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  • Python and C++ Sockets converting packet data

    - by yeus
    First of all, to clarify my goal: There exist two programs written in C in our laboratory. I am working on a Proxy Server (bidirectional) for them (which will also mainpulate the data). And I want to write that proxy server in Python. It is important to know that I know close to nothing about these two programs, I only know the definition file of the packets. Now: assuming a packet definition in one of the C++ programs reads like this: unsigned char Packet[0x32]; // Packet[Length] int z=0; Packet[0]=0x00; // Spare Packet[1]=0x32; // Length Packet[2]=0x01; // Source Packet[3]=0x02; // Destination Packet[4]=0x01; // ID Packet[5]=0x00; // Spare for(z=0;z<=24;z+=8) { Packet[9-z/8]=((int)(720000+armcontrolpacket->dof0_rot*1000)/(int)pow((double)2,(double)z)); Packet[13-z/8]=((int)(720000+armcontrolpacket->dof0_speed*1000)/(int)pow((double)2,(double)z)); Packet[17-z/8]=((int)(720000+armcontrolpacket->dof1_rot*1000)/(int)pow((double)2,(double)z)); Packet[21-z/8]=((int)(720000+armcontrolpacket->dof1_speed*1000)/(int)pow((double)2,(double)z)); Packet[25-z/8]=((int)(720000+armcontrolpacket->dof2_rot*1000)/(int)pow((double)2,(double)z)); Packet[29-z/8]=((int)(720000+armcontrolpacket->dof2_speed*1000)/(int)pow((double)2,(double)z)); Packet[33-z/8]=((int)(720000+armcontrolpacket->dof3_rot*1000)/(int)pow((double)2,(double)z)); Packet[37-z/8]=((int)(720000+armcontrolpacket->dof3_speed*1000)/(int)pow((double)2,(double)z)); Packet[41-z/8]=((int)(720000+armcontrolpacket->dof4_rot*1000)/(int)pow((double)2,(double)z)); Packet[45-z/8]=((int)(720000+armcontrolpacket->dof4_speed*1000)/(int)pow((double)2,(double)z)); Packet[49-z/8]=((int)armcontrolpacket->timestamp/(int)pow(2.0,(double)z)); } if(SendPacket(sock,(char*)&Packet,sizeof(Packet))) return 1; return 0; What would be the easiest way to receive that data, convert it into a readable python format, manipulate them and send them forward to the receiver?

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  • Reading and writing C++ vector to a file

    - by JB
    For some graphics work I need to read in a large amount of data as quickly as possible and would ideally like to directly read and write the data structures to disk. Basically I have a load of 3d models in various file formats which take too long to load so I want to write them out in their "prepared" format as a cache that will load much faster on subsequent runs of the program. Is it safe to do it like this? My worries are around directly reading into the data of the vector? I've removed error checking, hard coded 4 as the size of the int and so on so that i can give a short working example, I know it's bad code, my question really is if it is safe in c++ to read a whole array of structures directly into a vector like this? I believe it to be so, but c++ has so many traps and undefined behavour when you start going low level and dealing directly with raw memory like this. I realise that number formats and sizes may change across platforms and compilers but this will only even be read and written by the same compiler program to cache data that may be needed on a later run of the same program. #include <fstream> #include <vector> using namespace std; struct Vertex { float x, y, z; }; typedef vector<Vertex> VertexList; int main() { // Create a list for testing VertexList list; Vertex v1 = {1.0f, 2.0f, 3.0f}; list.push_back(v1); Vertex v2 = {2.0f, 100.0f, 3.0f}; list.push_back(v2); Vertex v3 = {3.0f, 200.0f, 3.0f}; list.push_back(v3); Vertex v4 = {4.0f, 300.0f, 3.0f}; list.push_back(v4); // Write out a list to a disk file ofstream os ("data.dat", ios::binary); int size1 = list.size(); os.write((const char*)&size1, 4); os.write((const char*)&list[0], size1 * sizeof(Vertex)); os.close(); // Read it back in VertexList list2; ifstream is("data.dat", ios::binary); int size2; is.read((char*)&size2, 4); list2.resize(size2); // Is it safe to read a whole array of structures directly into the vector? is.read((char*)&list2[0], size2 * sizeof(Vertex)); }

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  • Using pointers, references, handles to generic datatypes, as generic and flexible as possible

    - by Patrick
    In my application I have lots of different data types, e.g. Car, Bicycle, Person, ... (they're actually other data types, but this is just for the example). Since I also have quite some 'generic' code in my application, and the application was originally written in C, pointers to Car, Bicycle, Person, ... are often passed as void-pointers to these generic modules, together with an identification of the type, like this: Car myCar; ShowNiceDialog ((void *)&myCar, DATATYPE_CAR); The 'ShowNiceDialog' method now uses meta-information (functions that map DATATYPE_CAR to interfaces to get the actual data out of Car) to get information of the car, based on the given data type. That way, the generic logic only has to be written once, and not every time again for every new data type. Of course, in C++ you could make this much easier by using a common root class, like this class RootClass { public: string getName() const = 0; }; class Car : public RootClass { ... }; void ShowNiceDialog (RootClass *root); The problem is that in some cases, we don't want to store the data type in a class, but in a totally different format to save memory. In some cases we have hundreds of millions of instances that we need to manage in the application, and we don't want to make a full class for every instance. Suppose we have a data type with 2 characteristics: A quantity (double, 8 bytes) A boolean (1 byte) Although we only need 9 bytes to store this information, putting it in a class means that we need at least 16 bytes (because of the padding), and with the v-pointer we possibly even need 24 bytes. For hundreds of millions of instances, every byte counts (I have a 64-bit variant of the application and in some cases it needs 6 GB of memory). The void-pointer approach has the advantage that we can almost encode anything in a void-pointer and decide how to use it if we want information from it (use it as a real pointer, as an index, ...), but at the cost of type-safety. Templated solutions don't help since the generic logic forms quite a big part of the application, and we don't want to templatize all this. Additionally, the data model can be extended at run time, which also means that templates won't help. Are there better (and type-safer) ways to handle this than a void-pointer? Any references to frameworks, whitepapers, research material regarding this?

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  • How do I do high quality scaling of a image?

