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  • best practice for boolean REST results

    - by Andrew Patterson
    I have a resource /system/resource And I wish to ask the system a boolean question about the resource that can't be answered by processing on the client (i.e I can't just GET the resource and look through the actual resource data - it requires some processing on the backend using data not available to the client). eg /system/resource/related/otherresourcename I want this is either return true or false. Does anyone have any best practice examples for this type of interaction? Possibilities that come to my mind: use of HTTP status code, no returned body (smells wrong) return plain text string (True, False, 1, 0) - Not sure what string values are appropriate to use, and furthermore this seems to be ignoring the Accept media type and always returning plain text come up with a boolean object for each of my support media types and return the appropriate type (a JSON document with a single boolean result, an XML document with a single boolean field). However this seems unwieldy. I don't particularly want to get into a long discussion about the true meaning of a RESTful system etc - I have used the word REST in the title because it best expresses the general flavour of system I am designing (even if perhaps I am tending more towards RPC over the web rather than true REST). However, if someone has some thoughts on how a true RESTful system avoids this problem entirely I would be happy to hear them.

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  • Data Binding to an object in C#

    - by Allen
    Objective-c/cocoa offers a form of binding where a control's properties (ie text in a textbox) can be bound to the property of an object. I am trying to duplicate this functionality in C# w/ .Net 3.5. I have created the following very simple class in the file MyClass.cs: class MyClass { private string myName; public string MyName { get { return myName; } set { myName = value; } } public MyClass() { myName = "Allen"; } } I also created a simple form with 1 textbox and 1 button. I init'd one instance of Myclass inside the form code and built the project. Using the DataSource Wizard in Vs2008, i selected to create a data source based on object, and selected the MyClass assembly. This created a datasource entity. I changed the databinding of the textbox to this datasource; however, the expected result (that the textbox's contents would be "allen") was not achieved. Further, putting text into the textbox is not updating the name property of the object. I know i'm missing something fundamental here. At some point i should have to tie my instance of the MyClass class that i initialized inside the form code to the textbox, but that hasn't occurred. Everything i've looked at online seems to gloss over using DataBinding with an object (or i'm missing the mark entirely), so any help is great appreciated. ----Edit--- Utilizing what i learned by the answers, i looked at the code generated by Visual Studio, it had the following: this.myClassBindingSource.DataSource = typeof(BindingTest.MyClass); if i comment that out and substitute : this.myClassBindingSource.DataSource = new MyClass(); i get the expected behavior. Why is the default code generated by VS like it is? Assuming this is more correct than the method that works, how should i modify my code to work within the bounds of what VS generated?

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  • Best practices for Java logging from multiple threads?

    - by Jason S
    I want to have a diagnostic log that is produced by several tasks managing data. These tasks may be in multiple threads. Each task needs to write an element (possibly with subelements) to the log; get in and get out quickly. If this were a single-task situation I'd use XMLStreamWriter as it seems like the best match for simplicity/functionality without having to hold a ballooning XML document in memory. But it's not a single-task situation, and I'm not sure how to best make sure this is "threadsafe", where "threadsafe" in this application means that each log element should be written to the log correctly and serially (one after the other and not interleaved in any way). Any suggestions? I have a vague intuition that the way to go is to use a queue of log elements (with each one able to be produced quickly: my application is busy doing real work that's performance-sensitive), and have a separate thread which handles the log elements and sends them to a file so the logging doesn't interrupt the producers. The logging doesn't necessarily have to be XML, but I do want it to be structured and machine-readable. edit: I put "threadsafe" in quotes. Log4j seems to be the obvious choice (new to me but old to the community), why reinvent the wheel...

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  • Does Team Foundation support cross-app workitem groups?

