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  • Radio Button selection Changes Toast on Android

    - by Bub
    I was writing a simple test application. There are two radio buttons within the app. There id's are "radio_red" and "radio_blue". I wanted to create an onClickListener event that read the text associated to the button and then returned a basic "Right" or "Wrong" toast. Here is a sample of the code: private OnClickListener radio_listener = new OnClickListener() { public void onClick(View v){ RadioButton rb = (RadioButton) v; String ans = rb.getText().toString(); String an1 = ""; if (ans.trim() == "Yes") { ans = "That's Right."; } else if (ans.trim() == "No") { ans = "thats wrong."; } else { ans = "none."; } Toast.makeText(v.getContext(), ans , Toast.LENGTH_SHORT).show(); } So far no joy. Here is my code snippet. I've checked my "main.xml" and the text associated to the buttons are referneced correctly. I added trim to make sure of that. However, all that is ever returned in the toast is "none." What am I missing? Thanks in advance for any help.

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  • Get the src part of a string [duplicate]

    - by Kay Lakeman
    This question already has an answer here: Grabbing the href attribute of an A element 7 answers First post ever here, and i really hope you can help. I use a database where a large piece of html is stored, now i just need the src part of the image tag. I already found a thread, but i just doesn't do the trick. My code: Original string: <p><img alt=\"\" src=\"http://domain.nl/cms/ckeditor/filemanager/userfiles/background.png\" style=\"width: 80px; height: 160px;\" /></p> How i start: $image = strip_tags($row['information'], '<img>'); echo stripslashes($image); This returns: <img alt="" src="http://domain.nl/cms/ckeditor/filemanager/userfiles/background.png" style="width: 80px; height: 160px;" /> Next step: extract the src part: preg_match('/< *img[^>]*src *= *["\']?([^"\']*)/i', $image, $matches); echo $matches ; This last echo returns: Array What is going wrong? Thanks in advance for your anwser.

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  • Installing SVN plugin for Eclipse on Ubuntu

    - by Zac
    I am a brand new Linux user configuring my first-ever dev sandbox in Ubuntu. I have installed Java and Eclipse and am trying to get either Subversive or Subclipse (I don't have a preference either way) but have a few questions before I start that process. I just opened Synaptic and downloaded subversion through it. (1) I'm not really sure how SVN deploys locally. My understanding is that SVN has a client and a server; the server manages the repository(ies) and the clieent just sends commands to the server. Is this correct? If so, then what did I download through Synaptic? The client, and/or the server? (2) Do these Eclipse plugins come with SVN (client or server...?) or do you have to pre-install SVN prior to installing these plugins? Basically: is SVN a pre-req for Subclipse or Subversive? Looking back at these 2 questions if someone could first explain to me the architecture of SVN, then explain how that architecture translates to downloading SVN via Synaptic, and then how it translates to downloading/installing either Eclipse plugin, I would see the "big picture" a lot better. Thanks for any and all help!

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  • How to convert Big Endian and how to flip the highest bit?

    - by Robert Frank
    I am using a TStream to read binary data (thanks to this post: http://stackoverflow.com/questions/2878180/how-to-use-a-tfilestream-to-read-2d-matrices-into-dynamic-array). My next problem is that the data is Big Endian. From my reading, the Swap() method is seemingly deprecated. How would I swap the types below? 16-bit two's complement binary integer 32-bit two's complement binary integer 64-bit two's complement binary integer IEEE single precision floating-point - Are IEEE affected by Big Endian? And, finally, since the data is unsigned, the creators of this dataset have stored the unsigned values as signed integers (excluding the IEEE). They instruct that one need only add an offset (2^15, 2^31, and 2^63) to recover the unsigned data. But, they note that flipping the most significant bit is the fastest way to do that. How does one efficiently flip the most significant bit of a 16, 32, or 64-bit integer? So, if the data on disk (16-bit) is "85 FB" - the desired result after reading the data and swapping and bit flipping would be 1531. Is there a way to accomplish the swapping and bit flipping with generics so it fits into the generic answer at the link above? Yes, kids, THIS is how scientific astronomical data is stored by NASA, ESO, and all professional astronomers. This FITS standard is considered by some to be one of the most successful standards ever created in its proliferation and flexibility!

