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  • waveInProc / Windows audio question...

    - by BTR
    I'm using the Windows API to get audio input. I've followed all the steps on MSDN and managed to record audio to a WAV file. No problem. I'm using multiple buffers and all that. I'd like to do more with the buffers than simply write to a file, so now I've got a callback set up. It works great and I'm getting the data, but I'm not sure what to do with it once I have it. Here's my callback... everything here works: // Media API callback void CALLBACK AudioRecorder::waveInProc(HWAVEIN hWaveIn, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2) { // Data received if (uMsg == WIM_DATA) { // Get wav header LPWAVEHDR mBuffer = (WAVEHDR *)dwParam1; // Now what? for (unsigned i = 0; i != mBuffer->dwBytesRecorded; ++i) { // I can see the char, how do get them into my file and audio buffers? cout << mBuffer->lpData[i] << "\n"; } // Re-use buffer mResultHnd = waveInAddBuffer(hWaveIn, mBuffer, sizeof(mInputBuffer[0])); // mInputBuffer is a const WAVEHDR * } } // waveInOpen cannot use an instance method as its callback, // so we create a static method which calls the instance version void CALLBACK AudioRecorder::staticWaveInProc(HWAVEIN hWaveIn, UINT uMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2) { // Call instance version of method reinterpret_cast<AudioRecorder *>(dwParam1)->waveInProc(hWaveIn, uMsg, dwInstance, dwParam1, dwParam2); } Like I said, it works great, but I'm trying to do the following: Convert the data to short and copy into an array Convert the data to float and copy into an array Copy the data to a larger char array which I'll write into a WAV Relay the data to an arbitrary output device I've worked with FMOD a lot and I'm familiar with interleaving and all that. But FMOD dishes everything out as floats. In this case, I'm going the other way. I guess I'm basically just looking for resources on how to go from LPSTR to short, float, and unsigned char. Thanks much in advance!

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  • C# + Querying XML with LINQ

    - by user336786
    Hello, I'm learning to use LINQ. I have seen some videos online that have really impressed me. In an effort to learn LINQ myself, I decided to try to write a query to the NOAA web service. If you put "http://www.weather.gov/forecasts/xml/sample_products/browser_interface/ndfdBrowserClientByDay.php?zipCodeList=20001&format=24+hourly&startDate=2010-06-10&numDays=5" in your browser's address bar, you will see some XML. I have successfully retrieved that XML in a C# program. I am loading the XML into a LINQable entity by doing the following: string xml = QueryWeatherService(); XDocument weather = XDocument.Parse(xml); I have a class called DailyForecast defined as follows: public class DailyForecast { public float HighTemperature { get; set; } public float LowTemperature { get; set; } public float PrecipitationPossibility { get; set; } public string WeatherSummary { get; set; } } I'm trying write a LINQ query that adheres to the structure of my DailyForecast class. At this time, I've only gotten to this far: var results = from day in response.Descendants("parameters") select day; Not very far I know. Because of the structure of the XML returned, I'm not sure it is possible to solely use a LINQ query. I think the only way to do this is via a loop and traverse the XML. I'm seeking someone to correct me if I'm wrong. Can someone please tell me if I can get results using purely LINQ that adhere to the structure of the DailyForecast class? If so, how? Thank you!

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  • How do you tell that your unit tests are correct?

    - by Jacob Adams
    I've only done minor unit testing at various points in my career. Whenever I start diving into it again, it always troubles me how to prove that my tests are correct. How can I tell that there isn't a bug in my unit test? Usually I end up running the app, proving it works, then using the unit test as a sort of regression test. What is the recommended approach and/or what is the approach you take to this problem? Edit: I also realize that you could write small, granular unit tests that would be easy to understand. However, if you assume that small, granular code is flawless and bulletproof, you could just write small, granular programs and not need unit testing. Edit2: For the arguments "unit testing is for making sure your changes don't break anything" and "this will only happen if the test has the exact same flaw as the code", what if the test overfits? It's possible to pass both good and bad code with a bad test. My main question is what good is unit testing since if your tests can be flawed you can't really improve your confidence in your code, can't really prove your refactoring worked, and can't really prove that you met the specification?