    - by pbhogan
    I'm writing some code to scale a 32 bit RGBA image in C/C++. I have written a few attempts that have been somewhat successful, but they're slow and most importantly the quality of the sized image is not acceptable. I compared the same image scaled by OpenGL (i.e. my video card) and my routine and it's miles apart in quality. I've Google Code Searched, scoured source trees of anything I thought would shed some light (SDL, Allegro, wxWidgets, CxImage, GD, ImageMagick, etc.) but usually their code is either convoluted and scattered all over the place or riddled with assembler and little or no comments. I've also read multiple articles on Wikipedia and elsewhere, and I'm just not finding a clear explanation of what I need. I understand the basic concepts of interpolation and sampling, but I'm struggling to get the algorithm right. I do NOT want to rely on an external library for one routine and have to convert to their image format and back. Besides, I'd like to know how to do it myself anyway. :) I have seen a similar question asked on stack overflow before, but it wasn't really answered in this way, but I'm hoping there's someone out there who can help nudge me in the right direction. Maybe point me to some articles or pseudo code... anything to help me learn and do. Here's what I'm looking for: 1. No assembler (I'm writing very portable code for multiple processor types). 2. No dependencies on external libraries. 3. I am primarily concerned with scaling DOWN, but will also need to write a scale up routine later. 4. Quality of the result and clarity of the algorithm is most important (I can optimize it later). My routine essentially takes the following form: DrawScaled( uint32 *src, uint32 *dst, src_x, src_y, src_w, src_h, dst_x, dst_y, dst_w, dst_h ); Thanks! UPDATE: To clarify, I need something more advanced than a box resample for downscaling which blurs the image too much. I suspect what I want is some kind of bicubic (or other) filter that is somewhat the reverse to a bicubic upscaling algorithm (i.e. each destination pixel is computed from all contributing source pixels combined with a weighting algorithm that keeps things sharp. EXAMPLE: Here's an example of what I'm getting from the wxWidgets BoxResample algorithm vs. what I want on a 256x256 bitmap scaled to 55x55. And finally: the original 256x256 image

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  • Parsing XML data with Namespaces in PHP

    - by osbmedia
    I'm trying to work with this XML feed that uses namespaces and i'm not able to get past the colon in the tags. Here's how the XML feed looks like: <r25:events pubdate="2010-05-19T13:58:08-04:00"> <r25:event xl:href="event.xml?event_id=328" id="BRJDMzI4" crc="00000022" status="est"> <r25:event_id>328</r25:event_id> <r25:event_name>Testing 09/2005-08/2006</r25:event_name> <r25:alien_uid/> <r25:event_priority>0</r25:event_priority> <r25:event_type_id xl:href="evtype.xml?type_id=105">105</r25:event_type_id> <r25:event_type_name>CABINET</r25:event_type_name> <r25:node_type>C</r25:node_type> <r25:node_type_name>cabinet</r25:node_type_name> <r25:state>1</r25:state> <r25:state_name>Tentative</r25:state_name> <r25:event_locator>2005-AAAAMQ</r25:event_locator> <r25:event_title/> <r25:favorite>F</r25:favorite> <r25:organization_id/> <r25:organization_name/> <r25:parent_id/> <r25:cabinet_id xl:href="event.xml?event_id=328">328</r25:cabinet_id> <r25:cabinet_name>cabinet 09/2005-08/2006</r25:cabinet_name> <r25:start_date>2005-09-01</r25:start_date> <r25:end_date>2006-08-31</r25:end_date> <r25:registration_url/> <r25:last_mod_dt>2008-02-27T14:22:43-05:00</r25:last_mod_dt> <r25:last_mod_user>abc00296004</r25:last_mod_user> </r25:event> </r25:events> And here is what I'm using for code - I'll trying to throw these into a bunch of arrays where I can format the output however I want: <?php $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, "http://somedomain.com/blah.xml"); curl_setopt ($ch, CURLOPT_HTTPHEADER, Array("Content-Type: text/xml")); curl_setopt($ch, CURLOPT_USERPWD, "username:password"); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); $output = curl_exec($ch); curl_close($ch); $xml = new SimpleXmlElement($output); foreach ($xml->events->event as $entry){ $dc = $entry->children('http://www.collegenet.com/r25'); echo $entry->event_name . "<br />"; echo $entry->event_id . "<br /><br />"; }

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  • PDF Report generation

    - by IniTech
    EDIT : I completed this project using ABCpdf. For anyone interested, I love this product and their support is A+. Everything I listed as a 'Con' for the HTML - PDF solution was easily doable in ABCpdf. I've been charged with creating a data driven pdf report. After reviewing the plethora of options, I have narrowed it down to 2. I need you all to to help me decide, or offer alternatives I haven't considered. Here are the requirements: 100% Data driven Eventually PDF (a stop in HTML is fine, so long as it is converted) Can be run with multiple sets of data (the layout is always the same, the data is variable) Contains normal analysis-style copy (saved in DB with html markup) Contains tables (data for tables is generated at run-time) Header/Page # on each page Table of Contents .NET (VB or C#) Done quickly Now, because of the fact that the report is going to be generated with multiple sets of data, I don't think a stamped pdf template will work since I won't know how long or how many pages a certain piece of the report could require. So, I think my best options are: Programmatic creation using an iText-like solution. Generate in HTML and convert to PDF using a third-party application (ABCPdf is the tool I have played with so far) Both solutions have their pro's and con's. Programmatic solution: Pros: Flexible Easy page numbering/page header/table of contents Free Cons: Time consuming (to write a layer on top of iText to do what I need and keep maintainable) Since the copy is already stored in the db with html markup, I would have to parse through the data before I place it into the pdf, ensuring I don't have to break the paragraph into chunks so I can apply bold, italic, underline, etc. to specific phrases. This seems like a huge PITA, and I hope I am wrong about that assumption. HTML - PDF Pros: Easy to generate from db (no parsing necessary) Many tools for conversion Uses technology I am already familiar with Built-in "Print Preview" - not a req, but nice Cons: (Edited after project completion. All of my assumptions were incorrect and ABCpdf is awesome) 1. Almost impossible to generate page headers - Not True 2. Very difficult to generate page numbers Not True 3. Nearly impossible to generate table of contents Not True 4. (Cross-browser support isn't a con; Since its internal, I can dictate what browser to use) 5. Conversion tool quirks - may not convert exactly as rendered in browser Not True 6. Overall, I think it would be very hard to format the HTML exactly as I would want it to appear/convert to PDF. Not True That's it - I need the communitys help in deciding which way I should go. I might be wrong about some of my Pro/Con assumptions. If I am, please tell me. All thoughts and suggestions are welcome and appreciated. Thanks

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  • Is "Systems Designer" the job title that best describes what I do? [closed]

