Search Results

Search found 15376 results on 616 pages for 'once'.

Page 476/616 | < Previous Page | 472 473 474 475 476 477 478 479 480 481 482 483  | Next Page >

  • How best to calculate derived currency rate conversions using C#/LINQ?

    - by chillitom
    class FxRate { string Base { get; set; } string Target { get; set; } double Rate { get; set; } } private IList<FxRate> rates = new List<FxRate> { new FxRate {Base = "EUR", Target = "USD", Rate = 1.3668}, new FxRate {Base = "GBP", Target = "USD", Rate = 1.5039}, new FxRate {Base = "USD", Target = "CHF", Rate = 1.0694}, new FxRate {Base = "CHF", Target = "SEK", Rate = 8.12} // ... }; Given a large yet incomplete list of exchange rates where all currencies appear at least once (either as a target or base currency): What algorithm would I use to be able to derive rates for exchanges that aren't directly listed? I'm looking for a general purpose algorithm of the form: public double Rate(string baseCode, string targetCode, double currency) { return ... } In the example above a derived rate would be GBP-CHF or EUR-SEK (which would require using the conversions for EUR-USD, USD-CHF, CHF-SEK) Whilst I know how to do the conversions by hand I'm looking for a tidy way (perhaps using LINQ) to perform these derived conversions perhaps involving multiple currency hops, what's the nicest way to go about this?

    Read the article

  • wmd editor, why does it keep showing html instead of just going straight to markup

    - by Ke
    hi, im wondering how wmd is supposed to work, when i type in the textarea the text doesnt have html, but once the text is stored in db it turns to html. wmd also shows all this html when reloading the content? is it supposed to work like this? Do I have to sanitize the text before its put into the db? if so how? I thought wmd doesnt deal with html? except in code blocks. Also there are p tags being added Using the beneath html it gets added directly. I guess this could cause xss attacks? - (1) <a onmouseover="alert(1)" href="#">read this!</a> - (2) <p <script>alert(1)</script>hello - (3) </td <script>alert(1)</script>hello I wonder how is wmd supposed to work? I thought it was supposed to enter everything in its own mark up, store its on mark up and retrieve it etc. instead of storing plain html Chees Ke

    Read the article

  • Remove redundant SQL code

    - by Dave Jarvis
    Code The following code calculates the slope and intercept for a linear regression against a slathering of data. It then applies the equation y = mx + b against the same result set to calculate the value of the regression line for each row. Can the two separate sub-selects be joined so that the data and its slope/intercept are calculated without executing the data gathering part of the query twice? SELECT AVG(D.AMOUNT) as AMOUNT, Y.YEAR * ymxb.SLOPE + ymxb.INTERCEPT as REGRESSION_LINE, Y.YEAR as YEAR, MAKEDATE(Y.YEAR,1) as AMOUNT_DATE FROM CITY C, STATION S, YEAR_REF Y, MONTH_REF M, DAILY D, (SELECT ((avg(t.AMOUNT * t.YEAR)) - avg(t.AMOUNT) * avg(t.YEAR)) / (stddev( t.AMOUNT ) * stddev( t.YEAR )) as CORRELATION, ((sum(t.YEAR) * sum(t.AMOUNT)) - (count(1) * sum(t.YEAR * t.AMOUNT))) / (power(sum(t.YEAR), 2) - count(1) * sum(power(t.YEAR, 2))) as SLOPE, ((sum( t.YEAR ) * sum( t.YEAR * t.AMOUNT )) - (sum( t.AMOUNT ) * sum(power(t.YEAR, 2)))) / (power(sum(t.YEAR), 2) - count(1) * sum(power(t.YEAR, 2))) as INTERCEPT FROM ( SELECT AVG(D.AMOUNT) as AMOUNT, Y.YEAR as YEAR, MAKEDATE(Y.YEAR,1) as AMOUNT_DATE FROM CITY C, STATION S, YEAR_REF Y, MONTH_REF M, DAILY D WHERE $X{ IN, C.ID, CityCode } AND SQRT( POW( C.LATITUDE - S.LATITUDE, 2 ) + POW( C.LONGITUDE - S.LONGITUDE, 2 ) ) < $P{Radius} AND S.STATION_DISTRICT_ID = Y.STATION_DISTRICT_ID AND Y.YEAR BETWEEN 1900 AND 2009 AND M.YEAR_REF_ID = Y.ID AND M.CATEGORY_ID = $P{CategoryCode} AND M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' GROUP BY Y.YEAR ) t ) ymxb WHERE $X{ IN, C.ID, CityCode } AND SQRT( POW( C.LATITUDE - S.LATITUDE, 2 ) + POW( C.LONGITUDE - S.LONGITUDE, 2 ) ) < $P{Radius} AND S.STATION_DISTRICT_ID = Y.STATION_DISTRICT_ID AND Y.YEAR BETWEEN 1900 AND 2009 AND M.YEAR_REF_ID = Y.ID AND M.CATEGORY_ID = $P{CategoryCode} AND M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' GROUP BY Y.YEAR Question How do I execute the duplicate bits only once per query, instead of twice? The duplicate bit is the WHERE clause: $X{ IN, C.ID, CityCode } AND SQRT( POW( C.LATITUDE - S.LATITUDE, 2 ) + POW( C.LONGITUDE - S.LONGITUDE, 2 ) ) < $P{Radius} AND S.STATION_DISTRICT_ID = Y.STATION_DISTRICT_ID AND Y.YEAR BETWEEN 1900 AND 2009 AND M.YEAR_REF_ID = Y.ID AND M.CATEGORY_ID = $P{CategoryCode} AND M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' Related http://stackoverflow.com/questions/1595659/how-to-eliminate-duplicate-calculation-in-sql Thank you!