    - by drachenstern
    We're currently using Visual Source Safe and BugNet and looking to migrate up and away from VSS. I've been pushing for either SVN ( a) we're an ASP.NET shop, b) DCVS is not an option - no matter how much I like Hg ;-) or TFS. Well we finally got a new dev server, so I talked the boss into installing TFS on it (30 day trial). In the meantime, we had started experimenting with FogBugz. We really like FogBugz for about 80% of what we want to do, and the other 20% is probably stuff that we don't know what we want. I'm pushing for TFS because it allows for IDE integrated (mostly) everything. He's pushing for FogBugz because he can group tasks by customer and then project and manage everything from one dashboard. (which means I lose most of my IDE integration - no huge loss I agree) Does TFS support a single dashboard that would span all our solutions (in this case each solution is a full app that we sell to a vertical market client) and let us assign workitems to each solution-spanning-group? So for instance I think we envision something like this: PROJECT1 - Bugtracker and workitems PROJECT2 - Bugtracker and workitems PROJECT3 - Bugtracker and workitems CUSTOMER1 - Deployment schedules, required features, specific notes (Uses PROJECT1, PROJECT2) CUSTOMER2 - Deployment schedules, required features, specific notes (Uses PROJECT2, PROJECT3) CUSTOMER3 - Deployment schedules, required features, specific notes (Uses PROJECT1, PROJECT3) Hopefully that makes sense. naturally it's more complicated than this but I think I've given the details enough to paint a picture. I offered the option of creating dummy projects per customer but he doesn't like that and it doesn't really give us the single dashboard view that we're hoping to end up with (and that FogBugz as we've sorta implmented things does do now). Has anyone got a good suggestion on a management app that would accomplish what both of us want?

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  • Possible to Inspect Innards of Core C# Functionality

    - by Nick Babcock
    I was struck today, with the inclination to compare the innards of Buffer.BlockCopy and Array.CopyTo. I am curious to see if Array.CopyTo called Buffer.BlockCopy behind the scenes. There is no practical purpose behind this, I just want to further my understanding of the C# language and how it is implemented. Don't jump the gun and accuse me of micro-optimization, but you can accuse me of being curious! When I ran ILasm on mscorlib.dll I received this for Array.CopyTo .method public hidebysig newslot virtual final instance void CopyTo(class System.Array 'array', int32 index) cil managed { // Code size 0 (0x0) } // end of method Array::CopyTo and this for Buffer.BlockCopy .method public hidebysig static void BlockCopy(class System.Array src, int32 srcOffset, class System.Array dst, int32 dstOffset, int32 count) cil managed internalcall { .custom instance void System.Security.SecuritySafeCriticalAttribute::.ctor() = ( 01 00 00 00 ) } // end of method Buffer::BlockCopy Which, frankly, baffles me. I've never run ILasm on a dll/exe I didn't create. Does this mean that I won't be able to see how these functions are implemented? Searching around only revealed a stackoverflow question, which Marc Gravell said [Buffer.BlockCopy] is basically a wrapper over a raw mem-copy While insightful, it doesn't answer my question if Array.CopyTo calls Buffer.BlockCopy. I'm specifically interested in if I'm able to see how these two functions are implemented, and if I had future questions about the internals of C#, if it is possible for me to investigate it. Or am I out of luck?

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  • Scala Interpreter scala.tools.nsc.interpreter.IMain Memory leak

    - by Peter
    I need to write a program using the scala interpreter to run scala code on the fly. The interpreter must be able to run an infinite amount of code without being restarted. I know that each time the method interpret() of the class scala.tools.nsc.interpreter.IMain is called, the request is stored, so the memory usage will keep going up forever. Here is the idea of what I would like to do: var interpreter = new IMain while (true) { interpreter.interpret(some code to be run on the fly) } If the method interpret() stores the request each time, is there a way to clear the buffer of stored requests? What I am trying to do now is to count the number of times the method interpret() is called then get a new instance of IMain when the number of times reaches 100, for instance. Here is my code: var interpreter = new IMain var counter = 0 while (true) { interpreter.interpret(some code to be run on the fly) counter = counter + 1 if (counter > 100) { interpreter = new IMain counter = 0 } } However, I still see that the memory usage is going up forever. It seems that the IMain instances are not garbage-collected by the JVM. Could somebody help me solve this issue? I really need to be able to keep my program running for a long time without restarting, but I cannot afford such a memory usage just for the scala interpreter. Thanks in advance, Pet

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  • objective C architecture question

    - by thekevinscott
    Hey folks, I'm currently teaching myself objective C. I've gone through the tutorials, but I find I learn best when slogging through a project of my own, so I've embarked on making a backgammon app. Now that I'm partway in, I'm realizing there's some overall architecture things I just don't understand. I've established a "player" class, a "piece" class, and a "board" class. A piece theoretically belongs to both a player and the board. For instance, a player has a color, and every turn makes a move; so the player owns his pieces. At the same time, when moving a piece, it has to check whether it's a valid move, whether there are pieces on the board, etc. From my reading it seems like it's frowned upon to reach across classes. For instance, when a player makes a move, where should the function live that moves the piece? Should it exist on board? This would be my instinct, as the board should decide whether a move is valid or not; but the piece needs to initialize that query, as its the one being moved, no? Any info to help a noob would be super appreciated. Thanks guys!

