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  • How CPU finds ISR and distinguishes between devices

    - by ripunjay-tripathi-gmail-com
    I should first share all what I know - and that is complete chaos. There are several different questions on the topic, so please don't get irritated :). 1) To find an ISR, CPU is provided with a interrupt number. In x86 machines (286/386 and above) there is a IVT with ISRs in it; each entry of 4 bytes in size. So we need to multiply interrupt number by 4 to find the ISR. So first bunch of questions is - I am completely confused in mechanism of CPU receiving the interrupt. To raise an interrupt, firstly device shall probe for IRQ - then what ? The interrupt number travels "on IRQ" towards CPU? I also read something like device putting ISR address on data bus ; whats that then ? What is the concept of devices overriding the ISR. Can somebody tell me few example devices where CPU polls for interrupts? And where does it finds ISR for them ? 2) If two devices share an IRQ (which is very much possible), how does CPU differs amongst them ? What if both devices raise an interrupt of same priority simultaneously. I got to know there will be masking of same type and low priority interrupts - but how this communication happens between CPU and device controller? I studied the role of PIC and APIC for this problem, but could not understand. Thanks for reading. Thank you very much for answering.

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  • Python minidom and UTF-8 encoded XML with hash references

    - by Jakob Simon-Gaarde
    Hi I am experiencing some difficulty in my home project where I need to parse a SOAP request. The SOAP is generated with gSOAP and involves string parameters with special characters like the danish letters "æøå". gSOAP builds SOAP requests with UTF-8 encoding by default, but instead of sending the special chatacters in raw format (ie. bytes C3A6 for the special character "æ") it sends what I think is called character hash references (ie. &#195;&#166;). I don't completely understand why gSOAP does it this way as I can see that it has marked the incomming payload as being UTF-8 encoded anyway (Content-Type: text/xml; charset=utf-8), but this is besides the question (I think). Anyway I guess gSOAP probably is obeying transport rules, or what? When I parse the request from gSOAP in python with xml.dom.minidom.parseString() I get element values as unicode objects which is fine, but the character hash references are not decoded as UTF-8 character codes. It unescapes the character hash references, but does not decode the string afterwards. In the end I have a unicode string object with UTF-8 encoding: So if the string "æble" is contained in the XML, it comes like this in the request: "&#195;&#166;ble" After parsing the XML the unicode string in the DOM Text Node's data member looks like this: u'\xc3\xa6ble' I would expect it to look like this: u'\xe6ble' What am I doing wrong? Should I unescape the SOAP XML before parsing it, or is it somewhere else I should be looking for the solution, maybe gSOAP? Thanks in advance. Best regards Jakob Simon-Gaarde

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  • Cassandra random read speed

    - by Jody Powlette
    We're still evaluating Cassandra for our data store. As a very simple test, I inserted a value for 4 columns into the Keyspace1/Standard1 column family on my local machine amounting to about 100 bytes of data. Then I read it back as fast as I could by row key. I can read it back at 160,000/second. Great. Then I put in a million similar records all with keys in the form of X.Y where X in (1..10) and Y in (1..100,000) and I queried for a random record. Performance fell to 26,000 queries per second. This is still well above the number of queries we need to support (about 1,500/sec) Finally I put ten million records in from 1.1 up through 10.1000000 and randomly queried for one of the 10 million records. Performance is abysmal at 60 queries per second and my disk is thrashing around like crazy. I also verified that if I ask for a subset of the data, say the 1,000 records between 3,000,000 and 3,001,000, it returns slowly at first and then as they cache, it speeds right up to 20,000 queries per second and my disk stops going crazy. I've read all over that people are storing billions of records in Cassandra and fetching them at 5-6k per second, but I can't get anywhere near that with only 10mil records. Any idea what I'm doing wrong? Is there some setting I need to change from the defaults? I'm on an overclocked Core i7 box with 6gigs of ram so I don't think it's the machine. Here's my code to fetch records which I'm spawning into 8 threads to ask for one value from one column via row key: ColumnPath cp = new ColumnPath(); cp.Column_family = "Standard1"; cp.Column = utf8Encoding.GetBytes("site"); string key = (1+sRand.Next(9)) + "." + (1+sRand.Next(1000000)); ColumnOrSuperColumn logline = client.get("Keyspace1", key, cp, ConsistencyLevel.ONE); Thanks for any insights

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  • implementing a download manager that supports resuming

    - by Idan K
    hi, I intend on writing a small download manager in C++ that supports resuming (and multiple connections per download). From the info I gathered so far, when sending the http request I need to add a header field with a key of "Range" and the value "bytes=startoff-endoff". Then the server returns a http response with the data between those offsets. So roughly what I have in mind is to split the file to the number of allowed connections per file and send a http request per splitted part with the appropriate "Range". So if I have a 4mb file and 4 allowed connections, I'd split the file to 4 and have 4 http requests going, each with the appropriate "Range" field. Implementing the resume feature would involve remembering which offsets are already downloaded and simply not request those. Is this the right way to do this? What if the web server doesn't support resuming? (my guess is it will ignore the "Range" and just send the entire file) When sending the http requests, should I specify in the range the entire splitted size? Or maybe ask smaller pieces, say 1024k per request? When reading the data, should I write it immediately to the file or do some kind of buffering? I guess it could be wasteful to write small chunks. Should I use a memory mapped file? If I remember correctly, it's recommended for frequent reads rather than writes (I could be wrong). Is it memory wise? What if I have several downloads simultaneously? If I'm not using a memory mapped file, should I open the file per allowed connection? Or when needing to write to the file simply seek? (if I did use a memory mapped file this would be really easy, since I could simply have several pointers). Note: I'll probably be using Qt, but this is a general question so I left code out of it.

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  • Can you force a crash if a write occurs to a given memory location with finer than page granularity?