    Read the article

  • FF extension: saving a value in preferences and retrieving in the js file

    - by encryptor
    I am making an extension which should take a link as the user input only once. Then the entire extension keeps using that link on various functions in the JS file. When the user changes it, the value accessed by the js file also changes accordingly. I am using the following but it does not work for me var pref_manager = Components.classes["@mozilla.org/preferencesservice;1"].getService(Components.interfaces.nsIPrefService) function setInstance(){ if (pref_manager.prefHasUserValue("myvar")) { instance = pref_manager.getString("myvar"); alert(instance); } if(instance == null){ instance = prompt("Please enter webcenter host and port"); // Setting the value pref_manager.setString("myvar", instance); } } instance is the global variable in which i take the user input. The alert (instance) does not show up, which means there is some problem by the way i am saving the pref or extracting it. Can someone please help me with this. I have never worked with preferences before. so even if there are minor problems i might not be able to figure out.

    Read the article

  • What database systems should an startup company consider?

    - by Am
    Right now I'm developing the prototype of a web application that aggregates large number of text entries from a large number of users. This data must be frequently displayed back and often updated. At the moment I store the content inside a MySQL database and use NHibernate ORM layer to interact with the DB. I've got a table defined for users, roles, submissions, tags, notifications and etc. I like this solution because it works well and my code looks nice and sane, but I'm also worried about how MySQL will perform once the size of our database reaches a significant number. I feel that it may struggle performing join operations fast enough. This has made me think about non-relational database system such as MongoDB, CouchDB, Cassandra or Hadoop. Unfortunately I have no experience with either. I've read some good reviews on MongoDB and it looks interesting. I'm happy to spend the time and learn if one turns out to be the way to go. I'd much appreciate any one offering points or issues to consider when going with none relational dbms?

    Read the article

  • Why are my connections not closed even if I explicitly dispose of the DataContext?

    - by Chris Simpson
    I encapsulate my linq to sql calls in a repository class which is instantiated in the constructor of my overloaded controller. The constructor of my repository class creates the data context so that for the life of the page load, only one data context is used. In my destructor of the repository class I explicitly call the dispose of the DataContext though I do not believe this is necessary. Using performance monitor, if I watch my User Connections count and repeatedly load a page, the number increases once per page load. Connections do not get closed or reused (for about 20 minutes). I tried putting Pooling=false in my config to see if this had any effect but it did not. In any case with pooling I wouldn't expect a new connection for every load, I would expect it to reuse connections. I've tried putting a break point in the destructor to make sure the dispose is being hit and sure enough it is. So what's happening? Some code to illustrate what I said above: The controller: public class MyController : Controller { protected MyRepository rep; public MyController () { rep = new MyRepository(); } } The repository: public class MyRepository { protected MyDataContext dc; public MyRepository() { dc = getDC(); } ~MyRepository() { if (dc != null) { //if (dc.Connection.State != System.Data.ConnectionState.Closed) //{ // dc.Connection.Close(); //} dc.Dispose(); } } // etc } Note: I add a number of hints and context information to the DC for auditing purposes. This is essentially why I want one connection per page load

    Read the article

  • How should I progressively enhance this content with JavaScript?