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  • How do you keep application logic separate from UI when UI components have built-in functionality?

    - by Al C
    I know it's important to keep user interface code separated from domain code--the application is easier to understand, maintain, change, and (sometimes) isolate bugs. But here's my mental block ... Delphi comes with components with methods that do what I want, e.g., a RichText Memo component lets me work with rich text. Other components, like TMS's string grid not only do what I want, but I paid extra for the functionality. These features put the R in RAD. It seems illogical to write my own classes to do things somebody else has already done for me. It's reinventing the wheel [ever tried working directly with rich text? :-) ] But if I use the functionality built into components like these, then I will end up with lots of intermingled UI and domain code--I'll have a form with most of my code built into its event handlers. How do you deal with this issue? ... Or, if I want to continue using the code others have already written for me, how would you suggest I deal with the issue?

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  • How can I map to a field that is joined in via one of three possible tables

    - by Mongus Pong
    I have this object : public class Ledger { public virtual Person Client { get; set; } // .... } The Ledger table joins to the Person table via one of three possible tables : Bill, Receipt or Payment. So we have the following tables : Ledger LedgerID PK Bill BillID PK, LedgerID, ClientID Receipt ReceiptID PK, LedgerID, ClientID Payment PaymentID PK, LedgerID, ClientID If it was just the one table, I could map this as : Join ( "Bill", x => { x.ManyToOne ( ledger => ledger.Client, mapping => mapping.Column ( "ClientID" ) ); x.Key ( l => l.Column ( "LedgerID" ) ); } ); This won't work for three tables. For a start the Join performs an inner join. Since there will only ever be one of Bill, Receipt or Payment - an inner join on these tables will always return zero rows. Then it would need to know to do a Coalesce on the ClientID of each of these tables to know the ClientID to grab the data from. Is there a way to do this? Or am I asking too much of the mappings here?

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  • How to catch unintentional function interpositioning?

    - by SiegeX
    Reading through my book Expert C Programming, I came across the chapter on function interpositioning and how it can lead to some serious hard to find bugs if done unintentionally. The example given in the book is the following: my_source.c mktemp() { ... } main() { mktemp(); getwd(); } libc mktemp(){ ... } getwd(){ ...; mktemp(); ... } According to the book, what happens in main() is that mktemp() (a standard C library function) is interposed by the implementation in my_source.c. Although having main() call my implementation of mktemp() is intended behavior, having getwd() (another C library function) also call my implementation of mktemp() is not. Apparently, this example was a real life bug that existed in SunOS 4.0.3's version of lpr. The book goes on to explain the fix was to add the keyword static to the definition of mktemp() in my_source.c; although changing the name altogether should have fixed this problem as well. This chapter leaves me with some unresolved questions that I hope you guys could answer: Does GCC have a way to warn about function interposition? We certainly don't ever intend on this happening and I'd like to know about it if it does. Should our software group adopt the practice of putting the keyword static in front of all functions that we don't want to be exposed? Can interposition happen with functions introduced by static libraries? Thanks for the help. EDIT I should note that my question is not just aimed at interposing over standard C library functions, but also functions contained in other libraries, perhaps 3rd party, perhaps ones created in-house. Essentially, I want to catch any instance of interpositioning regardless of where the interposed function resides.

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  • Can no longer debug ActiveX controls in Visual Studio 2008

    - by Phenglei Kai
    For a long time I would throw up a DebugBreak() or ASSERT(false) in the startup code of my ActiveX control, load up IE, go to a localhost page hosting my control, wait for the dialog to show up, then debug my application. I could also launch it under the debugger by setting IE as the container. I tried again for the first time in 2 months and now this no longer works. If I use the ASSERT(false) method, when I get the Visual C++ Debug dialog and click "retry", IE simply closes without any debugger activity. When I try launching from VS2008 and hoping the DebugBreak() will kick in after I load the page, VS2008 does break, but it says either the "RPC Server is Unavailable" or the "RPC Client Call failed." I am never allowed to have my application in the debugger and it doesn't show up in the modules list of VS. The stack trace in VS2008 only contains Microsoft DLLs and modules and not a hint of my code. I assume it's something I've picked up through Windows Update that broke this. Has anyone else ever seen this issue and know how to make it go away? As it stands, I'm now completely unable to debug my ActiveX control.