    - by ivo-rossi
    After having worked as Java developer for almost 3 years in the same company that I currently work at, I moved to a new position associated with the development of the same application. I’m in this new position for more than 1 year now. My official job title is Systems Designer, but I’m not sure this is a title that expresses well what I do. So my question here is what would be the most appropriate job title for me? I see this question as important for my career development. After all, I should be able to explain in one word what I do. And it’s no longer “Java Developer”. Well, in more than one word, this is what I do: The business analysts gather requirements / business problems to be solved with the clients and then discuss these requirements with me. Given the requirements, I design the high level solutions to be implemented in our system (e.g. a new screen on the client application, modifications to existing reports, extension to the XML export format of some objects, etc). I base my decision on the current capabilities of the system, the overall impact that the solutions would have on the system and the estimated effort to implement them (as I was a developer of this same application for almost 3 years before I moved to this position, I’m confident in my estimates). The solutions are discussed iteratively with the business analysts until we agree that they are good. The outcome of this analysis is what we call the “requirements design” document, which is written by me, shared with clients for approval and then also with the team that is going to implement the solutions and test them. Note that there are a few problems that I need to find a solution for that are non-functional. If the users are unhappy with the performance of a certain tool, I will investigate what can be done to speed it up. I will do some research – often based in the Java code itself - to identify possibilities of optimizations. But in this new position I no longer code, the main outcome of my work is really the “requirements design”. Is “Systems Designer” really the most appropriate job title?

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  • How can I create the XML::Simple data structure using a Perl XML SAX parser?

    - by DVK
    Summary: I am looking a fast XML parser (most likely a wrapper around some standard SAX parser) which will produce per-record data structure 100% identical to those produced by XML::Simple. Details: We have a large code infrastructure which depends on processing records one-by-one and expects the record to be a data structure in a format produced by XML::Simple since it always used XML::Simple since early Jurassic era. An example simple XML is: <root> <rec><f1>v1</f1><f2>v2</f2></rec> <rec><f1>v1b</f1><f2>v2b</f2></rec> <rec><f1>v1c</f1><f2>v2c</f2></rec> </root> And example rough code is: sub process_record { my ($obj, $record_hash) = @_; # do_stuff } my $records = XML::Simple->XMLin(@args)->{root}; foreach my $record (@$records) { $obj->process_record($record) }; As everyone knows XML::Simple is, well, simple. And more importantly, it is very slow and a memory hog—due to being a DOM parser and needing to build/store 100% of data in memory. So, it's not the best tool for parsing an XML file consisting of large amount of small records record-by-record. However, re-writing the entire code (which consist of large amount of "process_record"-like methods) to work with standard SAX parser seems like an big task not worth the resources, even at the cost of living with XML::Simple. I'm looking for an existing module which will probably be based on a SAX parser (or anything fast with small memory footprint) which can be used to produce $record hashrefs one by one based on the XML pictured above that can be passed to $obj->process_record($record) and be 100% identical to what XML::Simple's hashrefs would have been. I don't care much what the interface of the new module is; e.g whether I need to call next_record() or give it a callback coderef accepting a record.

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  • Add Access-Control-Allow-Origin to header in PHP

    - by SANDeveloper
    I am trying to workaround CORS restriction on a WebGL application. I have a Web Service which resolves URL and returns images. Since this web service is not CORS enabled, I can't use the returned images as textures. I was planning to: Write a PHP script to handle image requests Image requests would be sent through the query string as a url parameter The PHP Script will: Call the web service with the query string url Fetch the image response (web service returns a content-type:image response) Add the CORS header (Add Access-Control-Allow-Origin) to the response Send the response to the browser I tried to implement this using a variety of techniques including CURL, HTTPResponse, plain var_dump etc. but got stuck at some point in each. So I have 2 questions: Is the approach good enough? Considering the approach is good enough: I made the most progress with CURL. I could get the image header and data with: $ch = curl_init(); $url = $_GET["url"]; curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_HEADER, true); curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type:image/jpeg')); //Execute request $response = curl_exec($ch); //get the default response headers $headers = curl_getinfo($ch); //close connection curl_close($ch); But this doesn't actually change set the response content-type to image/jpeg. It dumps the header + response into a new response of content-type text/html and display the header and the image BLOB data in the browser. How do I get it to send the response in the format I want? Managed to get it working: $ch = curl_init(); $url = $_GET["url"]; curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_HEADER, false); //Execute request $response = curl_exec($ch); //get the default response headers $headers = curl_getinfo($ch); curl_setopt($ch, CURLOPT_HTTPHEADER, $headers); header('Content-Type: image/jpeg'); header("Access-Control-Allow-Origin: *"); // header("Expires: Sat, 26 Jul 2017 05:00:00 GMT"); //close connection curl_close($ch); flush();

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  • Running a graph returns E_FAIL

    - by Manish
    Hi, I have been struggling for a while now to get my filter graph to run .I am trying to crop a .wmv file into smaller duration .wmv files .It looks quite a simple task I dont know why its is getting so complicated.I follow this Source- SampleGrabber-WMA sf writer. Here is my code IBaseFilter* pASFWriter; ICaptureGraphBuilder2 * pBuilder=NULL; CoCreateInstance(CLSID_CaptureGraphBuilder2,NULL,CLSCTX_INPROC_SERVER,IID_ICaptureGraphBuilder2,(LPVOID*)&pBuilder); pBuilder-SetFiltergraph(pGraphBuilder); pBuilder-SetOutputFileName(&MEDIASUBTYPE_Asf,OUTFILE,&pASFWriter,NULL); IConfigAsfWriter *pConfig=NULL; HRESULT hr80 = pASFWriter-QueryInterface(IID_IConfigAsfWriter, (void**)&pConfig); if (SUCCEEDED(hr80)) { // Configure the ASF Writer filter. pConfig-Release(); } IBaseFilter *pSource=NULL; pGraphBuilder->AddSourceFilter(FILENAME,L"Source",&pSource); IBaseFilter *pGrabberF2=NULL; ISampleGrabber *pGrabber2=NULL; CoCreateInstance(CLSID_SampleGrabber,NULL,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&pGrabberF2)); pGraphBuilder->AddFilter(pGrabberF2,L"Sample Grabber2"); AM_MEDIA_TYPE mt1; ZeroMemory(&mt1,sizeof(mt1)); mt1.majortype=MEDIATYPE_Video; mt1.subtype=MEDIASUBTYPE_RGB24; pGrabberF2->QueryInterface(IID_ISampleGrabber,(void**)(&pGrabber2)); pGrabber2->SetBufferSamples(TRUE); pGrabber2->SetOneShot(FALSE); pGrabber->SetMediaType(&mt1); pSource->EnumPins(&pEnum2); pEnum2->Next(1,&pPin2,NULL); HRESULT hr108=ConnectFilters(pGraphBuilder,pPin2,pGrabberF2);//Source to Grabber pGrabberF2->EnumPins(&pEnum3); IEnumPins *pEnum4=NULL; pASFWriter->EnumPins(&pEnum4); IPin* pPin4=NULL; while (S_OK==pEnum3->Next(1,&pPin3,NULL)&& S_OK==pEnum4->Next(1,&pPin4,NULL)){ pGraphBuilder->Connect(pPin3,pPin4);//Grabber to FileWriter } pGraphBuilder->RenderFile(FILENAME,NULL);//FILENAME=INPUTFILENAME (.wmv format) pMediaPosition->put_CurrentPosition(start); pMediaPosition->put_StopTime(stop); HRESULT test1=pMediaControl->Run(); All of it runs fine(returns S_OK) .But test1 returns E_FAIL and no file is created.Can somebody help?