    - by Sean Dunwoody
    The background to this problem is that I'm doing a computing project which involves Some drop down boxes for input, and a text input where the user can input a date. I've used YUI to enhance the form, so the calendar input uses the YUI calendar widget and the drop down list is converted into a horizontal list of inputs where the user only has to click once to select any input as opposed to two clicks with the drop down box (hope that makes sense, not sure how to explain it clearly) The problem is, that in the design section of my project I stated that I would follow the progressive enhancement principles. I am struggling however to ensure that users without JavaScript are able to view the drop down box / text input on said page. This is not because I do not necessarily know how, but the two methods I've tried seem unsatisfactory. Method 1 - I tried using YUI to hide the text box and drop down list, this seemed like the ideal solution however there was quite a noticeable lag when loading the page (especially for the first time), the text box and drop down list where visibile for at least a second. I included the script for this just before the end of the body tag, is there any way that I can run it onload with YUI? Would that help? Method 2 - Use the noscript tag . . . however I am loathed to do this as while it would be a simple solution, I have read various bad things about the noscript tag. Is there a way of making mehtod one work? Or is there a better way of doing this that I am yet to encounter?

    Read the article

  • Combining the jquery Calendar picker with the jquery validation and getting them to play nice?

    - by MBonig
    I'm just starting to get into jquery/javascript programming so this may be a beginner question but I sure can't seem to find anything about it. I have a text field on a form. I've used the JQuery UI Calendar picker to make data entry better. I've also added jquery validation to ensure that if the user enters the date by hand that it's still valid. Here is the html: <input class="datepicker" id="Log_ServiceStartTime_date" name="Log_ServiceStartTime_date" type="text" value="3/16/2010"></input> and javascript: $('form').validate(); $('#Log_ServiceStartTime_date').rules('add','required'); $('#Log_ServiceStartTime_date').rules('add','date'); the problem I'm having is this: If a user puts in a bad date, or no date at all, the validation correctly kicks in and the error description displays. However, if the user clicks on the textbox to bring up the calendar picker and selects a date, the date fills into the field but the validation does not go away. If the user clicks into the textbox and then back out, the validation correctly goes away. How can I get the calendar picker to kick off the validation routine once a date is selected? thanks

    Read the article

  • advanced winform framework

    - by alfredo dobrekk
    Hi, i m starting a new project that would basically take input from user and save them to database among about 30 screens, and i would like to find a framework that will allow the maximum number of these features out of the box : .net c#. windows form. unit testing continuous integration screens with lists, combo boxes, text boxes, add, delete, save, cancel that are easy to update when you add a property to your classes or a field to your database. auto completion on controls to help user find its way use of an orm like nhibernate easy multithreading and display of wait screens for user easy undo redo tabbed child windows search forms ability to grant access to some functionnalities according to user profiles mvp/mvvm or whatever design patterns either some code generation from database to c# classe or generation of database schema from c# classes some kind of database versioning / upgrade to easily update database when i release patches to application once in production code metrics analysis some code generator i can use against my entities that would generate some rough form i can rearrange after code documentation generator ... Any ideas ? I know its lot but i really would like to use existing code to build upon so i can focus on business rules. Do u have any suggestion to add to the list before starting ? What open source tools would u use to achieve these ?

    Read the article

  • BCrypt says long, similar passwords are equivalent - problem with me, the gem, or the field of crypt