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  • Ideal HTTP cache control headers for different types of resources

    - by chris_l
    I want to find a minimal set of headers, that work with "all" caches and browsers (also when using HTTPS!) On my (GWT-based) web site, I'll have three kinds of resources: 1. Forever cacheable (public / equal for all users) These files don't ever change, and they get a filename based on the MD5 of their contents (this is GWT's approach). They should get cached as much as possible, even when using HTTPS (so I assume, I should set Cache-Control: public, especially for Firefox?) 2. Changing for every new version of the site (public / equal for all users) These files can be cached, but probably need to be revalidated every time. 3. Individual for each request (private / user specific) These resources (e. g. JSON responses) should never be cached unencrypted to disk under no circumstances. (Maybe I'll have a few specific requests that could be cached.) I have a general idea on which headers I would probably use for each type, but there's always something I could be missing.

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  • Does ASP.NET Tracing work in MVC2 Views?

    - by AUSTX_RJL
    I have a VS 2010 MVC2 .NET 4.0 web application. ASP.NET tracing is enabled both in the Page directive (Trace="true) and in the Web.config: <trace enabled="true" requestLimit="10" pageOutput="true" traceMode="SortByTime" localOnly="true" writeToDiagnosticsTrace="true" /> A standard trace listener is also configured in the Web.config: <trace autoflush="true" indentsize="4"> <listeners> <add name="WebPageTrace" type="System.Web.WebPageTraceListener, System.Web, Version=4.0.30319.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> <add name="TextWriterTrace" type="System.Diagnostics.TextWriterTraceListener" initializeData="textListener.log" /> </listeners> </trace> Tracing works fine from the controller, but when I add a Trace in the View (.aspx) nothing ever shows: <% System.Diagnostics.Trace.WriteLine("Message System.Diagnostics.Trace from View"); %> <% Page.Trace.Write("Message Page.Trace from View"); %> Is this supposed to work? Is there something else that is needed to enable Tracing from a View? Thanks

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  • cellForRowAtIndexPath not called for all sections

    - by Wynn
    I have a UITableView that has five sections. Just as the title describes cellForRowAtIndexPath is only being called for the first four. All connections have been made concerning the datasource and delegate. Also, my numberOfSectionsInTableView clearly returns 5. Printing out the number of sections from within cellForRowAtIndexPath shows the correct number, thus confirming that cellForRowAtIndexPath is simply not being called for all sections. What on earth is going on? I looked pretty hard for an answer to this question but could't find one. If this has already been answered please forgive me and point me in the correct direction. My cellForRowAtIndexPath: - (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [theTableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]; } switch (indexPath.section) { case 0: cell.textLabel.text = ticket.description; break; case 1: cell.textLabel.text = ticket.ticketStatus; break; case 2: cell.textLabel.text = ticket.priority; break; case 3: cell.textLabel.text = ticket.customerOfficePhone; break; case 4: { //This never ever gets executed Comment *comment = [ticket.comments objectAtIndex:indexPath.row]; cell.textLabel.text = comment.commentContent; break; } } return cell; } My numberOfSectionsInTableView: - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 5; } My numberOfRowsInSection: - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { NSInteger numberOfRows; if (section == 4) { numberOfRows = [ticket.comments count]; } else { numberOfRows = 1; } return numberOfRows; } Any suggestions are appreciated. Thanks in advance.

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  • How not to lose binding source updates?