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  • How can I receive messages using over http without MSMQ

    - by pduncan
    I need a reliable messaging framework that runs over http/https (due to client security requirements) and that doesn't use MSMQ (because some clients will use Windows XP Home). The clients only need to be able to receive messages, not send them. We already have a message queue on the server for each user, and the receivers have been getting messages by connecting to an HttpHandler on the server and getting a Stream from WebResponse.GetResponseStream() We keep this stream open, and pull messages off of it using Stream.Read(). This MOSTLY works, but Stream.Read() is a blocking call, and we can't reliably interrupt it. We need to be able to stop and start the receiver without losing messages, but the old stream often hangs around, even after we call Thread.Abort on its thread. Any suggestions?

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  • what is the wrong with this code"length indicator implementation" ?

    - by cj
    Hello, this is an implementation of length indicator field but it hang and i think stuck at a loop and don't show any thing. // readx22.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include "iostream" #include "fstream" #include "stdio.h" using namespace std; class Student { public: string id; size_t id_len; string first_name; size_t first_len; string last_name; size_t last_len; string phone; size_t phone_len; string grade; size_t grade_len; void read(fstream &ven); void print(); }; void Student::read(fstream &ven) { size_t cnt; ven >> cnt; id_len=cnt; id.reserve( cnt ); while ( -- cnt ) { id.push_back( ven.get() ); } ven >> cnt; first_len=cnt; first_name.reserve( cnt ); while ( -- cnt ) { first_name.push_back( ven.get() ); } ven >> cnt; last_len=cnt; last_name.reserve( cnt ); while ( -- cnt ) { last_name.push_back( ven.get() ); } ven >> cnt; phone_len=cnt; phone.reserve( cnt ); while ( -- cnt ) { phone.push_back( ven.get() ); } ven >> cnt; grade_len=cnt; grade.reserve( cnt ); while ( -- cnt ) { grade.push_back( ven.get() ); } } void Student::print() { // string::iterator it; for ( int i=0 ; i<id_len; i++) cout << id[i]; } int main() { fstream in; in.open ("fee.txt", fstream::in); Student x; x.read(in); x.print(); return 0; } thanks

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  • How to get server message correctly

    - by Leo
    Problem I send the message "12345" from the socket server to the client: myPrintWriter.println("12345"); After that I read this message on client: int c; while ((c = inputStream.read( )) != -1) { byte[] buffer2 = new byte[1]; buffer2[0] = (byte) c; String symbol = new String(buffer2 , "UTF-8"); String symbolCode = Integer.toString((int)buffer2[0]); Log.v(symbol, symbolCode); } Log.v("c == -1", "Disconnected"); What I see in log: With out.println("abcrefg"); Why? I think it's line termination symbol. I need to get string "12345" or any other and next strings correctly. Help me please.

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  • How do I implement a collection in Scala 2.8?

    - by Simon Reinhardt
    In trying to write an API I'm struggling with Scala's collections in 2.8(.0-beta1). Basically what I need is to write something that: adds functionality to immutable sets of a certain type where all methods like filter and map return a collection of the same type without having to override everything (which is why I went for 2.8 in the first place) where all collections you gain through those methods are constructed with the same parameters the original collection had (similar to how SortedSet hands through an ordering via implicits) which is still a trait in itself, independent of any set implementations. Additionally I want to define a default implementation, for example based on a HashSet. The companion object of the trait might use this default implementation. I'm not sure yet if I need the full power of builder factories to map my collection type to other collection types. I read the paper on the redesign of the collections API but it seems like things have changed a bit since then and I'm missing some details in there. I've also digged through the collections source code but I'm not sure it's very consistent yet. Ideally what I'd like to see is either a hands-on tutorial that tells me step-by-step just the bits that I need or an extensive description of all the details so I can judge myself which bits I need. I liked the chapter on object equality in "Programming in Scala". :-) But I appreciate any pointers to documentation or examples that help me understand the new collections design better.

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  • TeamCity Mercurial, How to handle tags and releases

    - by Garrett
    Hi First off, i'm new to Teamcity comming from CC. I have a server up and running and building my projects, so far so good :). My problem is this: Whenever I make a Mercurial Tag, I would like TeamCity to react in a special way, so that the resulting binaries/artifacts from the Tag build, are made avaliable for download (automatic release when tagging). In short can I do automated release so that when I create a Tag AND it builds successfully then the result is copied to some location X, but ONLY when I Tag. Im pretty sure that this can be done, but when I read the posts around the net and read the documentation, I tend to get a little confused about artifacts/build scripts/publishing and how to do it. Can anyone give me some hints about where/how to start or guide me to a location with a tutorial/example of how to do this? I want it soooooo bad :-D. Kind regards

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  • Starting a code library.