    - by PreciousBodilyFluids
    I've been experimenting with BCrypt, and found the following. If it matters, I'm running ruby 1.9.2dev (2010-04-30 trunk 27557) [i686-linux] require 'bcrypt' # bcrypt-ruby gem, version 2.1.2 @long_string_1 = 'f287ed6548e91475d06688b481ae8612fa060b2d402fdde8f79b7d0181d6a27d8feede46b833ecd9633b10824259ebac13b077efb7c24563fce0000670834215' @long_string_2 = 'f6ebeea9b99bcae4340670360674482773a12fd5ef5e94c7db0a42800813d2587063b70660294736fded10217d80ce7d3b27c568a1237e2ca1fecbf40be5eab8' def salted(string) @long_string_1 + string + @long_string_2 end encrypted_password = BCrypt::Password.create(salted('password'), :cost => 10) puts encrypted_password #=> $2a$10$kNMF/ku6VEAfLFEZKJ.ZC.zcMYUzvOQ6Dzi6ZX1UIVPUh5zr53yEu password = BCrypt::Password.new(encrypted_password) puts password.is_password?(salted('password')) #=> true puts password.is_password?(salted('passward')) #=> true puts password.is_password?(salted('75747373')) #=> true puts password.is_password?(salted('passwor')) #=> false At first I thought that once the passwords got to a certain length, the dissimilarities would just be lost in all the hashing, and only if they were very dissimilar (i.e. a different length) would they be recognized as different. That didn't seem very plausible to me, from what I know of hash functions, but I didn't see a better explanation. Then, I tried shortening each of the long_strings to see where BCrypt would start being able to tell them apart, and I found that if I shortened each of the long strings to 100 characters or so, the final attempt ('passwor') would start returning true as well. So now I don't know what to think. What's the explanation for this?

    Read the article

  • Neural Networks or Human-computer interaction

    - by Shahin
    I will be entering my third year of university in my next academic year, once I've finished my placement year as a web developer, and I would like to hear some opinions on the two modules in the Title. I'm interested in both, however I want to pick one that will be relevant to my career and that I can apply to systems I develop. I'm doing an Internet Computing degree, it covers web development, networking, database work and programming. Though I have had myself set on becoming a web developer I'm not so sure about that any more so am trying not to limit myself to that area of development. I know HCI would help me as a web developer, but do you think it's worth it? Do you think Neural Network knowledge could help me realistically in a system I write in the future? Thanks. EDIT: Hi guys, I thought it would be useful to follow-up with what I decided to do and how it's worked out. I picked Artificial Neural Networks over HCI, and I've really enjoyed it. Having a peek into cognitive science and machine learning has ignited my interest for the subject area, and I will be hoping to take on a postgraduate project a few years from now when I can afford it. I have got a job which I am starting after my final exams (which are in a few days) and I was indeed asked if I had done a module in HCI or similar. It didn't seem to matter, as it isn't a front-end developer position! I would recommend taking the module if you have it as an option, as well as any module consisting of biological computation, it will open up more doors should you want to go onto postgraduate research in the future. Thanks again, Shahin

    Read the article

  • Shortest acyclic path on directed cyclic graph with negative weights/cycles

    - by Janathan
    I have a directed graph which has cycles. All edges are weighted, and the weights can be negative. There can be negative cycles. I want to find a path from s to t, which minimizes the total weight on the path. Sure, it can go to negative infinity when negative cycles exist. But what if I disallow cycles in the path (not in the original graph)? That is, once the path leaves a node, it can not enter the node again. This surely avoids the negative infinity problem, but surprisingly no known algorithm is found by a search on Google. The closest is Floyd–Warshall algorithm, but it does not allow negative cycles. Thanks a lot in advance. Edit: I may have generalized my original problem too much. Indeed, I am given a cyclic directed graph with nonnegative edge weights. But in addition, each node has a positive reward too. I want to find a simple path which minimizes (sum of edge weights on the path) - (sum of node rewards covered by the path). This can be surely converted to the question that I posted, but some structure is lost. And some hint from submodular analysis suggests this motivating problem is not NP-hard. Thanks a lot

    Read the article

  • Newb Question: scanf() in C

    - by riemannliness
    So I started learning C today, and as an exercise i was told to write a program that asks the user for numbers until they type a 0, then adds the even ones and the odd ones together. Here is is (don't laugh at my bad style): #include <stdio.h>; int main() { int esum = 0, osum = 0; int n, mod; puts("Please enter some numbers, 0 to terminate:"); scanf("%d", &n); while (n != 0) { mod = n % 2; switch(mod) { case 0: esum += n; break; case 1: osum += n; } scanf("%d", &n); } printf("The sum of evens:%d,\t The sum of odds:%d", esum, osum); return 0; } My question concerns the mechanics of the scanf() function. It seems that when you enter several numbers at once separated by spaces (eg. 1 22 34 2 8), the scanf() function somehow remembers each distinct numbers in the line, and steps through the while loop for each one respectively. Why/how does this happen? Example interaction within command prompt: - Please enter some numbers, 0 to terminate: 42 8 77 23 11 (enter) 0 (enter) - The sum of evens:50, The sum of odds:111 I'm running the program through the command prompt, it's compiled for win32 platforms with visual studio.

