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  • What is the return type of my linq query?

    - by Ulhas Tuscano
    I have two tables A & B. I can fire Linq queries & get required data for individual tables. As i know what each of the tables will return as shown in example. But, when i join both the tables i m not aware of the return type of the Linq query. This problem can be solved by creating a class which will hold ID,Name and Address properties inside it. but,everytime before writing a join query depending on the return type i will have to create a class which is not a convinient way Is there any other mathod available to achieve this private IList<A> GetA() { var query = from a in objA select a; return query.ToList(); } private IList<B> GetB() { var query = from b in objB select b; return query.ToList(); } private IList<**returnType**?> GetJoinAAndB() { var query = from a in objA join b in objB on a.ID equals b.AID select new { a.ID, a.Name, b.Address }; return query.ToList(); }

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  • Why does PDO print my password when the connection fails?

    - by Joe Hopfgartner
    I have a simple website where I establish a connection to a Mysql server using PDO. $dbh = new PDO('mysql:host=localhost;dbname=DB;port=3306', 'USER', 'SECRET',array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8")); I had some traffic on my site and the servers connection limit was reached, and the website throw this error, with my PLAIN password in it! Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[08004] [1040] Too many connections' in /home/premiumize-me/html/index.php:64 Stack trace: #0 /home/premiumize-me/html/index.php(64): PDO-__construct('mysql:host=loca...', 'USER', 'SECRET', Array) #1 {main} thrown in /home/premiumize-me/html/index.php on line 64 Ironically I switched to PDO for security reasons, this really shocked me. Because this exact error is something you can provoke very easily on most sites using simple http flooding. I now wrapped my conenction into a try/catch clause, but still. I think this is catastrophic! So I am new to PDO and my questino is: What do I have to consider to be safe! How to I establish a connection in a secure way? Are there other known security holes like this one that I have to be aware of?

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  • SQL developer here -- Nesting with select * finicky in Oracle 10g?

    - by John Sullivan
    I am writing a simple diagnostic query I will execute in my Oracle 10g scratchpad. I am trying to do this as part of a step to build the query. In the SQL Scratchpad for Oracle 10g Enterprise Manager Console, this statement runs fine. SELECT * FROM v$session sess, v$sql sql WHERE sql.sql_id(+) = sess.sql_id and sql.sql_text <> ' ' If I try to wrap that up in Select * from () tb2 I get an error, "ORA-00918: Column Ambiguously Defined". I didn't think that could ever happen with this kind of statement so I am a bit confused. select * from (SELECT * FROM v$session sess, v$sql sql WHERE sql.sql_id(+) = sess.sql_id and sql.sql_text <> ' ') tb2 You should always be able to select * from the result set of another select * statement using this structure as far as I'm aware... right? Is Oracle/10g/the scratchpad trying to force me to accept a certain syntactic structure to prevent excessive nesting? Is this a bug in scratchpad or something about how oracle works?

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  • HIbernate 3.5.1 - can I just drop in EHCache 2.0.1?

    - by caerphilly
    I'm using Hibernate 3.5.1, which comes with EHCache 1.5 bundled. If I want to use the latest EHCache release (2.0.1), is it just a matter of removing the ehcache-1.5.jar from my project, and replacing with ehcache-core-2.0.1.jar? Any issues to be aware of? Also - is a cache "region" in the Hibernate mapping file that same as a cache "name" in the ehcache configuration xml? What I want to do is define 2 named cache regions - one for read-only reference entities that won't change (lookup lists etc), and one for all other entities. So in ehcache I want to define two elements; <cache name="readonly"> ... </cache> <cache name="mutable"> ... </cache> And then in my Hibernate mapping files, I will specify the cache to be used for each entity: <hibernate-mapping> <class name="lookuplist"> <cache region="readonly" usage="read-only"/> <property> ... </property> </class> </hibernate-mapping> Will that work? Some of the documentation seems to imply that a separate region/cache gets created for each mapped class... Thanks.