    - by Fyodor Soikin
    Suppose I have a modal dialog with a textbox and OK/Cancel buttons. And it is built on MVVM - i.e. it has a ViewModel object with a string property that the textbox is bound to. Say, I enter some text in the textbox and then grab my mouse and click "OK". Everything works fine: at the moment of click, the textbox loses focus, which causes the binding engine to update the ViewModel's property. I get my data, everybody's happy. Now suppose I don't use my mouse. Instead, I just hit Enter on the keyboard. This also causes the "OK" button to "click", since it is marked as IsDefault="True". But guess what? The textbox doesn not lose focus in this case, and therefore, the binding engine remains innocently ignorant, and I don't get my data. Dang! Another variation of the same scenario: suppose I have a data entry form right in the main window, enter some data into it, and then hit Ctrl+S for "Save". Guess what? My latest entry doesn't get saved! This may be somewhat remedied by using UpdateSourceTrigger=PropertyChanged, but that is not always possible. One obvious case would be the use of StringFormat with binding - the text keeps jumping back into "formatted" state as I'm trying to enter it. And another case, which I have encountered myself, is when I have some time-consuming processing in the viewmodel's property setter, and I only want to perform it when the user is "done" entering text. This seems like an eternal problem: I remember trying to solve it systematically from ages ago, ever since I've started working with interactive interfaces, but I've never quite succeeded. In the past, I always ended up using some sort of hacks - like, say, adding an "EnsureDataSaved" method to every "presenter" (as in "MVP") and calling it at "critical" points, or something like that... But with all the cool technologies, as well as empty hype, of WPF, I expected they'd come up with some good solution.

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  • Stop NSXMLParser Instance from Causing _NSAutoreleaseNoPool

    - by PF1
    Hi Everyone: In my iPhone application, I have an instance of NSXMLParser that is set to a custom delegate to read the XML. This is then moved into its own thread so it can update the data in the background. However, ever since I have done this, it has been giving me a lot of _NSAutoreleaseNoPool warnings in the console. I have tried to add a NSAutoreleasePool to each of my delegate classes, however, this hasn't seemed to solve the problem. I have included my method of creating the NSXMLParser in case that is at fault. NSURL *url = [[NSURL alloc] initWithString:@"http://www.mywebsite.com/xmlsource.xml"]; NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url]; CustomXMLParser *parser = [[CustomXMLParser alloc] init]; parser.managedObjectContext = self.managedObjectContext; parser = [parser initXMLParser]; [xmlParser setDelegate:parser]; [NSThread detachNewThreadSelector:@selector(parse) toTarget:xmlParser withObject:nil]; If anyone has any ideas to get rid of this problem, I would really appreciate it. Thanks.

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  • If attacker has original data, and encrypted data, can they determine the passphrase?

    - by Brad Cupit
    If an attacker has several distinct items (for example: e-mail addresses) and knows the encrypted value of each item, can the attacker more easily determine the secret passphrase used to encrypt those items? Meaning, can they determine the passphrase without resorting to brute force? This question may sound strange, so let me provide a use-case: User signs up to a site with their e-mail address Server sends that e-mail address a confirmation URL (for example: https://my.app.com/confirmEmailAddress/bill%40yahoo.com) Attacker can guess the confirmation URL and therefore can sign up with someone else's e-mail address, and 'confirm' it without ever having to sign in to that person's e-mail account and see the confirmation URL. This is a problem. Instead of sending the e-mail address plain text in the URL, we'll send it encrypted by a secret passphrase. (I know the attacker could still intercept the e-mail sent by the server, since e-mail are plain text, but bear with me here.) If an attacker then signs up with multiple free e-mail accounts and sees multiple URLs, each with the corresponding encrypted e-mail address, could the attacker more easily determine the passphrase used for encryption? Alternative Solution I could instead send a random number or one-way hash of their e-mail address (plus random salt). This eliminates storing the secret passphrase, but it means I need to store that random number/hash in the database. The original approach above does not require this extra table. I'm leaning towards the the one-way hash + extra table solution, but I still would like to know the answer: does having multiple unencrypted e-mail addresses and their encrypted counterparts make it easier to determine the passphrase used?

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  • Nhibernate + Gridview + TargetInvocationException

    - by Scott
    For our grid views, we're setting the data sources as a list of results from an Nhibernate query. We're using lazy loading, so the objects are actually proxied... most of the time. In some instances the list will consist of types of Student and Composition_Aop_Proxy_jklasjdkl31231, which implements the same members as the Student class. We've still got the session open, so the lazy loading would resolve fine, if GridView didn't throw an error about the different types in the gridview. Our current workaround is to clone the object, which results in fetching all of the data that can be lazily loaded, even though most of it won't be accessed.. ever. This, however, converts the proxy into an actual object and the grid view is happy. The performance implications kind of scare me as we're getting closer to rolling the code out as is. I've tried evicting the object after a save, which should ensure that everything is a proxy, but this doesn't seem like a good idea either. Does anyone have any suggestions/workarounds?