    Read the article

  • Style row banding and selection in tr:table using CSS

    - by Alex Larzelere
    I've got a tr:table that I need to style using CSS. All the normal style functions of a table are working, but row banding and row selection aren't coming up. When I view the rendered source, I'm not seeing a difference in the rows for an id or class to grab on to, and the official documentation doesn't have any attributes for declaring a style class for either. Is this possible and if so what do I need to do to get my CSS to grab onto it? <tr:table id="myTable" value="#{tableValues}" rowBandingInterval="1"> <tr:column> ##Stuff## </tr:column> <tr:column> ##Stuff## </tr:column> <tr:column> ##Stuff## </tr:column> </tr:table> Edit Let me try to clairfy what's happening. First, using the declaration above tells jsf to generate a table, and the attribute rowBandingInterval tells it to give each row alternating colors (If it was set to 2, then it would do 2 rows one color, 2 rows another, 2 rows the original, etc.) Once the page gets rendered into standard html, trinidad (and jsf) apply their own classes and IDs to the html. My normal procedure is to look at the rendered html, find the class that it is appling and add CSS rules for it. However in this case, no additional styles are added (nothing in the rendered html denotes one row to be different from another). So the question is, how do I tell trinidad to either give alternating rows and the user selected row different classes/IDs for me to grab on to with CSS?

    Read the article

  • Static Property losing its value intermittently ?

    - by joedotnot
    Is there something fundamentally wrong with the following design, or can anyone see why would the static properties sometimes loose their values ? I have a class library project containing a class AppConfig; this class is consumed by a Webforms project. The skeleton of AppConfig class is as follows: Public Class AppConfig Implements IConfigurationSectionHandler Private Const C_KEY1 As String = "WebConfig.Key.1" Private Const C_KEY2 As String = "WebConfig.Key.2" Private Const C_KEY1_DEFAULT_VALUE as string = "Key1defaultVal" Private Const C_KEY2_DEFAULT_VALUE as string = "Key2defaultVal" Private Shared m_field1 As String Private Shared m_field2 As String Public Shared ReadOnly Property ConfigValue1() As String Get ConfigValue1= m_field1 End Get End Property Public Shared ReadOnly Property ConfigValue2() As String Get ConfigValue2 = m_field2 End Get End Property Public Shared Sub OnApplicationStart() m_field1 = ReadSetting(C_KEY1, C_KEY1_DEFAULT_VALUE) m_field2 = ReadSetting(C_KEY2, C_KEY1_DEFAULT_VALUE) End Sub Public Overloads Shared Function ReadSetting(ByVal key As String, ByVal defaultValue As String) As String Try Dim setting As String = System.Configuration.ConfigurationManager.AppSettings(key) If setting Is Nothing Then ReadSetting = defaultValue Else ReadSetting = setting End If Catch ReadSetting = defaultValue End Try End Function Public Function Create(ByVal parent As Object, ByVal configContext As Object, ByVal section As System.Xml.XmlNode) As Object Implements System.Configuration.IConfigurationSectionHandler.Create Dim objSettings As NameValueCollection Dim objHandler As NameValueSectionHandler objHandler = New NameValueSectionHandler objSettings = CType(objHandler.Create(parent, configContext, section), NameValueCollection) Return 1 End Function End Class The Static Properties get set once on application start, from the Application_Start event of the Global.asax Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs) //Fires when the application is started AppConfig.OnApplicationStart() End Sub Thereafter, whenever we want to access a value in the Web.Config from anywhere, e.g. aspx page code-behind or another class or referenced class, we simply call the static property. For example, AppConfig.ConfigValue1() AppConfig.ConfigValue2() This is turn returns the value stored in the static backing fields m_field1, m_field2 Problem is sometimes these values are empty string, when clearly the Web.Config entry has values. Is there something fundamentally wrong with the above design, or is it reasonable to expect the static properties would keep their value for the life of the Application session?

