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• C++: How do I pass a function(without knowing its parameters) to another function?

  - by Ninja

  Hi all. I'm trying to create a function that will store and repeat another function given as a parameter for a specific amount of time or repeats given. But when you want to pass a function as a parameter you have to know all of its parameters before hand. How would I do if I wanted to pass the function as one parameter, and the parameters as another? void AddTimer(float time, int repeats, void (*func), params); // I know params has no type and that (*func) is missing parameters but it is just to show you what I mean Thanks in advance

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• testing existing attribute of a @classmethod function, yields AttributeError

  - by alex

  i have a function which is a class method, and i want to test a attribute of the class which may or may not be None, but will exist always. class classA(): def __init__(self, var1, var2 = None): self.attribute1 = var1 self.attribute2 = var2 @classmethod def func(self,x): if self.attribute2 is None: do something i get the error AttributeError: class classA has no attribute 'attributeB' when i access the attribute like i showed but if on command line i can see it works, x = classA() x.attributeB is None True so the test works. if i remove the @classmethod decorator from func, the problem disapears. if i leave the @classmethod decorator, it only seems to affect variables which are supplied default values in the super-class's constructor. whats going on in the above code?

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• Use C function in C++ program; "multiply-defined" error

  - by eom

  I am trying to use this code for the Porter stemming algorithm in a C++ program I've already written. I followed the instructions near the end of the file for using the code as a separate module. I created a file, stem.c, that ends after the definition and has extern int stem(char * p, int i, int j) ... It worked fine in Xcode but it does not work for me on Unix with gcc 4.1.1--strange because usually I have no problem moving between the two. I get the error ld: fatal: symbol `stem(char*, int, int)' is multiply-defined: (file /var/tmp//ccrWWlnb.o type=FUNC; file /var/tmp//cc6rUXka.o type=FUNC); ld: fatal: File processing errors. No output written to cluster I've looked online and it seems like there are many things I could have wrong, but I'm not sure what combination of a header file, extern "C", etc. would work.

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• Why doesn't functools.partial return a real function (and how to create one that does)?

  - by epsilon

  So I was playing around with currying functions in Python and one of the things that I noticed was that functools.partial returns a partial object rather than an actual function. One of the things that annoyed me about this was that if I did something along the lines of: five = partial(len, 'hello') five('something') then we get TypeError: len() takes exactly 1 argument (2 given) but what I want to happen is TypeError: five() takes no arguments (1 given) Is there a clean way to make it work like this? I wrote a workaround, but it's too hacky for my taste (doesn't work yet for functions with varargs): def mypartial(f, *args): argcount = f.func_code.co_argcount - len(args) params = ''.join('a' + str(i) + ',' for i in xrange(argcount)) code = ''' def func(f, args): def %s(%s): return f(*(args+(%s))) return %s ''' % (f.func_name, params, params, f.func_name) exec code in locals() return func(f, args)

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• Order of execution and style of coding in Python

  - by Jason

  Hi guys. I am new to Python so please don't flame me if the question is too basic :) I have read that Python is executed from top - to - bottom. If this is the case, why do programs go like this: def func2(): def func1(): #call func2() def func() #call func1() if __name__ == '__main__': call func() So from what I have seen, the main function goes at last and the other functions are stacked on top of it. Am I wrong in saying this? If no, why isn't the main function or the function definitions written from top to bottom?

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• Function to register functions to be called if event invoked.

  - by zaidwaqi

  Hi, I have a Panel which contains 20 PictureBox controls. If a user clicks on any of the controls, I want a method within the Panel to be called. How do I do this? public class MyPanel : Panel { public MyPanel() { for(int i = 0; i < 20; i++) { Controls.Add(new PictureBox()); } } // DOESN'T WORK. // function to register functions to be called if the pictureboxes are clicked. public void RegisterFunction( <function pointer> func ) { foreach ( Control c in Controls ) { c.Click += new EventHandler( func ); } } } How do I implement RegisterFunction()? Also, if there are cool C# features that can make the code more elegant, please share. Thanks.

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• F# - Function with no arguments?

  - by Rubys

  When thinking in a functional mindset, given that functions are supposed to be pure, one can conclude any function with no arguments is basically just a value. However, reallity gets in the way, and with different inputs, I might not need a certain function, and if that function is computationally expensive, I'd like to not evaluate it if it's not needed. I found a workaround, using let func _ = ... and calling it with func 1 or whatever, but that feels very non-idiomatic and confusing to the reader. This boils down to one question: In F#, Is there a proper way to declare a function with zero arguments, without having it evaluated on declaration?

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• does overload operator-> a compile time action?

  - by Brent

  when I tried to compile the code: struct S { void func2() {} }; class O { public: inline S* operator->() const; private: S* ses; }; inline S* O::operator->() const { return ses; } int main() { O object; object->func(); return 0; } there is a compile error reported: D:\code>g++ operatorp.cpp -S -o operatorp.exe operatorp.cpp: In function `int main()': operatorp.cpp:27: error: 'struct S' has no member named 'func' it seems that invoke the overloaded function of "operator-" is done during compile time? I'd add "-S" option for compile only.

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• Using SQLAlchemy, how can I return a count with multiple columns

  - by Andy

  I am attempting to run a query like this: SELECT comment_type_id, name, count(comment_type_id) FROM comments, commenttypes WHERE comment_type_id=commenttypes.id GROUP BY comment_type_id Without the join between comments and commenttypes for the name column, I can do this using: session.query(Comment.comment_type_id,func.count(Comment.comment_type_id)).group_by(Comment.comment_type_id).all() However, if I try to do something like this, I get incorrect results: session.query(Comment.comment_type_id, Comment.comment_type, func.count(Comment.comment_type_id)).group_by(Comment.comment_type_id).all() I have two problems with the results: (1, False, 82920) (2, False, 588) (3, False, 4278) (4, False, 104370) Problems: The False is not correct The counts are wrong My expected results are: (1, 'Comment Type 1', 13820) (2, 'Comment Type 2', 98) (3, 'Comment Type 2', 713) (4, 'Comment Type 2', 17395) How can I adjust my command to pull the correct name value and the correct count?

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• Confusion regarding a function definition in C

  - by user34790

  I found this function definition void *func(void *param) { } Actually, I have a certain confusion regarding this function definition. What does void * mean in the return type of the function as well as the argument. I am a beginner in C. So please don't mind. Thank you void *func(void *param) { int s = (int)param; .... } Well looking at the above program which I found. I think it should have been int *s = (int *)param; isn't it? I am confused

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• closing sockets on linux and windows

  - by robUK

  Hello, gcc 4.4.4 c89 Visual Studio VC++ 2008 I am writing a cross platform client server application. It will run on both linux and windows. However, I am just wondering what I have done for closing the sockets is correct. I close the file descriptor. However, if there is a problem with closing it. What is the best way to handle this. Maybe some data is still being sent or received? Many thanks for any advice, if(close(sockfd) == -1) { #if defined ( _WIN32 ) fprintf(stderr, "[ %d ] [ %s ] [ %s ] [ %d ]\n", WSAGetLastError(), strerror(errno), __func__, __LINE__); #elif( __linux__ ) fprintf(stderr, "[ %s ] [ %s ] [ %d ]\n", strerror(errno), __func__, __LINE__); #endif return CS_FAILURE; }

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• Method to register method to be called when event is raised

  - by zaidwaqi

  I have a Panel which contains 20 PictureBox controls. If a user clicks on any of the controls, I want a method within the Panel to be called. How do I do this? public class MyPanel : Panel { public MyPanel() { for(int i = 0; i < 20; i++) { Controls.Add(new PictureBox()); } } // DOESN'T WORK. // function to register functions to be called if the pictureboxes are clicked. public void RegisterFunction( <function pointer> func ) { foreach ( Control c in Controls ) { c.Click += new EventHandler( func ); } } } How do I implement RegisterFunction()? Also, if there are cool C# features that can make the code more elegant, please share.