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  • 32-bit JVM on 64-bit Windows crashes on launch with -Xmx1300m and plenty of free memory

    - by Konrad Garus
    I'm struggling with Java heap space settings. The default Java on Windows is the 32-bit client regardless of OS version (that's what Oracle recommends to all users). It appears to set max heap size to 256 MB by default, and that is too little for me. I use a custom launcher to start the application. I would like it to use more memory on computers with plenty RAM, and default to -Xmx512m on those with less RAM. As far as I'm aware, the only way is the static -Xmx setting (that has to be set on launch). I have a user who has 8 GB RAM, 64-bit Windows and 32-bit Java 7. Maximum memory visible to the JVM is 4G (as returned by querying OperatingSystemMXBean). I understand why, no issue. For some reason my application is unable to start for this user with -Xmx1300m, even though he has 2.3G free memory. He closed some applications (having 5G free memory), and still it would not launch. The error reported to me was: error occured during init of vm could not reserve enough space for object heap What's going on? Could it be that the 32-bit JVM is only able to address the "first" 4G of memory and has to have a 1300M block available within those first 4 gigabytes? How can I solve this problem, except for asking everyone to install 64-bit Java (what is unlikely to be acceptable)?

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  • C++ - Distributing different headers than development

    - by Ben
    I was curious about doing this in C++: Lets say I have a small library that I distribute to my users. I give my clients both the binary and the associated header files that they need. For example, lets assume the following header is used in development: #include <string> ClassA { public: bool setString(const std::string & str); private: std::string str; }; Now for my question. For deployment, is there anything fundamentally wrong with me giving a 'reduced' header to my clients? For example, could I strip off the private section and simply give them this: #include <string> ClassA { public: bool setString(const std::string & str); }; My gut instinct says "yes, this is possible, but there are gotchas", so that is why I am asking this question here. If this is possible and also safe, it looks like a great way to hide private variables, and thus even avoid forward declaration in some cases. I am aware that the symbols will still be there in the binary itself, and that this is just a visibility thing at the source code level. Thanks!

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  • WCF: get generic type object (e.g. MyObject<T>) from remote machine

    - by Aaron
    I have two applications that are communicating through WCF. On the server the following object exists: public class MyObject<T> { ... public Entry<T> GetValue() } Where Entry<T> is another object with T Data as a public property. T could be any number of types (string, double, etc) On the client I have ClientObject<T> that needs to get the value of Data from the server (same type). Since I'm using WCF, I have to define my ServiceContract as an interface, and I can't have ClientObject<T> call Entry<T> GetMyObjectValue (string Name) which calls GetValue on the correct MyObject<T> because my interface isn't aware of the type information. I've tried implementing separate GetValue functions (GetMyObjectValueDouble, GetMyObjectValueString) in the interface and then have ClientObject determine the correct one to call. However, Entry<T> val = (Entry<T>)GetMyObjectValueDouble(...); doesn't work because it's not sure about the type information. How can I go about getting a generic object over WCF with the correct type information? Let me know if there are other details I can provide. Thanks!

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  • C++ STL: How to iterate vector while requiring access to element and its index?

    - by Ashwin
    I frequently find myself requiring to iterate over STL vectors. While I am doing this I require access to both the vector element and its index. I used to do this as: typedef std::vector<Foo> FooVec; typedef FooVec::iterator FooVecIter; FooVec fooVec; int index = 0; for (FooVecIter i = fooVec.begin(); i != fooVec.end(); ++i, ++index) { Foo& foo = *i; if (foo.somethingIsTrue()) // True for most elements std::cout << index << ": " << foo << std::endl; } After discovering BOOST_FOREACH, I shortened this to: typedef std::vector<Foo> FooVec; FooVec fooVec; int index = -1; BOOST_FOREACH( Foo& foo, fooVec ) { ++index; if (foo.somethingIsTrue()) // True for most elements std::cout << index << ": " << foo << std::endl; } Is there a better or more elegant way to iterate over STL vectors when both reference to the vector element and its index is required? I am aware of the alternative: for (int i = 0; i < fooVec.size(); ++i) But I keep reading about how it is not a good practice to iterate over STL containers like this.