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  • How do I strip multiple (optional) parts of a SQL string using .NET Regular Expressions?

    - by Luc
    I've been working on this for a few hours now and can't find any help on it. Basically, I'm trying to strip a SQL string into various parts (fields, from, where, having, groupBy, orderBy). I refuse to believe that I'm the first person to ever try to do this, so I'd like to ask for some advise from the StackOverflow community. :) To understand what I need, assume the following SQL string: select * from table1 inner join table2 on table1.id = table2.id where field1 = 'sam' having table1.field3 > 0 group by table1.field4 order by table1.field5 I created a regular expression to group the parts accordingly: select\s+(?<fields>.+)\s+from\s+(?<from>.+)\s+where\s+(?<where>.+)\s+having\s+(?<having>.+)\s+group\sby\s+(?<groupby>.+)\s+order\sby\s+(?<orderby>.+) This gives me the following results: fields => * from => table1 inner join table2 on table1.id = table2.id where => field1 = 'sam' having => table1.field3 > 0 groupby => table1.field4 orderby => table1.field5 The problem that I'm faced with is that if any part of the SQL string is missing after the 'from' clause, the regular expression doesn't match. To fix that, I've tried putting each optional part in it's own (...)? group but that doesn't work. It simply put all the optional parts (where, having, groupBy, and orderBy) into the 'from' group. Any ideas?

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  • Absence of property syntax in Java

    - by Vojislav Stojkovic
    C# has syntax for declaring and using properties. For example, one can declare a simple property, like this: public int Size { get; set; } One can also put a bit of logic into the property, like this: public string SizeHex { get { return String.Format("{0:X}", Size); } set { Size = int.Parse(value, NumberStyles.HexNumber); } } Regardless of whether it has logic or not, a property is used in the same way as a field: int fileSize = myFile.Size; I'm no stranger to either Java or C# -- I've used both quite a lot and I've always missed having property syntax in Java. I've read in this question that "it's highly unlikely that property support will be added in Java 7 or perhaps ever", but frankly I find it too much work to dig around in discussions, forums, blogs, comments and JSRs to find out why. So my question is: can anyone sum up why Java isn't likely to get property syntax? Is it because it's not deemed important enough when compared to other possible improvements? Are there technical (e.g. JVM-related) limitations? Is it a matter of politics? (e.g. "I've been coding in Java for 50 years now and I say we don't need no steenkin' properties!") Is it a case of bikeshedding?

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  • How important is the .NET programming language when you choose a new job?

    - by Luhmann
    We are currently hiring at the company where I work, and here the codebase is in VB.Net. We are worried that we miss out on a lot of brilliant programmers, who would never ever consider working with VB.Net. My own background is Java and C#, and I was somewhat sceptical as to whether it would work out with VB, as - to be honest - i didn't care much for VB. After a month or so, I was completely fluent in VB, and a few months later i discovered to my surprise, that I actually like VB. I still code my free time projects in C# and Boo though. So my question is firstly, how important is language for you, when you choose a new programming job? Lets say if its a great company, salary is good, and generally an attractive work-place. Would you say no to the perfect job, if the language wasn't your preferred dialect? VB or C# is one thing, but how about Java or C# etc. Secondly if the best developers won't join your company because of your language or platform, would you consider changing, to get the right people? (This is not a language bashing thread, so please no religious language wars) NB: This is Community Wiki

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  • The proper way to script periodically pulling a page from an https site