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• javascript var declaration within loop

  - by Trouts

  hello, /*Test scope problem*/ for(var i=1; i<3; i++){ //declare variables var no = i; //verify no alert('setting '+no); //timeout to recheck setTimeout(function(){ alert('test '+no); }, 500); } it alerts "setting 1" and "setting 2" as expected, but after the timeout it outputs "test 2" twice - for some reason the variable "no" is not reset after the first loop... i've found only an "ugly" workaround... /*Test scope problem*/ var func=function(no){ //verify no alert('setting '+no); //timeout to recheck setTimeout(function(){ alert('test '+no); }, 500); } for(var i=1; i<3; i++){ func(i); } Any ideas on how to workaround this problem in a more direct way? or is this the only way?

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• xcode 4 creating a 2d grid (range and domain)

  - by user1706978

  I'm learning how to program c and i'm trying to make a program the finds the range (using an equation with x as the domain) of a 2d grid...ive already attempted it, but it's giving me all these errors on Xcode, any help?(As you can see, I'm quite stuck!) #include <stdio.h> #include <stdlib.h> float domain; float domain = 2.0; float domainsol(float x ) { domain = x; float func = 1.25 * x + 5.0; return func; } int main(int argc, const char * argv[]) { }

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• How to fill a structure when a pointer to it, is passed as an argument to a function

  - by Ram

  I have a function: func (struct passwd* pw) { struct passwd* temp; struct passwd* save; temp = getpwnam("someuser"); /* since getpwnam returns a pointer to a static * data buffer, I am copying the returned struct * to a local struct. */ if(temp) { save = malloc(sizeof *save); if (save) { memcpy(save, temp, sizeof(struct passwd)); /* Here, I have to update passed pw* with this save struct. */ *pw = *save; /* (~ memcpy) */ } } } The function which calls func(pw) is able to get the updated information. But is it fine to use it as above. The statement *pw = *save is not a deep copy. I do not want to copy each and every member of structure one by one like pw-pw_shell = strdup(save-pw_shell) etc. Is there any better way to do it? Thanks.

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• How to break closures in JavaScript

  - by Not a Name

  Is there any way to break a closure easily in JavaScript? The closest I have gotten is this: var src = 3; function foo () { return function () { return src; } } function bar (func) { var src = 9; return eval('('+func.toString()+')')(); // Line breaks closure } alert(bar(foo())); Which prints 9, instead of 3 as a closure would dictate. However, this approach seems kind of ugly to me, are there any better ways?

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• Path Inclusion/Global variable not working?

  - by Dan LaManna

  Simply put, my config file includes my database class, and the config file has in it: global $db; $db = new database(DB_HOST, DB_NAME, DB_USER, DB_PASS); That file is root/config.php Moving on to root/functions/func.newpage.php doesn't have any includes/requires, and uses $db-classfunction since the file I'm working with: root/newpage.php - requires the config file, as well as func.newpage.php. However I still come up with: Undefined variable db. Anything you guys are seeing I'm not? Thanks! Let me know if more details are needed.

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• Red Hat Yum not working out of the box?

  - by Tucker

  I have a server runnning Red Hat Enterprise Linux v5.6 in the cloud. My project constraints do not allow me to use another OS. When I created the cloud server, I was able to SSH into it and access the shell. I next ran the command: sudo yum update But the command failed. About a month ago I created another server with the same machine image and didn't have that error. Why is it failing now? The following is the terminal output sudo yum update Loaded plugins: security Repository rhel-server is listed more than once in the configuration Traceback (most recent call last): File "/usr/bin/yum", line 29, in ? yummain.user_main(sys.argv[1:], exit_code=True) File "/usr/share/yum-cli/yummain.py", line 309, in user_main errcode = main(args) File "/usr/share/yum-cli/yummain.py", line 178, in main result, resultmsgs = base.doCommands() File "/usr/share/yum-cli/cli.py", line 345, in doCommands self._getTs(needTsRemove) File "/usr/lib/python2.4/site-packages/yum/depsolve.py", line 101, in _getTs self._getTsInfo(remove_only) File "/usr/lib/python2.4/site-packages/yum/depsolve.py", line 112, in _getTsInfo pkgSack = self.pkgSack File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 662, in <lambda> pkgSack = property(fget=lambda self: self._getSacks(), File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 502, in _getSacks self.repos.populateSack(which=repos) File "/usr/lib/python2.4/site-packages/yum/repos.py", line 260, in populateSack sack.populate(repo, mdtype, callback, cacheonly) File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 168, in populate if self._check_db_version(repo, mydbtype): File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 226, in _check_db_version return repo._check_db_version(mdtype) File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1233, in _check_db_version repoXML = self.repoXML File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1406, in <lambda> repoXML = property(fget=lambda self: self._getRepoXML(), File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1398, in _getRepoXML self._loadRepoXML(text=self) File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1388, in _loadRepoXML return self._groupLoadRepoXML(text, ["primary"]) File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1372, in _groupLoadRepoXML if self._commonLoadRepoXML(text): File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1208, in _commonLoadRepoXML result = self._getFileRepoXML(local, text) File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 989, in _getFileRepoXML cache=self.http_caching == 'all') File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 826, in _getFile http_headers=headers, File "/usr/lib/python2.4/site-packages/urlgrabber/mirror.py", line 412, in urlgrab return self._mirror_try(func, url, kw) File "/usr/lib/python2.4/site-packages/urlgrabber/mirror.py", line 398, in _mirror_try return func_ref( *(fullurl,), **kwargs ) File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line 936, in urlgrab return self._retry(opts, retryfunc, url, filename) File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line 854, in _retry r = apply(func, (opts,) + args, {}) File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line 922, in retryfunc fo = URLGrabberFileObject(url, filename, opts) File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line 1010, in __init__ self._do_open() File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line 1093, in _do_open fo, hdr = self._make_request(req, opener) File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line 1202, in _make_request fo = opener.open(req) File "/usr/lib64/python2.4/urllib2.py", line 358, in open response = self._open(req, data) File "/usr/lib64/python2.4/urllib2.py", line 376, in _open '_open', req) File "/usr/lib64/python2.4/urllib2.py", line 337, in _call_chain result = func(*args) File "/usr/lib64/python2.4/site-packages/M2Crypto/m2urllib2.py", line 82, in https_open h.request(req.get_method(), req.get_selector(), req.data, headers) File "/usr/lib64/python2.4/httplib.py", line 810, in request self._send_request(method, url, body, headers) File "/usr/lib64/python2.4/httplib.py", line 833, in _send_request self.endheaders() File "/usr/lib64/python2.4/httplib.py", line 804, in endheaders self._send_output() File "/usr/lib64/python2.4/httplib.py", line 685, in _send_output self.send(msg) File "/usr/lib64/python2.4/httplib.py", line 652, in send self.connect() File "/usr/lib64/python2.4/site-packages/M2Crypto/httpslib.py", line 47, in connect self.sock.connect((self.host, self.port)) File "/usr/lib64/python2.4/site-packages/M2Crypto/SSL/Connection.py", line 174, in connect ret = self.connect_ssl() File "/usr/lib64/python2.4/site-packages/M2Crypto/SSL/Connection.py", line 167, in connect_ssl return m2.ssl_connect(self.ssl, self._timeout) M2Crypto.SSL.SSLError: certificate verify failed