    - by Joseph Garvin
    I'm writing a program that for performance reasons uses shared memory (alternatives have been evaluated, and they are not fast enough for my task, so suggestions to not use it will be downvoted). In the shared memory region I am writing many structs of a fixed size. There is one program responsible for writing the structs into shared memory, and many clients that read from it. However, there is one member of each struct that clients need to write to (a reference count, which they will update atomically). All of the other members should be read only to the clients. Because clients need to change that one member, they can't map the shared memory region as read only. But they shouldn't be tinkering with the other members either, and since these programs are written in C++, memory corruption is possible. Ideally, it should be as difficult as possible for one client to crash another. I'm only worried about buggy clients, not malicious ones, so imperfect solutions are allowed. I can try to stop clients from overwriting by declaring the members in the header they use as const, but that won't prevent memory corruption (buffer overflows, bad casts, etc.) from overwriting. I can insert canaries, but then I have to constantly pay the cost of checking them. Instead of storing the reference count member directly, I could store a pointer to the actual data in a separate mapped write only page, while keeping the structs in read only mapped pages. This will work, the OS will force my application to crash if I try to write to the pointed to data, but indirect storage can be undesirable when trying to write lock free algorithms, because needing to follow another level of indirection can change whether something can be done atomically. Is there any way to mark smaller areas of memory such that writing them will cause your app to blow up? Some platforms have hardware watchpoints, and maybe I could activate one of those with inline assembly, but I'd be limited to only 4 at a time on 32-bit x86 and each one could only cover part of the struct because they're limited to 4 bytes. It'd also make my program painful to debug ;)

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  • Should I move big data blobs in JSON or in separate binary connection?

    - by Amagrammer
    QUESTION: Is it better to send large data blobs in JSON for simplicity, or send them as binary data over a separate connection? If the former, can you offer tips on how to optimize the JSON to minimize size? If the latter, is it worth it to logically connect the JSON data to the binary data using an identifier that appears in both, e.g., as "data" : "< unique identifier " in the JSON and with the first bytes of the data blob being < unique identifier ? CONTEXT: My iPhone application needs to receive JSON data over the 3G network. This means that I need to think seriously about efficiency of data transfer, as well as the load on the CPU. Most of the data transfers will be relatively small packets of text data for which JSON is a natural format and for which there is no point in worrying much about efficiency. However, some of the most critical transfers will be big blobs of binary data -- definitely at least 100 kilobytes of data, and possibly closer to 1 megabyte as customers accumulate a longer history with the product. (Note: I will be caching what I can on the iPhone itself, but the data still has to be transferred at least once.) It is NOT streaming data. I will probably use a third-party JSON SDK -- the one I am using during development is here. Thanks

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  • Django upload failing on request data read error

    - by Jake
    Hi All, I've got a Django app that accepts uploads from jQuery uploadify, a jQ plugin that uses flash to upload files and give a progress bar. Files under about 150k work, but bigger files always fail and almost always at around 192k (that's 3 chunks) completed, sometimes at around 160k. The Exception I get is below. exceptions.IOError request data read error File "/usr/lib/python2.4/site-packages/django/core/handlers/wsgi.py", line 171, in _get_post self._load_post_and_files() File "/usr/lib/python2.4/site-packages/django/core/handlers/wsgi.py", line 137, in _load_post_and_files self._post, self._files = self.parse_file_upload(self.META, self.environ[\'wsgi.input\']) File "/usr/lib/python2.4/site-packages/django/http/__init__.py", line 124, in parse_file_upload return parser.parse() File "/usr/lib/python2.4/site-packages/django/http/multipartparser.py", line 192, in parse for chunk in field_stream: File "/usr/lib/python2.4/site-packages/django/http/multipartparser.py", line 314, in next output = self._producer.next() File "/usr/lib/python2.4/site-packages/django/http/multipartparser.py", line 468, in next for bytes in stream: File "/usr/lib/python2.4/site-packages/django/http/multipartparser.py", line 314, in next output = self._producer.next() File "/usr/lib/python2.4/site-packages/django/http/multipartparser.py", line 375, in next data = self.flo.read(self.chunk_size) File "/usr/lib/python2.4/site-packages/django/http/multipartparser.py", line 405, in read return self._file.read(num_bytes) When running locally on the Django development server, big files work. I've tried setting my FILE_UPLOAD_HANDLERS = ("django.core.files.uploadhandler.TemporaryFileUploadHandler",) in case it was the memory upload handler, but it made no difference. Does anyone know how to fix this?

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  • Inserting an image into sqlserver gives an "operand type clash"

    - by Termedi
    I'm trying to save an image in a sql server 2000 database. The data type of the column is image. Here is the code: Image Upload: <?php include('config.php'); if(is_uploaded_file($_FILES['userfile']['tmp_name'])) { $fileName = $_FILES['userfile']['name']; $tmpName = $_FILES['userfile']['tmp_name']; $fileSize = $_FILES['userfile']['size']; $fileType = $_FILES['userfile']['type']; $size = filesize($tmpName); set_magic_quotes_runtime(0);//to desactive the default escape spacials caracters made by PHP in the externes files $img_binaire = base64_encode(fread(fopen(str_replace("'","''",$tmpName), "r"), $size)); $query = "INSERT INTO test_image (image_name, image_content, image_size) ". "VALUES ('{$fileName}','{$img_binaire}', '{$size}')"; odbc_exec($conn, $query) or die('Error, query failed'); echo "<br>File $fileName uploaded<br>"; echo "<br>File Size: $fileSize <br>"; } ?> Image Show: <?php include('config.php'); $sql = "select * from test_image where id =2"; $rsl = odbc_exec($conn, $sql); $image_info = odbc_fetch_array($rsl); //$count = sizeof($image_info['image_content']); //header('Accept-Ranges: bytes'); //header('Content-Length: '.$image_info['image_size']); //header("Content-length: 17397"); header('Content-Type: image/jpeg'); echo base64_decode($image_info['image_content']); //echo bindec($image_info['image_content']); ?> It gives the following error: Error: Warning: odbc_exec() [function.odbc-exec]: SQL error: [Microsoft][ODBC SQL Server Driver][SQL Server]Operand type clash: text is incompatible with image, SQL state 22005 in SQLExecDirect in C:\xampp\htdocs\test\upload.php on line 25 Error, query failed What do I need to do differently?