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  • Python Django Global Variables

    - by Joe J
    Hi all, I'm looking for simple but recommended way in Django to store a variable in memory only. When Apache restarts or the Django development server restarts, the variable is reset back to 0. More specifically, I want to count how many times a particular action takes place on each model instance (database record), but for performance reasons, I don't want to store these counts in the database. I don't care if the counts disappear after a server restart. But as long as the server is up, I want these counts to be consistent between the Django shell and the web interface, and I want to be able to return how many times the action has taken place on each model instance. I don't want the variables to be associated with a user or session because I might want to return these counts without being logged in (and I want the counts to be consistent no matter what user is logged in). Am I describing a global variable? If so, how do I use one in Django? I've noticed the files like the urls.py, settings.py and models.py seems to be parsed only once per server startup (by contrast to the views.py which seems to be parsed eache time a request is made). Does this mean I should declare my variables in one of those files? Or should I store it in a model attribute somehow (as long as it sticks around for as long as the server is running)? This is probably an easy question, but I'm just not sure how it's done in Django. Any comments or advice is much appreciated. Thanks, Joe

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  • how to manage a "resource" array efficiently

    - by Haiyuan Zhang
    The senario of my question is that one need to use a fixed size of array to keep track of certain number of "objects" . The object here can be as simply as a integer or as complex as very fancy data structure. And "keep track" here means to allocate one object when other part of the app need one instance of object and recyle it for future allocation when one instance of the object is returned .Finally ,let me use c++ to put my problme in a more descriptive way . #define MAX 65535 /* 65535 just indicate that many items should be handled . performance demanding! */ typedef struct { int item ; }Item_t; Item_t items[MAX] ; class itemManager { private : /* up to you.... */ public : int get() ; /* get one index to a free Item_t in items */ bool put(int index) ; /* recyle one Item_t indicate by one index in items */ } how will you implement the two public functions of itemManager ? it's up to you to add any private member .

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  • Calling a SLSB with Seam security from a servlet

    - by wilth
    Hello, I have an existing application written in SEAM that uses SEAM Security (http://docs.jboss.org/seam/2.1.1.GA/reference/en-US/html/security.html). In a stateless EJB, I might find something like this: @In Identity identity; ... if(identity.hasRole("admin")) throw new AuthException(); As far as I understand, Seam injects the Identity object from the SessionContext of the servlet that invokes the EJB (this happens "behind the scenes", since Seam doesn't really use servlets) and removes it after the call. Is this correct? Is it now possible to access this EJB from another servlet (in this case, that servlet is the server side of a GWT application)? Do I have to "inject" the correct Identity instance? If I don't do anything, Seam injects an instance, but doesn't correctly correlate the sessions and instances of Identity (so the instances of Identity are shared between sessions and sometimes calls get new instances etc.). Any help and pointers are very welcome - thanks! Technology: EJB3, Seam 2.1.2. The servlets are actually the server-side of a GWT app, although I don't think this matters much. I'm using JBoss 5.

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  • How to pull one commit at a time from a remote git repository?

    - by Norman Ramsey
    I'm trying to set up a darcs mirror of a git repository. I have something that works OK, but there's a significant problem: if I push a whole bunch of commits to the git repo, those commits get merged into a single darcs patchset. I really want to make sure each git commit gets set up as a single darcs patchset. I bet this is possible by doing some kind of git fetch followed by interrogation of the local copy of the remote branch, but my git fu is not up to the job. Here's the (ksh) code I'm using now, more or less: git pull -v # pulls all the commits from remote --- bad! # gets information about only the last commit pulled -- bad! author="$(git log HEAD^..HEAD --pretty=format:"%an <%ae>")" logfile=$(mktemp) git log HEAD^..HEAD --pretty=format:"%s%n%b%n" > $logfile # add all new files to darcs and record a patchset. this part is OK darcs add -q --umask=0002 -r . darcs record -a -A "$author" --logfile="$logfile" darcs push -a rm -f $logfile My idea is Try git fetch to get local copy of the remote branch (not sure exactly what arguments are needed) Somehow interrogate the local copy to get a hash for every commit since the last mirroring operation (I have no idea how to do this) Loop through all the hashes, pulling just that commit and recording the associated patchset (I'm pretty sure I know how to do this if I get my hands on the hash) I'd welcome either help fleshing out the scenario above or suggestions about something else I should try. Ideas?