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• How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

  - by codeartist

  I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>> locate mysql Output: /etc/mysql /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/abstractions/mysql /etc/apparmor.d/cache/usr.sbin.mysqld /etc/apparmor.d/cache/usr.sbin.mysqld-akonadi /etc/apparmor.d/local/usr.sbin.mysqld /etc/bash_completion.d/mysqladmin /etc/init/mysql.conf /etc/logcheck/ignore.d.paranoid/mysql-server-5_5 /etc/logcheck/ignore.d.server/mysql-server-5_5 /etc/logcheck/ignore.d.workstation/mysql-server-5_5 /etc/logrotate.d/mysql-server /etc/mysql/conf.d /etc/mysql/debian-start /etc/mysql/debian.cnf /etc/mysql/conf.d/mysqld_safe_syslog.cnf /home/pkr/.mysql_history /home/pkr/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,libqt4-sql-mysql,,349051c3a57da571aa832adb39177aff /home/pkr/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,mysql-client,,cbf77a486cdc80547317981a33144427 /home/pkr/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,mysql-client,,de8220dee4d957a9502caa79e8d2fdda /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,any,any,any,libqt4-sql-mysql,page,1,helpful,,17fb2e657321dc51526ee8fe9928da30 /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,any,any,any,mysql-client,page,1,helpful,,a4c1b6e8200f36ab5745c6f81f14da0a /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,oneiric,any,libqt4-sql-mysql,page,1,helpful,,c54295fb82b8183350cd34f22c3547ef /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,oneiric,any,mysql-client,page,1,helpful,,fcf201c1abff3f774af89173a84de2cc /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,precise,any,libqt4-sql-mysql,page,1,helpful,,0cd86648584efeccfb16119012f89540 /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,precise,any,mysql-client,page,1,helpful,,eb84724e9da7851ff8862a227d8bac59 /home/pkr/.local/share/akonadi/mysql.conf /home/pkr/.local/share/akonadi/db_data/mysql /home/pkr/.local/share/akonadi/db_data/mysql.err /home/pkr/.local/share/akonadi/db_data/mysql.err.old /home/pkr/.local/share/akonadi/db_data/mysql/columns_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/columns_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/columns_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/db.MYD /home/pkr/.local/share/akonadi/db_data/mysql/db.MYI /home/pkr/.local/share/akonadi/db_data/mysql/db.frm /home/pkr/.local/share/akonadi/db_data/mysql/event.MYD /home/pkr/.local/share/akonadi/db_data/mysql/event.MYI /home/pkr/.local/share/akonadi/db_data/mysql/event.frm /home/pkr/.local/share/akonadi/db_data/mysql/func.MYD /home/pkr/.local/share/akonadi/db_data/mysql/func.MYI /home/pkr/.local/share/akonadi/db_data/mysql/func.frm /home/pkr/.local/share/akonadi/db_data/mysql/general_log.CSM /home/pkr/.local/share/akonadi/db_data/mysql/general_log.CSV /home/pkr/.local/share/akonadi/db_data/mysql/general_log.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_category.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_category.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_category.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_keyword.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_keyword.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_keyword.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_relation.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_relation.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_relation.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_topic.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_topic.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_topic.frm /home/pkr/.local/share/akonadi/db_data/mysql/host.MYD /home/pkr/.local/share/akonadi/db_data/mysql/host.MYI /home/pkr/.local/share/akonadi/db_data/mysql/host.frm /home/pkr/.local/share/akonadi/db_data/mysql/ndb_binlog_index.MYD /home/pkr/.local/share/akonadi/db_data/mysql/ndb_binlog_index.MYI /home/pkr/.local/share/akonadi/db_data/mysql/ndb_binlog_index.frm /home/pkr/.local/share/akonadi/db_data/mysql/plugin.MYD /home/pkr/.local/share/akonadi/db_data/mysql/plugin.MYI /home/pkr/.local/share/akonadi/db_data/mysql/plugin.frm /home/pkr/.local/share/akonadi/db_data/mysql/proc.MYD /home/pkr/.local/share/akonadi/db_data/mysql/proc.MYI /home/pkr/.local/share/akonadi/db_data/mysql/proc.frm /home/pkr/.local/share/akonadi/db_data/mysql/procs_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/procs_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/procs_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/proxies_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/proxies_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/proxies_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/servers.MYD /home/pkr/.local/share/akonadi/db_data/mysql/servers.MYI /home/pkr/.local/share/akonadi/db_data/mysql/servers.frm /home/pkr/.local/share/akonadi/db_data/mysql/slow_log.CSM /home/pkr/.local/share/akonadi/db_data/mysql/slow_log.CSV /home/pkr/.local/share/akonadi/db_data/mysql/slow_log.frm /home/pkr/.local/share/akonadi/db_data/mysql/tables_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/tables_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/tables_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_leap_second.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_leap_second.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_leap_second.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_name.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_name.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_name.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition_type.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition_type.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition_type.frm /home/pkr/.local/share/akonadi/db_data/mysql/user.MYD /home/pkr/.local/share/akonadi/db_data/mysql/user.MYI /home/pkr/.local/share/akonadi/db_data/mysql/user.frm /usr/bin/mysql /usr/bin/mysql_install_db /usr/bin/mysql_upgrade /usr/bin/mysqlcheck /usr/sbin/mysqld /usr/share/mysql /usr/share/app-install/desktop/gmysqlcc:gmysqlcc.desktop /usr/share/app-install/desktop/mysql-client.desktop /usr/share/app-install/desktop/mysql-navigator:mysql-navigator.desktop /usr/share/app-install/desktop/mysql-server.desktop /usr/share/app-install/icons/gmysqlcc-32.png /usr/share/app-install/icons/mysql-navigator.png /usr/share/doc/mysql-client-core-5.5 /usr/share/doc/mysql-server-core-5.5 /usr/share/kde4/apps/katepart/syntax/sql-mysql.xml /usr/share/man/man1/mysql.1.gz /usr/share/man/man1/mysql_install_db.1.gz /usr/share/man/man1/mysql_upgrade.1.gz /usr/share/man/man1/mysqlcheck.1.gz /usr/share/man/man8/mysqld.8.gz /var/cache/apt/archives/akonadi-backend-mysql_1.7.2-0ubuntu1_all.deb /var/cache/apt/archives/libmysqlclient-dev_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/libmysqlclient18_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/libqt4-sql-mysql_4%3a4.8.1-0ubuntu4.1_i386.deb /var/cache/apt/archives/mysql-client-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-client-core-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-client_5.5.22-0ubuntu1_all.deb /var/cache/apt/archives/mysql-common_5.5.22-0ubuntu1_all.deb /var/cache/apt/archives/mysql-server-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-server-core-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-server_5.5.22-0ubuntu1_all.deb /var/lib/dpkg/info/mysql-client-core-5.5.list /var/lib/dpkg/info/mysql-client-core-5.5.md5sums /var/lib/dpkg/info/mysql-server-5.5.list /var/lib/dpkg/info/mysql-server-5.5.postrm /var/lib/dpkg/info/mysql-server-core-5.5.list /var/lib/dpkg/info/mysql-server-core-5.5.md5sums /var/log/mysql /var/log/mysql.err /var/log/mysql.log /var/log/mysql.log.1.gz /var/log/mysql.log.2.gz /var/log/mysql.log.3.gz /var/log/mysql.log.4.gz /var/log/mysql.log.5.gz /var/log/mysql.log.6.gz /var/log/mysql.log.7.gz /var/log/upstart/mysql.log.1.gz /var/log/upstart/mysql.log.2.gz /var/log/upstart/mysql.log.3.gz /var/log/upstart/mysql.log.4.gz /var/log/upstart/mysql.log.5.gz /var/log/upstart/mysql.log.6.gz /var/log/upstart/mysql.log.7.gz What should I do now? Please help me out in this :( I was trying to find out if there is any way I can remove mysql related every file and then reinstall mysql. I need it for Qt connectivity. I don't understand what to do! Please help :(

