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  • How to address thread-safety of service data used for maintaining static local variables in C++?

    - by sharptooth
    Consider the following scenario. We have a C++ function with a static local variable: void function() { static int variable = obtain(); //blahblablah } the function needs to be called from multiple threads concurrently, so we add a critical section to avoid concurrent access to the static local: void functionThreadSafe() { CriticalSectionLockClass lock( criticalSection ); static int variable = obtain(); //blahblablah } but will this be enough? I mean there's some magic that makes the variable being initialized no more than once. So there's some service data maintained by the runtime that indicates whether each static local has already been initialized. Will the critical section in the above code protect that service data as well? Is any extra protection required for this scenario?

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  • How to send data securely over a public channel?

    - by Daniel
    Hi! I have a smart client application being deployed with a CickOnce webpage. here's the current scenario. 1.User runs the application, and the application shows a login form. 2.User enters ID/Password in the login form, and the application sends that information to the server. 3.The server authenticates the user and sends configuration and data to the application. Different users have different configuration and data for their application. I was concerned that anyone can download the application from the webpage if they know the URL. So I'm trying to change the authentication scheme, so that users can login at the webpage to download the application. I want to send the authentication info from the webpage(Program running at the server) to the smart client app, so that application can download the configuration information from the server, without prompting users to make a login again. How can the webpage send the ID/Passoword to the application securely?

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  • What is the most efficient way to pass data (list of pairs of [Integer + Double]) between two Google App Engine instances?

    - by ruslan
    What is the most efficient way to pass data (list of pairs of [Integer, Double]) between two Google App Engine instances ? Currently I use Java binary serialization. Frontend servlet receives data from the client in JSON format. I convert it to byte[] using ObjectOutput.writeObject and then send it to backend servlet via HTTP POST. It's not in production yet. Should I just pass client's JSON as it is to backend? It seems more logical. But it's bigger in size. Or should I use Google Protocol Buffers as stated in this benchmark article ? Thank you!!!

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  • how i insert values from list of Data Grid View,current time ,EmployeeID using button click event (C

    - by Six fourty
    hi, it show me this error Incorrect syntax near the keyword 'Select' to make to clear Employee ID in this case is FK in the table (Attendance detail) and the other thing is i am using Data Grid View from another table(Employee information) to Show the list of the staff in my form. then i want to transfer each selected cell value from Data Grid View to attendance detail table. 10q private void time_in_Click(object sender, EventArgs e) { employee_InformationDataGridView.SelectedCells[0].Style.ForeColor = Color.Green; time_in.Enabled = false; time_out.Enabled = true; con = new SqlConnection(GlobalClass.conn); con.Open(); SqlCommand cmd = new SqlCommand("Insert into Attendancedetail Values(" + "Select from EmployeeInformation(EmployeeID)" + ",'" + employee_InformationDataGridView.SelectedCells[0] + "','" + DateTime.Now.ToLongDateString() + "','" + null + "','" + null + "','" + DateTime.Now.ToLongTimeString() + "'," + null + ")", con); int i = cmd.ExecuteNonQuery(); MessageBox.Show(i.ToString() + " record inserted"); }

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  • how to select all the data from many tables?

    - by Syom
    how to select all the data from many tables? i try `"SELECT * FROM `table1`, `table2`"` , but result none understandable for me. it returns only some rows from table1, and 3 times all the data from table2. i've red one same question here, but don't understand the answer. so could you help me? thanks in advance. update: when i try (SELECT * FROM `videos`) UNION (SELECT * FROM `users`) it returns #1222 - The used SELECT statements have a different number of columns

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  • How to know if a MySQL UPDATE query fails because information being supplied matches data already in

    - by Mike
    I have a query where the user types a block of text in a textarea field. They are able to save this information in a database. The problem is that if they have not changed the information or if the information matches the data already in the database, I recieve a '0' for affected rows. Usually I display an error that says the query failed when there are no affected rows. How would I 'know' that the 0 affected rows is because the data already exists, so that I can display a more specific error?

