipt asyncronous function

  - by Ben

  Hi there, i have a problem understanding how this could/should be solved. I have two functions. In the first function ( I call it loadData() ) I'm doing an asyncronous request to the server to load some data. In the second function ( saveData() ) I'm also doing an asyn request to the server to write some data. In the callback of this request I'm callin loadData() to refresh the data. Now the problem: In the saveData() function I want to wait for loadData() to be finished bevore I show a dialog (like alert('Data saved')) I guess this is a common problem, but I couldn't find the solution for it (if there is one..) A solution would be to make the requests syncronous, but the framework I'm using doesn't offer that and I hope there's a better solution.. Thanks to all!

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• Unable to diligently close the excel process running in memory

  - by NewAutoUser

  I have developed a VB.Net code for retrieving data from excel file .I load this data in one form and update it back in excel after making necessary modifications in data. This complete flow works fine but most of the times I have observed that even if I close the form; the already loaded excel process does not get closed properly. I tried all possible ways to close it but could not be able to resolve the issue. Find below code which I am using for connecting to excel and let me know if any other approach I may need to follow to resolve this issue. Note: I do not want to kill the excel process as it will kill other instances of the excel Dim connectionString As String connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & ExcelFilePath & "; Extended Properties=excel 8.0; Persist Security Info=False" excelSheetConnection = New ADODB.Connection If excelSheetConnection.State = 1 Then excelSheetConnection.Close() excelSheetConnection.Open(connectionString) objRsExcelSheet = New ADODB.Recordset If objRsExcelSheet.State = 1 Then objRsExcelSheet.Close() Try If TestID = "" Then objRsExcelSheet.Open("Select * from [" & ActiveSheet & "$]", excelSheetConnection, 1, 1) Else objRsExcelSheet.Open("Select Test_ID,Test_Description,Expected_Result,Type,UI_Element,Action,Data,Risk from [" & ActiveSheet & "$] WHERE TEST_Id LIKE '" & TestID & ".%'", excelSheetConnection, 1, 1) End If getExcelData = objRsExcelSheet Catch errObj As System.Runtime.InteropServices.COMException MsgBox(errObj.Message, , errObj.Source) Return Nothing End Try excelSheetConnection = Nothing objRsExcelSheet = Nothing

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• Is it possible to persist two profiles with the Profile Provider Model?

  - by NickGPS

  I have a website that needs to store two sets of user data into separate data stores. The first set of data is used by the SiteCore CMS and holds information about the user. The second set of data is used by a personalisation application that stores its own user data. The reason they aren't stored together in the same profile object is because the personalisation application is used across multiple websites that do not all use SiteCore. I am able to create multiple Profile Providers - I currently have one from SiteCore and a custom provider that I have written and these both work in isolation. The problem exists when you try to configure both in the same web.config file. It seems you can only specify a single Profile object in the web.config file, rather than one for each provider. This means that regardless of which provider is being used the .Net framework sends through the profile object that is specified in the "inherits" parameter in the profile section of the web.config file. My questions are - Is it possible to specify a different Profile object for each Profile Provider? If so, how and where is this specified? Thanks, Nick

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• Match Anything Except a Sub-pattern

  - by Tim Lytle

  I'd like to accomplish what this (invalid I believe) regular expression tries to do: <p><a>([^(<\/a>)]+?)<\/a></p>uniquestring Essentially match anything except a closing anchor tag. Simple non-greedy doesn't help here because `uniquestring' may very well be after another distant closing anchor tag: <p><a>text I don't <tag>want</tag> to match</a></p>random data<p><a>text I do <tag>want to</tag> match</a></p>uniquestring more matches <p><a>of <tag>text I do</tag> want to match</a></p>uniquestring So I have more tag in between the anchor tags. And I'm using the presence of uniquestring to determine if I want to match the data. So a simple non-greedy ends up matching everything from the start of the data I don't want to the end of the data I do want. I know I'm edging close to the problems regular expressions (or at least my knowledge of them) aren't good at solving. I could just through the data at an HTML/XML parser, but it is just one simple(ish) search. Is there some easy way to do this that I'm just missing?

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• Private API and SMS content URI's on Android

  - by Shadow

  Without accessing private API's to get Content URI's, etc. for SMS, how are we expected to query this data? I am currently in the process of writing my own SMS app and I want to stay as compatible as possible. Without storing the information myself in my own database (such that I can store the text messages so that other programs can access the data when/if they delete my app) and without using private API's how the heck are we suppose to query SMS data?

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• @Resource annotation is null at run-time.