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• How to remove MySQL completely with config and library files?

  - by codeartist

  I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>> locate mysql Output: /etc/mysql /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/abstractions/mysql /etc/apparmor.d/cache/usr.sbin.mysqld /etc/apparmor.d/cache/usr.sbin.mysqld-akonadi /etc/apparmor.d/local/usr.sbin.mysqld /etc/bash_completion.d/mysqladmin /etc/init/mysql.conf /etc/logcheck/ignore.d.paranoid/mysql-server-5_5 /etc/logcheck/ignore.d.server/mysql-server-5_5 /etc/logcheck/ignore.d.workstation/mysql-server-5_5 /etc/logrotate.d/mysql-server /etc/mysql/conf.d /etc/mysql/debian-start /etc/mysql/debian.cnf /etc/mysql/conf.d/mysqld_safe_syslog.cnf /home/pkr/.mysql_history /home/pkr/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,libqt4-sql-mysql,,349051c3a57da571aa832adb39177aff /home/pkr/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,mysql-client,,cbf77a486cdc80547317981a33144427 /home/pkr/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,mysql-client,,de8220dee4d957a9502caa79e8d2fdda /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,any,any,any,libqt4-sql-mysql,page,1,helpful,,17fb2e657321dc51526ee8fe9928da30 /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,any,any,any,mysql-client,page,1,helpful,,a4c1b6e8200f36ab5745c6f81f14da0a /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,oneiric,any,libqt4-sql-mysql,page,1,helpful,,c54295fb82b8183350cd34f22c3547ef /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,oneiric,any,mysql-client,page,1,helpful,,fcf201c1abff3f774af89173a84de2cc /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,precise,any,libqt4-sql-mysql,page,1,helpful,,0cd86648584efeccfb16119012f89540 /home/pkr/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,en,ubuntu,precise,any,mysql-client,page,1,helpful,,eb84724e9da7851ff8862a227d8bac59 /home/pkr/.local/share/akonadi/mysql.conf /home/pkr/.local/share/akonadi/db_data/mysql /home/pkr/.local/share/akonadi/db_data/mysql.err /home/pkr/.local/share/akonadi/db_data/mysql.err.old /home/pkr/.local/share/akonadi/db_data/mysql/columns_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/columns_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/columns_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/db.MYD /home/pkr/.local/share/akonadi/db_data/mysql/db.MYI /home/pkr/.local/share/akonadi/db_data/mysql/db.frm /home/pkr/.local/share/akonadi/db_data/mysql/event.MYD /home/pkr/.local/share/akonadi/db_data/mysql/event.MYI /home/pkr/.local/share/akonadi/db_data/mysql/event.frm /home/pkr/.local/share/akonadi/db_data/mysql/func.MYD /home/pkr/.local/share/akonadi/db_data/mysql/func.MYI /home/pkr/.local/share/akonadi/db_data/mysql/func.frm /home/pkr/.local/share/akonadi/db_data/mysql/general_log.CSM /home/pkr/.local/share/akonadi/db_data/mysql/general_log.CSV /home/pkr/.local/share/akonadi/db_data/mysql/general_log.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_category.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_category.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_category.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_keyword.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_keyword.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_keyword.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_relation.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_relation.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_relation.frm /home/pkr/.local/share/akonadi/db_data/mysql/help_topic.MYD /home/pkr/.local/share/akonadi/db_data/mysql/help_topic.MYI /home/pkr/.local/share/akonadi/db_data/mysql/help_topic.frm /home/pkr/.local/share/akonadi/db_data/mysql/host.MYD /home/pkr/.local/share/akonadi/db_data/mysql/host.MYI /home/pkr/.local/share/akonadi/db_data/mysql/host.frm /home/pkr/.local/share/akonadi/db_data/mysql/ndb_binlog_index.MYD /home/pkr/.local/share/akonadi/db_data/mysql/ndb_binlog_index.MYI /home/pkr/.local/share/akonadi/db_data/mysql/ndb_binlog_index.frm /home/pkr/.local/share/akonadi/db_data/mysql/plugin.MYD /home/pkr/.local/share/akonadi/db_data/mysql/plugin.MYI /home/pkr/.local/share/akonadi/db_data/mysql/plugin.frm /home/pkr/.local/share/akonadi/db_data/mysql/proc.MYD /home/pkr/.local/share/akonadi/db_data/mysql/proc.MYI /home/pkr/.local/share/akonadi/db_data/mysql/proc.frm /home/pkr/.local/share/akonadi/db_data/mysql/procs_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/procs_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/procs_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/proxies_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/proxies_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/proxies_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/servers.MYD /home/pkr/.local/share/akonadi/db_data/mysql/servers.MYI /home/pkr/.local/share/akonadi/db_data/mysql/servers.frm /home/pkr/.local/share/akonadi/db_data/mysql/slow_log.CSM /home/pkr/.local/share/akonadi/db_data/mysql/slow_log.CSV /home/pkr/.local/share/akonadi/db_data/mysql/slow_log.frm /home/pkr/.local/share/akonadi/db_data/mysql/tables_priv.MYD /home/pkr/.local/share/akonadi/db_data/mysql/tables_priv.MYI /home/pkr/.local/share/akonadi/db_data/mysql/tables_priv.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_leap_second.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_leap_second.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_leap_second.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_name.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_name.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_name.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition.frm /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition_type.MYD /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition_type.MYI /home/pkr/.local/share/akonadi/db_data/mysql/time_zone_transition_type.frm /home/pkr/.local/share/akonadi/db_data/mysql/user.MYD /home/pkr/.local/share/akonadi/db_data/mysql/user.MYI /home/pkr/.local/share/akonadi/db_data/mysql/user.frm /usr/bin/mysql /usr/bin/mysql_install_db /usr/bin/mysql_upgrade /usr/bin/mysqlcheck /usr/sbin/mysqld /usr/share/mysql /usr/share/app-install/desktop/gmysqlcc:gmysqlcc.desktop /usr/share/app-install/desktop/mysql-client.desktop /usr/share/app-install/desktop/mysql-navigator:mysql-navigator.desktop /usr/share/app-install/desktop/mysql-server.desktop /usr/share/app-install/icons/gmysqlcc-32.png /usr/share/app-install/icons/mysql-navigator.png /usr/share/doc/mysql-client-core-5.5 /usr/share/doc/mysql-server-core-5.5 /usr/share/kde4/apps/katepart/syntax/sql-mysql.xml /usr/share/man/man1/mysql.1.gz /usr/share/man/man1/mysql_install_db.1.gz /usr/share/man/man1/mysql_upgrade.1.gz /usr/share/man/man1/mysqlcheck.1.gz /usr/share/man/man8/mysqld.8.gz /var/cache/apt/archives/akonadi-backend-mysql_1.7.2-0ubuntu1_all.deb /var/cache/apt/archives/libmysqlclient-dev_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/libmysqlclient18_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/libqt4-sql-mysql_4%3a4.8.1-0ubuntu4.1_i386.deb /var/cache/apt/archives/mysql-client-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-client-core-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-client_5.5.22-0ubuntu1_all.deb /var/cache/apt/archives/mysql-common_5.5.22-0ubuntu1_all.deb /var/cache/apt/archives/mysql-server-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-server-core-5.5_5.5.22-0ubuntu1_i386.deb /var/cache/apt/archives/mysql-server_5.5.22-0ubuntu1_all.deb /var/lib/dpkg/info/mysql-client-core-5.5.list /var/lib/dpkg/info/mysql-client-core-5.5.md5sums /var/lib/dpkg/info/mysql-server-5.5.list /var/lib/dpkg/info/mysql-server-5.5.postrm /var/lib/dpkg/info/mysql-server-core-5.5.list /var/lib/dpkg/info/mysql-server-core-5.5.md5sums /var/log/mysql /var/log/mysql.err /var/log/mysql.log /var/log/mysql.log.1.gz /var/log/mysql.log.2.gz /var/log/mysql.log.3.gz /var/log/mysql.log.4.gz /var/log/mysql.log.5.gz /var/log/mysql.log.6.gz /var/log/mysql.log.7.gz /var/log/upstart/mysql.log.1.gz /var/log/upstart/mysql.log.2.gz /var/log/upstart/mysql.log.3.gz /var/log/upstart/mysql.log.4.gz /var/log/upstart/mysql.log.5.gz /var/log/upstart/mysql.log.6.gz /var/log/upstart/mysql.log.7.gz What should I do now? Please help me out in this :( I was trying to find out if there is any way I can remove mysql related every file and then reinstall mysql. I need it for Qt connectivity. I don't understand what to do! Please help :(