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  • How to route tree-structured URLs with ASP.NET Routing?

    - by Venemo
    Hello Everyone, I would like to achieve something very similar to this question, with some enhancements. There is an ASP.NET MVC web application. I have a tree of entities. For example, a Page class which has a property called Children, which is of type IList<Page>. (An instance of the Page class corresponds to a row in a database.) I would like to assign a unique URL to every Page in the database. I handle Page objects with a Controller called PageController. Example URLs: http://mysite.com/Page1/ http://mysite.com/Page1/SubPage/ http://mysite.com/Page/ChildPage/GrandChildPage/ You get the picture. So, I'd like every single Page object to have its own URL that is equal to its parent's URL plus its own name. In addition to that, I also would like the ability to map a single Page to the / (root) URL. I would like to apply these rules: If a URL can be handled with any other route, or a file exists in the filesystem in the specified URL, let the default URL mapping happen If a URL can be handled by the virtual path provider, let that handle it If there is no other, map the other URLs to the PageController class I also found this question, and also this one and this one, but they weren't of much help, since they don't provide an explanation about my first two points. I see the following possible soutions: Map a route for each page invidually. This requires me to go over the entire tree when the application starts, and adding an exact match route to the end of the route table. I could add a route with {*path} and write a custom IRouteHandler that handles it, but I can't see how could I deal with the first two rules then, since this handler would get to handle everything. So far, the first solution seems to be the right one, because it is also the simplest. I would really appreciate your thoughts on this. Thank you in advance!

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  • Threads in WCF service

    - by dragonfly
    Hi, there is a piece of code: class WCFConsoleHostApp : IBank { private static int _instanceCounter; public WCFConsoleHostApp () { Interlocked.Increment(ref _instanceCounter); Console.WriteLine(string.Format("{0:T} Instance nr " + _instanceCounter + " created", DateTime.Now)); } private static int amount; static void Main(string[] args) { ServiceHost host = new ServiceHost(typeof(WCFConsoleHostApp)); host.Open(); Console.WriteLine("Host is running..."); Console.ReadLine(); } #region IBank Members BankOperationResult IBank.Put(int amount) { Console.WriteLine(string.Format("{0:00} {1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread) + " Putting..."); WCFConsoleHostApp.amount += amount; Thread.Sleep(20000); Console.WriteLine(string.Format("{0:00} {1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread) + " Putting done"); return new BankOperationResult { CurrentAmount = WCFConsoleHostApp.amount, Success = true }; } BankOperationResult IBank.Withdraw(int amount) { Console.WriteLine(string.Format("{0:00} {1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread) + " Withdrawing..."); WCFConsoleHostApp.amount -= amount; Thread.Sleep(20000); Console.WriteLine(string.Format("{0:00} {1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread) + " Withdrawing done"); return new BankOperationResult { CurrentAmount = WCFConsoleHostApp.amount, Success = true }; } #endregion } My test client application calls that service in 50 threads (service is PerCall). What I found very disturbing is when I added Thread.Sleep(20000) WCF creates one service instance per second using different thread from pool. When I remove Thread.Sleep(20000) 50 instances are instanciated straight away, and about 2-4 threads are used to do it - which in fact I consider normal. Could somebody explain why when Thread.Sleep causes those funny delays in creating instances?

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  • Architecture Guidance Needed?