    - by Rob Stevenson-Leggett
    Hi, I've been meaning to start a library of reusable code snippets for a while and never seem to get round to it. I think my main problems are: Where to start. What structure should my library take? Should it be a compiled library (where appropriate or just classes I can drop into any project? Or a library project that can be included? In my experience, a built library will quickly become out of date and the source will get lost. So I'm leaning towards source libraries that I can export from SVN and include in any project. Intellectual property. I am employeed, so a lot of the code I write is not my IP. How can I ensure that I don't give my own IP away using it on projects in work and at home? I'm thinking the best way would be to licence my library with an open source licence and make sure I only add to it in my own time using my own equipment and therefore making sure that if I use it in a work project the same rules apply as if I was using a third party library. I write in many different languages and often would require two or more parts of this library. Should I look at implementing a few template projects and a core project for each of my chosen reusable components and languages? Has anyone else got this sort of library and how do you organise and update it?

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  • cant open device

    - by yoavstr
    I have a little problem. I install this module into my kernel and its written under /proc When I try to open() it from user mode I get the following message: "Can't open device file: my_dev" static int module_permission(struct inode *inode, int op, struct nameidata *foo) { //if its write if ((op == 2)&&(writer == DOESNT_EXIST)){ writer = EXIST ; return 0; } //if its read if (op == 4 ){ numOfReaders++; return 0; } return -EACCES; } int procfs_open(struct inode *inode, struct file *file) { try_module_get(THIS_MODULE); return 0; } static struct file_operations File_Ops_4_Our_Proc_File = { .read = procfs_read, .write = procfs_write, .open = procfs_open, .release = procfs_close, }; static struct inode_operations Inode_Ops_4_Our_Proc_File = { .permission = module_permission, /* check for permissions */ }; int init_module() { /* create the /proc file */ Our_Proc_File = create_proc_entry(PROC_ENTRY_FILENAME, 0644, NULL); /* check if the /proc file was created successfuly */ if (Our_Proc_File == NULL){ printk(KERN_ALERT "Error: Could not initialize /proc/%s\n", PROC_ENTRY_FILENAME); return -ENOMEM; } Our_Proc_File->owner = THIS_MODULE; Our_Proc_File->proc_iops = &Inode_Ops_4_Our_Proc_File; Our_Proc_File->proc_fops = &File_Ops_4_Our_Proc_File; Our_Proc_File->mode = S_IFREG | S_IRUGO | S_IWUSR; Our_Proc_File->uid = 0; Our_Proc_File->gid = 0; Our_Proc_File->size = 80; //i added init the writewr status writer = DOESNT_EXIST; numOfReaders = 0 ; printk(KERN_INFO "/proc/%s created\n", PROC_ENTRY_FILENAME); return 0; }

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  • Can I safely move my project to .NET 4.0?

    - by Decker
    I've migrated my project to VS2010 but have not yet targeted .NET 4.0. It's currently targeting 3.5 SP1 (and CLR 2). The project relies on several third party components -- mostly open source -- that were presumably built against the 2.0 CLR. Can I simply retarget my project to the 4.0 runtime? Or do I have to get new versions of all the referenced assemblies on which it depends? I've read a little about the new in-process side-by-side feature of .NET 4.0, but I don't think it applies here (the example I read was about two different .NET plug ins to an office application). My situation is different. My solution directly references assemblies and I wouldn't think side-by-side applies -- unless I don't understand its purpose. TIA

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  • Should I base my Embedded Linux product on Qt?

    - by Udi
    My company is developing a medical product. One of the components is a pda-like platform that will run embedded linux. We were considering Qt as the UI framework but found out that Qt is a lot more than that (we are not familiar with Qt). In general, the device needs to do the following: 1. Receive measurements over USB HID from another device (USB HID is used for convenience). 2. Process the measurements. 3. Store them in a database. 4. Interact with the user using the device's touch screen lcd. 5. Communicate (wi-fi, tcp-ip) with a central management station that collects the data and configures the device. 6. Include a web server to allow accessing the device via a browser. We intend to program in C++. My questions are: 1. Is that a good choice for such a device? 2. Assuming we choose Qt, how do we build our product? - Do we use Qt just as a GUI framework and write the application code in a separate process (passing messages between Qt and the application process)? - Do we write the entire application inside Qt, using all of the services the tool has to offer? - Another approach?