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• Passthrough Objects – Duck Typing++

  - by EltonStoneman

  [Source: http://geekswithblogs.net/EltonStoneman] Can't see a genuine use for this, but I got the idea in my head and wanted to work it through. It's an extension to the idea of duck typing, for scenarios where types have similar behaviour, but implemented in differently-named members. So you may have a set of objects you want to treat as an interface, which don't implement the interface explicitly, and don't have the same member names so they can't be duck-typed into implicitly implementing the interface. In a fictitious example, I want to call Get on whichever ICache implementation is current, and have the call passed through to the relevant method – whether it's called Read, Retrieve or whatever: A sample implementation is up on github here: PassthroughSample. This uses Castle's DynamicProxy behind the scenes in the same way as my duck typing sample, but allows you to configure the passthrough to specify how the inner (implementation) and outer (interface) members are mapped:       var setup = new Passthrough();     var cache = setup.Create("PassthroughSample.Tests.Stubs.AspNetCache, PassthroughSample.Tests")                             .WithPassthrough("Name", "CacheName")                             .WithPassthrough("Get", "Retrieve")                             .WithPassthrough("Set", "Insert")                             .As<ICache>(); - or using some ugly Lambdas to avoid the strings :     Expression<Func<ICache, string, object>> get = (o, s) => o.Get(s);     Expression<Func<Memcached, string, object>> read = (i, s) => i.Read(s);     Expression<Action<ICache, string, object>> set = (o, s, obj) => o.Set(s, obj);     Expression<Action<Memcached, string, object>> insert = (i, s, obj) => i.Put(s, obj);       ICache cache = new Passthrough<ICache, Memcached>()                     .Create()                     .WithPassthrough(o => o.Name, i => i.InstanceName)                     .WithPassthrough(get, read)                     .WithPassthrough(set, insert)                     .As();   - or even in config:   ICache cache = Passthrough.GetConfigured<ICache>(); ...  <passthrough>     <types>       <typename="PassthroughSample.Tests.Stubs.ICache, PassthroughSample.Tests"             passesThroughTo="PassthroughSample.Tests.Stubs.AppFabricCache, PassthroughSample.Tests">         <members>           <membername="Name"passesThroughTo="RegionName"/>           <membername="Get"passesThroughTo="Out"/>           <membername="Set"passesThroughTo="In"/>         </members>       </type>   Possibly useful for injecting stubs for dependencies in tests, when your application code isn't using an IoC container. Possibly it also has an alternative implementation using .NET 4.0 dynamic objects, rather than the dynamic proxy.

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• The last MVVM you'll ever need?