    - by vijay
    We are about to automate number of process for our reporting team. (The reports are like daily reports, weekly reports, monthly reports, etc..) Mostly the process is like pulling some data from the oracle and then fill them in particular excel template files. Each reports and so their templates are different from each other. Except the excel file manipulation, there are hardly any business logic behind these. Client wanted an integrated tool and all the automated processes are placed as menus/submenus. Right now roughly there are around 30 process waiting to be automated. And we are expecting more new reports in the next quarter. I am nowhere to near having any practical experience when comes to architecuring. Already i have been maintaining two or three systems(they are more than 4yrs old.) for this prestegious client.The possiblity of the above mentioned tool will be manintained for another 3 yrs is very likely. From my past experience i've been through the pain of implmenting change requests to the rigd & undocumented code base resulting in the break down of the system and then eventually myself. So My main and top most concern is the maintainablity. When i was searching for these i came across this link, Smart Clients Using CAB and SCSF is the above link appropriate for my requirement? Also Should i place each automated processes in separate forms under a single project, or place them in separate projects under a single solution.. Please correct me if have missed any other important information. Thx.

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  • cant get connexion using MongoTor

    - by Abdelouahab Pp
    i was trying to change my code to make it asynchronous using MongoTor here is my simple code: class BaseHandler(tornado.web.RequestHandler): @property def db(self): if not hasattr(self,"_db"): _db = Database.connect('localhost:27017', 'essog') return _db @property def fs(self): if not hasattr(BaseHandler,"_fs"): _fs = gridfs.GridFS(self.db) return _fs class LoginHandler(BaseHandler): @tornado.web.asynchronous @tornado.gen.engine def post(self): email = self.get_argument("email") password = self.get_argument("pass1") try: search = yield tornado.gen.Task(self.db.users.find, {"prs.mail":email}) .... i got this error: Traceback (most recent call last): File "C:\Python27\lib\site-packages\tornado-2.4.post1-py2.7.egg\tornado\web.py", line 1043, in _stack_context_handle_exception raise_exc_info((type, value, traceback)) File "C:\Python27\lib\site-packages\tornado-2.4.post1-py2.7.egg\tornado\web.py", line 1162, in wrapper return method(self, *args, **kwargs) File "C:\Python27\lib\site-packages\tornado-2.4.post1-py2.7.egg\tornado\gen.py", line 122, in wrapper runner.run() File "C:\Python27\lib\site-packages\tornado-2.4.post1-py2.7.egg\tornado\gen.py", line 365, in run yielded = self.gen.send(next) File "G:\Mon projet\essog\handlers.py", line 92, in post search = yield tornado.gen.Task(self.db.users.find, {"prs.mail":email}) File "G:\Mon projet\essog\handlers.py", line 62, in db _db = Database.connect('localhost:27017', 'essog') File "build\bdist.win-amd64\egg\mongotor\database.py", line 131, in connect database.init(addresses, dbname, read_preference, **kwargs) File "build\bdist.win-amd64\egg\mongotor\database.py", line 62, in init ioloop_is_running = IOLoop.instance().running() AttributeError: 'SelectIOLoop' object has no attribute 'running' ERROR:tornado.access:500 POST /login (::1) 3.00ms and, excuse me for this other question, but how do i make distinct in this case? here is what worked in blocking mode: search = self.db.users.find({"prs.mail":email}).distinct("prs.mail")[0] Update: it seems that this error happenes when there is no Tornado running! it's the same error raised when using only the module in console. test = Database.connect("localhost:27017", "essog") --------------------------------------------------------------------------- AttributeError Traceback (most recent call last) in () ---- 1 test = Database.connect("localhost:27017", "essog") C:\Python27\lib\site-packages\mongotor-0.0.10-py2.7.egg\mongotor\database.pyc in connect(cls, addresses, dbname, read_preference, **kwargs) 131 132 database = Database() -- 133 database.init(addresses, dbname, read_preference, **kwargs) 134 135 return database C:\Python27\lib\site-packages\mongotor-0.0.10-py2.7.egg\mongotor\database.pyc in init(self, addresses, dbname, read_preference, **kwargs) 60 self._nodes.append(node) 61 --- 62 ioloop_is_running = IOLoop.instance().running() 63 self._config_nodes(callback=partial(self._on_config_node, ioloop_is_running)) 64 AttributeError: 'SelectIOLoop' object has no attribute 'running'

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  • Log4Net GetLogger creates rolling files even for the unreferenced files