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  • Xpath expression to retrieve oldest/earliest node

    - by gkrogers
    I have an XML snippet, so: <STATES> <STATE> <NAME>Alabama</NAME> <ABBREVIATION>AL</ABBREVIATION> <CAPITAL>Montgomery</CAPITAL> <POPULATION>4661900</POPULATION> <AREA>52419</AREA> <DATEOFSTATEHOOD>14 December 1819</DATEOFSTATEHOOD> </STATE> <STATE> <NAME>Alaska</NAME> <ABBREVIATION>AK</ABBREVIATION> <CAPITAL>Juneau</CAPITAL> <POPULATION>698473</POPULATION> <AREA>663268</AREA> <DATEOFSTATEHOOD>1 January 1959</DATEOFSTATEHOOD> </STATE> <STATE> <NAME>Delaware</NAME> <ABBREVIATION>DE</ABBREVIATION> <CAPITAL>Dover</CAPITAL> <POPULATION>885122</POPULATION> <AREA>2490</AREA> <DATEOFSTATEHOOD>7 December 1787</DATEOFSTATEHOOD> </STATE> </STATES> <etc, etc.> I want to retrieve (for example) the capital of the oldest state (i.e. "Dover"). I have managed to get this far: //STATES/STATE[DATEOFSTATEHOOD='7 December 1787']/CAPITAL/text() but can't figure out how to say 'DATEOFSTATEHOOD={the earliest DATEOFSTATEHOOD}'. Can anybody point me in the right direction, please? SOLUTION: Matt's solution is more or less spot on. I had to reformat the dates (I used YYYYMMDDD) because, as was pointed out, Xpath 1.0 doesn't support the date format I was using. Also, Microsoft's XML library (4.0 and 6.0) returned the whole node list with Matt's expression. Reversing the test fixed that problem, making it return just the earliest node. So: //STATES/STATE[(DATEOFSTATEHOOD < //STATES/STATE/DATEOFSTATEHOOD)]/CAPITAL/text()

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  • How to stream semi-live audio over internet

    - by Thomas Tempelmann
    I want to write something like Skype, i.e. I have a constant audio stream on one computer and then recompress it in a format that's suitable for a latent internet connection, receive it on the other end and play it. Let's also assume that the internet connection is fairly modern and fast, i.e. DSL or alike, no slow connections over phone and such. The involved computers will also be rather modern (Dual Core Intel CPUs at 2GHz or more). I know how to handle the audio on the machines. What I don't know is how to transmit the audio in an efficient way. The challenges are: I'd like get good audio quality across the line. The stream should be received without drops. The stream may, however, be received with a little delay (a second delay is acceptable). I imagine that the transport software could first determine the average (and max) latency, then start the stream and tell the receiver to wait for that max latency before starting to play the audio. With that, if the latency doesn't get any higher, the entire stream will be playable on the other side without stutter or drops. If, due to unexpected IP latencies or blockages, the stream does get cut off, I want to be able to notice this so that I can take actions (e.g. abort the stream) and eventually start a new transmission. What are my options if I want do use ready-made software for the compression and tranmission? I have no intention to write my own audio compression engine, really. OTOH, I plan to sell the solution in a vertical market, meaning I can afford a few dollars of license fees per copy, but not $100s. I guess the simplest solution would be to just open a TCP stream, send a few packets back and forth to determine their running time (or even use UDP for that), then use the results as the guide for my max latency value, then simply fire the audio data in its raw form (uncompressed 16 bit stereo), along with a timing code over the TCP connection. The receiver reads the data and plays it with the pre-determined delay. That might just work with the type of fast connection I expect. I just wonder if there are better solutions to reach this goal, with better performance (lower latency) and less data (compressed). BTW, I first try to implement this on OS X, but might want to do it on Windows, too, if it proves successful.

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  • How to replace all id attributes of a child collection of complex types using jQuery in ASP.net MVC

    - by TJB
    Here's my situation: I'm writing an ASP.net MVC 1 website and I have a create/edit form that uses the default model binding to parse the form into a strongly typed complex object. The object I'm posting has a child collection of another complex type and the way I format my id's for the model binder is as follows: <div class="childContainer" > <!-- There's one of these for each property for each child collection item --> <%= Html.TextBox("ChildCollectionName[0].ChildPropertyName", /* blah blah */ ) %> <%= Html.TextBox("ChildCollectionName[0].OtherChildPropertyName", /* blah blah */ ) %> <!-- ... --> </div> This gets rendered as <div class="childContainer" > <input id="ChildCollectionName[0]_ChildPropertyName" ... /> <input id="ChildCollectionName[0]_OtherChildPropertyName" ... /> ... </div> <div class="childContainer" > <input id="ChildCollectionName[1]_ChildPropertyName" ... /> <input id="ChildCollectionName[1]_OtherChildPropertyName" ... /> ... </div> For each entry in the chlid collection. This collection is dynamically created in the form using jQuery, so entries can be added, removed etc. and whenever there's an operation on the collection I need to update the indexes so that it's bound correctly on the server side. What's the best way to replace all the html input id's when I'm updating the index within the child e.g. replace all [*] -- [N] where N is the correct index. using jQuery / JavaScript ? I have something coded now, but its buggy and I think there is a simpler solution. Also, if you have an easier way to identify the child collection I'll take any advice on that as well. Thanx!