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  • Speed/expensive of SQLite query vs. List.contains() for "in-set" icon on list rows

    - by kpdvx
    An application I'm developing requires that the app main a local list of things, let's say books, in a local "library." Users can access their local library of books and search for books using a remote web service. The app will be aware of other users of the app through this web service, and users can browse other users' lists of books in their library. Each book is identified by a unique bookId (represented as an int). When viewing books returned through a search result or when viewing another user's book library, the individual list row cells need to visually represent if the book is in the user's local library or not. A user can have at most 5,000 books in the library, stored in SQLite on the device (and synchronized with the remote web service). My question is, to determine if the book shown in the list row is in the user's library, would it be better to directly ask SQLite (via SELECT COUNT(*)...) or to maintain, in-memory, a List or int[] array of some sort containing the unique bookIds. So, on each row display do I query SQLite or check if the List or int[] array contains the unique bookId? Because the user can have at most 5,000 books, each bookId occupies 4 bytes so at most this would use ~ 20kB. In thinking about this, and in typing this out, it seems obvious to me that it would be far better for performance if I maintained a list or int[] array of in-library bookIds vs. querying SQLite (the only caveat to maintaining an int[] array is that if books are added or removed I'll need to grow or shrink the array by hand, so with this option I'll most likely use an ArrayList or Vector, though I'm not sure of the additional memory overhead of using Integer objects as opposed to primitives). Opinions, thoughts, suggestions?

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  • LINQ to SQL: NOTing a prebuilt expression

    - by ck
    I'm building a library of functions for one of my core L2S classes, all of which return a bool to allow checking for certain situations. Example: Expression<Func<Account, bool>> IsSomethingX = a => a.AccountSupplementary != null && a.AccountSupplementary.SomethingXFlag != null && a.AccountSupplementary.SomethingXFlag.Value; Now to query where this is not true, I CAN'T do this: var myAccounts= context.Accounts .Where(!IsSomethingX); // does not compile However, using the syntax from the PredicateBuilder class, I've come up with this: public static IQueryable<T> WhereNot<T>(this IQueryable<T> items, Expression<Func<T, bool>> expr1) { var invokedExpr = Expression.Invoke(expr1, expr1.Parameters.Cast<Expression>()); return items.Where(Expression.Lambda<Func<T, bool>> (Expression.Not(invokedExpr), expr1.Parameters)); } var myAccounts= context.Accounts .WhereNot(IsSomethingX); // does compile which actually produces the correct SQL. Does this look like a good solution, and is there anything I need to be aware of that might cause me problems in future?

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  • Is this a safe PHP mail function?

    - by Eystein
    I've finally got this PHP email script working (didn't work on localhost…), but my concern is that it's not safe. So - is this safe for spamming and any other security pitfalls I'm not aware of? <?php $email = '[email protected]'; $subject = 'Notify about stuff'; $notify = $_REQUEST['email']; if (!preg_match("/\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/", $notify)) { echo "<h4>Your email address doesn't validate, please check that you typed it correct.</h4>"; echo "<a href='javascript:history.back(1);'>Back</a>"; } elseif(mail($email, $subject, $notify)) { echo "<h4>Thank you, you will be notified.</h4>"; } else { echo "<h4>Sorry, your email didn't get registered.</h4>"; } ?> Unrelated: is there a PHP function I can use instead of javascript:history.back(1) ?