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  • Unable to upload large files on FTP using Apache commons-net-3.1

    - by Nitin
    I am trying to upload the one large file ( more than 8 MB) using storeFile(remote, local) method of FTPClient but it results false.It get uploaded with some extra bytes.Following is the code with Output: public class Main { public static void main(String[] args) { FTPClient client = new FTPClient(); FileInputStream fis = null; try { client.connect("208.106.181.143"); client.setFileTransferMode(client.BINARY_FILE_TYPE); client.login("abc", "java"); int reply = client.getReplyCode(); System.out.println("Received Reply from FTP Connection:" + reply); if(FTPReply.isPositiveCompletion(reply)){ System.out.println("Connected Success"); } client.changeWorkingDirectory("/"+"Everbest"+"/"); client.makeDirectory("ETPSupplyChain5.3-EvbstSP3"); client.changeWorkingDirectory("/"+"Everbest"+"/"+"ETPSupplyChain5.3-EvbstSP3"+"/"); FTPFile[] names = client.listFiles(); String filename = "E:\\Nitin\\D-Drive\\Installer.rar"; fis = new FileInputStream(filename); boolean result = client.storeFile("Installer.rar", fis); int replyAfterupload = client.getReplyCode(); System.out.println("Received Reply from FTP Connection replyAfterupload:" + replyAfterupload); System.out.println("result:"+result); for (FTPFile name : names) { System.out.println("Name = " + name); } client.logout(); fis.close(); client.disconnect(); } catch (SocketException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } o/p: Received Reply from FTP Connection:230 Connected Success 32 /Everbest/ETPSupplyChain5.3-EvbstSP3 Received Reply from FTP Connection replyAfterupload:150 result:false

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  • [Cocoa] Can't find leak in my code.

    - by ryyst
    Hi, I've been spending the last few hours trying to find the memory leak in my code. Here it is: NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; expression = [expression stringByTrimmingCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]]; // expression is an NSString object. NSArray *arguments = [NSArray arrayWithObjects:expression, [@"~/Desktop/file.txt" stringByExpandingTildeInPath], @"-n", @"--line-number", nil]; NSPipe *outPipe = [[NSPipe alloc] init]; NSTask *task = [[NSTask alloc] init]; [task setLaunchPath:@"/usr/bin/grep"]; [task setArguments:arguments]; [task setStandardOutput:outPipe]; [outPipe release]; [task launch]; NSData *data = [[outPipe fileHandleForReading] readDataToEndOfFile]; [task waitUntilExit]; [task release]; NSString *string = [[NSString alloc] initWithBytes:[data bytes] length:[data length] encoding:NSUTF8StringEncoding]; string = [string stringByReplacingOccurrencesOfString:@"\r" withString:@""]; int linesNum = 0; NSMutableArray *possibleMatches = [[NSMutableArray alloc] init]; if ([string length] > 0) { NSArray *lines = [string componentsSeparatedByString:@"\n"]; linesNum = [lines count]; for (int i = 0; i < [lines count]; i++) { NSString *currentLine = [lines objectAtIndex:i]; NSArray *values = [currentLine componentsSeparatedByString:@"\t"]; if ([values count] == 20) [possibleMatches addObject:currentLine]; } } [string release]; [pool release]; return [possibleMatches autorelease]; I tried to follow the few basic rules of Cocoa memory management, but somehow there still seems to be a leak, I believe it's an array that's leaking. It's noticeable if possibleMatches is large. You can try the code by using any large file as "~/Desktop/file.txt" and as expression something that yields many results when grep-ing. What's the mistake I'm making? Thanks for any help! -- Ry

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  • Database version is zero on initial install

    - by mahesh
    I have released an app (World Time) with initial database. Now i want to update the app with a database upgrade. I have put in the upgrade code in OnUpgrade() and checking for the newVersion. But it was not being called in my local testing... So i put in the debug statement to get the database version and it is zero . Any idea why it is not being versioned ? Following is the code to copy the database from my Assets folder ... InputStream myInput = myContext.getAssets().open(DB_NAME); // Path to the just created empty db String outFileName = DB_PATH + DB_NAME; //Open the empty db as the output stream OutputStream myOutput = new FileOutputStream(outFileName); //transfer bytes from the inputfile to the outputfile byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } //Close the streams myOutput.flush(); myOutput.close(); myInput.close(); -- Mahesh http://android.maheshdixit.com

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  • Implementing parts of rfc4226 (HOTP) in mysql

    - by Moose Morals
    Like the title says, I'm trying to implement the programmatic parts of RFC4226 "HOTP: An HMAC-Based One-Time Password Algorithm" in SQL. I think I've got a version that works (in that for a small test sample, it produces the same result as the Java version in the code), but it contains a nested pair of hex(unhex()) calls, which I feel can be done better. I am constrained by a) needing to do this algorithm, and b) needing to do it in mysql, otherwise I'm happy to look at other ways of doing this. What I've got so far: -- From the inside out... -- Concatinate the users secret, and the number of time its been used -- find the SHA1 hash of that string -- Turn a 40 byte hex encoding into a 20 byte binary string -- keep the first 4 bytes -- turn those back into a hex represnetation -- convert that into an integer -- Throw away the most-significant bit (solves signed/unsigned problems) -- Truncate to 6 digits -- store into otp -- from the otpsecrets table select (conv(hex(substr(unhex(sha1(concat(secret, uses))), 1, 4)), 16, 10) & 0x7fffffff) % 1000000 into otp from otpsecrets; Is there a better (more efficient) way of doing this?

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  • Delphi, PGDac vs Zeos, Fetch, Lookup?