    - by ybastiand
    Hi, I have a C# solution that contains three executables. I have each of these three executables sharing the same log4net configuration file. At startup of each of the executable, they retrieve a logger (one logger per executable, as per configuration file further below). When one of the executable performs Log.GetLogger(), it creates all the rolling files instead of only the one rolling file that is referred to as appender-ref in the executable's logger configuration. For instance, when I startup my sending daemon executable, it performs Log.GetLogger("SendingDaemonLogger") which creates 3 files Log/RuleScheduler.txt, Log/NotificationGenerator.txt and Log/NotificationSender.txt instead of only the desired Log/NotificationSender.txt. Then when I startup another of the executables, for instance the rule scheduler daemon, this other process cannot write in Log/RuleScheduler.txt because it has been created and locked by the sending daemon process. I am guessing that there may be three different solutions to my problem: The GetLogger should only create the rolling file appenders that are referenced in the config I should have one config file per executable, this way each config file could list only one rolling file appender and starting each of the executable would not create the rolling files of the other daemons. I am however reluctant to do this because some of the configuration (SMTP appender, console appender) is shared between the daemons and I don't want to have duplicate copies to maintain. Unless there is a way to have a config file including another one? Maybe there is a way to configure the rolling file so that concurrent access across processes is allowed? This solution still isn't perfect in my opinion because any of the daemons should not be creating the rolling files of some other daemons. Thanks in advance for your help! I have difficulties for posting the config file properly here (this website interprets as HTML). Please go to the following link for seeing my log4net configuration file: log4Net configuration file

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  • GWT serialization issue

    - by Eddy
    I am having a heck of a time returning an ArrayList of objects that implement IsSerializable via RPC. The IsSerializable pojo contains one variable, a String, and has a 0 parameter constructor. I have removed the .gwt.rpc file from my war and still I get: com.google.gwt.user.client.rpc.SerializationException: Type 'com.test.myApp.client.model.Test' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = com.test.myApp.client.model.Test@17a9692 at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:610) I am using GWT 2.0.2 with jdk 1.6.0_18. Any ideas on what might be going on or what I am doing wrong? Here is the code for the Test class and the remote method is returning ArrayList. I even modified the code for it to just return one instance of Test with the same result: the exception above. package com.test.myApp.client.model; import com.google.gwt.user.client.rpc.IsSerializable; public class Test implements IsSerializable{ private String s; public Test() {} public Test(String s) { this.s = s; } public String getS() { return s; } public void setS(String s) { this.s = s; } } Greatly appreciate the help! Eddy

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  • C sharp code cleanup : resharper

    - by Ankit Rathod
    Hello, I just used Resharper in one application and it made me feel as if i don't know how to code at all in C# :(. On every line it gave me it's suggestions :- Few of Resharper's favorite suggestions are :- 1) SomObject o = new SomeObject(); Resharper will convert to : var o = new SomeObject() 2) this.Loaded += new RoutedEventHandler(MainPage_Loaded); to this.Loaded += MainPage_Loaded; 3) convert my variables and putting _ in front of all instance variables. 4) Removing class parent's name. I tested this on Silverlight. public partial class MainPage : UserControl to public partial class MainPage EDIT :- 5) replace instance variable this.variable = somevalue to variable = somevalue Are all of these really necessary? Is it really going to affect the efficiency of my program? I mean what good is it going to do by replacing my class names with var keyword. After all var is also replaced with class name at compile time. Is it doing because it has been programmed to do or do these things really affect in some or another way? Thanks in advance :)

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  • How to minimize total cost of shortest path tree

    - by Michael
    I have a directed acyclic graph with positive edge-weights. It has a single source and a set of targets (vertices furthest from the source). I find the shortest paths from the source to each target. Some of these paths overlap. What I want is a shortest path tree which minimizes the total sum of weights over all edges. For example, consider two of the targets. Given all edge weights equal, if they share a single shortest path for most of their length, then that is preferable to two mostly non-overlapping shortest paths (fewer edges in the tree equals lower overall cost). Another example: two paths are non-overlapping for a small part of their length, with high cost for the non-overlapping paths, but low cost for the long shared path (low combined cost). On the other hand, two paths are non-overlapping for most of their length, with low costs for the non-overlapping paths, but high cost for the short shared path (also, low combined cost). There are many combinations. I want to find solutions with the lowest overall cost, given all the shortest paths from source to target. Does this ring any bells with anyone? Can anyone point me to relevant algorithms or analogous applications? Cheers!