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  • How do you create a MANIFEST.MF that's available when you're testing and running from a jar in produ

    - by warvair
    I've spent far too much time trying to figure this out. This should be the simplest thing and everyone who distributes Java applications in jars must have to deal with it. I just want to know the proper way to add versioning to my Java app so that I can access the version information when I'm testing, e.g. debugging in Eclipse and running from a jar. Here's what I have in my build.xml: <target name="jar" depends = "compile"> <property name="version.num" value="1.0.0"/> <buildnumber file="build.num"/> <tstamp> <format property="TODAY" pattern="yyyy-MM-dd HH:mm:ss" /> </tstamp> <manifest file="${build}/META-INF/MANIFEST.MF"> <attribute name="Built-By" value="${user.name}" /> <attribute name="Built-Date" value="${TODAY}" /> <attribute name="Implementation-Title" value="MyApp" /> <attribute name="Implementation-Vendor" value="MyCompany" /> <attribute name="Implementation-Version" value="${version.num}-b${build.number}"/> </manifest> <jar destfile="${build}/myapp.jar" basedir="${build}" excludes="*.jar" /> </target> This creates /META-INF/MANIFEST.MF and I can read the values when I'm debugging in Eclipse thusly: public MyClass() { try { InputStream stream = getClass().getResourceAsStream("/META-INF/MANIFEST.MF"); Manifest manifest = new Manifest(stream); Attributes attributes = manifest.getMainAttributes(); String implementationTitle = attributes.getValue("Implementation-Title"); String implementationVersion = attributes.getValue("Implementation-Version"); String builtDate = attributes.getValue("Built-Date"); String builtBy = attributes.getValue("Built-By"); } catch (IOException e) { logger.error("Couldn't read manifest."); } } But, when I create the jar file, it loads the manifest of another jar (presumably the first jar loaded by the application - in my case, activation.jar). Also, the following code doesn't work either although all the proper values are in the manifest file. Package thisPackage = getClass().getPackage(); String implementationVersion = thisPackage.getImplementationVersion(); Any ideas?

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  • Improving performance on data pasting 2000 rows with validations

    - by Lohit
    I have N rows (which could be nothing less than 1000) on an excel spreadsheet. And in this sheet our project has 150 columns like this: Now, our application needs data to be copied (using normal Ctrl+C) and pasted (using Ctrl+V) from the excel file sheet on our GUI sheet. Copy pasting 1000 records takes around 5-6 seconds which is okay for our requirement, but the problem is when we need to make sure the data entered is valid. So we have to validate data in each row generate appropriate error messages and format the data as per requirement. So we need to at runtime parse and evaluate data in each row. Now all the formatting of data and validations come from the back-end database and we have it in a data-table (dtValidateAndFormatConditions). The conditions would be around 50. So you can see how slow this whole process becomes since N X 150 X 50 operations are required to complete this whole process. Initially it took approximately 2-3 minutes but now i have reduced it to 20 - 30 seconds. However i have increased the speed by making an expression parser of my own - and not by any algorithm, is there any other way i can improve performance, by using Divide and Conquer or some other mechanism. Currently i am not really sure how to go about this. Here is what part of my code looks like: public virtual void ValidateAndFormatOnCopyPaste(DataTable DtCopied, int CurRow) { foreach (DataRow dRow in dtValidateAndFormatConditions.Rows) { string Condition = dRow["Condition"]; string FormatValue = Value = dRow["Value"]; GetValidatedFormattedData(DtCopied,ref Condition, ref FormatValue ,iRowIndex); Condition = Parse(Condition); dRow["Condition"] = Condition; FormatValue = Parse(FormatValue ); dRow["Value"] = FormatValue; } } The above code gets called row-wise like this: public override void ValidateAndFormat(DataTable dtChangedRecords, CellRange cr) { int iRowStart = cr.Row, iRowEnd = cr.Row + cr.RowCount; for (int iRow = iRowStart; iRow < iRowEnd; iRow++) { ValidateAndFormatOnCopyPaste(dtChangedRecords,iRow); } } Please know my question needs a more algorithmic solution than code optimization, however any answers containing code related optimizations will be appreciated as well. (Tagged Linq because although not seen i have been using linq in some parts of my code).

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  • clarification on the concept of "web service"

    - by udit
    Im a little confused on the varying definitions and implementations of web services available as implementations. Need some clarification please. Ones I have used till now: If a vendor gives me a specific format of XML that I can send populated with data to request and I make a simple HTTP POST over the internet passing in the XML String as the payload, is this a web service call ? If so, is there a specific name to it, this kind of web service ? Because obviously, it does not use anything like Axis, WSDL or SOAP to establish this connection. A variant of this is If the vendor gives me an XSD, I use JAXB to make a java class out of it and pass in the serialized version of the object, which eventually works out to be the same as option 1. RESTful web service: Vendor gives me a URL like http://restfulservice/products and I can make HTTP Requests to the URL and depending on what HTTP verb I use, the appropropriate action is called and the response sent over the wire. Ones I have only read about\ have a vague idea about SOAP. How does this work?.. Ive read the W3Schools tutorial and I undertsand that there is a very specific form of XML that is standardized according to W3C standards that we use to pass the same kind of messages as we did in option 1. But how does this work in real life? Vendor sends me what? Do I generate classes? Do I serialize some objects and http post them over to an address? Or do the generated objects themselves have connection methods that will do them for me? What about WSDL? When does a vendor send me WSDL and what do I do with it ? I guess I can generate classes from it. If yes, then what do I do with the generated classes ? When do I need that axis jar to generate classes from something that the vendor sends ? As you can see, I have some clear and other mostly vague ideas about the different kinds of web services available. would help if someone ould clarify and\or point to more real-world resources. I've looked a little bit into Java Web Services on the internet and the numerous four letter acronyms that get thrown at me make me dizzy. Thanks

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  • How do I return clean JSON from a WCF Service?

    - by user208662
    I am trying to return some JSON from a WCF service. This service simply returns some content from my database. I can get the data. However, I am concerned about the format of my JSON. Currently, the JSON that gets returned is formatted like this: {"d":"[{\"Age\":35,\"FirstName\":\"Peyton\",\"LastName\":\"Manning\"},{\"Age\":31,\"FirstName\":\"Drew\",\"LastName\":\"Brees\"},{\"Age\":29,\"FirstName\":\"Tony\",\"LastName\":\"Romo\"}]"} In reality, I would like my JSON to be formatted as cleanly as possible. I believe (I may be incorrect), that the same collection of results, represented in clean JSON, should look like so: [{"Age":35,"FirstName":"Peyton","LastName":"Manning"},{"Age":31,"FirstName":"Drew","LastName":"Brees"},{"Age":29,"FirstName":"Tony","LastName":"Romo"}] I have no idea where the “d” is coming from. I also have no clue why the escape characters are being inserted. My entity looks like the following: [DataContract] public class Person { [DataMember] public string FirstName { get; set; } [DataMember] public string LastName { get; set; } [DataMember] public int Age { get; set; } public Person(string firstName, string lastName, int age) { this.FirstName = firstName; this.LastName = lastName; this.Age = age; } } The service that is responsible for returning the content is defined as: [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class TestService { [OperationContract] [WebGet(ResponseFormat = WebMessageFormat.Json)] public string GetResults() { List<Person> results = new List<Person>(); results.Add(new Person("Peyton", "Manning", 35)); results.Add(new Person("Drew", "Brees", 31)); results.Add(new Person("Tony", "Romo", 29)); // Serialize the results as JSON DataContractJsonSerializer serializer = new DataContractJsonSerializer(results.GetType()); MemoryStream memoryStream = new MemoryStream(); serializer.WriteObject(memoryStream, results); // Return the results serialized as JSON string json = Encoding.Default.GetString(memoryStream.ToArray()); return json; } } How do I return “clean” JSON from a WCF service? Thank you!