    - by durumdara
    Hi! I used Zeos to test to know: is ZTable uses fetch technics, or not? May in the future we migrate our lesser system to PGSQL, and this used now "Table" components (as BDE, but it have an SQL-like server). These tables use real cursors, a "Window" with N record, so lookup is very fast, because the Locate/Lookup is started on server, and only these N records are refreshed, no matter, how many records in the lookup table. PGSQL uses fetch technics as I know, and I tested it with a table (id int, name varchar(100)), and 1 million records. (I also trying this with mysql). The adapter is Zeos. ID, sec to find, allocated memory in bytes on client. MySQL 500000 2,761 113 196 344 1000000 3,214 225 471 232 313800 0,437 225 471 232 328066 0,468 225 471 232 276374 0,390 225 471 232 905984 1,264 225 471 232 260253 0,359 225 471 232 PGSQL 500000 3,042 113 188 184 1000000 3,744 225 463 064 313800 0,436 225 463 064 328066 0,452 225 463 064 276374 0,375 225 463 064 905984 1,295 225 463 064 260253 0,359 225 463 064 142023 0,203 225 463 064 As you see the records are fetched locally, this cause the 225 MB usage, and searches are slow a little, based where is the record we must find. I want to ask more things: a.) Is PGDAC have some technics to we can use the lookups without pay the fetch with memory and secs? b.) Or is PG ODBC driver can help in this problem with ADO? (As I know ADO can use server side cursors)? c.) Have anybody some experience with lookup tables, and performance? Is this critical question or it is not? (With client memory usage too). d.) If no chance to avoid fetch hell with lookups, what we can do? Server Side Joins, and unique code for Lookup field changing without real Lookup? Thanks for your help: dd

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  • EVP_PKEY from char buffer in x509 (PKCS7)

    - by sid
    Hi All, I have a DER certificate from which I am retrieving the Public key in unsigned char buffer as following, is it the right way of getting? pStoredPublicKey = X509_get_pubkey(x509); if(pStoredPublicKey == NULL) { printf(": publicKey is NULL\n"); } if(pStoredPublicKey->type == EVP_PKEY_RSA) { RSA *x = pStoredPublicKey->pkey.rsa; bn = x->n; } else if(pStoredPublicKey->type == EVP_PKEY_DSA) { } else if(pStoredPublicKey->type == EVP_PKEY_EC) { } else { printf(" : Unkown publicKey\n"); } //extracts the bytes from public key & convert into unsigned char buffer buf_len = (size_t) BN_num_bytes (bn); key = (unsigned char *)malloc (buf_len); n = BN_bn2bin (bn, (unsigned char *) key); for (i = 0; i < n; i++) { printf("%02x\n", (unsigned char) key[i]); } keyLen = EVP_PKEY_size(pStoredPublicKey); EVP_PKEY_free(pStoredPublicKey); And, With this unsigned char buffer, How do I get back the EVP_PKEY for RSA? OR Can I use following ???, EVP_PKEY *d2i_PublicKey(int type, EVP_PKEY **a, unsigned char **pp, long length); int i2d_PublicKey(EVP_PKEY *a, unsigned char **pp);

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  • A UnicodeDecodeError that occurs with json in python on Windows, but not Mac.

    - by ventolin
    On windows, I have the following problem: >>> string = "Don´t Forget To Breathe" >>> import json,os,codecs >>> f = codecs.open("C:\\temp.txt","w","UTF-8") >>> json.dump(string,f) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python26\lib\json\__init__.py", line 180, in dump for chunk in iterable: File "C:\Python26\lib\json\encoder.py", line 294, in _iterencode yield encoder(o) UnicodeDecodeError: 'utf8' codec can't decode bytes in position 3-5: invalid data (Notice the non-ascii apostrophe in the string.) However, my friend, on his mac (also using python2.6), can run through this like a breeze: > string = "Don´t Forget To Breathe" > import json,os,codecs > f = codecs.open("/tmp/temp.txt","w","UTF-8") > json.dump(string,f) > f.close(); open('/tmp/temp.txt').read() '"Don\\u00b4t Forget To Breathe"' Why is this? I've also tried using UTF-16 and UTF-32 with json and codecs, but to no avail.

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  • GCC - How to realign stack?

    - by psihodelia
    I try to build an application which uses pthreads and __m128 SSE type. According to GCC manual, default stack alignment is 16 bytes. In order to use __m128, the requirement is the 16-byte alignment. My target CPU supports SSE. I use a GCC compiler which doesn't support runtime stack realignment (e.g. -mstackrealign). I cannot use any other GCC compiler version. My test application looks like: #include <xmmintrin.h> #include <pthread.h> void *f(void *x){ __m128 y; ... } int main(void){ pthread_t p; pthread_create(&p, NULL, f, NULL); } The application generates an exception and exits. After a simple debugging (printf "%p", &y), I found that the variable y is not 16-byte aligned. My question is: how can I realign the stack properly (16-byte) without using any GCC flags and attributes (they don't help)? Should I use GCC inline Assembler within this thread function f()?

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  • How to read LARGE Sqlite file to be copied into Android emulator, or device from assets folder?

    - by Peter SHINe ???
    I guess many people already read this article: Using your own SQLite database in Android applications: http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/comment-page-2/#comment-12368 However it's keep bringing IOException at while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } I’am trying to use a large DB file. It’s as big as 8MB I built it using sqlite3 in Mac OS X, inserted UTF-8 encoded strings (for I am using Korean), added android_meta table with ko_KR as locale, as instructed above. However, When I debug, it keeps showing IOException at length=myInput.read(buffer) I suspect it’s caused by trying to read a big file. If not, I have no clue why. I tested the same code using much smaller text file, and it worked fine. Can anyone help me out on this? I’ve searched many places, but no place gave me the clear answer, or good solution. Good meaning efficient or easy. I will try use BufferedInput(Output)Stream, but if the simpler one cannot work, I don’t think this will work either. Can anyone explain the fundamental limits in file input/output in Android, and the right way around it, possibly? I will really appreciate anyone’s considerate answer. Thank you. WITH MORE DETAIL: private void copyDataBase() throws IOException{ //Open your local db as the input stream InputStream myInput = myContext.getAssets().open(DB_NAME); // Path to the just created empty db String outFileName = DB_PATH + DB_NAME; //Open the empty db as the output stream OutputStream myOutput = new FileOutputStream(outFileName); //transfer bytes from the inputfile to the outputfile byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } //Close the streams myOutput.flush(); myOutput.close(); myInput.close(); }