    - by DarthShader
    I want to create a command-line script for Cygwin/Bash that logs into a site, navigates to a specific page and compares it with the results of the last run. So far, I have it working with Lynx like so: ----snpipped, just setting variables---- echo "# Command logfile created by Lynx 2.8.5rel.5 (29 Oct 2005) ----snipped the recorded keystrokes------- key Right Arrow key p key Right Arrow key ^U" >> $tmp1 #p, right arrow initiate the page saving #"type" the filename inside the "where to save" dialog for i in $(seq 0 $((${#tmp2} - 1))) do echo "key ${tmp2:$i:1}" >> $tmp1 done #hit enter and quit echo "key ^J key y key q key y " >> $tmp1 lynx -accept_all_cookies -cmd_script=$tmp1 https://thewebpage.com/login diff $tmp2 $oldComp mv $tmp2 $oldComp It definitely does not feel "right": the cmd_script consists of relative user actions instead of specifying the exact link names and actions. So, if anything on the site ever changes, switches places, or a new link is added - I will have to re-create the actions. Also, I can't check for any errors so I can't abort the script if something goes wrong (login failed, etc) Another alternative I have been looking at is Mechanize with Ruby (as a note - I have 0 experience with Ruby). What would be the best way to improve or rewrite this?

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  • Arduino variable going blank after first pass.

    - by user541597
    I have an arduino sketch that takes a timet and when that timet is equal to the current time it sets the new timet to timet + 2. For example: char* convert(char* x, String y){ int hour; int minute; sscanf(x, "%d:%d", &hour, &minute); char buf[6]; if (y == "6"){ if (hour > 17){ hour = (hour+6)%24; snprintf(buf, 10, "%d:%d", hour, minute ); }else if (hour < 18){ //hour = hour + 6; minute = (minute + 2); snprintf(buf, 10, "%d:%d", hour, minute); } } if (y == "12"){ if (hour > 11){ hour = (hour+12)%24; snprintf(buf, 10, "%d:%d", hour, minute ); } else if (hour < 12){ hour = hour + 12; snprintf(buf, 10, "%d:%d", hour, minute); } } if (y == "24"){ hour = (hour+24)%24; snprintf(buf, 10, "%d:%d", hour, minute ); } return buf; } sketch starts for example at 1:00am timet is set to 1:02, at system time 1:02 timet == system time my loops looks like this: if (timet == currenttime){ timet = convert(timet) } From this now when ever I check the value of timet it should equal 1:04, however I am getting the correct value at the first run after the execution of convert however everytime after that my timet value is blank. I tried changing the code instead of using the if loop I only run the convert function when I send for example t through the serial monitor, this works fine and outputs the correct timet after the execution of the convert function, So I figured the problem is in the if loop... Any ideas?

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  • Approach for caching data from data logger

    - by filip-fku
    Greetings, I've been working on a C#.NET app that interacts with a data logger. The user can query and obtain logs for a specified time period, and view plots of the data. Typically a new data log is created every minute and stores a measurement for a few parameters. To get meaningful information out of the logger, a reasonable number of logs need to be acquired - data for at least a few days. The hardware interface is a UART to USB module on the device, which restricts transfers to a maximum of about 30 logs/second. This becomes quite slow when reading in the data acquired over a number of days/weeks. What I would like to do is improve the perceived performance for the user. I realize that with the hardware speed limitation the user will have to wait for the full download cycle at least the first time they acquire a larger set of data. My goal is to cache all data seen by the app, so that it can be obtained faster if ever requested again. The approach I have been considering is to use a light database, like SqlServerCe, that can store the data logs as they are received. I am then hoping to first search the cache prior to querying a device for logs. The cache would be updated with any logs obtained by the request that were not already cached. Finally my question - would you consider this to be a good approach? Are there any better alternatives you can think of? I've tried to search SO and Google for reinforcement of the idea, but I mostly run into discussions of web request/content caching. Thanks for any feedback!

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  • Is there any point in using a volatile long?

    - by Adamski
    I occasionally use a volatile instance variable in cases where I have two threads reading from / writing to it and don't want the overhead (or potential deadlock risk) of taking out a lock; for example a timer thread periodically updating an int ID that is exposed as a getter on some class: public class MyClass { private volatile int id; public MyClass() { ScheduledExecutorService execService = Executors.newScheduledThreadPool(1); execService.scheduleAtFixedRate(new Runnable() { public void run() { ++id; } }, 0L, 30L, TimeUnit.SECONDS); } public int getId() { return id; } } My question: Given that the JLS only guarantees that 32-bit reads will be atomic is there any point in ever using a volatile long? (i.e. 64-bit). Caveat: Please do not reply saying that using volatile over synchronized is a case of pre-optimisation; I am well aware of how / when to use synchronized but there are cases where volatile is preferable. For example, when defining a Spring bean for use in a single-threaded application I tend to favour volatile instance variables, as there is no guarantee that the Spring context will initialise each bean's properties in the main thread.