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  • beforeSave() returned some error

    - by kwokwai
    Hi all, I got a simple input text field in a HTML form: <input type="text" name="data[User][pswd]" id="data[User][pswd]"> The scripts for the Controller's action that captured the data is as follows: function register(){ $temp = $this->data; if(strlen($temp['User']['pswd'])>6) { if ($this->User->save($this->data)) { $this->Session->setFlash('Data was Saved'); } } } // this script works And in the Model controller, I got these lines of codes: function beforeSave() { $raw = $this->data; if(strlen($raw['User']['pswd'])>6){ md5($raw['User']['pswd']); } return true; } // this script failed to work The data was stored into the Database successfully but it was not undergone any MD5 encryption. I think that there must be some errors in the Model's script because I saw some errors flashed after the data was saved, but the screen that showed the errors immediately refreshed in a second after the data was saved successfully and I couldn't see the detail of the errors that caused the problem. Could you help me out please?

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  • How to restore data on Power Failure using C++ programming on windows.

    - by Tarun
    Hi, In my program I am writing a file of my programs states. I am writing the file many times to the file during the program run, because the program changes some variables that that i need to store very frequently. Now, if , for some reasons my power fails. Then most of the time I loose data in that file. Please, tell me any mechanism which can protect data even if the power fails. (I have written C++ program on windows). Thank you

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  • Can SQLite file copied successfully on the data folder of an unrooted android device ?

    - by student
    I know that in order to access the data folder on the device, it needs to be rooted. However, if I just want to copy the database from my assets folder to the data folder on my device, will the copying process works on an unrooted phone? The following is my Database Helper class. From logcat, I can verify that the methods call to copyDataBase(), createDataBase() and openDataBase() are returned successfully. However, I got this error message android.database.sqlite.SQLiteException: no such table: TABLE_NAME: when my application is executing rawQuery. I'm suspecting the database file is not copied successfully (cannot be too sure as I do not have access to data folder), yet the method call to copyDatabase() are not throwing any exception. What could it be? Thanks. ps: My device is still unrooted, I hope it is not the main cause of the error. public DatabaseHelper(Context context) { super(context, DB_NAME, null, 1); this.myContext = context; } public void createDataBase() throws IOException{ boolean dbExist = checkDataBase(); String s = new Boolean(dbExist).toString(); Log.d("dbExist", s ); if(dbExist){ //do nothing - database already exist Log.d("createdatabase","DB exists so do nothing"); }else{ this.getReadableDatabase(); try { copyDataBase(); Log.d("copydatabase","Successful return frm method call!"); } catch (IOException e) { throw new Error("Error copying database"); } } } private boolean checkDataBase(){ File dbFile = new File(DB_PATH + DB_NAME); return dbFile.exists(); } private void copyDataBase() throws IOException{ //Open your local db as the input stream InputStream myInput = null; myInput = myContext.getAssets().open(DB_NAME); Log.d("copydatabase","InputStream successful!"); // 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(); } public void openDataBase() throws SQLException{ //Open the database String myPath = DB_PATH + DB_NAME; myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); } /* @Override public synchronized void close() { if(myDataBase != null) myDataBase.close(); super.close(); }*/ public void close() { // NOTE: openHelper must now be a member of CallDataHelper; // you currently have it as a local in your constructor if (myDataBase != null) { myDataBase.close(); } } @Override public void onCreate(SQLiteDatabase db) { } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }

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  • Getting an Ajax response from Zend Framework Controller

    - by JavaLava
    I'm doing an Ajax request on one of my views to a Controller but I am unable to send back a response to the Ajax method. In the snippet below, I am trying to send the word 'hellopanda' back but in the alert message, I'll get data as an object. View : $.ajax({ type: "POST", url: "localhost/some-activity", data: dataString, success: function(data) { alert( "Data is: " + data); //do something with data }, error: function(data){ alert( "Data is: " + data); //do something with data }, onComplete: function(){ } }); Controller: public function someActivityAction(){ //do stuff echo "hellopanda"; } I'm pretty sure the echo is the problem. Any insights on to how to do a proper response to the view would be greatly appreciated.

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  • What type of data should I send to view?