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  • Advice on designing and building distributed application to track vehicles

    - by dario-g
    I'm working on application for tracking vehicles. There will be about 10k or more vehicles. Each will be sending ~250bytes in each minute. Data contains gps location and everything from CAN Bus (every data that we can read from vehicle computer and dashboard). Data are sent by GSM/GPRS (using UDP protocol). Estimated rows with this data per day is ~2000k. I see there 3 main blocks. 1. Multithreaded Socket Server (MSS) - I have it. MSS stores received data to the queue (using NServiceBus). 2. Rule Processor Server (RPS) - this is core of this system. This block is responsible for parsing received data, storing in the database, processing rules, sending messages to Notifier Server (this will be sending e-mails/sms texts). Rule example. As I said between received bytes there will be information about current speed. When speed will be above 120 then: show alert in web application for specified users, send e-mail, send sms text. (There can be more than one instance of RPS). 3. Web application - allows reporting and defining rules by users, monitoring alerts, etc. I'm looking for advice how to design communication between RPS and Web application. Some questions: - Should Web application and RPS have separated databases or one central database will be enough? I have one domain model in web application. If there will be one central database then can I use the same model (objects) on RPS? So, how to send changed rules to RPS? I try to decouple this blocks as much as possible. I'm planning to create different instance of application for each client (each client will have separated database). One client will be have 10k vehicles, others only 100 vehicles.

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  • Creating a fixed length output string with sprintf containing floats

    - by Kungi
    Hi, I'm trying to create a file which has the following structure: - Each line has 32 bytes - Each line looks like this format string: "%10i %3.7f %3.7f\n" My Problem is the following: When i have a negative floating point numbers the line gets longer by one or even two characters because the - sign does not count to the "%3.7f". Is there any way to do this more nicely than this? if( node->lng > 0 && node->lat > 0 ) { sprintf( osm_node_repr, "%10i %3.7f %3.7f\n", node->id, node->lng, node->lat ); } else if (node->lng > 0 && node->lat < 0) { sprintf( osm_node_repr, "%10i %3.7f %3.6f\n", node->id, node->lng, node->lat ); } else if (node->lng < 0 && node->lat > 0) { sprintf( osm_node_repr, "%10i %3.6f %3.7f\n", node->id, node->lng, node->lat ); } else if ( node->lng < 0 && node->lat < 0 ) { sprintf( osm_node_repr, "%10i %3.6f %3.6f\n", node->id, node->lng, node->lat ); } Thanks for your Answers, Andreas

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  • Setting up a pc bluetooth server for android