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  • What's the cleanest way to do byte-level manipulation?

    - by Jurily
    I have the following C struct from the source code of a server, and many similar: // preprocessing magic: 1-byte alignment typedef struct AUTH_LOGON_CHALLENGE_C { // 4 byte header uint8 cmd; uint8 error; uint16 size; // 30 bytes uint8 gamename[4]; uint8 version1; uint8 version2; uint8 version3; uint16 build; uint8 platform[4]; uint8 os[4]; uint8 country[4]; uint32 timezone_bias; uint32 ip; uint8 I_len; // I_len bytes uint8 I[1]; } sAuthLogonChallenge_C; // usage (the actual code that will read my packets): sAuthLogonChallenge_C *ch = (sAuthLogonChallenge_C*)&buf[0]; // where buf is a raw byte array These are TCP packets, and I need to implement something that emits and reads them in C#. What's the cleanest way to do this? My current approach involves [StructLayout(LayoutKind.Sequential, Pack = 1)] unsafe struct foo { ... } and a lot of fixed statements to read and write it, but it feels really clunky, and since the packet itself is not fixed length, I don't feel comfortable using it. Also, it's a lot of work. However, it does describe the data structure nicely, and the protocol may change over time, so this may be ideal for maintenance. What are my options? Would it be easier to just write it in C++ and use some .NET magic to use that?

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  • R.matlab/readMat : Error in readTag(this)

    - by Megan
    I am trying to read a matlab file into R using R.matlab but am encountering this error: require(R.matlab) r <- readMat("file.mat", verbose=T) Trying to read MAT v5 file stream... Error in readTag(this) : Unknown data type. Not in range [1,19]: 18569 In addition: Warning message: In readMat5Header(this, firstFourBytes = firstFourBytes) : Unknown MAT version tag: 512. Will assume version 5. How can this issue be solved or is there an alternative way to load matlab files? I can use hdf5load but have heard this can mess with the data. Thanks!

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  • WPF: Convert memory stream to BitmapImage?

    - by David Veeneman
    I have an image that was originally a PNG that I have converted to a byte[] and saved in a database. Originally, I simply read the PNG into a memory stream and converted the stream into a byte[]. Now I want to read the byte[] back and convert it to a BitmapImage, so that I can bind a WPF Image control to it. I am seeing a lot of contradictory and confusing code online to accomplish the task of converting a byte[] to a BitmapImage. I am not sure whether I need to add any code due to the fact that the image was originally a PNG. Can anyone provide the code to convert the stream to a BitmapImage? Thanks for your help.

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  • Reading in data from a file into an array

    - by Sam
    If I have an options file along the lines of this: size = 4 data = 1100010100110010 And I have a 2d size * size array that I want to populate the values in data into, what's the best way of doing it? To clarify, for the example I have I'd want an array like this: int[4][4] array = {{1,1,0,0}, {0,1,0,1}, {0,0,1,1}, {0,0,1,0}}. (Not real code but you get the idea). Size can be really be any number though. I'm thinking I'd have to read in the size, maloc an array and then maybe read in a string full of data then loop through each char in the data, cast it to an int and stick it in the appropriate index? But I really have no idea how to go about it, have been searching for a while with no luck. Any help would be cool! :)

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  • Should I be using Expression Blend to design really dynamic UIs?