    Read the article

  • Making it look like the computer is thinking in TicTacToe game

    - by rage
    here is a slice of code that i've written in VB.net Private Sub L00_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles L00.Click, L01.Click, L02.Click, L03.Click, L10.Click, L11.Click, L12.Click, L13.Click, L20.Click, L21.Click, L22.Click, L23.Click, L30.Click, L31.Click, L32.Click, L33.Click Dim ticTac As Label = CType(sender, Label) Dim strRow As String Dim strCol As String 'Once a move is made, do not allow user to change whether player/computer goes first, because it doesn't make sense to do so since the game has already started. ComputerFirstStripMenuItem.Enabled = False PlayerFirstToolStripMenuItem.Enabled = False 'Check to make sure clicked tile is a valid tile i.e and empty tile. If (ticTac.Text = String.Empty) Then ticTac.Text = "X" ticTac.ForeColor = ColorDialog1.Color ticTac.Tag = 1 'After the player has made his move it becomes the computers turn. computerTurn(sender, e) Else MessageBox.Show("Please pick an empty tile to make next move", "Invalid Move") End If End Sub Private Sub computerTurn(ByVal sender As System.Object, ByVal e As System.EventArgs) Call Randomize() row = Int(4 * Rnd()) col = Int(4 * Rnd()) 'Check to make sure clicked tile is a valid tile i.e and empty tile. If Not ticTacArray(row, col).Tag = 1 And Not ticTacArray(row, col).Tag = 4 Then ticTacArray(row, col).Text = "O" ticTacArray(row, col).ForeColor = ColorDialog2.Color ticTacArray(row, col).Tag = 4 checkIfGameOver(sender, e) Else 'Some good ole pseudo-recursion(doesn't require a base case(s)). computerTurn(sender, e) End If End Sub Everything works smoothly, except i'm trying to make it seem like the computer has to "think" before making its move. So what i've tried to do is place a System.Threading.Sleep() call in different places in the code above. The problem is that instead of making the computer look like its thinking, the program waits and then puts the X and O together at the same time. Can someone help me make it so that the program puts an X wherever i click AND THEN wait before it places an O? Edit: in case any of you are wondering, i realize that the computers AI is ridiculously dumb, but its just to mess around right now. Later on i will implement a serious AI..hopefully.

    Read the article

  • LoginControl not working correctly with Firefox, requires double login attempt.

    - by CmdrTallen
    Any idea why LoginControl requires users authenticate twice with FireFox but works correctly (once) with IE? I am using a custom MembershipProvider and RoleProvider, if that matters. Authentication portion of my web.config; <authentication mode="Forms"> <forms timeout="50000000" protection="All" requireSSL="false" slidingExpiration="true" cookieless="AutoDetect" domain="" enableCrossAppRedirects="true"> <credentials passwordFormat="SHA1" /> </forms> </authentication> Membership section; <membership defaultProvider="CustomMembershipProvider"> <providers> <add name="CustomMembershipProvider" type="CustomCrateMembershipProvider" connectionString="" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="true" applicationName="/" requiresUniqueEmail="true" passwordFormat="Hashed" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="5" minRequiredNonalphanumericCharacters="1" passwordAttemptWindow="10" passwordStrengthRegularExpression=""/> </providers> </membership> <roleManager defaultProvider="CustomRoleProvider" enabled="true"> <providers> <add name="CustomRoleProvider" type="CustomRoleProvider"/> </providers> </roleManager> Only code behind related to login; protected void OnLoggedIn(object sender, EventArgs e) { } protected void OnLoggingOut(object sender, EventArgs e) { }

    Read the article

  • Creating a tar file with checksums included

    - by wazoox
    Here's my problem : I need to archive to tar files a lot ( up to 60 TB) of big files (usually 30 to 40 GB each). I would like to make checksums ( md5, sha1, whatever) of these files before archiving; however not reading every file twice (once for checksumming, twice for tar'ing) is more or less a necessity to achieve a very high archiving performance (LTO-4 wants 120 MB/s sustained, and the backup window is limited). So I'd need some way to read a file, feeding a checksumming tool on one side, and building a tar to tape on the other side, something along : tar cf - files | tee tarfile.tar | md5sum - Except that I don't want the checksum of the whole archive (this sample shell code does just this) but a checksum for each individual file in the archive. I've studied GNU tar, Pax, Star options. I've looked at the source from Archive::Tar. I see no obvious way to achieve this. It looks like I'll have to hand-build something in C or similar to achieve what I need. Perl/Python/etc simply won't cut it performance-wise, and the various tar programs miss the necessary "plugin architecture". Does anyone know of any existing solution to this before I start code-churning ?