    - by Del
    Alright, I've been reading a lot of topics the past two or three days and nothing seems to have asked this. I am writing a PC side server for my andriod device, this is for exchanging some information and general debugging. Eventually I will be connecting to a SPP device to control a microcontroller. I have managed, using the following (Android to pc) to connect to rfcomm channel 11 and exchange data between my android device and my pc. Method m = device.getClass().getMethod("createRfcommSocket", new Class[] { int.class }); tmp = (BluetoothSocket) m.invoke(device, Integer.valueOf(11)); I have attempted the createRfcommSocketToServiceRecord(UUID) method, with absolutely no luck. For the PC side, I have been using the C Bluez stack for linux. I have the following code which registers the service and opens a server socket: int main(int argc, char **argv) { struct sockaddr_rc loc_addr = { 0 }, rem_addr = { 0 }; char buf[1024] = { 0 }; char str[1024] = { 0 }; int s, client, bytes_read; sdp_session_t *session; socklen_t opt = sizeof(rem_addr); session = register_service(); s = socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM); loc_addr.rc_family = AF_BLUETOOTH; loc_addr.rc_bdaddr = *BDADDR_ANY; loc_addr.rc_channel = (uint8_t) 11; bind(s, (struct sockaddr *)&loc_addr, sizeof(loc_addr)); listen(s, 1); client = accept(s, (struct sockaddr *)&rem_addr, &opt); ba2str( &rem_addr.rc_bdaddr, buf ); fprintf(stderr, "accepted connection from %s\n", buf); memset(buf, 0, sizeof(buf)); bytes_read = read(client, buf, sizeof(buf)); if( bytes_read 0 ) { printf("received [%s]\n", buf); } sprintf(str,"to Android."); printf("sent [%s]\n",str); write(client, str, sizeof(str)); close(client); close(s); sdp_close( session ); return 0; } sdp_session_t *register_service() { uint32_t svc_uuid_int[] = { 0x00000000,0x00000000,0x00000000,0x00000000 }; uint8_t rfcomm_channel = 11; const char *service_name = "Remote Host"; const char *service_dsc = "What the remote should be connecting to."; const char *service_prov = "Your mother"; uuid_t root_uuid, l2cap_uuid, rfcomm_uuid, svc_uuid; sdp_list_t *l2cap_list = 0, *rfcomm_list = 0, *root_list = 0, *proto_list = 0, *access_proto_list = 0; sdp_data_t *channel = 0, *psm = 0; sdp_record_t *record = sdp_record_alloc(); // set the general service ID sdp_uuid128_create( &svc_uuid, &svc_uuid_int ); sdp_set_service_id( record, svc_uuid ); // make the service record publicly browsable sdp_uuid16_create(&root_uuid, PUBLIC_BROWSE_GROUP); root_list = sdp_list_append(0, &root_uuid); sdp_set_browse_groups( record, root_list ); // set l2cap information sdp_uuid16_create(&l2cap_uuid, L2CAP_UUID); l2cap_list = sdp_list_append( 0, &l2cap_uuid ); proto_list = sdp_list_append( 0, l2cap_list ); // set rfcomm information sdp_uuid16_create(&rfcomm_uuid, RFCOMM_UUID); channel = sdp_data_alloc(SDP_UINT8, &rfcomm_channel); rfcomm_list = sdp_list_append( 0, &rfcomm_uuid ); sdp_list_append( rfcomm_list, channel ); sdp_list_append( proto_list, rfcomm_list ); // attach protocol information to service record access_proto_list = sdp_list_append( 0, proto_list ); sdp_set_access_protos( record, access_proto_list ); // set the name, provider, and description sdp_set_info_attr(record, service_name, service_prov, service_dsc); int err = 0; sdp_session_t *session = 0; // connect to the local SDP server, register the service record, and // disconnect session = sdp_connect( BDADDR_ANY, BDADDR_LOCAL, SDP_RETRY_IF_BUSY ); err = sdp_record_register(session, record, 0); // cleanup //sdp_data_free( channel ); sdp_list_free( l2cap_list, 0 ); sdp_list_free( rfcomm_list, 0 ); sdp_list_free( root_list, 0 ); sdp_list_free( access_proto_list, 0 ); return session; } And another piece of code, in addition to 'sdptool browse local' which can verifty that the service record is running on the pc: int main(int argc, char **argv) { uuid_t svc_uuid; uint32_t svc_uuid_int[] = { 0x00000000,0x00000000,0x00000000,0x00000000 }; int err; bdaddr_t target; sdp_list_t *response_list = NULL, *search_list, *attrid_list; sdp_session_t *session = 0; str2ba( "01:23:45:67:89:AB", &target ); // connect to the SDP server running on the remote machine session = sdp_connect( BDADDR_ANY, BDADDR_LOCAL, SDP_RETRY_IF_BUSY ); // specify the UUID of the application we're searching for sdp_uuid128_create( &svc_uuid, &svc_uuid_int ); search_list = sdp_list_append( NULL, &svc_uuid ); // specify that we want a list of all the matching applications' attributes uint32_t range = 0x0000ffff; attrid_list = sdp_list_append( NULL, &range ); // get a list of service records that have UUID 0xabcd err = sdp_service_search_attr_req( session, search_list, \ SDP_ATTR_REQ_RANGE, attrid_list, &response_list); sdp_list_t *r = response_list; // go through each of the service records for (; r; r = r-next ) { sdp_record_t *rec = (sdp_record_t*) r-data; sdp_list_t *proto_list; // get a list of the protocol sequences if( sdp_get_access_protos( rec, &proto_list ) == 0 ) { sdp_list_t *p = proto_list; // go through each protocol sequence for( ; p ; p = p-next ) { sdp_list_t *pds = (sdp_list_t*)p-data; // go through each protocol list of the protocol sequence for( ; pds ; pds = pds-next ) { // check the protocol attributes sdp_data_t *d = (sdp_data_t*)pds-data; int proto = 0; for( ; d; d = d-next ) { switch( d-dtd ) { case SDP_UUID16: case SDP_UUID32: case SDP_UUID128: proto = sdp_uuid_to_proto( &d-val.uuid ); break; case SDP_UINT8: if( proto == RFCOMM_UUID ) { printf("rfcomm channel: %d\n",d-val.int8); } break; } } } sdp_list_free( (sdp_list_t*)p-data, 0 ); } sdp_list_free( proto_list, 0 ); } printf("found service record 0x%x\n", rec-handle); sdp_record_free( rec ); } sdp_close(session); } Output: $ ./search rfcomm channel: 11 found service record 0x10008 sdptool: Service Name: Remote Host Service Description: What the remote should be connecting to. Service Provider: Your mother Service RecHandle: 0x10008 Protocol Descriptor List: "L2CAP" (0x0100) "RFCOMM" (0x0003) Channel: 11 And for logcat I'm getting this: 07-22 15:57:06.087: ERROR/BTLD(215): ****************search UUID = 0000*********** 07-22 15:57:06.087: INFO//system/bin/btld(209): btapp_dm_GetRemoteServiceChannel() 07-22 15:57:06.087: INFO//system/bin/btld(209): ##### USerial_Ioctl: BT_Wake, 0x8003 #### 07-22 15:57:06.097: INFO/ActivityManager(88): Displayed activity com.example.socktest/.socktest: 79 ms (total 79 ms) 07-22 15:57:06.697: INFO//system/bin/btld(209): ##### USerial_Ioctl: BT_Sleep, 0x8004 #### 07-22 15:57:07.517: WARN/BTLD(215): ccb timer ticks: 2147483648 07-22 15:57:07.517: INFO//system/bin/btld(209): ##### USerial_Ioctl: BT_Wake, 0x8003 #### 07-22 15:57:07.547: WARN/BTLD(215): info:x10 07-22 15:57:07.547: INFO/BTL-IFS(215): send_ctrl_msg: [BTL_IFS CTRL] send BTLIF_DTUN_SIGNAL_EVT (CTRL) 10 pbytes (hdl 14) 07-22 15:57:07.547: DEBUG/DTUN_HCID_BZ4(253): dtun_dm_sig_link_up() 07-22 15:57:07.547: INFO/DTUN_HCID_BZ4(253): dtun_dm_sig_link_up: dummy_handle = 342 07-22 15:57:07.547: DEBUG/ADAPTER(253): adapter_get_device(00:02:72:AB:7C:EE) 07-22 15:57:07.547: ERROR/BluetoothEventLoop.cpp(88): pollData[0] is revented, check next one 07-22 15:57:07.547: ERROR/BluetoothEventLoop.cpp(88): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/253/hci0/dev_00_02_72_AB_7C_EE 07-22 15:57:07.777: WARN/BTLD(215): process_service_search_attr_rsp 07-22 15:57:07.787: INFO/BTL-IFS(215): send_ctrl_msg: [BTL_IFS CTRL] send BTLIF_DTUN_SIGNAL_EVT (CTRL) 13 pbytes (hdl 14) 07-22 15:57:07.787: INFO/DTUN_HCID_BZ4(253): dtun_dm_sig_rmt_service_channel: success=0, service=00000000 07-22 15:57:07.787: ERROR/DTUN_HCID_BZ4(253): discovery unsuccessful! 07-22 15:57:08.497: INFO//system/bin/btld(209): ##### USerial_Ioctl: BT_Sleep, 0x8004 #### 07-22 15:57:09.507: INFO//system/bin/btld(209): ##### USerial_Ioctl: BT_Wake, 0x8003 #### 07-22 15:57:09.597: INFO/BTL-IFS(215): send_ctrl_msg: [BTL_IFS CTRL] send BTLIF_DTUN_SIGNAL_EVT (CTRL) 11 pbytes (hdl 14) 07-22 15:57:09.597: DEBUG/DTUN_HCID_BZ4(253): dtun_dm_sig_link_down() 07-22 15:57:09.597: INFO/DTUN_HCID_BZ4(253): dtun_dm_sig_link_down device = 0xf7a0 handle = 342 reason = 22 07-22 15:57:09.597: ERROR/BluetoothEventLoop.cpp(88): pollData[0] is revented, check next one 07-22 15:57:09.597: ERROR/BluetoothEventLoop.cpp(88): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/253/hci0/dev_00_02_72_AB_7C_EE 07-22 15:57:09.597: DEBUG/BluetoothA2dpService(88): Received intent Intent { act=android.bluetooth.device.action.ACL_DISCONNECTED (has extras) } 07-22 15:57:10.107: INFO//system/bin/btld(209): ##### USerial_Ioctl: BT_Sleep, 0x8004 #### 07-22 15:57:12.107: DEBUG/BluetoothService(88): Cleaning up failed UUID channel lookup: 00:02:72:AB:7C:EE 00000000-0000-0000-0000-000000000000 07-22 15:57:12.107: ERROR/Socket Test(5234): connect() failed 07-22 15:57:12.107: DEBUG/ASOCKWRP(5234): asocket_abort [31,32,33] 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): blz20_wrp_shutdown: s 31, how 2 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_shutdown: fd (-1:31), bta -1, rc 0, wflags 0x0 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): __close_prot_rfcomm: fd 31 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): __close_prot_rfcomm: bind not completed on this socket 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): btlif_signal_event: fd (-1:31), bta -1, rc 0, wflags 0x0 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): btlif_signal_event: event BTLIF_BTS_EVT_ABORT matched 07-22 15:57:12.107: DEBUG/BTL_IFC_WRP(5234): wrp_close_s_only: wrp_close_s_only [31] (31:-1) [] 07-22 15:57:12.107: DEBUG/BTL_IFC_WRP(5234): wrp_close_s_only: data socket closed 07-22 15:57:12.107: DEBUG/BTL_IFC_WRP(5234): wsactive_del: delete wsock 31 from active list [ad3e1494] 07-22 15:57:12.107: DEBUG/BTL_IFC_WRP(5234): wrp_close_s_only: wsock fully closed, return to pool 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): btsk_free: success 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_write: wrote 1 bytes out of 1 on fd 33 07-22 15:57:12.107: DEBUG/ASOCKWRP(5234): asocket_destroy 07-22 15:57:12.107: DEBUG/ASOCKWRP(5234): asocket_abort [31,32,33] 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): blz20_wrp_shutdown: s 31, how 2 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_shutdown: btsk not found, normal close (31) 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_write: wrote 1 bytes out of 1 on fd 33 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): blz20_wrp_close: s 33 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_close: btsk not found, normal close (33) 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): blz20_wrp_close: s 32 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_close: btsk not found, normal close (32) 07-22 15:57:12.107: INFO/BLZ20_WRAPPER(5234): blz20_wrp_close: s 31 07-22 15:57:12.107: DEBUG/BLZ20_WRAPPER(5234): blz20_wrp_close: btsk not found, normal close (31) 07-22 15:57:12.157: DEBUG/Sensors(88): close_akm, fd=151 07-22 15:57:12.167: ERROR/CachedBluetoothDevice(477): onUuidChanged: Time since last connect14970690 07-22 15:57:12.237: DEBUG/Socket Test(5234): -On Stop- Sorry for bombarding you guys with what seems like a difficult question and a lot to read, but I've been working on this problem for a while and I've tried a lot of different things to get this working. Let me reiterate, I can get it to work, but not using service discovery protocol. I've tried a several different UUIDs and on two different computers, although I only have my HTC Incredible to test with. I've also heard some rumors that the BT stack wasn't working on the HTC Droid, but that isn't the case, at least, for PC interaction.

