static vs non static - Page 526

is there a simple timed lock algorithm avoiding deadlock on multiple mutexes?

- by Vicente Botet Escriba

C++0x thread library or Boost.thread define a non-member variadic template function that locks all mutex at once that helps to avoid deadlock. template <class L1, class L2, class... L3> void lock(L1&, L2&, L3&...); The same can be applied to a non-member variadic template function try_lock_until, which locks all the mutex until a given time is reached that helps to avoid deadlock like lock(...). template <class Clock, class Duration, class L1, class L2, class... L3> void try_lock_until( const chrono::time_point<Clock,Duration>& abs_time, L1&, L2&, L3&...); I have an implementation that follows the same design as the Boost function boost::lock(...). But this is quite complex. As I can be missing something evident I wanted to know if: is there a simple timed lock algorithm avoiding deadlock on multiple mutexes? If no simple implementation exists, can this justify a proposal to Boost? P.S. Please avoid posting complex solutions.

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Strange compilation error on reference passing argument to function

- by Grewdrewgoo Goobergabbsoen

Here's the code: #include <iostream> using namespace std; void mysize(int &size, int size2); int main() { int *p; int val; p = &val; cout << p; mysize(&val, 20); // Error is pointed here! } void mysize(int &size, int size2) { cout << sizeof(size); size2 = size2 + 6000; cout << size2; } Here's the error output from GCC: In function 'int main()': Line 10: error: invalid initialization of non-const reference of type 'int&' from a temporary of type 'int*' compilation terminated due to -Wfatal-errors. What does that imply? I do not understand the error message ... invalid initialization of a non-constant? I declared the prototype function above with two parameters to take, one a reference of an integer and one just an integer value itself. I passed the reference of the int (see line 10), yet this error keeps being thrown at me. What is the issue?

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Binding Javascript Event Handlers to a an Ajax HTML Response?

- by John

Let's say I have the following HTML code <div id="outer"> <div id="inner">Hello World</div> </div> At the end of my HTML page, I use javascript to attach event handlers like so, document.getElementById('inner').onclick = function() {alert(this.innerHTML);} document.getElementById('outer').onclick = function() { /* An Ajax Call where the response, which will be a string of HTML content, then goes into document.getElementById('outer').innerHTML */ document.getElementById('inner').onclick = function() {alert(this.innerHTML);} } In the above code, I am expecting <div id="inner">Hello World 2</div> to come back which requires me to re-attach the onclick event handler. This makes sense because the new response coming back is just a string, and I have to tell the browser that after converting to DOM, i also need some event handlers So my question is, is there a better way to manage event handlers on AJAX response that contains HTML content? I could use inline javascript within the html response, but then it prevents me from achieving non-intrusive javascript. So is there a way to achieve non-intrusive javascript and an efficient way to "maintain" event handlers of ajax html responses?

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Update table with index is too slow

- by pauloya

Hi, I was watching the Profiler on a live system of our application and I saw that there was an update instruction that we run periodically (every second) that was quite slow. It took around 400ms every time. The query includes this update (which is the slow part) UPDATE BufferTable SET LrbCount = LrbCount + 1, LrbUpdated = getdate() WHERE LrbId = @LrbId This is the table CREATE TABLE BufferTable( LrbId [bigint] IDENTITY(1,1) NOT NULL, ... LrbInserted [datetime] NOT NULL, LrbProcessed [bit] NOT NULL, LrbUpdated [datetime] NOT NULL, LrbCount [tinyint] NOT NULL, ) The table has 2 indexes (non unique and non clustered) with the fields by this order: * Index1 - (LrbProcessed, LrbCount) * Index2 - (LrbInserted, LrbCount, LrbProcessed) When I looked at this I thought that the problem would come from Index1 since LrbCount is changing a lot and it changes the order of the data in the index. But after desactivating index1 I saw the query was taking the same time as initially. Then I rebuilt index1 and desactivated index2, this time the query was very fast. It seems to me that Index2 should be faster to update, the order of the data shouldn't change since the LrbInserted time is not changed. Can someone explain why index2 is much heavier to update then index1? Thank you!

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Optimal (Time paradigm) solution to check variable within boundary

- by kumar_m_kiran

Hi All, Sorry if the question is very naive. I will have to check the below condition in my code 0 < x < y i.e code similar to if(x > 0 && x < y) The basic problem at system level is - currently, for every call (Telecom domain terminology), my existing code is hit (many times). So performance is very very critical, Now, I need to add a check for boundary checking (at many location - but different boundary comparison at each location). At very normal level of coding, the above comparison would look very naive without any issue. However, when added over my statistics module (which is dipped many times), performance will go down. So I would like to know the best possible way to handle the above scenario (kind of optimal way for limits checking technique). Like for example, if bit comparison works better than normal comparison or can both the comparison be evaluation in shorter time span? Other Info x is unsigned integer (which must be checked to be greater than 0 and less than y). y is unsigned integer. y is a non-const and varies for every comparison. Here time is the constraint compared to space. Language - C++. Now, later if I need to change the attribute of y to a float/double, would there be another way to optimize the check (i.e will the suggested optimal technique for integer become non-optimal solution when y is changed to float/double). Thanks in advance for any input. PS : OS used is SUSE 10 64 bit x64_64, AIX 5.3 64 bit, HP UX 11.1 A 64.