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  • efficient thread-safe singleton in C++

    - by user168715
    The usual pattern for a singleton class is something like static Foo &getInst() { static Foo *inst = NULL; if(inst == NULL) inst = new Foo(...); return *inst; } However, it's my understanding that this solution is not thread-safe, since 1) Foo's constructor might be called more than once (which may or may not matter) and 2) inst may not be fully constructed before it is returned to a different thread. One solution is to wrap a mutex around the whole method, but then I'm paying for synchronization overhead long after I actually need it. An alternative is something like static Foo &getInst() { static Foo *inst = NULL; if(inst == NULL) { pthread_mutex_lock(&mutex); if(inst == NULL) inst = new Foo(...); pthread_mutex_unlock(&mutex); } return *inst; } Is this the right way to do it, or are there any pitfalls I should be aware of? For instance, are there any static initialization order problems that might occur, i.e. is inst always guaranteed to be NULL the first time getInst is called?

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  • Converting WAR to EAR and other Glassfish stories

    - by Random
    Hello! I am really new in this so I hopefully don't make any terrible mistake. I apologize before hand if I have. In my project I was using tomcat and deploying WAR files. But now some bosses wants to deploy EAR files. So there we go. I first downloaded Glassfish (don't know if it's the apropiate application server for a newbie like me), instaled it and all (I even deployed the hello.war in the autodeploy _< ). Then prepared an EAR file. From what I know, I just need to create an Enterprise Application Project in Eclipse and add to the module my war file. This changes the application.xml file automatically (thanks eclipse project!). So I exported it to an EAR file and uploaded it to the glassfish server. Wonders of wonders, it doesn't work. I also tried deploying the old WAR file in this new shiny glassfish but it goes on http-404 not found error. The glassfish seems to say that my project is not in ~/domains/domain1/docroot. By the way I am using windows and I am aware of some problems between glassfish and windows due to some updating open files or such. So I have to questions: First, Am I doing the EAR package correctly? Second, Do I need to do some especial configuration to the glassfish server to deploy EAR and WAR files? Thanks!

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  • escape exactly what in javascript

    - by Emin
    Hi all, Being a newbie in javascript I came to a situation where I need more information on escaping characters in a string. Basically I know that in order to escape " I need to replace it with \" but what I don't know is for which characters I need to escape a particular string for. Is there a list of these "characters to escape"? or is it any character that is not a-zA-Z0-9 ? In my situation, I don't have control over the content that is being displayed on my page. Users enter some text and save it. I then use a webservice to extract them from the database, build a json array of objects, then iterate the array when I need to display them. In this case, I have - naturally - no idea of what the text the user has entered and therefore for what characters I need to escape. I also use jQuery for this specific project (just in case it has a function I am not aware of, to do what I need) Providing examples would be appreciated but I also want to learn the theory and logic behind it. Hope someone can be of any help.

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  • Is it okay to rely on javascript for menu layout?

    - by Ryan
    I have a website template where I do not know the number of menu items or the size of the menu items that will be required. The js below works exactly the way I want it to, however this is the most js I've every written. Are there any disadvantages or potential problems with this method that I'm not aware of because I'm a js beginner? I'm currently manually setting the padding for each site. Thank you! var width_of_text = 0; var number_of_li = 0; // measure the width of each <li> and add it to the total with, increment li counter $('li').each(function() { width_of_text += $(this).width(); number_of_li++; }); // calculate the space between <li>'s so the space is equal var padding = Math.floor((900 - width_of_text)/(number_of_li - 1)); // add the padding the all but the first <li> $('li').each(function(index) { if (index !== 0) { $(this).css("padding-left", padding); } });

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  • Mulitple variable containing "for loop" is not working in my code...