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  • youtube - video upload failure - unable to convert file - encoding the video wrong?

    - by Anthony
    I am using .NET to create a video uploading application. Although it's communicating with YouTube and uploading the file, the processing of that file fails. YouTube gives me the error message, "Upload failed (unable to convert video file)." This supposedly means that "your video is in a format that our converters don't recognize..." I have made attempts with two different videos, both of which upload and process fine when I do it manually. So I suspect that my code is a.) not encoding the video properly and/or b.) not sending my API request properly. Below is how I am constructing my API PUT request and encoding the video: Any suggestions on what the error could be would be appreciated. Thanks P.S. I'm not using the client library because my application will use the resumable upload feature. Thus, I am manually constructing my API requests. Documentation: http://code.google.com/intl/ja/apis/youtube/2.0/developers_guide_protocol_resumable_uploads.html#Uploading_the_Video_File Code: // new PUT request for sending video WebRequest putRequest = WebRequest.Create(uploadURL); // set properties putRequest.Method = "PUT"; putRequest.ContentType = getMIME(file); //the MIME type of the uploaded video file //encode video byte[] videoInBytes = encodeVideo(file); public static byte[] encodeVideo(string video) { try { byte[] fileInBytes = File.ReadAllBytes(video); Console.WriteLine("\nSize of byte array containing " + video + ": " + fileInBytes.Length); return fileInBytes; } catch (Exception e) { Console.WriteLine("\nException: " + e.Message + "\nReturning an empty byte array"); byte [] empty = new byte[0]; return empty; } }//encodeVideo //encode custom headers in a byte array byte[] PUTbytes = encode(putRequest.Headers.ToString()); public static byte[] encode(string headers) { ASCIIEncoding encoding = new ASCIIEncoding(); byte[] bytes = encoding.GetBytes(headers); return bytes; }//encode //entire request contains headers + binary video data putRequest.ContentLength = PUTbytes.Length + videoInBytes.Length; //send request - correct? sendRequest(putRequest, PUTbytes); sendRequest(putRequest, videoInBytes); public static void sendRequest(WebRequest request, byte[] encoding) { Stream stream = request.GetRequestStream(); // The GetRequestStream method returns a stream to use to send data for the HttpWebRequest. try { stream.Write(encoding, 0, encoding.Length); } catch (Exception e) { Console.WriteLine("\nException writing stream: " + e.Message); } }//sendRequest

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  • How to verify if the private key matches with the certificate..?

    - by surendhar_s
    I have the private key stored as .key file.. -----BEGIN RSA PRIVATE KEY----- MIICXAIBAAKBgQD5YBS6V3APdgqaWAkijIUHRK4KQ6eChSaRWaw9L/4u8o3T1s8J rUFHQhcIo5LPaQ4BrIuzHS8yzZf0m3viCTdZAiDn1ZjC2koquJ53rfDzqYxZFrId 7a4QYUCvM0gqx5nQ+lw1KoY/CDAoZN+sO7IJ4WkMg5XbgTWlSLBeBg0gMwIDAQAB AoGASKDKCKdUlLwtRFxldLF2QPKouYaQr7u1ytlSB5QFtIih89N5Avl5rJY7/SEe rdeL48LsAON8DpDAM9Zg0ykZ+/gsYI/C8b5Ch3QVgU9m50j9q8pVT04EOCYmsFi0 DBnwNBRLDESvm1p6NqKEc7zO9zjABgBvwL+loEVa1JFcp5ECQQD9/sekGTzzvKa5 SSVQOZmbwttPBjD44KRKi6LC7rQahM1PDqmCwPFgMVpRZL6dViBzYyWeWxN08Fuv p+sIwwLrAkEA+1f3VnSgIduzF9McMfZoNIkkZongcDAzjQ8sIHXwwTklkZcCqn69 qTVPmhyEDA/dJeAK3GhalcSqOFRFEC812QJAXStgQCmh2iaRYdYbAdqfJivMFqjG vgRpP48JHUhCeJfOV/mg5H2yDP8Nil3SLhSxwqHT4sq10Gd6umx2IrimEQJAFNA1 ACjKNeOOkhN+SzjfajJNHFyghEnJiw3NlqaNmEKWNNcvdlTmecObYuSnnqQVqRRD cfsGPU661c1MpslyCQJBAPqN0VXRMwfU29a3Ve0TF4Aiu1iq88aIPHsT3GKVURpO XNatMFINBW8ywN5euu8oYaeeKdrVSMW415a5+XEzEBY= -----END RSA PRIVATE KEY----- And i extracted public key from ssl certificate file.. Below is the code i tried to verify if private key matches with ssl certificate or not.. I used the modulus[i.e. private key get modulus==public key get modulus] to check if they are matching.. And this seems to hold only for RSAKEYS.. But i want to check for other keys as well.. Is there any other alternative to do the same..?? private static boolean verifySignature(File serverCertificateFile, File serverCertificateKey) { try { byte[] certificateBytes = FileUtils.readFileToByteArray(serverCertificateFile); //byte[] keyBytes = FileUtils.readFileToByteArray(serverCertificateKey); RandomAccessFile raf = new RandomAccessFile(serverCertificateKey, "r"); byte[] buf = new byte[(int) raf.length()]; raf.readFully(buf); raf.close(); PKCS8EncodedKeySpec kspec = new PKCS8EncodedKeySpec(buf); KeyFactory kf; try { kf = KeyFactory.getInstance("RSA"); RSAPrivateKey privKey = (RSAPrivateKey) kf.generatePrivate(kspec); CertificateFactory certFactory = CertificateFactory.getInstance("X.509"); InputStream in = new ByteArrayInputStream(certificateBytes); //Generate Certificate in X509 Format X509Certificate cert = (X509Certificate) certFactory.generateCertificate(in); RSAPublicKey publicKey = (RSAPublicKey) cert.getPublicKey(); in.close(); return privKey.getModulus() == publicKey.getModulus(); } catch (NoSuchAlgorithmException ex) { logger.log(Level.SEVERE, "Such algorithm is not found", ex); } catch (CertificateException ex) { logger.log(Level.SEVERE, "certificate exception", ex); } catch (InvalidKeySpecException ex) { Logger.getLogger(CertificateConversion.class.getName()).log(Level.SEVERE, null, ex); } } catch (IOException ex) { logger.log(Level.SEVERE, "Signature verification failed.. This could be because the file is in use", ex); } return false; } And the code isn't working either.. throws invalidkeyspec exception