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Bizarre C++ compiler problem

- by Yassin

Hi, I have the following C++ code: typedef istream_iterator<string> isi; // (1) vector<string> lineas(isi(cin), isi()); // (2) //vector<string> lineas; //copy(isi(cin), isi(), back_inserter(lineas)); typedef vector<string>::iterator vci; for (vci it = lineas.begin(); it != lineas.end(); ++it) cout << *it << endl; However, I get the error while compiling: test.cpp: In function 'int main(int, char**)': test.cpp:16: error: request for member 'begin' in 'lineas', which is of non-class type 'std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >(main(int, char**)::isi, main(int, char**)::isi (*)())' test.cpp:16: error: request for member 'end' in 'lineas', which is of non-class type 'std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >(main(int, char**)::isi, main(int, char**)::isi (*)())' However, if I replace (1) by (2), it compiles. I'm using g++ 4.4.0 What's wrong?

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Java reflection Method invocations yield result faster than Fields?

- by omerkudat

I was microbenchmarking some code (please be nice) and came across this puzzle: when reading a field using reflection, invoking the getter Method is faster than reading the Field. Simple test class: private static final class Foo { public Foo(double val) { this.val = val; } public double getVal() { return val; } public final double val; // only public for demo purposes } We have two reflections: Method m = Foo.class.getDeclaredMethod("getVal", null); Field f = Foo.class.getDeclaredField("val"); Now I call the two reflections in a loop, invoke on the Method, and get on the Field. A first run is done to warm up the VM, a second run is done with 10M iterations. The Method invocation is consistently 30% faster, but why? Note that getDeclaredMethod and getDeclaredField are not called in the loop. They are called once and executed on the same object in the loop. I also tried some minor variations: made the field non-final, transitive, non-public, etc. All of these combinations resulted in statistically similar performance. Edit: This is on WinXP, Intel Core2 Duo, Sun JavaSE build 1.6.0_16-b01, running under jUnit4 and Eclipse.

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Programming Practice

- by deepti

public DataTable UserUpdateTempSettings(int install_id, int install_map_id, string Setting_value,string LogFile) { SqlConnection oConnection = new SqlConnection(sConnectionString); DataSet oDataset = new DataSet(); DataTable oDatatable = new DataTable(); SqlDataAdapter MyDataAdapter = new SqlDataAdapter(); try { oConnection.Open(); cmd = new SqlCommand("SP_HOTDOC_PRINTTEMPLATE_PERMISSION", oConnection); cmd.Parameters.Add(new SqlParameter ("@INSTALL_ID", install_id)); cmd.Parameters.Add(new SqlParameter ("@INSTALL_MAP_ID", install_map_id)); cmd.Parameters.Add(new SqlParameter("@SETTING_VALUE", Setting_value)); if (LogFile != "") { cmd.Parameters.Add(new SqlParameter("@LOGFILE",LogFile)); } cmd.CommandType = CommandType.StoredProcedure; MyDataAdapter.SelectCommand = cmd; cmd.ExecuteNonQuery(); MyDataAdapter.Fill(oDataset); oDatatable = oDataset.Tables[0]; return oDatatable; } catch (Exception ex) { Utils.ShowError(ex.Message); return oDatatable; } finally { if ((oConnection.State != ConnectionState.Closed) || (oConnection.State != ConnectionState.Broken)) { oConnection.Close(); } oDataset = null; oDatatable = null; oConnection.Dispose(); oConnection = null; } } i have used execute non query.. normally its not used with data adapter... if iam not using its giving me error.. is it bad programming practice to use execute non query with data adapter

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Selecting records in SQL that have the minimum value for that record based on another field

- by Ryan

I have a set of data, and while the number of fields and tables it joins with is quite complex, I believe I can distill my problem down using the required fields/tables here for illustration regarding this particular problem. I have three tables: ClientData, Sources, Prices Here is what my current query looks like before selecting the minimum value: select c.RecordID, c.Description, s.Source, p.Price, p.Type, p.Weight from ClientData c inner join Sources s ON c.RecordID = s.RecordID inner join Prices p ON s.SourceID = p.SourceID This produces the following result: RecordID Description Source Price Type Weight ============================================================= 001002003 ABC Common Stock Vendor 1 104.5 Close 1 001002003 ABC Common Stock Vendor 1 103 Bid 2 001002003 ABC Common Stock Vendor 2 106 Close 1 001002003 ABC Common Stock Vendor 2 100 Unknwn 0 111222333 DEF Preferred Stk Vendor 3 80 Bid 2 111222333 DEF Preferred Stk Vendor 3 82 Mid 3 111222333 DEF Preferred Stk Vendor 2 81 Ask 4 What I am trying to do is display prices that belong to the same record which have the minimum non-zero weight for that record (so the weight must be greater than 0, but it has to be the minimum from amongst the remaining weights). So in the above example, for record 001002003 I would want to show the close prices from Vendor 1 and Vendor 2 because they both have a weight of 1 (the minimum weight for that record). But for 111222333 I would want to show just the bid price from Vendor 3 because its weight of 2 is the minimum, non-zero for that record. The result that I'm after would like like: RecordID Description Source Price Type Weight ============================================================= 001002003 ABC Common Stock Vendor 1 104.5 Close 1 001002003 ABC Common Stock Vendor 2 106 Close 1 111222333 DEF Preferred Stk Vendor 3 80 Bid 2 Any ideas on how to achieve this? EDIT: This is for SQL Compact Edition.