    - by OM The Eternity
    Below is the code I am working with and the last for loop i am iterating is not working... I think i am doing something wrong using multiple variable in a for loop,also I m aware of the fact that it can be done. $updaterbk = "SELECT j1. * FROM jos_audittrail j1 LEFT OUTER JOIN jos_audittrail j2 ON ( j1.trackid != j2.trackid AND j1.field != j2.field AND j1.changedone < j2.changedone ) WHERE j1.operation = 'UPDATE' AND j2.id IS NULL "; $selectupdrbk = mysql_query($updaterbk); while($row1 = mysql_fetch_array($selectupdrbk)) { $updrbk[] = $row1; } foreach($updrbk as $upfield) { if(!in_array($upfield['field'],$exist)) { $exist[] = $upfield['field']; $existval[] = $upfield['oldvalue']; //echo $updqueryrbk = "UPDATE `".$upfield['table_name']."` SET "; } } print_r($existval); for($i=0;$j=0;$i<count($exist);$j<count($existval);$i++;$j++) { $updqueryrbk.= $exist[$i]['field']."=".$existval[$j]['oldvalue'].","; $updqueryrbk.="="; $updqueryrbk.= $existval[$j]['oldvalue']; $updqueryrbk.=","; }

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  • How to proxy calls to the instance of an object

    - by mr.b
    Edit: Changed question title from "Does C# allow method overloading, PHP style (__call)?" - figured out it doesn't have much to do with actual question. Also edited question text. What I want to accomplish is to proxy calls to a an instance of an object methods, so I could log calls to any of its methods. Right now, I have code similar to this: class ProxyClass { static logger; public AnotherClass inner { get; private set; } public ProxyClass() { inner = new AnotherClass(); } } class AnotherClass { public void A() {} public void B() {} public void C() {} // ... } // meanwhile, in happyCodeLandia... ProxyClass pc = new ProxyClass(); pc.inner.A(); // need to write log message like "method A called" pc.inner.B(); // need to write log message like "method B called" // ... So, how can I proxy calls to an object instance in extensible way? Method overloading would be most obvious solution (if it was supported in PHP way). By extensible, meaning that I don't have to modify ProxyClass whenever AnotherClass changes. In my case, AnotherClass can have any number of methods, so it wouldn't be appropriate to overload or wrap all methods to add logging. I am aware that this might not be the best approach for this kind of problem, so if anyone has idea what approach to use, shoot. Thanks!

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  • 2-column table with two foreign keys. Performance/design question.

    - by Emanuel
    Hello everyone! I recently ran into a quite complex problem and after looking around a lot I couldn't find a solution to it. I've found answers to my questions many times before on stackoverflow.com, so I decided to post here. So I'm making a user/group managment system for a web-based project, and I'm storing all related data into a postgreSQL database. This system relies on three tables: USERS GROUPS GROUP_USERS The two first tables simply define all the users and all the groups on the site, and the last table, GROUP_USERS, stores the groups every user is part of. It only has two columns: USER_ID GROUP_ID Since every user can be a member of several groups, I decided to make a separate table for this purpose, rather than storing a comma separated column in the USERS-table. Now, both columns are foreign keys, and I want to make them both primary keys as well, this since each combination of USER_ID and GROUP_ID has to be unique, and if I give them the constraint UNIQUE pgAdmin tells me that each table should have at least one Primary key. But now I am stuck with what seems to be a lot of indexes and relations to a very small table only containing numbers. In the end, I want this table to be as fast as possible, even if containing tens of thousands of rows. Size on disk shouldn't be a problem since its just all numbers anyway, but it feels quite stupid to have a full-sized index refering to a smaller table. Should I stick with my current solution, store comma-separated values in a column in the USERS-table or is there any other solution I should be aware of. PS. I don't want to use an array-column, even if they are supported by postgreSQL. I want to be as generic as possible so I can switch database later on, if necessary. EDIT: I other words, will using a compound primary key and two foreign keys in one table with only two columns have a negative impact on performance rather than the opposite due to the size of the generated index? Thank you!