  - by Nuri Halperin

  As my MVC projects mature and grow, the need to have some omnipresent, ambient model properties quickly emerge. The application no longer has only one dynamic pieced of data on the page: A sidebar with a shopping cart, some news flash on the side – pretty common stuff. The rub is that a controller is invoked in context of a single intended request. The rest of the data, even though it could be just as dynamic, is expected to appear on it's own. There are many solutions to this scenario. MVVM prescribes creating elaborate objects which expose your new data as a property on some uber-object with more properties exposing the "side show" ambient data. The reason I don't love this approach is because it forces fairly acute awareness of the view, and soon enough you have many MVVM objects laying around, and views have to start doing null-checks in order to ensure you really supplied all the values before binding to them. Ick. Just as unattractive is the ViewData dictionary. It's not strongly typed, and in both this and the MVVM approach someone has to populate these properties – n'est pas? Where does that live? With MVC2, we get the formerly-futures  feature Html.RenderAction(). The feature allows you plant a line in a view, of the format: <% Html.RenderAction("SessionInterest", "Session"); %> While this syntax looks very clean, I can't help being bothered by it. MVC was touting a very strong separation of concerns, the Model taking on the role of the business logic, the controller handling route and performing minimal view-choosing operations and the views strictly focused on rendering out angled-bracket tags. The RenderAction() syntax has the view calling some controller and invoking it inline with it's runtime rendering. This – to my taste – embeds too much  knowledge of controllers into the view's code – which was allegedly forbidden.  The one way flow "Controller Receive Data –> Controller invoke Model –> Controller select view –> Controller Hand data to view" now gets a "View calls controller and gets it's own data" which is not so one-way anymore. Ick. I toyed with some other solutions a bit, including some base controllers, special view classes etc. My current favorite though is making use of the ExpandoObject and dynamic features with C# 4.0. If you follow Phil Haack or read a bit from David Heyden you can see the general picture emerging. The game changer is that using the new dynamic syntax, one can sprout properties on an object and make use of them in the view. Well that beats having a bunch of uni-purpose MVVM's any day! Rather than statically exposed properties, we'll just use the capability of adding members at runtime. Armed with new ideas and syntax, I went to work: First, I created a factory method to enrich the focuse object: public static class ModelExtension { public static dynamic Decorate(this Controller controller, object mainValue) { dynamic result = new ExpandoObject(); result.Value = mainValue; result.SessionInterest = CodeCampBL.SessoinInterest(); result.TagUsage = CodeCampBL.TagUsage(); return result; } } This gives me a nice fluent way to have the controller add the rest of the ambient "side show" items (SessionInterest, TagUsage in this demo) and expose them all as the Model: public ActionResult Index() { var data = SyndicationBL.Refresh(TWEET_SOURCE_URL); dynamic result = this.Decorate(data); return View(result); } So now what remains is that my view knows to expect a dynamic object (rather than statically typed) so that the ASP.NET page compiler won't barf: <%@ Page Language="C#" Title="Ambient Demo" MasterPageFile="~/Views/Shared/Ambient.Master" Inherits="System.Web.Mvc.ViewPage<dynamic>" %> Notice the generic ViewPage<dynamic>. It doesn't work otherwise. In the page itself, Model.Value property contains the main data returned from the controller. The nice thing about this, is that the master page (Ambient.Master) also inherits from the generic ViewMasterPage<dynamic>. So rather than the page worrying about all this ambient stuff, the side bars and panels for ambient data all reside in a master page, and can be rendered using the RenderPartial() syntax: <% Html.RenderPartial("TagCloud", Model.SessionInterest as Dictionary<string, int>); %> Note here that a cast is necessary. This is because although dynamic is magic, it can't figure out what type this property is, and wants you to give it a type so its binder can figure out the right property to bind to at runtime. I use as, you can cast if you like. So there we go – no violation of MVC, no explosion of MVVM models and voila – right? Well, I could not let this go without a tweak or two more. The first thing to improve, is that some views may not need all the properties. In that case, it would be a waste of resources to populate every property. The solution to this is simple: rather than exposing properties, I change d the factory method to expose lambdas - Func<T> really. So only if and when a view accesses a member of the dynamic object does it load the data. public static class ModelExtension { // take two.. lazy loading! public static dynamic LazyDecorate(this Controller c, object mainValue) { dynamic result = new ExpandoObject(); result.Value = mainValue; result.SessionInterest = new Func<Dictionary<string, int>>(() => CodeCampBL.SessoinInterest()); result.TagUsage = new Func<Dictionary<string, int>>(() => CodeCampBL.TagUsage()); return result; } } Now that lazy loading is in place, there's really no reason not to hook up all and any possible ambient property. Go nuts! Add them all in – they won't get invoked unless used. This now requires changing the signature of usage on the ambient properties methods –adding some parenthesis to the master view: <% Html.RenderPartial("TagCloud", Model.SessionInterest() as Dictionary<string, int>); %> And, of course, the controller needs to call LazyDecorate() rather than the old Decorate(). The final touch is to introduce a convenience method to the my Controller class , so that the tedium of calling Decorate() everywhere goes away. This is done quite simply by adding a bunch of methods, matching View(object), View(string,object) signatures of the Controller class: public ActionResult Index() { var data = SyndicationBL.Refresh(TWEET_SOURCE_URL); return AmbientView(data); } //these methods can reside in a base controller for the solution: public ViewResult AmbientView(dynamic data) { dynamic result = ModelExtension.LazyDecorate(this, data); return View(result); } public ViewResult AmbientView(string viewName, dynamic data) { dynamic result = ModelExtension.LazyDecorate(this, data); return View(viewName, result); } The call to AmbientView now replaces any call the View() that requires the ambient data. DRY sattisfied, lazy loading and no need to replace core pieces of the MVC pipeline. I call this a good MVC day. Enjoy!

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• Authenticating clients in the new WCF Http stack