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Java Daemon Threading with JNI

- by gwin003

I have a Java applet that creates a new non-daemon thread like so: Thread childThread = new Thread(new MyRunnable(_this)); childThread.setDaemon(false); childThread.start(); Then my MyRunnable object calls a native method that is implemented in C++: @Override public void run() { while (true) { if (!ran) { System.out.println("isDaemon: " + Thread.currentThread().isDaemon()); _applet.invokePrintManager(_applet.fFormType, _applet.fFormName, _applet.fPrintImmediately, _applet.fDataSet); ran = true; } } } This C++ method calls into a C# DLL that shows a form. My problem is, whenever the user navigates away from the page with a Java applet on it, JVM (and my C# form) is killed. I need the form and JVM to remain open until it is closed by the user. I tried setting my thread to be a non-daemon thread, which is working because System.out.println("isDaemon: " + Thread.currentThread().isDaemon() prints isDaemon: false. Is there something related to the way that the C# form is created (is there another thread I'm not accounting for) or something I am overlooking?? My thread is not a daemon thread, but the JVM is being killed anyways.

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Rebuilding indexes does not change the fragmentation % for nonclustered indexes.

- by Noddy

For starters, I am no DBA and I am working on rebuilding the indexes. I made use of the amazing TSQL script from msdn to alter index based onthe fragmente percent returned by dm_db_index_physical_stats and if the fragment percent is more than 30 then do a REBUILD or do a REORGANISE. What I found out was, in the first iteration, there were 87 records which needed defrag.I ran the script and all the 87 indexes (clustered & nonclustered) were rebuilt or reindexed. When I got the stats from dm_db_index_physical_stats , there were still 27 records which needed defrag and all of theses were NON CLUSTERED Indexes. All the Clustered indexes were fixed. No matter how many times I run the script to defrag these records, I still have the same indexes to be defraged and most of them with the same fragmentation %. Nothing seems to change after this. Note: I did not perform any inserts/ updates/ deletes to the tables during these iterations. Still the Rebuild/reorganise did not result in any change. More information: Using SQL 2008 Script as available in msdn http://msdn.microsoft.com/en-us/library/ms188917.aspx Could you please explain why these 27 records of non clustered indexes are not being changed/ modified ? Any help on this would be highly appreciated. Nod

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error while installing the libmemcached