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  • PHP Encrypt/Decrypt with TripleDes, PKCS7, and ECB

    - by Brandon Green
    I've got my encryption function working properly however I cannot figure out how to get the decrypt function to give proper output. Here is my encrypt function: function Encrypt($data, $secret) { //Generate a key from a hash $key = md5(utf8_encode($secret), true); //Take first 8 bytes of $key and append them to the end of $key. $key .= substr($key, 0, 8); //Pad for PKCS7 $blockSize = mcrypt_get_block_size('tripledes', 'ecb'); $len = strlen($data); $pad = $blockSize - ($len % $blockSize); $data .= str_repeat(chr($pad), $pad); //Encrypt data $encData = mcrypt_encrypt('tripledes', $key, $data, 'ecb'); return base64_encode($encData); } Here is my decrypt function: function Decrypt($data, $secret) { $text = base64_decode($data); $data = mcrypt_decrypt('tripledes', $secret, $text, 'ecb'); $block = mcrypt_get_block_size('tripledes', 'ecb'); $pad = ord($data[($len = strlen($data)) - 1]); return substr($data, 0, strlen($data) - $pad); } Right now I am using a key of test and I'm trying to encrypt 1234567. I get the base64 output from encryption I'm looking for, but when I go to decrypt I get a blank response. I'm not very well versed in encryption/decryption so any help is much appreciated!!