  - by cibrax

  About this time last year, I wrote a couple of posts about how to use the “Interceptors” from the REST starker kit for implementing several authentication mechanisms like “SAML”, “Basic Authentication” or “OAuth” in the WCF Web programming model. The things have changed a lot since then, and Glenn finally put on our hands a new version of the Web programming model that deserves some attention and I believe will help us a lot to build more Http oriented services in the .NET stack. What you can get today from wcf.codeplex.com is a preview with some cool features like Http Processors (which I already discussed here), a new and improved version of the HttpClient library, Dependency injection and better TDD support among others. However, the framework still does not support an standard way of doing client authentication on the services (This is something planned for the upcoming releases I believe). For that reason, moving the existing authentication interceptors to this new programming model was one of the things I did in the last few days. In order to make authentication simple and easy to extend,  I first came up with a model based on what I called “Authentication Interceptors”. An authentication interceptor maps to an existing Http authentication mechanism and implements the following interface, public interface IAuthenticationInterceptor{ string Scheme { get; } bool DoAuthentication(HttpRequestMessage request, HttpResponseMessage response, out IPrincipal principal);} An authentication interceptors basically needs to returns the http authentication schema that implements in the property “Scheme”, and implements the authentication mechanism in the method “DoAuthentication”. As you can see, this last method “DoAuthentication” only relies on the HttpRequestMessage and HttpResponseMessage classes, making the testing of this interceptor very simple (There is no need to do some black magic with the WCF context or messages). After this, I implemented a couple of interceptors for supporting basic authentication and brokered authentication with SAML (using WIF) in my services. The following code illustrates how the basic authentication interceptors looks like. public class BasicAuthenticationInterceptor : IAuthenticationInterceptor{ Func<UsernameAndPassword, bool> userValidation; string realm;  public BasicAuthenticationInterceptor(Func<UsernameAndPassword, bool> userValidation, string realm) { if (userValidation == null) throw new ArgumentNullException("userValidation");  if (string.IsNullOrEmpty(realm)) throw new ArgumentNullException("realm");  this.userValidation = userValidation; this.realm = realm; }  public string Scheme { get { return "Basic"; } }  public bool DoAuthentication(HttpRequestMessage request, HttpResponseMessage response, out IPrincipal principal) { string[] credentials = ExtractCredentials(request); if (credentials.Length == 0 || !AuthenticateUser(credentials[0], credentials[1])) { response.StatusCode = HttpStatusCode.Unauthorized; response.Content = new StringContent("Access denied"); response.Headers.WwwAuthenticate.Add(new AuthenticationHeaderValue("Basic", "realm=" + this.realm));  principal = null;  return false; } else { principal = new GenericPrincipal(new GenericIdentity(credentials[0]), new string[] {});  return true; } }  private string[] ExtractCredentials(HttpRequestMessage request) { if (request.Headers.Authorization != null && request.Headers.Authorization.Scheme.StartsWith("Basic")) { string encodedUserPass = request.Headers.Authorization.Parameter.Trim();  Encoding encoding = Encoding.GetEncoding("iso-8859-1"); string userPass = encoding.GetString(Convert.FromBase64String(encodedUserPass)); int separator = userPass.IndexOf(':');  string[] credentials = new string[2]; credentials[0] = userPass.Substring(0, separator); credentials[1] = userPass.Substring(separator + 1);  return credentials; }  return new string[] { }; }  private bool AuthenticateUser(string username, string password) { var usernameAndPassword = new UsernameAndPassword { Username = username, Password = password };  if (this.userValidation(usernameAndPassword)) { return true; }  return false; }} This interceptor receives in the constructor a callback in the form of a Func delegate for authenticating the user and the “realm”, which is required as part of the implementation. The rest is a general implementation of the basic authentication mechanism using standard http request and response messages. I also implemented another interceptor for authenticating a SAML token with WIF. public class SamlAuthenticationInterceptor : IAuthenticationInterceptor{ SecurityTokenHandlerCollection handlers = null;  public SamlAuthenticationInterceptor(SecurityTokenHandlerCollection handlers) { if (handlers == null) throw new ArgumentNullException("handlers");  this.handlers = handlers; }  public string Scheme { get { return "saml"; } }  public bool DoAuthentication(HttpRequestMessage request, HttpResponseMessage response, out IPrincipal principal) { SecurityToken token = ExtractCredentials(request);  if (token != null) { ClaimsIdentityCollection claims = handlers.ValidateToken(token);  principal = new ClaimsPrincipal(claims);  return true; } else { response.StatusCode = HttpStatusCode.Unauthorized; response.Content = new StringContent("Access denied");  principal = null;  return false; } }  private SecurityToken ExtractCredentials(HttpRequestMessage request) { if (request.Headers.Authorization != null && request.Headers.Authorization.Scheme == "saml") { XmlTextReader xmlReader = new XmlTextReader(new StringReader(request.Headers.Authorization.Parameter));  var col = SecurityTokenHandlerCollection.CreateDefaultSecurityTokenHandlerCollection(); SecurityToken token = col.ReadToken(xmlReader);  return token; }  return null; }}This implementation receives a “SecurityTokenHandlerCollection” instance as part of the constructor. This class is part of WIF, and basically represents a collection of token managers to know how to handle specific xml authentication tokens (SAML is one of them). I also created a set of extension methods for injecting these interceptors as part of a service route when the service is initialized. var basicAuthentication = new BasicAuthenticationInterceptor((u) => true, "ContactManager");var samlAuthentication = new SamlAuthenticationInterceptor(serviceConfiguration.SecurityTokenHandlers); // use MEF for providing instancesvar catalog = new AssemblyCatalog(typeof(Global).Assembly);var container = new CompositionContainer(catalog);var configuration = new ContactManagerConfiguration(container); RouteTable.Routes.AddServiceRoute<ContactResource>("contact", configuration, basicAuthentication, samlAuthentication);RouteTable.Routes.AddServiceRoute<ContactsResource>("contacts", configuration, basicAuthentication, samlAuthentication); In the code above, I am injecting the basic authentication and saml authentication interceptors in the “contact” and “contacts” resource implementations that come as samples in the code preview. I will use another post to discuss more in detail how the brokered authentication with SAML model works with this new WCF Http bits. The code is available to download in this location.

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• CLR via C# 3rd Edition is out

  - by Abhijeet Patel

  Time for some book news update. CLR via C#, 3rd Edition seems to have been out for a little while now. The book was released in early Feb this year, and needless to say my copy is on it’s way. I can barely wait to dig in and chew on the goodies that one of the best technical authors and software professionals I respect has in store. The 2nd edition of the book was an absolute treat and this edition promises to be no less. Here is a brief description of what’s new and updated from the 2nd edition. Part I – CLR Basics Chapter 1-The CLR’s Execution Model Added about discussion about C#’s /optimize and /debug switches and how they relate to each other. Chapter 2-Building, Packaging, Deploying, and Administering Applications and Types Improved discussion about Win32 manifest information and version resource information. Chapter 3-Shared Assemblies and Strongly Named Assemblies Added discussion of TypeForwardedToAttribute and TypeForwardedFromAttribute. Part II – Designing Types Chapter 4-Type Fundamentals No new topics. Chapter 5-Primitive, Reference, and Value Types Enhanced discussion of checked and unchecked code and added discussion of new BigInteger type. Also added discussion of C# 4.0’s dynamic primitive type. Chapter 6-Type and Member Basics No new topics. Chapter 7-Constants and Fields No new topics. Chapter 8-Methods Added discussion of extension methods and partial methods. Chapter 9-Parameters Added discussion of optional/named parameters and implicitly-typed local variables. Chapter 10-Properties Added discussion of automatically-implemented properties, properties and the Visual Studio debugger, object and collection initializers, anonymous types, the System.Tuple type and the ExpandoObject type. Chapter 11-Events Added discussion of events and thread-safety as well as showing a cool extension method to simplify the raising of an event. Chapter 12-Generics Added discussion of delegate and interface generic type argument variance. Chapter 13-Interfaces No new topics. Part III – Essential Types Chapter 14-Chars, Strings, and Working with Text No new topics. Chapter 15-Enums Added coverage of new Enum and Type methods to access enumerated type instances. Chapter 16-Arrays Added new section on initializing array elements. Chapter 17-Delegates Added discussion of using generic delegates to avoid defining new delegate types. Also added discussion of lambda expressions. Chapter 18-Attributes No new topics. Chapter 19-Nullable Value Types Added discussion on performance. Part IV – CLR Facilities Chapter 20-Exception Handling and State Management This chapter has been completely rewritten. It is now about exception handling and state management. It includes discussions of code contracts and constrained execution regions (CERs). It also includes a new section on trade-offs between writing productive code and reliable code. Chapter 21-Automatic Memory Management Added discussion of C#’s fixed state and how it works to pin objects in the heap. Rewrote the code for weak delegates so you can use them with any class that exposes an event (the class doesn’t have to support weak delegates itself). Added discussion on the new ConditionalWeakTable class, GC Collection modes, Full GC notifications, garbage collection modes and latency modes. I also include a new sample showing how your application can receive notifications whenever Generation 0 or 2 collections occur. Chapter 22-CLR Hosting and AppDomains Added discussion of side-by-side support allowing multiple CLRs to be loaded in a single process. Added section on the performance of using MarshalByRefObject-derived types. Substantially rewrote the section on cross-AppDomain communication. Added section on AppDomain Monitoring and first chance exception notifications. Updated the section on the AppDomainManager class. Chapter 23-Assembly Loading and Reflection Added section on how to deploy a single file with dependent assemblies embedded inside it. Added section comparing reflection invoke vs bind/invoke vs bind/create delegate/invoke vs C#’s dynamic type. Chapter 24-Runtime Serialization This is a whole new chapter that was not in the 2nd Edition. Part V – Threading Chapter 25-Threading Basics Whole new chapter motivating why Windows supports threads, thread overhead, CPU trends, NUMA Architectures, the relationship between CLR threads and Windows threads, the Thread class, reasons to use threads, thread scheduling and priorities, foreground thread vs background threads. Chapter 26-Performing Compute-Bound Asynchronous Operations Whole new chapter explaining the CLR’s thread pool. This chapter covers all the new .NET 4.0 constructs including cooperative cancelation, Tasks, the aralle class, parallel language integrated query, timers, how the thread pool manages its threads, cache lines and false sharing. Chapter 27-Performing I/O-Bound Asynchronous Operations Whole new chapter explaining how Windows performs synchronous and asynchronous I/O operations. Then, I go into the CLR’s Asynchronous Programming Model, my AsyncEnumerator class, the APM and exceptions, Applications and their threading models, implementing a service asynchronously, the APM and Compute-bound operations, APM considerations, I/O request priorities, converting the APM to a Task, the event-based Asynchronous Pattern, programming model soup. Chapter 28-Primitive Thread Synchronization Constructs Whole new chapter discusses class libraries and thread safety, primitive user-mode, kernel-mode constructs, and data alignment. Chapter 29-Hybrid Thread Synchronization Constructs Whole new chapter discussion various hybrid constructs such as ManualResetEventSlim, SemaphoreSlim, CountdownEvent, Barrier, ReaderWriterLock(Slim), OneManyResourceLock, Monitor, 3 ways to solve the double-check locking technique, .NET 4.0’s Lazy and LazyInitializer classes, the condition variable pattern, .NET 4.0’s concurrent collection classes, the ReaderWriterGate and SyncGate classes.