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  • Unable to parse variable length string separated by delimiter

    - by Technext
    Hi, I have a problem with parsing a string, which consists only of directory path. For ex. My input string is Abc\Program Files\sample\ My output should be Abc//Program Files//sample The script should work for input path of any length i.e., it can contain any no. of subdirectories. (For ex., abc\temp\sample\folder\joe) I have looked for help in many links but to no avail. Looks like FOR command extracts only one whole line or a string (when we use ‘token’ keyword in FOR syntax) but my problem is that I am not aware of the input path length and hence, the no. of tokens. My idea was to use \ as a delimiter and then extract each word before and after it (), and put the words to an output file along with // till we reach the end of the string. I tried implementing the following but it did not work: @echo off FOR /F "delims=\" %%x in (orig.txt) do ( IF NOT %%x == "" echo.%%x//output.txt ) The file orig.txt contains only one line i.e, Abc\Program Files\sample\ The output that I get contains only: Abc// The above output contains blank spaces as well after ‘Abc//’ My desired output should be: Abc//program Files//sample// Can anyone please help me with this? Regards, Technext

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  • [IE6] Cannot upload non-existent file

    - by geff_chang
    I am asking the same question as this: http://stackoverflow.com/questions/691323/trying-to-upload-a-non-existent-file-in-internet-explorer-form-is-not-submitted I'm not sure if the topic starter found a solution, since he did not post the answer. So, I'd like to ask you guys this question again. I have type=input in my form, and a submit button. If I type garbage input into the textbox (like the text "abc") in the file control's textbox, and click the submit button, the form is not submitted to the server. AND, no feedback is given to the user. Instead of this "Is-the-submit-button-broken?" behavior, is there a way I could notify the user that the file does not exist? (I am aware this is not possible, except with ActiveX, but I don't want to go into that) My client wants to hide the textbox of the file control, but I'm not sure if this is a good design. What do you guys suggest? (If it makes any difference, I am also using this jquery plugin: http://www.fyneworks.com/jquery/multiple-file-upload/)

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  • Casting pointer to object to void * in C++

    - by JB
    I've been reading StackOverflow too much and started doubting all the code I've ever written, I keep thinking "Is that undefined behavour?" even in code that has been working for ages. So my question - Is it safe and well defined behavour to cast a pointer to an object (In this case abstract interface classes) to a void* and then later on cast them back to the original class and call method using them? I'm fully aware that the code that does this is probably awful. I wouldn't even consider writing it like this now (this is old code which I don't really want to change), so I'm not looking for a discussion of better ways to do this. I already know how to write it better if I ever did this again. But if it's actually broken to rely on this in C++ then I'll have to look at changing the code, if it's merely awful code then changing it won't be a priority. I would have had no doubts about something this simple a year or two ago but as my understanding of C++ increases I actually find I have more and more worries about code being safe under the standards even if it works perfectly well. Perhaps reading too much stack overflow is a bad thing for productivity sometimes :P

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  • Django + GAE (Google App Engine) : most convenient path for a beginner?

    - by mac
    Some background info first: Goal: a medium-level complexity web app that I will need to maintain and possibly extend for a few years. Experience: good knowledge of python, some experience of MVC frameworks (in PHP). Desiderata: using django and google app engine. I read extensively about the compatibility issues between GAE and Django, and I am aware of the GAE patch, the norel project, and other similar pieces of code. I have also understood that the SDK provides some of the features of django "out of the box". Yet, given that I have no previous experience with neither Django nor GAE, I am unable to evaluate to which extent using a patched version of Django will strip away important features, or how far the framework provided in the SDK is compatible with Django. So I am rather confused on what would be the best way to proceed in my situation: Should I simply use a patched version of Django as the differences with the original Django are so minor that I would hardly notice them? Should I write my app completely in "regular django" and try to port it to GAE only afterwards, when I will have got a grasp on Django internals and philosophy? Should I write my app using the framework provided with the SDK and port it to django only afterwards? Should I... ? Thank you in advance for your time and advice.