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  • C#: Accessing PerformanceCounters for the ".NET CLR Memory category"

    - by Mads Ravn
    I'm trying to access the performance counters located in ".NET CLR Memory category" through C# using the PerformanceCounter class. However a cannot instantiate the categories with what I would expect was the correct category/counter name new PerformanceCounter(".NET CLR Memory", "# bytes in all heaps", Process.GetCurrentProcess().ProcessName); I tried looping through categories and counters using the following code string[] categories = PerformanceCounterCategory.GetCategories().Select(c => c.CategoryName).OrderBy(s => s).ToArray(); string toInspect = string.Join(",\r\n", categories); System.Text.StringBuilder interestingToInspect = new System.Text.StringBuilder(); string[] interestingCategories = categories.Where(s => s.StartsWith(".NET") || s.Contains("Memory")).ToArray(); foreach (string interestingCategory in interestingCategories) { PerformanceCounterCategory cat = new PerformanceCounterCategory(interestingCategory); foreach (PerformanceCounter counter in cat.GetCounters()) { interestingToInspect.AppendLine(interestingCategory + ":" + counter.CounterName); } } toInspect = interestingToInspect.ToString(); But could not find anything that seems to match. Is it not possible to observe these values from within the CLR or am I doing something wrong. The environment, should it matter, is .NET 4.0 running on a 64-bit windows 7 box.

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  • php ftp upload problem

    - by Autobyte
    Hi I am trying to write a small php function that will upload files to an FTP server and I keep getting the same error but I cannot find any fix by googling the problem, I am hoping you guys can help me here... The error I get is: Warning: ftp_put() [function.ftp-put]: Unable to build data connection: No route to host in . The file was created at the FTP server but it is zero bytes. Here is the code: <?php $file = "test.dat"; $ftp_server="ftp.server.com"; $ftp_user = "myname"; $ftp_pass = "mypass"; $destination_file = "test.dat"; $cid=ftp_connect($ftp_server); if(!$cid) { exit("Could not connect to server: $ftp_server\n"); } $login_result = ftp_login($cid, $ftp_user, $ftp_pass); if (!$login_result) { echo "FTP connection has failed!"; echo "Attempted to connect to $ftp_server for user $ftp_user"; exit; } else { echo "Connected to $ftp_server, for user $ftp_user"; } $upload = ftp_put($cid, $destination_file, $file, FTP_BINARY); if (!$upload) { echo "Failed upload for $source_file to $ftp_server as $destination_file<br>"; echo "FTP upload has failed!"; } else { echo "Uploaded $source_file to $ftp_server as $destination_file"; } ftp_close($cid); ?>

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  • Problems in getting data from CFStreamCreatePairWithSocketToHost

    - by gkedmi
    Hi I'm building an iPhoe app with a socket to a PC app , I need to get an image from this PC app. It's my first time using "CFStreamCreatePairWithSocketToHost".After I establish the socket with "NSOperation" I call CFStreamClientContext streamContext = {0, self, NULL, NULL, NULL}; BOOL success = CFReadStreamSetClient(myReadStream, kMyNetworkEvents,MyStreamCallBack,&streamContext); CFReadStreamScheduleWithRunLoop(myReadStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode); then I call CFWriteStreamWrite(myWriteStream, &writeBuffer, 3); // Open read stream. if (!CFReadStreamOpen(myReadStream)) { // Notify error } . . . while(!cancelled && !finished) { SInt32 result = CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.25, NO); if (result == kCFRunLoopRunStopped || result == kCFRunLoopRunFinished) { break; } if (([NSDate timeIntervalSinceReferenceDate] - _lastRead) MyConnectionTimeout) { // Call timed out cancelled = YES; break; } // Also handle stream status CFStreamStatus status = CFReadStreamGetStatus(myReadStream); } and then when I get "kCFStreamEventHasBytesAvailable" I use while (CFReadStreamHasBytesAvailable(myReadStream)) { CFReadStreamRead(myReadStream, readBuffer, 1000); //and buffer the the bytes } It's unpredictable , sometimes I get the whole picture , sometime I got just part of it , and I can't understand what make the different. can someone has an idea what is wrong here? thanks

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  • Encryption puzzle / How to create a ProxyStub for a Remote Assistance ticket

    - by Jon Clegg
    I am trying to create a ticket for Remote Assistance. Part of that requires creating a PassStub parameter. As of the documenation: http://msdn.microsoft.com/en-us/library/cc240115(PROT.10).aspx PassStub: The encrypted novice computer's password string. When the Remote Assistance Connection String is sent as a file over e-mail, to provide additional security, a password is used.<16 In part 16 they detail how to create as PassStub. In Windows XP and Windows Server 2003, when a password is used, it is encrypted using PROV_RSA_FULL predefined Cryptographic provider with MD5 hashing and CALG_RC4, the RC4 stream encryption algorithm. As PassStub looks like this in the file: PassStub="LK#6Lh*gCmNDpj" If you want to generate one yourself run msra.exe in Vista or run the Remote Assistance tool in WinXP. The documentation says this stub is the result of the function CryptEncrypt with the key derived from the password and encrypted with the session id (Those are also in the ticket file). The problem is that CryptEncrypt produces a binary output way larger then the 15 byte PassStub. Also the PassStub isn't encoding in any way I've seen before. Some interesting things about the PassStub encoding. After doing statistical analysis the 3rd char is always a one of: !#$&()+-=@^. Only symbols seen everywhere are: *_ . Otherwise the valid characters are 0-9 a-z A-Z. There are a total of 75 valid characters and they are always 15 bytes. Running msra.exe with the same password always generates a different PassStub, indicating that it is not a direct hash but includes the rasessionid as they say. Some other ideas I've had is that it is not the direct result of CryptEncrypt, but a result of the rasessionid in the MD5 hash. In MS-RA (http://msdn.microsoft.com/en-us/library/cc240013(PROT.10).aspx). The "PassStub Novice" is simply hex encoded, and looks to be the right length. The problem is I have no idea how to go from any hash to way the ProxyStub looks like.

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