- by Ahmet vardar

I get this while installing libmemcached root@server [/libmemcached]# make make all-am make[1]: Entering directory `/libmemcached' if /bin/sh ./libtool --tag=CXX --mode=compile g++ -DHAVE_CONFIG_H -I. -I. -I. -I. -I. -ggdb -DBUILDING_HASHKIT -MT libhashkit/libhashkit_libhashkit_la-aes.lo -MD -MP -MF "libhashkit/.deps/libhashkit_libhashkit_la-aes.Tpo" -c -o libhashkit/libhashkit_libhashkit_la-aes.lo `test -f 'libhashkit/aes.cc' || echo './'`libhashkit/aes.cc; \ then mv -f "libhashkit/.deps/libhashkit_libhashkit_la-aes.Tpo" "libhashkit/.deps/libhashkit_libhashkit_la-aes.Plo"; else rm -f "libhashkit/.deps/libhashkit_libhashkit_la-aes.Tpo"; exit 1; fi ./libtool: line 866: X--tag=CXX: command not found ./libtool: line 899: libtool: ignoring unknown tag : command not found ./libtool: line 866: X--mode=compile: command not found ./libtool: line 1032: *** Warning: inferring the mode of operation is deprecated.: command not found ./libtool: line 1033: *** Future versions of Libtool will require --mode=MODE be specified.: command not found ./libtool: line 1176: Xg++: command not found ./libtool: line 1176: X-DHAVE_CONFIG_H: command not found ./libtool: line 1176: X-I.: command not found ./libtool: line 1176: X-I.: command not found ./libtool: line 1176: X-I.: command not found ./libtool: line 1176: X-I.: command not found ./libtool: line 1176: X-I.: command not found ./libtool: line 1176: X-ggdb: command not found ./libtool: line 1176: X-DBUILDING_HASHKIT: command not found ./libtool: line 1176: X-MT: command not found ./libtool: line 1176: Xlibhashkit/libhashkit_libhashkit_la-aes.lo: No such file or directory ./libtool: line 1176: X-MD: command not found ./libtool: line 1176: X-MP: command not found ./libtool: line 1176: X-MF: command not found ./libtool: line 1176: Xlibhashkit/.deps/libhashkit_libhashkit_la-aes.Tpo: No such file or directory ./libtool: line 1176: X-c: command not found ./libtool: line 1228: Xlibhashkit/libhashkit_libhashkit_la-aes.lo: No such file or directory ./libtool: line 1233: libtool: compile: cannot determine name of library object from `': command not found make[1]: *** [libhashkit/libhashkit_libhashkit_la-aes.lo] Error 1 make[1]: Leaving directory `/libmemcached' make: *** [all] Error 2 OUTPUT OF ./configure checking build system type... x86_64-unknown-linux-gnu checking host system type... x86_64-unknown-linux-gnu checking target system type... x86_64-unknown-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for style of include used by make... GNU checking for gcc... gcc checking whether the C compiler works... yes checking for C compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking dependency style of gcc... gcc3 checking dependency style of gcc... (cached) gcc3 checking how to run the C preprocessor... gcc -E checking for grep that handles long lines and -e... /bin/grep checking for egrep... /bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking minix/config.h usability... no checking minix/config.h presence... no checking for minix/config.h... no checking whether it is safe to define __EXTENSIONS__... yes checking for isainfo... no checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking dependency style of g++... gcc3 checking dependency style of g++... (cached) gcc3 checking whether gcc and cc understand -c and -o together... yes checking how to create a ustar tar archive... gnutar checking whether __SUNPRO_C is declared... no checking whether __ICC is declared... no checking "C Compiler version--yes"... "gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-52)" checking "C++ Compiler version"... "g++ (GCC) 4.1.2 20080704 (Red Hat 4.1.2-52)" checking whether time.h and sys/time.h may both be included... yes checking whether struct tm is in sys/time.h or time.h... time.h checking for size_t... yes checking for special C compiler options needed for large files... no checking for _FILE_OFFSET_BITS value needed for large files... no checking for library containing clock_gettime... -lrt checking sys/socket.h usability... yes checking sys/socket.h presence... yes checking for sys/socket.h... yes checking size of off_t... 8 checking size of size_t... 8 checking size of long long... 8 checking if time_t is unsigned... no checking for setsockopt... yes checking for bind... yes checking whether the compiler provides atomic builtins... yes checking assert.h usability... yes checking assert.h presence... yes checking for assert.h... yes checking whether to enable assertions... yes checking whether it is safe to use -fdiagnostics-show-option... yes checking whether it is safe to use -floop-parallelize-all... no checking whether it is safe to use -Wextra... yes checking whether it is safe to use -Wformat... yes checking whether it is safe to use -Wconversion... no checking whether it is safe to use -Wmissing-declarations from C++... no checking whether it is safe to use -Wframe-larger-than... no checking whether it is safe to use -Wlogical-op... no checking whether it is safe to use -Wredundant-decls from C++... yes checking whether it is safe to use -Wattributes from C++... no checking whether it is safe to use -Wno-attributes... no checking for perl... perl checking for dpkg-gensymbols... no checking for lcov... no checking for genhtml... no checking for sphinx-build... no checking for working -pipe... yes checking for bison... bison checking for flex... flex checking how to print strings... printf checking for a sed that does not truncate output... /bin/sed checking for fgrep... /bin/grep -F checking for ld used by gcc... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B checking the name lister (/usr/bin/nm -B) interface... BSD nm checking whether ln -s works... yes checking the maximum length of command line arguments... 98304 checking whether the shell understands some XSI constructs... yes checking whether the shell understands "+="... yes checking how to convert x86_64-unknown-linux-gnu file names to x86_64-unknown-linux-gnu format... func_convert_file_noop checking how to convert x86_64-unknown-linux-gnu file names to toolchain format... func_convert_file_noop checking for /usr/bin/ld option to reload object files... -r checking for objdump... objdump checking how to recognize dependent libraries... pass_all checking for dlltool... no checking how to associate runtime and link libraries... printf %s\n checking for ar... ar checking for archiver @FILE support... @ checking for strip... strip checking for ranlib... ranlib checking command to parse /usr/bin/nm -B output from gcc object... ok checking for sysroot... no checking for mt... no checking if : is a manifest tool... no checking for dlfcn.h... yes checking for objdir... .libs checking if gcc supports -fno-rtti -fno-exceptions... no checking for gcc option to produce PIC... -fPIC -DPIC checking if gcc PIC flag -fPIC -DPIC works... yes checking if gcc static flag -static works... yes checking if gcc supports -c -o file.o... yes checking if gcc supports -c -o file.o... (cached) yes checking whether the gcc linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking whether -lc should be explicitly linked in... no checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... yes checking how to run the C++ preprocessor... g++ -E checking for ld used by g++... /usr/bin/ld -m elf_x86_64 checking if the linker (/usr/bin/ld -m elf_x86_64) is GNU ld... yes checking whether the g++ linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking for g++ option to produce PIC... -fPIC -DPIC checking if g++ PIC flag -fPIC -DPIC works... yes checking if g++ static flag -static works... yes checking if g++ supports -c -o file.o... yes checking if g++ supports -c -o file.o... (cached) yes checking whether the g++ linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking dynamic linker characteristics... (cached) GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether the -Werror option is usable... yes checking for simple visibility declarations... yes checking for ISO C++ 98 include files... checking whether memcached executable path has been provided... no checking for memcached... /usr/local/bin/memcached checking whether memcached_sasl executable path has been provided... no checking for memcached_sasl... no checking whether gearmand executable path has been provided... no checking for gearmand... no checking libgearman/gearmand.h usability... no checking libgearman/gearmand.h presence... no checking for libgearman/gearmand.h... no checking for library containing getopt_long... none required checking for library containing gethostbyname... none required checking for the pthreads library -lpthreads... no checking whether pthreads work without any flags... yes checking for joinable pthread attribute... PTHREAD_CREATE_JOINABLE checking if more special flags are required for pthreads... no checking for PTHREAD_PRIO_INHERIT... yes checking the location of cstdint... configure: WARNING: Could not find a cstdint header. <stdint.h> checking the location of cinttypes... configure: WARNING: Could not find a cinttypes header. <inttypes.h> checking whether byte ordering is bigendian... no checking for htonll... no checking for working SO_SNDTIMEO... yes checking for working SO_RCVTIMEO... yes checking for supported struct padding... yes checking for alarm... yes checking for dup2... yes checking for getline... yes checking for gettimeofday... yes checking for memchr... yes checking for memmove... yes checking for memset... yes checking for pipe2... no checking for select... yes checking for setenv... yes checking for socket... yes checking for sqrt... yes checking for strcasecmp... yes checking for strchr... yes checking for strdup... yes checking for strerror... yes checking for strtol... yes checking for strtoul... yes checking for strtoull... yes checking arpa/inet.h usability... yes checking arpa/inet.h presence... yes checking for arpa/inet.h... yes checking fcntl.h usability... yes checking fcntl.h presence... yes checking for fcntl.h... yes checking libintl.h usability... yes checking libintl.h presence... yes checking for libintl.h... yes checking limits.h usability... yes checking limits.h presence... yes checking for limits.h... yes checking malloc.h usability... yes checking malloc.h presence... yes checking for malloc.h... yes checking netdb.h usability... yes checking netdb.h presence... yes checking for netdb.h... yes checking netinet/in.h usability... yes checking netinet/in.h presence... yes checking for netinet/in.h... yes checking stddef.h usability... yes checking stddef.h presence... yes checking for stddef.h... yes checking sys/time.h usability... yes checking sys/time.h presence... yes checking for sys/time.h... yes checking execinfo.h usability... yes checking execinfo.h presence... yes checking for execinfo.h... yes checking cxxabi.h usability... yes checking cxxabi.h presence... yes checking for cxxabi.h... yes checking sys/sysctl.h usability... yes checking sys/sysctl.h presence... yes checking for sys/sysctl.h... yes checking umem.h usability... no checking umem.h presence... no checking for umem.h... no checking for C++ compiler vendor... gnu checking for working alloca.h... yes checking for alloca... yes checking for error_at_line... yes checking for pid_t... yes checking vfork.h usability... no checking vfork.h presence... no checking for vfork.h... no checking for fork... yes checking for vfork... yes checking for working fork... yes checking for working vfork... (cached) yes checking for stdlib.h... (cached) yes checking for GNU libc compatible malloc... yes checking for stdlib.h... (cached) yes checking for GNU libc compatible realloc... yes checking whether strerror_r is declared... yes checking for strerror_r... yes checking whether strerror_r returns char *... yes checking for stdbool.h that conforms to C99... yes checking for _Bool... no checking for int16_t... yes checking for int32_t... yes checking for int64_t... yes checking for int8_t... yes checking for off_t... yes checking for pid_t... (cached) yes checking for ssize_t... yes checking for uint16_t... yes checking for uint32_t... yes checking for uint64_t... yes checking for uint8_t... yes checking whether byte ordering is bigendian... (cached) no checking for an ANSI C-conforming const... yes checking for inline... inline checking for working volatile... yes checking for C/C++ restrict keyword... __restrict checking whether the compiler supports GCC C++ ABI name demangling... yes checking sasl/sasl.h usability... no checking sasl/sasl.h presence... no checking for sasl/sasl.h... no checking uuid/uuid.h usability... yes checking uuid/uuid.h presence... yes checking for uuid/uuid.h... yes checking for main in -luuid... yes checking for clock_gettime in -lrt... yes checking for floor in -lm... yes checking for sigignore... yes checking atomic.h usability... no checking atomic.h presence... no checking for atomic.h... no checking for setppriv... no checking for winsock2.h... no checking for poll.h... yes checking for sys/wait.h... yes checking for fnmatch.h... yes checking for MSG_NOSIGNAL... yes checking for MSG_DONTWAIT... yes checking for MSG_MORE... yes checking event.h usability... yes checking event.h presence... yes checking for event.h... yes checking for main in -levent... yes checking for endianness... little configure: creating ./config.status config.status: creating Makefile config.status: creating docs/conf.py config.status: creating libhashkit-1.0/configure.h config.status: creating libmemcached-1.0/configure.h config.status: creating libmemcached-1.2/configure.h config.status: creating libmemcached-2.0/configure.h config.status: creating support/libmemcached.pc config.status: creating support/libmemcached.spec config.status: creating support/libmemcached-fc.spec config.status: creating libtest/version.h config.status: creating config.h config.status: config.h is unchanged config.status: executing depfiles commands config.status: executing libtool commands --- Configuration summary for libmemcached version 1.0.6 * Installation prefix: /usr/local * System type: unknown-linux-gnu * Host CPU: x86_64 * C Compiler: gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-52) * Assertions enabled: yes * Debug enabled: no * Warnings as failure: no * SASL support: --- anyone knows how to solve this ?