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  • Renaming nodes and values with xslt

    - by T.K.
    Hello world, I'm new to xslt, and have a task that I'm not really sure where to go with. I want to rename nodes, but maintain the format all node declarations. In the actual context I'll be applying this to, I'll be doing a series of renames like this, but for the sake of brevity, the sample I've written up only involves renaming one node. I am using XSL 1.0. Input: <variables> <var> <RENAME> a </RENAME> </var> <var RENAME='b'/> <var> <DO_NOT_TOUCH> c </DO_NOT_TOUCH> </var> <var DO_NOT_TOUCH='d'/> </variables> Desired Output: <variables> <var> <DONE> a </DONE> </var> <var DONE='b'/> <var> <DO_NOT_TOUCH> c </DO_NOT_TOUCH> </var> <var DO_NOT_TOUCH='d'/> </variables> My xslt: <xsl:template match="RENAME"> <RENAMED> <xsl:apply-templates select="@*|node()"/> </RENAMED> </xsl:template> <xsl:template match="@*|node()"> <xsl:copy> <xsl:apply-templates select="@*|node()"/> </xsl:copy> </xsl:template> Current Output <variables> <var> <RENAMED> a </RENAMED> </var> <var RENAME="b"> </var> <var> <DO_NOT_TOUCH> c </DO_NOT_TOUCH> </var> <var DO_NOT_TOUCH="d"> </var> </variables>

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  • using LoadControl with object initializer to create properties

    - by lloydphillips
    In the past I've used UserControls to create email templates which I can fill properties on and then use LoadControl and then RenderControl to get the html for which to use for the body text of my email. This was within asp.net webforms. I'm in the throws of building an mvc website and wanted to do something similar. I've actually considered putting this functionality in a seperate class library and am looking into how I can do this so that in my web layer I can just call EmailTemplate.SubscriptionEmail() which will then generate the html from my template with properties in relevant places (obviously there needs to be parameters for email address etc in there). I wanted to create a single Render control method for which I can pass a string to the path of the UserControl which is my template. I've come across this on the web that kind of suits my needs: public static string RenderUserControl(string path, string propertyName, object propertyValue) { Page pageHolder = new Page(); UserControl viewControl = (UserControl)pageHolder.LoadControl(path); if (propertyValue != null) { Type viewControlType = viewControl.GetType(); PropertyInfo property = viewControlType.GetProperty(propertyName); if (property != null) property.SetValue(viewControl, propertyValue, null); else { throw new Exception(string.Format( "UserControl: {0} does not have a public {1} property.", path, propertyName)); } } pageHolder.Controls.Add(viewControl); StringWriter output = new StringWriter(); HttpContext.Current.Server.Execute(pageHolder, output, false); return output.ToString(); } My issue is that my UserControl(s) may have multiple and differing properties. So SubscribeEmail may require FirstName and EmailAddress where another email template UserControl (lets call it DummyEmail) would require FirstName, EmailAddress and DateOfBirth. The method above only appears to carry one parameter for propertyName and propertyValue. I considered an array of strings that I could put the varying properties into but then I thought it'd be cool to have an object intialiser so I could call the method like this: RenderUserControl("EmailTemplates/SubscribeEmail.ascs", new object() { Firstname="Lloyd", Email="[email protected]" }) Does that make sense? I was just wondering if this is at all possible in the first place and how I'd implement it? I'm not sure if it would be possible to map the properties set on 'object' to properties on the loaded user control and if it is possible where to start in doing this? Has anyone done something like this before? Can anyone help? Lloyd

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  • MATLAB image corner coordinates & referncing to cell arrays

    - by James
    Hi, I am having some problems comparing the elements in different cell arrays. The context of this problem is that I am using the bwboundaries function in MATLAB to trace the outline of an image. The image is of a structural cross section and I am trying to find if there is continuity throughout the section (i.e. there is only one outline produced by the bwboundaries command). Having done this and found where the is more than one section traced (i.e. it is not continuous), I have used the cornermetric command to find the corners of each section. The code I have is: %% Define the structural section as a binary matrix (Image is an I-section with the web broken) bw(20:40,50:150) = 1; bw(160:180,50:150) = 1; bw(20:60,95:105) = 1; bw(140:180,95:105) = 1; Trace = bw; [B] = bwboundaries(Trace,'noholes'); %Traces the outer boundary of each section L = length(B); % Finds number of boundaries if L > 1 disp('Multiple boundaries') % States whether more than one boundary found end %% Obtain perimeter coordinates for k=1:length(B) %For all the boundaries perim = B{k}; %Obtains perimeter coordinates (as a 2D matrix) from the cell array end %% Find the corner positions C = cornermetric(bw); Areacorners = find(C == max(max(C))) % Finds the corner coordinates of each boundary [rowindexcorners,colindexcorners] = ind2sub(size(Newgeometry),Areacorners) % Convert corner coordinate indexes into subcripts, to give x & y coordinates (i.e. the same format as B gives) %% Put these corner coordinates into a cell array Cornerscellarray = cell(length(rowindexcorners),1); % Initialises cell array of zeros for i =1:numel(rowindexcorners) Cornerscellarray(i) = {[rowindexcorners(i) colindexcorners(i)]}; %Assigns the corner indicies into the cell array %This is done so the cell arrays can be compared end for k=1:length(B) %For all the boundaries found perim = B{k}; %Obtains coordinates for each perimeter Z = perim; % Initialise the matrix containing the perimeter corners Sectioncellmatrix = cell(length(rowindexcorners),1); for i =1:length(perim) Sectioncellmatrix(i) = {[perim(i,1) perim(i,2)]}; end for i = 1:length(perim) if Sectioncellmatrix(i) ~= Cornerscellarray Sectioncellmatrix(i) = []; %Gets rid of the elements that are not corners, but keeps them associated with the relevent section end end end This creates an error in the last for loop. Is there a way I can check whether each cell of the array (containing an x and y coordinate) is equal to any pair of coordinates in cornercellarray? I know it is possible with matrices to compare whether a certain element matches any of the elements in another matrix. I want to be able to do the same here, but for the pair of coordinates within the cell array. The reason I don't just use the cornercellarray cell array itself, is because this lists all the corner coordinates and does not associate them with a specific traced boundary.