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  • Script throwing unexpected operator when using mysqldump

    - by Astron
    A portion of a script I use to backup MySQL databases has stopped working correctly after upgrading a Debian box to 6.0 Squeeze. I have tested the backup code via CLI and it works fine. I believe it is in the selection of the databases before the backup occurs, possibly something to do with the $skipdb variable. If there is a better way to perform the function then I'm will to try something new. Any insight would be greatly appreciated. $ sudo ./script.sh [: 138: information_schema: unexpected operator [: 138: -1: unexpected operator [: 138: mysql: unexpected operator [: 138: -1: unexpected operator Using bash -x script here is one of the iterations: + for db in '$DBS' + skipdb=-1 + '[' test '!=' '' ']' + for i in '$IGGY' + '[' mysql == test ']' + : + '[' -1 == -1 ']' ++ /bin/date +%F + FILE=/backups/hostname.2011-03-20.mysql.mysql.tar.gz + '[' no = yes ']' + /usr/bin/mysqldump --single-transaction -u root -h localhost '-ppassword' mysql + /bin/tar -czvf /backups/hostname.2011-03-20.mysql.mysql.tar.gz mysql.sql mysql.sql + rm -f mysql.sql Here is the code. if [ $MYSQL_UP = "yes" ]; then echo "MySQL DUMP" >> /tmp/update.log echo "--------------------------------" >> /tmp/update.log DBS="$($MYSQL -u $MyUSER -h $MyHOST -p"$MyPASS" -Bse 'show databases')" for db in $DBS do skipdb=-1 if [ "$IGGY" != "" ] ; then for i in $IGGY do [ "$db" == "$i" ] && skipdb=1 || : done fi if [ "$skipdb" == "-1" ] ; then FILE="$DEST$HOST.`$DATE +"%F"`.$db.mysql.tar.gz" if [ $ENCRYPT = "yes" ]; then $MYSQLDUMP -u $MyUSER -h $MyHOST -p"$MyPASS" $db > $db.sql && $TAR -czvf - $db.sql | $OPENSSL enc -aes-256-cbc -salt -out $FILE.enc -k $ENC_PASS && rm -f $db.sql else $MYSQLDUMP --single-transaction -u $MyUSER -h $MyHOST -p"$MyPASS" $db > $db.sql && $TAR -czvf $FILE $db.sql && rm -f $db.sql fi fi done fi

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  • Approach for replacing forms authentication in .NET application

    - by Ash Machine
    My question is about an approach, and I am looking for tips or links to help me develop a solution. I have an .NET 4.0 web forms application that works with Forms authentication using the aspnetdb SQL database of users and passwords. A new feature for the application is a new authentication mechanism using single sign on to allow access for thousands of new users. Essentially, when the user logs in through the new single-sign-on method, I will be able to identify them as legitimate users with a role. So I will have something like HttpContext.Current.Session["email_of_authenticated_user"] (their identity) and HttpContext.Current.Session["role_of_authenticated_user"] (their role). Importantly, I don't necessarily want to maintain these users and roles redundantly in the aspnetdb database which will be retired, but I do want to use the session objects above to allow the user to pass through the application as if they were in passing through with forms authentication. I don't think CustomRoleProviders or CustomMemberProviders are helpful since they do not allow for creating session-level users. So my question is how to use the session level user and role that I do have to "mimic" all the forms authentication goodness like enforcing: [System.Security.Permissions.PrincipalPermission(System.Security.Permissions.SecurityAction.Demand, Role = "Student")] or <authorization> <allow users="wilma, barney" /> </authorization> Thanks for any pointers.