    - by Robert Rossney
    My company's product is, at its core, a framework for developing metadata-driven UIs. I don't know how to characterize it less succinctly than that, and hope I won't need to for purposes of this question, but we'll see. I've been trying to come up to speed on WPF, and have been building UI prototypes here and there, and recently I decided to see if I could use Expression Blend to help with the design of these UIs. And I'm pretty mystified at this point. It appears to me as though Expresssion Blend is designed with the expectation that you already know all of the objects that are going to be present in the UI at design time. But our program generates these object dynamically at runtime. For instance, a data row might be presented in a horizontal StackPanel containing alternating TextBlocks (for captions) and TextBoxes (for data fields). The number of these objects depends on metadata about the number of columns in the data row. I can, pretty readily, write code that runs through a metadata record and populates a StackPanel dynamically, setting up the binding of all of the controls to properties in either the data or metadata. (A TextBox's Width might be bound to metadata, while its Text is bound to data.) But I can't even begin to figure out how to do something like this in Expression Blend. I can manually create all these controls, so that I have a set of controls that I can apply styles to and work out the visual design of the app, but it's really a pain to do this. I can write code that goes through my data model and emits XAML for all these controls, I suppose, and then copy and paste it. But I'm going to feel really stupid if it turns out there a way to do this sort of thing in Expression Blend and I've dropped back and punted because I'm too dim to figure out the right way to think of it. Is this enough information for someone to try formulating an answer?

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  • How can i get a file from remote machine?

    - by programmerist
    How can i get a file from remote computer? i know remote computer ip and 51124 port is open. i need this algorith: 1) Connect 192.xxx.x.xxx ip via 51124 port 2) filename:123456 (i want to search it on remote machine) 3) Get File 4) Save C:\ 51124 port is open. can i access and can i search any file according to filename? My code is below: IPEndPoint ipEnd = new IPEndPoint(IPAddress.Any, 51124); Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP); sock.Bind(ipEnd); sock.Listen(maxConnections); Socket serverSocket = sock.Accept(); byte[] data = new byte[bufferSize]; int received = serverSocket.Receive(data); int filenameLength = BitConverter.ToInt32(data, 0); string filename = Encoding.ASCII.GetString(data, 4, filenameLength); BinaryWriter bWrite = new BinaryWriter(File.Open(outPath + filename, FileMode.Create)); bWrite.Write(data, filenameLength + 4, received - filenameLength - 4); int received2 = serverSocket.Receive(data); while (received2 0) { bWrite.Write(data, 0, received2); received2 = serverSocket.Receive(data); } bWrite.Close(); serverSocket.Close(); sock.Close();

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  • download mail attachment with Java

    - by Don
    Hi, I had a look in the reference doc, and Spring seems to have pretty good support for sending mail. However, I need to login to a mail account, read the messages, and download any attachments. Is downloading mail attachments supported by the Spring mail API? I know you can do this with the Java Mail API, but in the past I've found that very verbose and unpleasant to work with. EDIT: I've received several replies pointing towards tutorials that describe how to send mail with attachments, but what I'm asking about is how to read attachments from received mail. Cheers, Don

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  • How can I manage a FIFO-queue in an database with SQL?

    - by Jonas
    I have two tables in my database, one for In and one for Out. They have two columns, Quantity and Price. How can I write a SQL-query that selects the correct price? In example: If I have 3 items in for 75 and then 3 items in for 80. Then I have two out for 75, and the third out should be for 75 (X) and the fourth out should be for 80 (Y). How can I write the price query for X and Y? They should use the price from the third and forth row. In example, is there any way to SELECT the third row in the In-table? I can not use auto_increment as identifier for i.e. "third" row, because the tables will contain post for other items too. The rows will not be deleted, they will be saved for accountability reasons. SELECT Price FROM In WHERE ...? NEW database design: +----+ | In | +----+------+-------+ | Supply_ID | Price | +-----------+-------+ | 1 | 75 | | 1 | 75 | | 1 | 75 | | 2 | 80 | | 2 | 80 | +-----------+-------+ +-----+ | Out | +-----+-------+-------+ | Delivery_ID | Price | +-------------+-------+ | 1 | 75 | | 1 | 75 | | 2 | X | <- ? | 3 | Y | <- ? +-------------+-------+ OLD database design: +----+ | In | +----+------+----------+-------+ | Supply_ID | Quantity | Price | +-----------+----------+-------+ | 1 | 3 | 75 | | 2 | 3 | 80 | +-----------+----------+-------+ +-----+ | Out | +-----+-------+----------+-------+ | Delivery_ID | Quantity | Price | +-------------+----------+-------+ | 1 | 2 | 75 | | 2 | 1 | X | <- ? | 3 | 1 | Y | <- ? +-------------+----------+-------+

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  • Getting visitors country from their IP