    - by Vizualni
    Hello, this question I've been asking myself since the day I started programming in MVC way. Should I send to view arrays filled with data or should I send it as on objects I retrieved from database? My model returns me data as objects. What would be the best way to create such a thing? $new_data = $model->find_by_id(1); echo $new_data->name; $new_data->name= "whatever"; $new_data->save(); For example. view.php echo $object->name; or echo $array['name'] Language is php :).

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  • Is it possible to use variables and data in in-template css properties?

    - by aruman89
    <td style="width:77px" id="<%=id%>"><div class="condbar"><div class="condprogress" style="width:Data.condition%; background:condColor"></div> <div class="condvalue"><%=condition%><span>%</span></div></div></td> I want to set the width of a div .roster_condprogress as a percentage according to data and change the color accordingly (using a variable for that). What is a correct way to write this? (if it exists)

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  • is it right way( safe) to assign post data value directly by name attibute value to a variable in

    - by I Like PHP
    i m working in PHP since one year, but now a days i got this way to assign post data value directly using name attribute . i m really curious to know the documentation about it.please refere me link regarding this . i explain by example here is my form <form method="post" action=""> <input type="text" name="userName" id="userName"> <input type="submit" name="doit" value="submit"> </form> to get the post data i always use $somevar=mysql_real_escape_string($_POST['userName']); but now i see another way $somevar= "userName"; i just want to know that is it safe n easy way??

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  • How to take data from textarea and decrypt using javascript?

    - by user1657555
    I need to take data from a textarea on a website and decrypt it using a simple algorithm. The data is in the form of numbers separated by a comma. It also needs to read a space as a space. It looks like 42,54,57, ,57,40,57,44. Heres what I have so far: var my_textarea = $('textarea[name = "words"]').first(); var my_value = $(my_textarea).val(); var my_array = my_value.split(","); for (i=0; i < my_array.length; i++) { var nv = my_array - 124; var acv = nv + 34; var my_result = String.fromCharCode(acv); } prompt("", my_result);

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  • PHP-FPM High Memory Usage

    - by Ruel
    I have a wordpress blog, that uses WP-SuperCache, and normally I get 100 visitors per day. With nginx + php-fpm it's blazing fast, and I have no regrets. One thing i noticed, php-fpm takes a lot of memory: top - 09:20:43 up 5 days, 15:53, 1 user, load average: 0.00, 0.00, 0.00 Tasks: 26 total, 1 running, 25 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1048576k total, 329956k used, 718620k free, 0k buffers Swap: 0k total, 0k used, 0k free, 0k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 10226 www-data 15 0 145m 52m 4584 S 0.0 5.1 0:07.55 php-fpm 10223 www-data 16 0 141m 48m 4692 S 0.0 4.8 0:08.70 php-fpm 20277 www-data 15 0 138m 46m 4368 S 0.0 4.5 0:07.55 php-fpm 20259 www-data 15 0 133m 41m 4600 S 0.0 4.0 0:06.68 php-fpm 12201 www-data 15 0 133m 41m 4632 S 0.0 4.0 0:08.31 php-fpm 11586 www-data 15 0 132m 40m 4292 S 0.0 3.9 0:03.27 php-fpm 29822 www-data 15 0 128m 36m 4356 S 0.0 3.6 0:05.26 php-fpm 28427 mysql 15 0 200m 7300 4764 S 0.0 0.7 0:47.89 mysqld 10202 root 18 0 98.3m 4320 1204 S 0.0 0.4 0:03.80 php-fpm 22524 root 18 0 86064 3396 2652 S 0.0 0.3 0:16.74 sshd 9882 www-data 18 0 42052 2572 804 S 0.0 0.2 0:27.52 nginx 9884 www-data 18 0 42052 2560 804 S 0.0 0.2 0:26.26 nginx 9881 www-data 18 0 42064 2524 804 S 0.0 0.2 0:29.24 nginx 9879 www-data 18 0 42032 2480 804 S 0.0 0.2 0:29.58 nginx 23771 root 15 0 12176 1820 1316 S 0.0 0.2 0:00.08 bash 28344 root 22 0 11932 1416 1184 S 0.0 0.1 0:00.00 mysqld_safe 18167 root 16 0 62628 1208 648 S 0.0 0.1 0:00.55 sshd 25941 root 15 0 12612 1192 928 R 0.0 0.1 0:02.21 top 11573 root 15 0 20876 1168 592 S 0.0 0.1 0:00.67 crond 9878 root 18 0 41000 1112 284 S 0.0 0.1 0:00.00 nginx 21736 root 23 0 21648 936 716 S 0.0 0.1 0:00.00 xinetd 11585 root 18 0 46748 816 428 S 0.0 0.1 0:00.00 saslauthd 14125 root 12 -4 12768 768 452 S 0.0 0.1 0:00.00 udevd 1 root 18 0 10352 728 616 S 0.0 0.1 0:17.93 init 24564 root 15 0 5912 680 544 S 0.0 0.1 0:01.90 syslogd 11618 root 18 0 46748 548 160 S 0.0 0.1 0:00.00 saslauthd Here's my php-fpm config: [global] pid = run/php-fpm.pid error_log = log/php-fpm.log log_level = notice [www] listen = 127.0.0.1:9000 user = www-data group = www-data pm = dynamic pm.max_children = 50 pm.start_servers = 3 pm.min_spare_servers = 3 pm.max_spare_servers = 10 pm.max_requests = 500 Sometimes it goes up to 400MB. And I'm planning to add a new website on my VPS. Is this normal?