    Read the article

  • A feeling that I'm not that good developer

    - by Karim
    Hi, Im having a strange feeling, but let me first introduce myself as a software developer. I started to program when I was still a kid, I had about 10 or 11 years. I really enjoy my work and never get bored from it. It's amazing how somebody could be paid for what he really likes to do and would be doing it anyway even for free. WHen I first started to program, I was feeling proud of what I was doing, each application I built was for me a success and after 2-3 year I had a feeling that I'm a coding guru. It was a nice feeling ;-) But the more I was in the field, the more types of software I started to develop I was starting to have a feeling that I'm completely wrong in that I'm guru. I felt that I'm not even a mediocre developer. Each new field I start to work on is giving me this feeling. Like when I once developed a device driver for a client, I saw how much I need to learn about device drivers. When I developed a video filter for an application, I saw how much do I still need to learn about DirectShow, Color Spaces, and all the theory behind that. The worst thing was when I started to learn algorithms. It was several years ago. I knew then the basic structures and algorithms like the sorting, some types of trees, some hashtables, strings etc.. and when I really wanted to learn a group of structures I learned about 5-6 new types and saw that in fact even this small group has several hundred subtypes of structures. It's depressing how little time people have in their lives to learn all this stuff. I'm now a software developer with about 10 years of experience and I still feel that I'm not a proficient developer when I think about things that others do in the industry. Is this normal what I'm experiencing or is it a sign of a destructive excessive ambition? Thanks in advance for any comments.

    Read the article

  • How to deserialize implementation classes in OSGi

    - by Daniel Schneller
    In an eRCP OSGi based application the user can push a button and go to a lock screen similar to that of Windows or Mac OS X. When this happens, the current state of the application is serialized to a file and control is handed over to the lock screen. In this mobile application memory is very tight, so we need to get rid of the original view/controller when the lock screen comes up. This works fine and we end up with a binary serialized file. Once the user logs back in, the file is read in again and the original state of the application restored. This works fine as well, except when the controller that was serialized contained a reference to an object which comes from a different bundle. In my concrete case the original controller (from bundle A) can call a web service and gets a result back. Nothing fancy, just some Strings and Numbers in a simple value holder class. However the controller only sees this as a Result interface; the actual runtime object (ResultImpl) is defined and created in a different bundle (bundle B, the webservice client implementation) and returned via a service call. When the deserialization now tries to thaw the controller from the file, it throws a ClassNotFound exception, complaining about not being able to deserialize the result object, because deserialization is called from bundle A, which cannot see the ResultImpl class from bundle B. Any ideas on how to work around that? The only thing I could come up with is to clone all the individual values into another object, defined in the controller's bundle, but this seems like quite a hassle.

    Read the article

  • PHP header redirection does not reload <iframe> in IE

    - by Marco Demaio
    When displaying data from DB usually I'm in this situation I'm in page A.php that shows data from DB, user performs some action (like edit/delete etc) and page B.php is loaded to perform the action, once page B performed the action, it redirects browser to page A, page A is auto reloaded during step (3) therefor it shows an updated situation of the data In order to make page B to redirect to page A i use a simple PHP header("Location: " . "A.php", TRUE, 302); This works well in all situations, except when pages A.php is displaied into an <iframe>: in such a case it does not reload (step 4 does not get done). This seems to happen only in IE7 (don't know about IE8), it works perfectly on FF/Safari. And only when using an <iframe>, if page A.php is not in <iframe> it gest refreshed also in IE7. In order to solve this I simply added a couple of headers in page A.php to set it to not be cached: header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1 header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past But I was curious if you might have experienced the same issue too in the past, and if you good give me some advice about this?

    Read the article

  • .Net long-running scheduled code execution

    - by Prof Plum
    I am working on a couple of projects now where I really wish there was some sort of component that I could specify a time and date, and then execute some sort of method. DateTime date = new DateTime(x,x,x,x,x,x); ScheduledMethod sMethod = new ScheduledMethod(date, [method delegate of some sort]); \\at the specified date, sMethod invokes [method delegate of some sort] I know that I can do this with Windows Workflow Foundation as a long running process, which is good for certain things, but are there any alternatives? Workflow is not exactly straight forward with the details, and it would be nice to be able to deploy something more simple for light weight tasks. An example would be a method that checks a network folder once a day and deletes any files that are more than 30 days old. I realize that this may be pie in the sky dreaming, but this would be extremely useful for automating certain mundane maintinence tasks (scheduled sql operations, file system cleansing, routine email sending, etc.). It does not necessarily have to be .Net, but that is where I am coming from. Any ideas?