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  • How to prevent Hibernate from nullifying relationship column during entity removal

    - by Grzegorz
    I have two entities, A and B. I need to easily retrieve entities A, joined with entities B on the condition of equal values of some column (some column from A equal to some column in B). Those columns are not primary or foreign keys, they contain same business data. I just need to have access from each instance of A to the collection of B's with the same value of this column. So I model it like this: class A { @OneToMany @JoinColumn(name="column_in_B", referencedColumnName="column_in_A") Collection<B> bs; This way, I can run queries like "select A join fetch a.bs b where b...." (Actually, the real relationship here is many-to-many. But when I use @ManyToMany, Hibernate forces me to use join table, which doesnt exist here. So I have to use @OneToMany as workaround). So far so good. The main problem is: whenever I delete an instance of A, hibernate calls "Update B set column_in_B = null", becuase it thinks the column_in_B is foreign key pointing at primary key in A (and because row in A is deleted, it tries to clean the foreign key in B). BUT the column_in_B IS NOT a foreign key, and can't be modified, because it causes data lost (and this column is NOT NULL anyway in my case, causing data integerity exception to be thrown). Plese help me with this. How to model such relationships with Hibernate? (I would call it "virtual relationships", or "secondary relationships" or so: as they are not based on foreign keys, they are just some shortcuts which allows for retrieving related objects and quering for them with HQL)

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  • Coldfusion Web Service Response Problem

    - by Ivan Paloscia
    I have a problem with the Web Service I recently developed. The problem is about the Web Service response. More precisely sometimes the Web Service sends back the following response: <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <soapenv:Body> <ns1:GetConstants2Response soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:ns1="http://usermanagerwstest"> <GetConstants2Return xsi:type="ns2:CFComponentSkeleton" xmlns:ns2="http://rpc.xml.coldfusion"/> </ns1:GetConstants2Response> </soapenv:Body> </soapenv:Envelope> Instead the correct response (that sometimes shows up in an intermittent way) is reported below: <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <soapenv:Body> <ns1:GetConstants2Response soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:ns1="http://usermanagerwstest"> <GetConstants2Return xsi:type="ns1:Constants2"> <BooleanTypeFalse xsi:type="xsd:string">0</BooleanTypeFalse> <BooleanTypeTrue xsi:type="xsd:string">1</BooleanTypeTrue> <GenderFemale xsi:type="xsd:string">F</GenderFemale> <GenderMale xsi:type="xsd:string">M</GenderMale> <LanguageEnglish xsi:type="xsd:string">inglese</LanguageEnglish> <LanguageItalian xsi:type="xsd:string">italiano</LanguageItalian> </GetConstants2Return> </ns1:GetConstants2Response> </soapenv:Body> </soapenv:Envelope> Where does the CFCComponentSkeleton comes from? I thank everybody in advance.

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  • How to fluent-map this (using fluent nhibernate)?

    - by vikasde
    I have two tables in my database "Styles" and "BannedStyles". They have a reference via the ItemNo. Now styles can be banned per store. So if style x is banned at store Y then its very possible that its not banned at store Z or vice verse. What is the best way now to map this to a single entity? Should I be mapping this to a single entity? My Style entity looks like this: public class Style { public virtual int ItemNo { get; set;} public virtual string SKU { get; set; } public virtual string StyleName { get; set; } public virtual string Description { get; set; } public virtual Store Store { get; set; } public virtual bool IsEntireStyleBanned { get; set; } }

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  • Base class deleted before subclass during python __del__ processing

    - by Oddthinking
    Context I am aware that if I ask a question about Python destructors, the standard argument will be to use contexts instead. Let me start by explaining why I am not doing that. I am writing a subclass to logging.Handler. When an instance is closed, it posts a sentinel value to a Queue.Queue. If it doesn't, a second thread will be left running forever, waiting for Queue.Queue.get() to complete. I am writing this with other developers in mind, so I don't want a failure to call close() on a handler object to cause the program to hang. Therefore, I am adding a check in __del__() to ensure the object was closed properly. I understand circular references may cause it to fail in some circumstances. There's not a lot I can do about that. Problem Here is some simple example code: explicit_delete = True class Base: def __del__(self): print "Base class cleaning up." class Sub(Base): def __del__(self): print "Sub-class cleaning up." Base.__del__(self) x = Sub() if explicit_delete: del x print "End of thread" When I run this I get, as expected: Sub-class cleaning up. Base class cleaning up. End of thread If I set explicit_delete to False in the first line, I get: End of thread Sub-class cleaning up. Exception AttributeError: "'NoneType' object has no attribute '__del__'" in <bound method Sub.__del__ of <__main__.Sub instance at 0x00F0B698>> ignored It seems the definition of Base is removed before the x._del_() is called. The Python Documentation on _del_() warns that the subclass needs to call the base-class to get a clean deletion, but here that appears to be impossible. Can you see where I made a bad step?

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