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  • Unable to use TweetDeck on Windows due to "Ooops, TweetDeck can't find your data" and "Sorry, Adobe

    - by Matt
    I'm running Adobe AIR 1.5.2 (latest) on Windows 7 (64-bit RTM) and downloaded TweetDeck 0.31.1 (latest). When I run TweetDeck I get the following errors: Ooops, TweetDeck can't find your data and Sorry, Adobe AIR has a problem running on this computer Other AIR applications install and run fine. I've uninstalled both TweetDeck and AIR and reinstalled. Following the uninstalls I've also removed all on-disk references to both TweetDeck and AIR, but no luck. UPDATE: Using Process Monitor I did a trace of Tweetdeck from the moment it launched until the first error occurred. I saw the following information in the output of the trace: 1 5:22:18.6522338 PM TweetDeck.exe 5580 CreateFile D:\ProgramData\Microsoft\Windows\Start Menu\Programs\rs\??\d:\Use\myusername\AppData\Roaming\Adobe\AIR\ELS\TweetDeckFast.F9107117265DB7542C1A806C8DB837742CE14C21.1\PrivateEncryptedDatak NAME INVALID Desired Access: Generic Write, Read Attributes, Disposition: OverwriteIf, Options: Synchronous IO Non-Alert, Non-Directory File, Attributes: N, ShareMode: Read, Write, AllocationSize: 0 In this trace output, Tweetdeck.exe is trying to create the file D:\ProgramData\Microsoft\Windows\Start Menu\Programs\rs\??\d:\Use\myusername\AppData\Roaming\Adobe\AIR\ELS\TweetDeckFast.F9107117265DB7542C1A806C8DB837742CE14C21.1\PrivateEncryptedDatak but the path specified is invalid. When looking at the path you can see that it is indeed an invalid path. First, there’s the “??” portion which doesn’t exist in the file system since the “?” is an invalid character in Windows/NTFS file systems. Additionally, looking at this path, it actually seems to be composed of two parts (is the "??" a delimiter?): Part 1: D:\ProgramData\Microsoft\Windows\Start Menu\Programs\rs\?? Part 2: d:\Use\myusername\AppData\Roaming\Adobe\AIR\ELS \TweetDeckFast.F9107117265DB7542C1A806C8DB837742CE14C21.1\PrivateEncryptedDatak (the problem here is that d:\Use... doesn’t even exist. What seems to be happening here is that Tweetdeck is looking for the user credentials (the “PrivateEncryptedDatak” file) but it’s looking in the wrong place, can’t find the file, and hence the error that Tweetdeck is giving (shown in the screenshot). I'm trying to determine how TweetDeck is getting this path. I searched the contents of all files on my hard disk hoping to find some TweetDeck or Adobe AIR configuration file containing this incorrect path, but I was unable to find anything. UPDATE: See Carl's comment regarding directory junctions and symbolic links under my accepted answer. This ended up being the problem. Edit by Gnoupi: People, the answer section is there to provide an actual ANSWER, not to say you have the same issue. It doesn't help anyone that you have the same problem. Eventually, if you think this is really worth mentioning, put it as a comment under the question. But simply, if what you want to add is not an answer to the question, then don't post it as an answer. This is not a forum, I recommend new users to read the FAQ: http://superuser.com/faq

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  • How to remove RAID flag on unstriped drive without losing data?