  - by Andrew

  I'm using GlassFish v3. The following field is declared in a class: @Resource private javax.sql.DataSource _data_source; The following is declare in web.xml: <data-source <namejava:app/env/data</name <class-namecom.mysql.jdbc.Driver</class-name <server-namelocalhost</server-name <port-number3306</port-number <usermyUser</user <passwordmyPass</password </data-source At run-time _data_source is empty. What am I doing wrong?

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• Is there a standard dialog for constructing an ADO.Net connection string (that is redistributable)?

  - by rathkopf

  I want to use a standard dialog to solicit user input of an ADO.net connection string. It is trivial to do for the oledb connection string as described here: MSDN Article on MSDASC.DataLinks().Prompt I've also found examples that use Microsoft.Data.ConnectionUI.dll and MicrosoftData.ConnectionUI.Dialog.dll from VS (HOWTO: Using the Choose Data Source dialog of Visual Studio 2005 from your own code). Unfortunately these DLLs are not licensed for redistribution. Is there a standard dialog for choosing a data source that can be distributed with my application?

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• MATLAB: svds() not converging

  - by Paul

  So using MATLAB's svds() function on some input data as such: [U, S, V, flag] = svds(data, nSVDs, 'L') I noticed that from run to run with the same data, I'd get drastically different output SVD sizes from run to run. When I checked whether 'flag' was set, I found that it was, indicating that the SVDs had not converged. My normal system here would be that if it really needs to converge, I'd do something like this: flag = 1 svdOpts = struct('tol', 1e-10, 'maxit', 600, 'disp', 0); while flag: if svdOpts.maxit > 1e6 error('There''s a real problem here.') end [U, S, V, flag] = svds(data, nSVDs, 'L', svdOpts) svdOpts.maxit = svdOpts.maxit*2 end But from what I can tell, when you use 'L' as the third argument, the fourth argument is ignored, meaning I just have to deal with the fact that it's not converging? I'm not even really sure how to use the 'sigma' argument in place of the 'L' argument. I've also tried reducing the number of SVDs calculated to no avail. Any help on this matter would be much appreciated. EDIT While following up on the comments below, I found that the problem had to do with the way I was building my data matrices. Turned out I had accidentally inverted a matrix and had an input of size (4000x1) rather than (20x200), which was what was refusing to converge. I also did some more timing tets and found that the fourth argument was not, in fact, being ignored, so that's on me. Thanks for the help guys.

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• KnockoutJS showing a sorted list by item category

  - by Darksbane

  I just started learning knockout this week and everything has gone well except for this one issue. I have a list of items that I sort multiple ways but one of the ways I want to sort needs to have a different display than the standard list. As an example lets say I have this code var BetterListModel = function () { var self = this; food = [ { "name":"Apple", "quantity":"3", "category":"Fruit", "cost":"$1", },{ "name":"Ice Cream", "quantity":"1", "category":"Dairy", "cost":"$6", },{ "name":"Pear", "quantity":"2", "category":"Fruit", "cost":"$2", },{ "name":"Beef", "quantity":"1", "category":"Meat", "cost":"$3", },{ "name":"Milk", "quantity":"5", "category":"Dairy", "cost":"$4", }]; self.allItems = ko.observableArray(food); // Initial items // Initial sort self.sortMe = ko.observable("name"); ko.utils.compareItems = function (l, r) { if (self.sortMe() =="cost"){ return l.cost > r.cost ? 1 : -1 } else if (self.sortMe() =="category"){ return l.category > r.category ? 1 : -1 } else if (self.sortMe() =="quantity"){ return l.quantity > r.quantity ? 1 : -1 }else { return l.name > r.name ? 1 : -1 } }; }; ko.applyBindings(new BetterListModel()); and the HTML <p>Your values:</p> <ul class="deckContents" data-bind="foreach:allItems().sort(ko.utils.compareItems)"> <li><div style="width:100%"><div class="left" style="width:30px" data-bind="text:quantity"></div><div class="left fixedWidth" data-bind="text:name"></div> <div class="left fixedWidth" data-bind="text:cost"></div> <div class="left fixedWidth" data-bind="text:category"></div><div style="clear:both"></div></div></li> </ul> <select data-bind="value:sortMe"> <option selected="selected" value="name">Name</option> <option value="cost">Cost</option> <option value="category">Category</option> <option value="quantity">Quantity</option> </select> </div> So I can sort these just fine by any field I might sort them by name and it will display something like this 3 Apple $1 Fruit 1 Beef $3 Meat 1 Ice Cream $6 Dairy 5 Milk $4 Dairy 2 Pear $2 Fruit Here is a fiddle of what I have so far http://jsfiddle.net/Darksbane/X7KvB/ This display is fine for all the sorts except the category sort. What I want is when I sort them by category to display it like this Fruit 3 Apple $1 Fruit 2 Pear $2 Fruit Meat 1 Beef $3 Meat Dairy 1 Ice Cream $6 Dairy 5 Milk $4 Dairy Does anyone have any idea how I might be able to display this so differently for that one sort?