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  • OcaIDE doesn't see JoCaml tools

    - by Surikator
    I'm having a problem while using OcaIDE in ocamlbuild mode. I'm trying to compile my own JoCaml sources. According to the JoCaml manual (bottom of page), to use ocamlbuild with JoCaml, I just need to add the -use-jocaml argument to ocamlbuild. Indeed, if I go to the root of my project and write ocamlbuild -use-jocaml foo.native it generates my executable just fine. However, in OcaIDE I get /bin/sh: jocamldep: command not found In OcaIDE, the -use-jocaml flag is passed in the "Other Flags" box (in Project Properties). And that certainly is working, as the complaint is precisely that it doesn't find jocaml stuff. The puzzling thing is that jocaml is installed and can be accessed from any random terminal window. For example, running jocamldep -modules foo.ml > foo.ml.depends on my project does generate the desired dependency file. So, it would seem I would have to configure OcaIDE and tell it where JoCaml executables are or something. This is done for OCaml, for example. But there is no place to do that for JoCaml. And it's really strange that, if jocamldep/jocamlc/etc are all accessible from anywhere, OcaIDE wouldn't be able to pick them. Any ideas? (I am aware I can do an ocamlbuild plugin and pass the flag in a "myocamlbuild.ml" file. I'll probably use that a latter stage after I get familiar with ocamlbuild plugins. But here the question is about OcaIDE. EDIT: Actually, ocamlbuild plugins don't seem to be a solution as, although there is an option -use-jocaml in ocamlbuild to enforce jocaml use (and it works fine), the plugin system doesn't support it, i.e. jocaml is not in the list of options.)

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  • Determine asymmetric latencies in a network

    - by BeeOnRope
    Imagine you have many clustered servers, across many hosts, in a heterogeneous network environment, such that the connections between servers may have wildly varying latencies and bandwidth. You want to build a map of the connections between servers my transferring data between them. Of course, this map may become stale over time as the network topology changes - but lets ignore those complexities for now and assume the network is relatively static. Given the latencies between nodes in this host graph, calculating the bandwidth is a relative simply timing exercise. I'm having more difficulty with the latencies - however. To get round-trip time, it is a simple matter of timing a return-trip ping from the local host to a remote host - both timing events (start, stop) occur on the local host. What if I want one-way times under the assumption that the latency is not equal in both directions? Assuming that the clocks on the various hosts are not precisely synchronized (at least that their error is of the the same magnitude as the latencies involved) - how can I calculate the one-way latency? In a related question - is this asymmetric latency (where a link is quicker in direction than the other) common in practice? For what reasons/hardware configurations? Certainly I'm aware of asymmetric bandwidth scenarios, especially on last-mile consumer links such as DSL and Cable, but I'm not so sure about latency. Added: After considering the comment below, the second portion of the question is probably better off on serverfault.

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  • Always send certain values with an ajax request/post

    - by DZittersteyn
    I'm building a system that displays a list of user, and on selection of a user requests some form of password. These values are saved in a hidden field on the page, and need to be sent with every request as a form of authentication. (I'm aware of the MITM-vulnerability that lies herein, but it's a very low-key system, so security is not a large concern). Now I need to send these values with each and every request, to auth the currently 'logged in' user. I'd like to automate this, via ajaxSetup, however i'm running into some issues. My first try was: init_user_auth: function(){ $.ajaxSetup({ data: { 'user' : site_user.selected_user_id(), 'passcode': site_user.selected_user_pc(), 'barcode' : site_user.selected_user_bc() } }); }, However, as I should have known, this reads the values once, at the time of the call to ajaxSetup, and never rereads them. What I need is a way to actually call the functions every time an ajax-call is made. I'm currently trying to understand what is happening here: https://groups.google.com/forum/?fromgroups=#!topic/jquery-dev/OBcEfgvTJ9I, however through the flamewar and very low-level stuff going on there, I'm not exactly sure I get what is going on. Is this the way to proceed, or should I just face facts and manually add login-info to each ajax-call?

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