    Read the article

  • Best way to dynamically get column names from oracle tables

    - by MNC
    Hi, We are using an extractor application that will export data from the database to csv files. Based on some condition variable it extracts data from different tables, and for some conditions we have to use UNION ALL as the data has to be extracted from more than one table. So to satisfy the UNION ALL condition we are using nulls to match the number of columns. Right now all the queries in the system are pre-built based on the condition variable. The problem is whenever there is change in the table projection (i.e new column added, existing column modified, column dropped) we have to manually change the code in the application. Can you please give some suggestions how to extract the column names dynamically so that any changes in the table structure do not require change in the code? My concern is the condition that decides which table to query. The variable condition is like if the condition is A, then load from TableX if the condition is B then load from TableA and TableY. We must know from which table we need to get data. Once we know the table it is straightforward to query the column names from the data dictionary. But there is one more condition, which is that some columns need to be excluded, and these columns are different for each table. I am trying to solve the problem only for dynamically generating the list columns. But my manager told me to make solution on the conceptual level rather than just fixing. This is a very big system with providers and consumers constantly loading and consuming data. So he wanted solution that can be general. So what is the best way for storing condition, tablename, excluded columns? One way is storing in database. Are there any other ways? If yes what is the best? As I have to give at least a couple of ideas before finalizing. Thanks,

    Read the article

  • IIS Flash Remoting Request Limit introduced with Coldfusion 9

    - by ciaranarcher
    Hi all We've just been our Coldfusion servers from Enterprise CF 8.01 to CF 9. They are running Win 2008. We ran into trouble on those servers that provide the Flash remoting back-end for a Flex application we provide. Once the CF 9 upgrade was complete we noticed that during busy times when many Flex clients were connecting, we appeared to have a hard limit of 25 Flash Remoting Requests running, despite having much higher limits (in fact 150) set in CF Admin. Initially we thought that this was an issue with the fact that Blaze DS was now bundled with CF 9 (rather than a separate install) so we decided to roll-back the CF 9 installation. This, unfortunately, didn't work and we were still stuck with out hard limit of 25 Flash Remoting requests. Then looking at IIS we noticed that the CF9 ISAPI filter was still installed (after we had ran the Web Service Configuration part of the install). That was removed and the CF 8 one was re-run and all of a sudden the Flash Remoting hard limit disappeared. So it seems that it might have had something to do with the wsconfig of CF 9 (C:\ColdFusion9\runtime\bin\wsconfig.exe) Has anyone else had this problem, or does anybody know of where these hard limits are configured in IIS? Any and all help appreciated!

    Read the article

  • iPhone: Does it ever make sense for an object to retain its delegate?

    - by randombits
    According to the rules of memory management in a non garbage collected world, one is not supposed to retain a the calling object in a delegate. Scenario goes like this: I have a class that inherits from UITableViewController and contains a search bar. I run expensive search operations in a secondary thread. This is all done with an NSOperationQueue and subclasses NSOperation instances. I pass the controller as a delegate that adheres to a callback protocol into the NSOperation. There are edge cases when the application crashes because once an item is selected from the UITableViewController, I dismiss it and thus its retain count goes to 0 and dealloc gets invoked on it. The delegate didn't get to send its message in time as the results are being passed at about the same time the dealloc happens. Should I design this differently? Should I call retain on my controller from the delegate to ensure it exists until the NSOperation itself is dealloc'd? Will this cause a memory leak? Right now if I put a retain on the controller, the crashes goes away. I don't want to leak memory though and need to understand if there are cases where retaining the delegate makes sense. Just to recap. UITableViewController creates an NSOperationQueue and NSOperation that gets embedded into the queue. The UITableViewController passes itself as a delegate to NSOperation. NSOperation calls a method on UITableViewController when it's ready. If I retain the UITableViewController, I guarantee it's there, but I'm not sure if I'm leaking memory. If I only use an assign property, edge cases occur where the UITableViewController gets dealloc'd and objc_msgSend() gets called on an object that doesn't exist in memory and a crash is imminent.

    Read the article

< Previous Page | 472 473 474 475 476 477 478 479 480 481 482 483  | Next Page >