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• Implementing an Interceptor Using NHibernate’s Built In Dynamic Proxy Generator

  - by Ricardo Peres

  NHibernate 3.2 came with an included proxy generator, which means there is no longer the need – or the possibility, for that matter – to choose Castle DynamicProxy, LinFu or Spring. This is actually a good thing, because it means one less assembly to deploy. Apparently, this generator was based, at least partially, on LinFu. As there are not many tutorials out there demonstrating it’s usage, here’s one, for demonstrating one of the most requested features: implementing INotifyPropertyChanged. This interceptor, of course, will still feature all of NHibernate’s functionalities that you are used to, such as lazy loading, and such. We will start by implementing an NHibernate interceptor, by inheriting from the base class NHibernate.EmptyInterceptor. This class does not do anything by itself, but it allows us to plug in behavior by overriding some of its methods, in this case, Instantiate: 1: public class NotifyPropertyChangedInterceptor : EmptyInterceptor 2: { 3: private ISession session = null; 4:  5: private static readonly ProxyFactory factory = new ProxyFactory(); 6:  7: public override void SetSession(ISession session) 8: { 9: this.session = session; 10: base.SetSession(session); 11: } 12:  13: public override Object Instantiate(String clazz, EntityMode entityMode, Object id) 14: { 15: Type entityType = Type.GetType(clazz); 16: IProxy proxy = factory.CreateProxy(entityType, new _NotifyPropertyChangedInterceptor(), typeof(INotifyPropertyChanged)) as IProxy; 17: 18: _NotifyPropertyChangedInterceptor interceptor = proxy.Interceptor as _NotifyPropertyChangedInterceptor; 19: interceptor.Proxy = this.session.SessionFactory.GetClassMetadata(entityType).Instantiate(id, entityMode); 20:  21: this.session.SessionFactory.GetClassMetadata(entityType).SetIdentifier(proxy, id, entityMode); 22:  23: return (proxy); 24: } 25: } Then we need a class that implements the NHibernate dynamic proxy behavior, let’s place it inside our interceptor, because it will only need to be used there: 1: class _NotifyPropertyChangedInterceptor : NHibernate.Proxy.DynamicProxy.IInterceptor 2: { 3: private PropertyChangedEventHandler changed = delegate { }; 4:  5: public Object Proxy 6: { 7: get; 8: set;} 9:  10: #region IInterceptor Members 11:  12: public Object Intercept(InvocationInfo info) 13: { 14: Boolean isSetter = info.TargetMethod.Name.StartsWith("set_") == true; 15: Object result = null; 16:  17: if (info.TargetMethod.Name == "add_PropertyChanged") 18: { 19: PropertyChangedEventHandler propertyChangedEventHandler = info.Arguments[0] as PropertyChangedEventHandler; 20: this.changed += propertyChangedEventHandler; 21: } 22: else if (info.TargetMethod.Name == "remove_PropertyChanged") 23: { 24: PropertyChangedEventHandler propertyChangedEventHandler = info.Arguments[0] as PropertyChangedEventHandler; 25: this.changed -= propertyChangedEventHandler; 26: } 27: else 28: { 29: result = info.TargetMethod.Invoke(this.Proxy, info.Arguments); 30: } 31:  32: if (isSetter == true) 33: { 34: String propertyName = info.TargetMethod.Name.Substring("set_".Length); 35: this.changed(this.Proxy, new PropertyChangedEventArgs(propertyName)); 36: } 37:  38: return (result); 39: } 40:  41: #endregion 42: } What this does for every interceptable method (those who are either virtual or from the INotifyPropertyChanged) is: For methods that came from the INotifyPropertyChanged interface, add_PropertyChanged and remove_PropertyChanged (yes, events are methods ), we add an implementation that adds or removes the event handlers to the delegate which we declared as changed; For all the others, we direct them to the place where they are actually implemented, which is the Proxy field; If the call is setting a property, it fires afterwards the PropertyChanged event. In order to use this, we need to add the interceptor to the Configuration before building the ISessionFactory: 1: using (ISessionFactory factory = cfg.SetInterceptor(new NotifyPropertyChangedInterceptor()).BuildSessionFactory()) 2: { 3: using (ISession session = factory.OpenSession()) 4: using (ITransaction tx = session.BeginTransaction()) 5: { 6: Customer customer = session.Get<Customer>(100); //some id 7: INotifyPropertyChanged inpc = customer as INotifyPropertyChanged; 8: inpc.PropertyChanged += delegate(Object sender, PropertyChangedEventArgs e) 9: { 10: //fired when a property changes 11: }; 12: customer.Address = "some other address"; //will raise PropertyChanged 13: customer.RecentOrders.ToList(); //will trigger the lazy loading 14: } 15: } Any problems, questions, do drop me a line!

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