    - by Alex Folland
    I have a Gigabyte Z68X-UD4-B3 motherboard. It advertises this new thing called "XHD", which is like RAID but makes a SSD and traditional-style drive work together to enable high speed with high capacity. I don't want to use this feature, and I already have Windows 7 64 installed without using this feature. When I first installed my 2 hard drives (1 SSD and 1 traditional-style drive) in my machine and booted it up for the first time, it ran a program from the mobo that asked me if I wanted to set up XHD. Thinking it would go to some config screen, I said yes. It immediately started doing something with my drives and finished. I considered that strange, but figured it wouldn't matter when I simply install Windows onto my SSD only. I now have my BIOS and Windows running in AHCI mode with no RAID arrays and separate drives. My SSD is one of those new Corsair Force GT drives which loses power every so often, causing Windows to BSOD. I've figured everything out about this problem, including installing the latest firmware from Corsair, and the only way to fix it at this point is by installing Intel Rapid Storage Technology to control AHCI instead of Windows, since the Windows AHCI driver disables the drive's power every once in a while and can't be configured not to do so. I've tried installing Intel Rapid Storage Technology. When I reboot my machine after doing so, it BSODs just after the Windows logo. I've figured out this is because my SSD and my traditional drive are flagged as RAID, as seen in the "Intel Matrix Storage Manager" program found by switching the BIOS hard drive handling to "RAID" mode. This is due to the XHD auto-config program I mentioned earlier. Normally, the BIOS is set to AHCI, and when the drives boot in AHCI mode, they work perfectly. So, I've concluded the data is stored in AHCI mode but the drives' flags are set to RAID. I've figured out that I can accomplish my objective by using the "Intel Matrix Storage Manager" program on the mobo (with "Reset disks to non-RAID"), but doing so would cause it to completely wipe the drives I select. I want to simply toggle these flags from RAID to AHCI so Intel Rapid Storage Technology doesn't fail and cause a BSOD upon booting, but without wiping the drives.

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  • Can I save & store a user's submission in a way that proves that the data has not been altered, and that the timestamp is accurate?

    - by jt0dd
    There are many situations where the validity of the timestamp attached to a certain post (submission of information) might be invaluable for the post owner's legal usage. I'm not looking for a service to achieve this, as requested in this great question, but rather a method for the achievement of such a service. For the legal (in most any law system) authentication of text content and its submission time, the owner of the content would need to prove: that the timestamp itself has not been altered and was accurate to begin with. that the text content linked to the timestamp had not been altered I'd like to know how to achieve this via programming (not a language-specific solution, but rather the methodology behind the solution). Can a timestamp be validated to being accurate to the time that the content was really submitted? Can data be stored in a form that it can be read, but not written to, in a proven way? In other words, can I save & store a user's submission in a way that proves that the data has not been altered, and that the timestamp is accurate? I can't think of any programming method that would make this possible, but I am not the most experienced programmer out there. Based on MidnightLightning's answer to the question I cited, this sort of thing is being done. Clarification: I'm looking for a method (hashing, encryption, etc) that would allow an average guy like me to achieve the desired effect through programming. I'm interested in this subject for the purpose of Defensive Publication. I'd like to learn a method that allows an every-day programmer to pick up his computer, write a program, pass information through it, and say: I created this text at this moment in time, and I can prove it. This means the information should be protected from the programmer who writes the code as well. Perhaps a 3rd party API would be required. I'm ok with that.

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  • C#, AES encryption check!