    - by Ali Abdulkarim Salem
    i want to get visitors country via their IP.. right now I'm using this ( http://api.hostip.info/country.php?ip=...... ) here's my code <?php if (isset($_SERVER['HTTP_CLIENT_IP'])) { $real_ip_adress = $_SERVER['HTTP_CLIENT_IP']; } if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) { $real_ip_adress = $_SERVER['HTTP_X_FORWARDED_FOR']; } else { $real_ip_adress = $_SERVER['REMOTE_ADDR']; } $cip = $real_ip_adress; $iptolocation = 'http://api.hostip.info/country.php?ip=' . $cip; $creatorlocation = file_get_contents($iptolocation); ?> Well, it's working properly, but the thing is, this returns the country code like US or CA., and not the whole country name like United States or Canada So, is there any good alternative to hostip.info offers this? I know that I can just write some code that will eventually turn this two letters to whole country name, but I'm just too lazy to write a code that contains all countries... P.S: For some reason I don't want to use any ready made CSV file or any code that will grab this information for me, something like ip2country ready made code and CSV.

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  • How should I implement simple caches with concurrency on Redis?

    - by solublefish
    Background I have a 2-tier web service - just my app server and an RDBMS. I want to move to a pool of identical app servers behind a load balancer. I currently cache a bunch of objects in-process. I hope to move them to a shared Redis. I have a dozen or so caches of simple, small-sized business objects. For example, I have a set of Foos. Each Foo has a unique FooId and an OwnerId. One "owner" may own multiple Foos. In a traditional RDBMS this is just a table with an index on the PK FooId and one on OwnerId. I'm caching this in one process simply: Dictionary<int,Foo> _cacheFooById; Dictionary<int,HashSet<int>> _indexFooIdsByOwnerId; Reads come straight from here, and writes go here and to the RDBMS. I usually have this invariant: "For a given group [say by OwnerId], the whole group is in cache or none of it is." So when I cache miss on a Foo, I pull that Foo and all the owner's other Foos from the RDBMS. Updates make sure to keep the index up to date and respect the invariant. When an owner calls GetMyFoos I never have to worry that some are cached and some aren't. What I did already The first/simplest answer seems to be to use plain ol' SET and GET with a composite key and json value: SET( "ServiceCache:Foo:" + theFoo.Id, JsonSerialize(theFoo)); I later decided I liked: HSET( "ServiceCache:Foo", theFoo.FooId, JsonSerialize(theFoo)); That lets me get all the values in one cache as HVALS. It also felt right - I'm literally moving hashtables to Redis, so perhaps my top-level items should be hashes. This works to first order. If my high-level code is like: UpdateCache(myFoo); AddToIndex(myFoo); That translates into: HSET ("ServiceCache:Foo", theFoo.FooId, JsonSerialize(theFoo)); var myFoos = JsonDeserialize( HGET ("ServiceCache:FooIndex", theFoo.OwnerId) ); myFoos.Add(theFoo.OwnerId); HSET ("ServiceCache:FooIndex", theFoo.OwnerId, JsonSerialize(myFoos)); However, this is broken in two ways. Two concurrent operations can read/modify/write at the same time. The latter "wins" the final HSET and the former's index update is lost. Another operation could read the index in between the first and second lines. It would miss a Foo that it should find. So how do I index properly? I think I could use a Redis set instead of a json-encoded value for the index. That would solve part of the problem since the "add-to-index-if-not-already-present" would be atomic. I also read about using MULTI as a "transaction" but it doesn't seem like it does what I want. Am I right that I can't really MULTI; HGET; {update}; HSET; EXEC since it doesn't even do the HGET before I issue the EXEC? I also read about using WATCH and MULTI for optimistic concurrency, then retrying on failure. But WATCH only works on top-level keys. So it's back to SET/GET instead of HSET/HGET. And now I need a new index-like-thing to support getting all the values in a given cache. If I understand it right, I can combine all these things to do the job. Something like: while(!succeeded) { WATCH( "ServiceCache:Foo:" + theFoo.FooId ); WATCH( "ServiceCache:FooIndexByOwner:" + theFoo.OwnerId ); WATCH( "ServiceCache:FooIndexAll" ); MULTI(); SET ("ServiceCache:Foo:" + theFoo.FooId, JsonSerialize(theFoo)); SADD ("ServiceCache:FooIndexByOwner:" + theFoo.OwnerId, theFoo.FooId); SADD ("ServiceCache:FooIndexAll", theFoo.FooId); EXEC(); //TODO somehow set succeeded properly } Finally I'd have to translate this pseudocode into real code depending how my client library uses WATCH/MULTI/EXEC; it looks like they need some sort of context to hook them together. All in all this seems like a lot of complexity for what has to be a very common case; I can't help but think there's a better, smarter, Redis-ish way to do things that I'm just not seeing. How do I lock properly? Even if I had no indexes, there's still a (probably rare) race condition. A: HGET - cache miss B: HGET - cache miss A: SELECT B: SELECT A: HSET C: HGET - cache hit C: UPDATE C: HSET B: HSET ** this is stale data that's clobbering C's update. Note that C could just be a really-fast A. Again I think WATCH, MULTI, retry would work, but... ick. I know in some places people use special Redis keys as locks for other objects. Is that a reasonable approach here? Should those be top-level keys like ServiceCache:FooLocks:{Id} or ServiceCache:Locks:Foo:{Id}? Or make a separate hash for them - ServiceCache:Locks with subkeys Foo:{Id}, or ServiceCache:Locks:Foo with subkeys {Id} ? How would I work around abandoned locks, say if a transaction (or a whole server) crashes while "holding" the lock?