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Finding a Relative Path in .NET

- by Rick Strahl

Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test.txt. Or if I pass c:\ I want to get back ..\..\ – in other words always return a non-hardcoded path based on some other known directory. I’ve had a routine in my library that does this via some lengthy string parsing routines, but ran into some Uri processing today that made me realize that this code could be greatly simplified by using the System.Uri class instead. Here’s the simple static method: /// <summary> /// Returns a relative path string from a full path based on a base path /// provided. /// </summary> /// <param name="fullPath">The path to convert. Can be either a file or a directory</param> /// <param name="basePath">The base path on which relative processing is based. Should be a directory.</param> /// <returns> /// String of the relative path. /// /// Examples of returned values: /// test.txt, ..\test.txt, ..\..\..\test.txt, ., .., subdir\test.txt /// </returns> public static string GetRelativePath(string fullPath, string basePath ) { // ForceBasePath to a path if (!basePath.EndsWith("\\")) basePath += "\\"; Uri baseUri = new Uri(basePath); Uri fullUri = new Uri(fullPath); Uri relativeUri = baseUri.MakeRelativeUri(fullUri); // Uri's use forward slashes so convert back to backward slashes return relativeUri.ToString().Replace("/", "\\"); } You can then call it like this: string relPath = FileUtils.GetRelativePath("c:\temp\templates","c:\temp\templates\subdir\test.txt") It’s not exactly rocket science but it’s useful in many scenarios where you’re working with files based on an application base directory. Right now I’m working on a templating solution (using the Razor Engine) where templates live in a base directory and are supplied as relative paths to that base directory. Resolving these relative paths both ways is important in order to properly check for existance of files and their change status in this case. Not the kind of thing you use every day, but useful to remember.© Rick Strahl, West Wind Technologies, 2005-2010Posted in .NET CSharp

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Will these headphones work with Ubuntu?