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• sql server query/subquery question

  - by parminder

  Hi Experts, I have a tables with data like this Id BookId TagId 34 113421 9 35 113421 10 36 113421 11 37 113421 1 38 113422 9 39 113422 1 40 113422 12 I need to write a query (SQL Server) which gives me data according to the tags say if I want bookIds where tagid =9 it should return bookid 113421 and 113422 as it exists in both the books, but If I ask data for tags 9 and 10 it should return only book 113421 as that is the only book where both the tags are present. Thanks Parminder

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• How can I efficiently manipulate 500k records in SQL Server 2005?

  - by cdeszaq

  I am getting a large text file of updated information from a customer that contains updates for 500,000 users. However, as I am processing this file, I often am running into SQL Server timeout errors. Here's the process I follow in my VB application that processes the data (in general): Delete all records from temporary table (to remove last month's data) (eg. DELETE * FROM tempTable) Rip text file into the temp table Fill in extra information into the temp table, such as their organization_id, their user_id, group_code, etc. Update the data in the real tables based on the data computed in the temp table The problem is that I often run commands like UPDATE tempTable SET user_id = (SELECT user_id FROM myUsers WHERE external_id = tempTable.external_id) and these commands frequently time out. I have tried bumping the timeouts up to as far as 10 minutes, but they still fail. Now, I realize that 500k rows is no small number of rows to manipulate, but I would think that a database purported to be able to handle millions and millions of rows should be able to cope with 500k pretty easily. Am I doing something wrong with how I am going about processing this data? Please help. Any and all suggestions welcome.

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• How to set buffer size in client-server app using sockets?

  - by nelly

  First of all i am new to networking so i may say dumb thing in here. Considering a client-server application using sockets(.net with c# if that matters). The client sends some data, the server process it and sends back a string. The client sends some other data, the serve process it, queries the db and sends back several hundreds of items from the database The client sends some other type of data and the server notifies some other clients . My question is how to set the buffer size correctly for reading/writing operation. Should i do something like this: byte[] buff = new byte[client.ReceiveBufferSize] ? I am thinking of something like this: Client sends data to the server(and the server will follow the same pattern) byte[] bytesToSend=new byte[2048] //2048 to be standard for any command send by the client bytes 0..1 ->command type bytes 1..2047 ->command parameters byte[] bytesToReceive=new byte[8]/byte[64]/byte[8192] //switch(command type) But..what is happening when a client is notified by the server without sending data? What is the correct way to accomplish what i am trying to do? Thanks for reading.

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• Sync between local service with a thread and an activity

  - by Henrik

  Hello all, I'm trying to think of a way on how to sync in between a local service and the main activity. The local service has, A thread with a socket connection that could receive data at any time. A list/array with data. At any time the socket could receive data and add it to the list. The activity needs to display this data. So when the activity starts up it needs to attach or start the local service and fetch the list. It also needs to be notified if the list is updated. I think I would need to sync my list somehow so the local service does not add a new entry to it while the activity fetches the list when connecting to the service. Any ideas? Thanks.

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• optimistic and pessimistic locks

  - by billmce

  Working on my first php/Codeigniter project and I’ve scoured the ‘net for information on locking access to editing data and haven’t found very much information. I expect it to be a fairly regular occurrence for 2 users to attempt to edit the same form simultaneously. My experience (in the stateful world of BBx, filePro, and other RAD apps) is that the data being edited is locked using a pessimistic lock—one user has access to the edit form at the time. The second user basically has to wait for the first to finish. I understand this can be done using Ajax sending XMLHttpRequests to maintain a ‘lock’ database. The php world, lacking state, seems to prefer optimistic locking. If I understand it correctly it works like this: both users get to access the data and they each record a ‘before changes’ version of the data. Before saving their changes, the data is once again retrieved and compared the ‘before changes’ version. If the two versions are identical then the users changes are written. If they are different; the user is shown what has changed since he/she started editing and some mechanism is added to resolve the differences—or the user is shown a ‘Sorry, try again’ message. I’m interested in any experience people here have had with implementing both pessimistic and optimistic locking. If there are any libraries, tools, or ‘how-to’s available I’m appreciate a link. Thanks

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