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  • php lampp permissions of fopen function

    - by marmoushismail
    hi i'm programming php using: netbeans 6.8 lampp for ubuntu (xampp) apache which came with xampp $fh = fopen("testfile2.txt", 'w') or die("Failed to create file"); $text ="hello man cool good"; fwrite($fh, $text) or die("Could not write to file"); fclose($fh); echo "File 'testfile.txt' written successfully"; //i get the next error: Warning: fopen(testfile2.txt) [function.fopen]: failed to open stream: Permission denied in /home/marmoush/allprojects/phpprojects/myindex.php on line 91 Failed to create file anyway i know what this error is; it's about folder and files permissions; i looked into the folder permission tab made access available for "others" group ( to read and write) the program worked result was a file (test.txt) so i looked at the created file permission it appears to be that (php , xampp or whoever) creates file with (nobody permission) I have 2 QUESTIONS: 1- what if i need the file created by (php code and xampp ) to have the "root or user or myname" permissions ?? where to set this setting 2-also my concern (what if i send this files to actual web server will it make nobody permissions also nobody ? when they create files

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  • Where should global Application Settings be stored on Windows 7?

    - by Kerido
    Hi everybody, I'm working hard on making my product work seamlessly on Windows 7. The problem is that there is a small set of global (not user-specific) application settings that all users should be able to change. On previous versions I used HKLM\Software\__Company__\__Product__ for that purpose. This allowed Power Users and Administrators to modify the Registry Key and everything worked correctly. Now that Windows Vista and Windows 7 have this UAC feature, by default, even an Administrator cannot access the Key for writing without elevation. A stupid solution would, of course, mean adding requireAdministrator option into the application manifest. But this is really unprofessional since the product itself is extremely far from administration-related tasks. So I need to stay with asInvoker. Another solution could mean programmatic elevation during moments when write access to the Registry Key is required. Let alone the fact that I don't know how to implement that, it's pretty awkward also. It interferes with normal user experience so much that I would hardly consider it an option. What I know should be relatively easy to accomplish is adding write access to the specified Registry Key during installation. I created a separate question for that. This also very similar to accessing a shared file for storing the settings. My feeling is that there must be a way to accomplish what I need, in a way that is secure, straightforward and compatible with all OS'es. Any ideas?

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  • How do I programmatically run all the JUnit tests in my Java application?

    - by Andrew McKinlay
    From Eclipse I can easily run all the JUnit tests in my application. I would like to be able to run the tests on target systems from the application jar, without Eclipse (or Ant or Maven or any other development tool). I can see how to run a specific test or suite from the command line. I could manually create a suite listing all the tests in my application, but that seems error prone - I'm sure at some point I'll create a test and forget to add it to the suite. The Eclipse JUnit plugin has a wizard to create a test suite, but for some reason it doesn't "see" my test classes. It may be looking for JUnit 3 tests, not JUnit 4 annotated tests. I could write a tool that would automatically create the suite by scanning the source files. Or I could write code so the application would scan it's own jar file for tests (either by naming convention or by looking for the @Test annotation). It seems like there should be an easier way. What am I missing?

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