- by david99world

Sorry for the vagueness of this question, but I just wondered if (shot in the dark) anyone knew if these wireless headphones... http://www.argos.co.uk/static/Product/partNumber/9004203.htm#pdpFullProductInformation Would work with ubuntu? I was thinking if the trasnmitter is USB then I might not get the drivers. Does anyone have any ideas of a way I could find out without paying for them then finding out I cant use them? Thanks, Dave

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NoSQL with RavenDB and ASP.NET MVC - Part 1

- by shiju

A while back, I have blogged NoSQL with MongoDB, NoRM and ASP.NET MVC Part 1 and Part 2 on how to use MongoDB with an ASP.NET MVC application. The NoSQL movement is getting big attention and RavenDB is the latest addition to the NoSQL and document database world. RavenDB is an Open Source (with a commercial option) document database for the .NET/Windows platform developed by Ayende Rahien. Raven stores schema-less JSON documents, allow you to define indexes using Linq queries and focus on low latency and high performance. RavenDB is .NET focused document database which comes with a fully functional .NET client API and supports LINQ. RavenDB comes with two components, a server and a client API. RavenDB is a REST based system, so you can write your own HTTP cleint API. As a .NET developer, RavenDB is becoming my favorite document database. Unlike other document databases, RavenDB is supports transactions using System.Transactions. Also it's supports both embedded and server mode of database. You can access RavenDB site at http://ravendb.netA demo App with ASP.NET MVCLet's create a simple demo app with RavenDB and ASP.NET MVC. To work with RavenDB, do the following steps. Go to http://ravendb.net/download and download the latest build.Unzip the downloaded file.Go to the /Server directory and run the RavenDB.exe. This will start the RavenDB server listening on localhost:8080You can change the port of RavenDB by modifying the "Raven/Port" appSetting value in the RavenDB.exe.config file.When running the RavenDB, it will automatically create a database in the /Data directory. You can change the directory name data by modifying "Raven/DataDirt" appSetting value in the RavenDB.exe.config file.RavenDB provides a browser based admin tool. When the Raven server is running, You can be access the browser based admin tool and view and edit documents and index using your browser admin tool. The web admin tool available at http://localhost:8080The below is the some screen shots of web admin tool Working with ASP.NET MVC To working with RavenDB in our demo ASP.NET MVC application, do the following steps Step 1 - Add reference to Raven Cleint API In our ASP.NET MVC application, Add a reference to the Raven.Client.Lightweight.dll from the Client directory. Step 2 - Create DocumentStoreThe document store would be created once per application. Let's create a DocumentStore on application start-up in the Global.asax.cs. documentStore = new DocumentStore { Url = "http://localhost:8080/" }; documentStore.Initialise(); The above code will create a Raven DB document store and will be listening the server locahost at port 8080 Step 3 - Create DocumentSession on BeginRequest Let's create a DocumentSession on BeginRequest event in the Global.asax.cs. We are using the document session for every unit of work. In our demo app, every HTTP request would be a single Unit of Work (UoW). BeginRequest += (sender, args) => HttpContext.Current.Items[RavenSessionKey] = documentStore.OpenSession(); Step 4 - Destroy the DocumentSession on EndRequest EndRequest += (o, eventArgs) => { var disposable = HttpContext.Current.Items[RavenSessionKey] as IDisposable; if (disposable != null) disposable.Dispose(); }; At the end of HTTP request, we are destroying the DocumentSession object.The below code block shown all the code in the Global.asax.cs private const string RavenSessionKey = "RavenMVC.Session"; private static DocumentStore documentStore; protected void Application_Start() { //Create a DocumentStore in Application_Start //DocumentStore should be created once per application and stored as a singleton. documentStore = new DocumentStore { Url = "http://localhost:8080/" }; documentStore.Initialise(); AreaRegistration.RegisterAllAreas(); RegisterRoutes(RouteTable.Routes); //DI using Unity 2.0 ConfigureUnity(); } public MvcApplication() { //Create a DocumentSession on BeginRequest //create a document session for every unit of work BeginRequest += (sender, args) => HttpContext.Current.Items[RavenSessionKey] = documentStore.OpenSession(); //Destroy the DocumentSession on EndRequest EndRequest += (o, eventArgs) => { var disposable = HttpContext.Current.Items[RavenSessionKey] as IDisposable; if (disposable != null) disposable.Dispose(); }; } //Getting the current DocumentSession public static IDocumentSession CurrentSession { get { return (IDocumentSession)HttpContext.Current.Items[RavenSessionKey]; } } We have setup all necessary code in the Global.asax.cs for working with RavenDB. For our demo app, Let’s write a domain class public class Category { public string Id { get; set; } [Required(ErrorMessage = "Name Required")] [StringLength(25, ErrorMessage = "Must be less than 25 characters")] public string Name { get; set;} public string Description { get; set; } } We have created simple domain entity Category. Let's create repository class for performing CRUD operations against our domain entity Category. public interface ICategoryRepository { Category Load(string id); IEnumerable<Category> GetCategories(); void Save(Category category); void Delete(string id); } public class CategoryRepository : ICategoryRepository { private IDocumentSession session; public CategoryRepository() { session = MvcApplication.CurrentSession; } //Load category based on Id public Category Load(string id) { return session.Load<Category>(id); } //Get all categories public IEnumerable<Category> GetCategories() { var categories= session.LuceneQuery<Category>() .WaitForNonStaleResults() .ToArray(); return categories; } //Insert/Update category public void Save(Category category) { if (string.IsNullOrEmpty(category.Id)) { //insert new record session.Store(category); } else { //edit record var categoryToEdit = Load(category.Id); categoryToEdit.Name = category.Name; categoryToEdit.Description = category.Description; } //save the document session session.SaveChanges(); } //delete a category public void Delete(string id) { var category = Load(id); session.Delete<Category>(category); session.SaveChanges(); } } For every CRUD operations, we are taking the current document session object from HttpContext object. session = MvcApplication.CurrentSession; We are calling the static method CurrentSession from the Global.asax.cs public static IDocumentSession CurrentSession { get { return (IDocumentSession)HttpContext.Current.Items[RavenSessionKey]; } } Retrieve Entities The Load method get the single Category object based on the Id. RavenDB is working based on the REST principles and the Id would be like categories/1. The Id would be created by automatically when a new object is inserted to the document store. The REST uri categories/1 represents a single category object with Id representation of 1. public Category Load(string id) { return session.Load<Category>(id); } The GetCategories method returns all the categories calling the session.LuceneQuery method. RavenDB is using a lucen query syntax for querying. I will explain more details about querying and indexing in my future posts. public IEnumerable<Category> GetCategories() { var categories= session.LuceneQuery<Category>() .WaitForNonStaleResults() .ToArray(); return categories; } Insert/Update entityFor insert/Update a Category entity, we have created Save method in repository class. If the Id property of Category is null, we call Store method of Documentsession for insert a new record. For editing a existing record, we load the Category object and assign the values to the loaded Category object. The session.SaveChanges() will save the changes to document store. //Insert/Update category public void Save(Category category) { if (string.IsNullOrEmpty(category.Id)) { //insert new record session.Store(category); } else { //edit record var categoryToEdit = Load(category.Id); categoryToEdit.Name = category.Name; categoryToEdit.Description = category.Description; } //save the document session session.SaveChanges(); } Delete Entity In the Delete method, we call the document session's delete method and call the SaveChanges method to reflect changes in the document store. public void Delete(string id) { var category = Load(id); session.Delete<Category>(category); session.SaveChanges(); } Let’s create ASP.NET MVC controller and controller actions for handling CRUD operations for the domain class Category public class CategoryController : Controller { private ICategoryRepository categoyRepository; //DI enabled constructor public CategoryController(ICategoryRepository categoyRepository) { this.categoyRepository = categoyRepository; } public ActionResult Index() { var categories = categoyRepository.GetCategories(); if (categories == null) return RedirectToAction("Create"); return View(categories); } [HttpGet] public ActionResult Edit(string id) { var category = categoyRepository.Load(id); return View("Save",category); } // GET: /Category/Create [HttpGet] public ActionResult Create() { var category = new Category(); return View("Save", category); } [HttpPost] public ActionResult Save(Category category) { if (!ModelState.IsValid) { return View("Save", category); } categoyRepository.Save(category); return RedirectToAction("Index"); } [HttpPost] public ActionResult Delete(string id) { categoyRepository.Delete(id); var categories = categoyRepository.GetCategories(); return PartialView("CategoryList", categories); } } RavenDB is an awesome document database and I hope that it will be the winner in .NET space of document database world. The source code of demo application available at http://ravenmvc.codeplex.com/