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  • j2me bluetooth client. Function startInquiry nothing found.

    - by Hugi
    I develop simple j2me bluetooth client and have problem with bluetooth device search. Function startInquiry nothing found. Client : nokia 5220 Server : my pc with bluetooth adapter All bluetooth devices is on. /* * To change this template, choose Tools | Templates * and open the template in the editor. */ import javax.microedition.midlet.*; import javax.bluetooth.*; import java.util.Vector; import javax.microedition.lcdui.*; /** * @author ????????????? */ public class Midlet extends MIDlet implements DiscoveryListener { private static Vector vecDevices=new Vector(); private static String connectionURL=null; private LocalDevice localDevice; private DiscoveryAgent agent; private RemoteDevice remoteDevice; private RemoteDevice[] devList; private Display display; private Form form; public void startApp() { display = Display.getDisplay(this); form = new Form( "Client" ); try { localDevice = LocalDevice.getLocalDevice(); } catch( BluetoothStateException e ) { e.printStackTrace(); } form.append("Address: "+localDevice.getBluetoothAddress()+"\n\n"); form.append("Name: "+localDevice.getFriendlyName()+"\n\n"); try { agent = localDevice.getLocalDevice().getDiscoveryAgent(); form.append("Starting device inquiry... \n\n"); boolean si = agent.startInquiry(DiscoveryAgent.GIAC, this); if ( si ) { form.append("true"); } else { form.append("false"); } } catch( BluetoothStateException e ) { } int deviceCount = vecDevices.size(); if(deviceCount <= 0){ form.append("No Devices Found ."); } else{ //print bluetooth device addresses and names in the format [ No. address (name) ] form.append("Bluetooth Devices: "); for (int i = 0; i < deviceCount; i++) { remoteDevice=(RemoteDevice)vecDevices.elementAt(i); form.append( remoteDevice.getBluetoothAddress() ); } } display.setCurrent(form); } public void pauseApp() { } public void destroyApp(boolean unconditional) { } public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) { //add the device to the vector if(!vecDevices.contains(btDevice)){ vecDevices.addElement(btDevice); } } public void inquiryCompleted(int discType) { } //implement this method since services are not being discovered public void servicesDiscovered(int transID, ServiceRecord[] servRecord) { if(servRecord!=null && servRecord.length>0){ connectionURL=servRecord[0].getConnectionURL(0,false); } } //implement this method since services are not being discovered public void serviceSearchCompleted(int transID, int respCode) { } }

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  • gcc optimization? bug? and its practial implication to project

    - by kumar_m_kiran
    Hi All, My questions are divided into three parts Question 1 Consider the below code, #include <iostream> using namespace std; int main( int argc, char *argv[]) { const int v = 50; int i = 0X7FFFFFFF; cout<<(i + v)<<endl; if ( i + v < i ) { cout<<"Number is negative"<<endl; } else { cout<<"Number is positive"<<endl; } return 0; } No specific compiler optimisation options are used or the O's flag is used. It is basic compilation command g++ -o test main.cpp is used to form the executable. The seemingly very simple code, has odd behaviour in SUSE 64 bit OS, gcc version 4.1.2. The expected output is "Number is negative", instead only in SUSE 64 bit OS, the output would be "Number is positive". After some amount of analysis and doing a 'disass' of the code, I find that the compiler optimises in the below format - Since i is same on both sides of comparison, it cannot be changed in the same expression, remove 'i' from the equation. Now, the comparison leads to if ( v < 0 ), where v is a constant positive, So during compilation itself, the else part cout function address is added to the register. No cmp/jmp instructions can be found. I see that the behaviour is only in gcc 4.1.2 SUSE 10. When tried in AIX 5.1/5.3 and HP IA64, the result is as expected. Is the above optimisation valid? Or, is using the overflow mechanism for int not a valid use case? Question 2 Now when I change the conditional statement from if (i + v < i) to if ( (i + v) < i ) even then, the behaviour is same, this atleast I would personally disagree, since additional braces are provided, I expect the compiler to create a temporary built-in type variable and them compare, thus nullify the optimisation. Question 3 Suppose I have a huge code base, an I migrate my compiler version, such bug/optimisation can cause havoc in my system behaviour. Ofcourse from business perspective, it is very ineffective to test all lines of code again just because of compiler upgradation. I think for all practical purpose, these kinds of error are very difficult to catch (during upgradation) and invariably will be leaked to production site. Can anyone suggest any possible way to ensure to ensure that these kind of bug/optimization does not have any impact on my existing system/code base? PS : When the const for v is removed from the code, then optimization is not done by the compiler. I believe, it is perfectly fine to use overflow mechanism to find if the variable is from MAX - 50 value (in my case).

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  • How to develop a Jquery plugin to find the first child that match with a selector?

    - by Ivan
    I'm trying to make a Jquery plugin (findFirst()) to find the first child with a given characteristics (something in the middle of the find() and children() functions. For instance, given this markup: <div id="start"> <div> <span>Hello world</span> <ul class="valid-result"> ... </ul> <ul class="valid-result"> <li> <ul class="not-a-result"> ... </ul> </li> </ul> <div> <ul class="valid-result"> ... </ul> </div> </div> </div> If you ask for $("#start").findFirst('ul') it should return all ul lists that I have tagged with the valid-result class, but not the ul with class not-a-result. It is, this function has to find the first elements that matches with a given selector, but not the inner elements that match this selector. This is the first time I try to code a Jquery function, and what I've already read doesn't helps me too much with this. The function I have developed is this: jQuery.fn.findFirst = function (sel) { return this.map(function() { return $(this).children().map(function() { if ($(this).is(sel)) { return $(this); } else { return $(this).findFirst(sel); } }); }); } It works in the sense it tries to return the expected result, but the format it returns the result is very rare for me. I suppose the problem is something I don't understand about Jquery. Here you have the JFiddle where I'm testing. EDIT The expected result after $("#start").findFirst('ul') is a set with all UL that have the class 'valid-result' BUT it's not possible to use this class because it doesn't exist in a real case (it's just to try to explain the result). This is not equivalent to first(), because first returns only one element!

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