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  • OpenGL ES and real world development

    - by Mark
    Hi Guys, I'm trying to learn OpenGL ES quickly (I know, I know, but these are the pressures that have been thrusted upon me) and I have been read around a fair bit, which lots of success at rendering basic models, some basic lighting and 'some' texturing success too. But this is CONSTANTLY the point at which all OpenGL ES tutorials end, they never say more of what a real life app may need. So I have a few questions that Im hoping arent too difficult. How do people get 3d models from their favorite 3d modeling tool into the iPhone/iPad application? I have seen a couple of blog posts where people have written some python scripts for tools like Blender which create .h files that you can use, is this what people seem to do everytime? Or do the "big" tooling suites (3DS, Maya, etc...) have exporting features? Say I have my model in a nice .h file, all the vertexes, texture points, etc.. are lined up, how to I make my model (say of a basic person) walk? Or to be more general, how do you animate "part" of a model (legs only, turn head, etc...)? Do they need to be a massive mash-up of many different tiny models, or can you pre-bake animations these days "into" models (somehow) Truely great 3D games for the iPhone are (im sure) unbelievably complex, but how do people (game dev firms) seem to manage that designer/developer workflow? Surely not all the animations, textures, etc... are done programatically. I hope these are not stupid questions, and in actual fact, my app that Im trying to investigate how to make is really quite simple, just a basic 3D model that I want to be able to pan/tilt around using touch. Has anyone ever done/seen anything like this that I might be able to read up on? Thanks for any help you can give, I appreciate all types of response big or small :) Cheers, Mark

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  • Cassandra instead of MySQL for social networking app

    - by Christopher McCann
    I am in the middle of building a new app which will have very similar features to Facebook and although obviously it wont ever have to deal with the likes of 400,000,000 million users it will still be used by a substantial user base and most of them will demand it run very very quickly. I have extensive experience with MySQL but a social app offers complexities which MySQL is not well suited too. I know Facebook, Twitter etc have moved towards Cassandra for a lot of their data but I am not sure how far to go with it. For example would you store such things as user data - username, passwords, addresses etc in Cassandra? Would you store e-mails, comments, status updates etc in Cassandra? I have also read alot that something like neo4j is much better for representing the friend relationships used by social apps as it is a graph database. I am only just starting down the NoSQL route so any guidance is greatly appreciated. Would anyone be able to advise me on this? I hope I am not being too general!

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  • Performance Comparison of Shell Scripts vs high level interpreted langs (C#/Java/etc.)

    - by dferraro
    Hi all, First - This is not meant to be a 'which is better, ignorant nonionic war thread'... But rather, I generally need help in making an architecture decision / argument to put forward to my boss. Skipping the details - I simply just would love to know and find the results of anyone who has done some performance comparisons of Shell vs [Insert General Purpose Programming Language (interpreted) here), such as C# or Java... Surprisingly, I have spent some time on Google on searching here to not find any of this data. Has anyone ever done these comparisons, in different use-cases; hitting a database like in a XYX # of loops doing different types of SQL (Oracle pref, but MSSQL would do) queries such as any of the CRUD ops - and also not hitting database and just regular 50k loop type comparison doing different types of calculations, and things of that nature? In particular - for right now, I need to a comparison of hitting an Oracle DB from a shell script vs, lets say C# (again, any GPPL thats interpreted would be fine, even the higher level ones like Python). But I also need to know about standard programming calculations / instructions/etc... Before you ask 'why not just write a quick test yourself? The answer is: I've been a Windows developer my whole life/career and have very limited knowledge of Shell scripting - not to mention *nix as a whole.... So asking the question on here from the more experienced guys would be grealty beneficial, not to mention time saving as we are in near perputual deadline crunch as it is ;). Thanks so much in advance,

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