    - by Data-Base
    I have this code for AES encryption, can some one verify that this code is good and not wrong? it works fine, but I'm more concern about the implementation of the algorithm // Plaintext value to be encrypted. //Passphrase from which a pseudo-random password will be derived. //The derived password will be used to generate the encryption key. //Password can be any string. In this example we assume that this passphrase is an ASCII string. //Salt value used along with passphrase to generate password. //Salt can be any string. In this example we assume that salt is an ASCII string. //HashAlgorithm used to generate password. Allowed values are: "MD5" and "SHA1". //SHA1 hashes are a bit slower, but more secure than MD5 hashes. //PasswordIterations used to generate password. One or two iterations should be enough. //InitialVector (or IV). This value is required to encrypt the first block of plaintext data. //For RijndaelManaged class IV must be exactly 16 ASCII characters long. //KeySize. Allowed values are: 128, 192, and 256. //Longer keys are more secure than shorter keys. //Encrypted value formatted as a base64-encoded string. public static string Encrypt(string PlainText, string Password, string Salt, string HashAlgorithm, int PasswordIterations, string InitialVector, int KeySize) { byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector); byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt); byte[] PlainTextBytes = Encoding.UTF8.GetBytes(PlainText); PasswordDeriveBytes DerivedPassword = new PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations); byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8); RijndaelManaged SymmetricKey = new RijndaelManaged(); SymmetricKey.Mode = CipherMode.CBC; ICryptoTransform Encryptor = SymmetricKey.CreateEncryptor(KeyBytes, InitialVectorBytes); MemoryStream MemStream = new MemoryStream(); CryptoStream CryptoStream = new CryptoStream(MemStream, Encryptor, CryptoStreamMode.Write); CryptoStream.Write(PlainTextBytes, 0, PlainTextBytes.Length); CryptoStream.FlushFinalBlock(); byte[] CipherTextBytes = MemStream.ToArray(); MemStream.Close(); CryptoStream.Close(); return Convert.ToBase64String(CipherTextBytes); } public static string Decrypt(string CipherText, string Password, string Salt, string HashAlgorithm, int PasswordIterations, string InitialVector, int KeySize) { byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector); byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt); byte[] CipherTextBytes = Convert.FromBase64String(CipherText); PasswordDeriveBytes DerivedPassword = new PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations); byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8); RijndaelManaged SymmetricKey = new RijndaelManaged(); SymmetricKey.Mode = CipherMode.CBC; ICryptoTransform Decryptor = SymmetricKey.CreateDecryptor(KeyBytes, InitialVectorBytes); MemoryStream MemStream = new MemoryStream(CipherTextBytes); CryptoStream cryptoStream = new CryptoStream(MemStream, Decryptor, CryptoStreamMode.Read); byte[] PlainTextBytes = new byte[CipherTextBytes.Length]; int ByteCount = cryptoStream.Read(PlainTextBytes, 0, PlainTextBytes.Length); MemStream.Close(); cryptoStream.Close(); return Encoding.UTF8.GetString(PlainTextBytes, 0, ByteCount); } Thank you

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  • How to efficiently store and update binary data in Mongodb?

    - by Rocketman
    I am storing a large binary array within a document. I wish to continually add bytes to this array and sometimes change the value of existing bytes. I was looking for some $append_bytes and $replace_bytes type of modifiers but it appears that the best I can do is $push for arrays. It seems like this would be doable by performing seek-write type operations if I had access somehow to the underlying bson on disk, but it does not appear to me that there is anyway to do this in mongodb (and probably for good reason). If I were instead to just query this binary array, edit or add to it, and then update the document by rewriting the entire field, how costly will this be? Each binary array will be on the order of 1-2MB, and updates occur once every 5 minutes and across 1000s of documents. Worse, yet there is no easy way to spread these out (in time) and they will usually be happening close to one another on the 5 minute intervals. Does anyone have a good feel for how disastrous this will be? Seems like it would be problematic. An alternative would be to store this binary data as separate files on disk, implement a thread pool to efficiently manipulate the files on disk, and reference the filename from my mongodb document. (I'm using python and pymongo so I was looking at pytables). I'd prefer to avoid this though if possible. Is there any other alternative that I am overlooking here? Thanks in advnace.

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  • Is it possible to cache all the data in a SQL Server CE database using LinqToSql?

    - by DanM
    I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

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