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Introducing the Earthquake Locator – A Bing Maps Silverlight Application, part 1

- by Bobby Diaz

Update: Live demo and source code now available! The recent wave of earthquakes (no pun intended) being reported in the news got me wondering about the frequency and severity of earthquakes around the world. Since I’ve been doing a lot of Silverlight development lately, I decided to scratch my curiosity with a nice little Bing Maps application that will show the location and relative strength of recent seismic activity. Here is a list of technologies this application will utilize, so be sure to have everything downloaded and installed if you plan on following along. Silverlight 3 WCF RIA Services Bing Maps Silverlight Control * Managed Extensibility Framework (optional) MVVM Light Toolkit (optional) log4net (optional) * If you are new to Bing Maps or have not signed up for a Developer Account, you will need to visit www.bingmapsportal.com to request a Bing Maps key for your application. Getting Started We start out by creating a new Silverlight Application called EarthquakeLocator and specify that we want to automatically create the Web Application Project with RIA Services enabled. I cleaned up the web app by removing the Default.aspx and EarthquakeLocatorTestPage.html. Then I renamed the EarthquakeLocatorTestPage.aspx to Default.aspx and set it as my start page. I also set the development server to use a specific port, as shown below. RIA Services Next, I created a Services folder in the EarthquakeLocator.Web project and added a new Domain Service Class called EarthquakeService.cs. This is the RIA Services Domain Service that will provide earthquake data for our client application. I am not using LINQ to SQL or Entity Framework, so I will use the <empty domain service class> option. We will be pulling data from an external Atom feed, but this example could just as easily pull data from a database or another web service. This is an important distinction to point out because each scenario I just mentioned could potentially use a different Domain Service base class (i.e. LinqToSqlDomainService<TDataContext>). Now we can start adding Query methods to our EarthquakeService that pull data from the USGS web site. Here is the complete code for our service class: using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.ServiceModel.Syndication; using System.Web.DomainServices; using System.Web.Ria; using System.Xml; using log4net; using EarthquakeLocator.Web.Model; namespace EarthquakeLocator.Web.Services { /// <summary> /// Provides earthquake data to client applications. /// </summary> [EnableClientAccess()] public class EarthquakeService : DomainService { private static readonly ILog log = LogManager.GetLogger(typeof(EarthquakeService)); // USGS Data Feeds: http://earthquake.usgs.gov/earthquakes/catalogs/ private const string FeedForPreviousDay = "http://earthquake.usgs.gov/earthquakes/catalogs/1day-M2.5.xml"; private const string FeedForPreviousWeek = "http://earthquake.usgs.gov/earthquakes/catalogs/7day-M2.5.xml"; /// <summary> /// Gets the earthquake data for the previous week. /// </summary> /// <returns>A queryable collection of <see cref="Earthquake"/> objects.</returns> public IQueryable<Earthquake> GetEarthquakes() { var feed = GetFeed(FeedForPreviousWeek); var list = new List<Earthquake>(); if ( feed != null ) { foreach ( var entry in feed.Items ) { var quake = CreateEarthquake(entry); if ( quake != null ) { list.Add(quake); } } } return list.AsQueryable(); } /// <summary> /// Creates an <see cref="Earthquake"/> object for each entry in the Atom feed. /// </summary> /// <param name="entry">The Atom entry.</param> /// <returns></returns> private Earthquake CreateEarthquake(SyndicationItem entry) { Earthquake quake = null; string title = entry.Title.Text; string summary = entry.Summary.Text; string point = GetElementValue<String>(entry, "point"); string depth = GetElementValue<String>(entry, "elev"); string utcTime = null; string localTime = null; string depthDesc = null; double? magnitude = null; double? latitude = null; double? longitude = null; double? depthKm = null; if ( !String.IsNullOrEmpty(title) && title.StartsWith("M") ) { title = title.Substring(2, title.IndexOf(',')-3).Trim(); magnitude = TryParse(title); } if ( !String.IsNullOrEmpty(point) ) { var values = point.Split(' '); if ( values.Length == 2 ) { latitude = TryParse(values[0]); longitude = TryParse(values[1]); } } if ( !String.IsNullOrEmpty(depth) ) { depthKm = TryParse(depth); if ( depthKm != null ) { depthKm = Math.Round((-1 * depthKm.Value) / 100, 2); } } if ( !String.IsNullOrEmpty(summary) ) { summary = summary.Replace("</p>", ""); var values = summary.Split( new string[] { "<p>" }, StringSplitOptions.RemoveEmptyEntries); if ( values.Length == 3 ) { var times = values[1].Split( new string[] { "<br>" }, StringSplitOptions.RemoveEmptyEntries); if ( times.Length > 0 ) { utcTime = times[0]; } if ( times.Length > 1 ) { localTime = times[1]; } depthDesc = values[2]; depthDesc = "Depth: " + depthDesc.Substring(depthDesc.IndexOf(":") + 2); } } if ( latitude != null && longitude != null ) { quake = new Earthquake() { Id = entry.Id, Title = entry.Title.Text, Summary = entry.Summary.Text, Date = entry.LastUpdatedTime.DateTime, Url = entry.Links.Select(l => Path.Combine(l.BaseUri.OriginalString, l.Uri.OriginalString)).FirstOrDefault(), Age = entry.Categories.Where(c => c.Label == "Age") .Select(c => c.Name).FirstOrDefault(), Magnitude = magnitude.GetValueOrDefault(), Latitude = latitude.GetValueOrDefault(), Longitude = longitude.GetValueOrDefault(), DepthInKm = depthKm.GetValueOrDefault(), DepthDesc = depthDesc, UtcTime = utcTime, LocalTime = localTime }; } return quake; } private T GetElementValue<T>(SyndicationItem entry, String name) { var el = entry.ElementExtensions.Where(e => e.OuterName == name).FirstOrDefault(); T value = default(T); if ( el != null ) { value = el.GetObject<T>(); } return value; } private double? TryParse(String value) { double d; if ( Double.TryParse(value, out d) ) { return d; } return null; } /// <summary> /// Gets the feed at the specified URL. /// </summary> /// <param name="url">The URL.</param> /// <returns>A <see cref="SyndicationFeed"/> object.</returns> public static SyndicationFeed GetFeed(String url) { SyndicationFeed feed = null; try { log.Debug("Loading RSS feed: " + url); using ( var reader = XmlReader.Create(url) ) { feed = SyndicationFeed.Load(reader); } } catch ( Exception ex ) { log.Error("Error occurred while loading RSS feed: " + url, ex); } return feed; } } } The only method that will be generated in the client side proxy class, EarthquakeContext, will be the GetEarthquakes() method. The reason being that it is the only public instance method and it returns an IQueryable<Earthquake> collection that can be consumed by the client application. GetEarthquakes() calls the static GetFeed(String) method, which utilizes the built in SyndicationFeed API to load the external data feed. You will need to add a reference to the System.ServiceModel.Web library in order to take advantage of the RSS/Atom reader. The API will also allow you to create your own feeds to serve up in your applications. Model I have also created a Model folder and added a new class, Earthquake.cs. The Earthquake object will hold the various properties returned from the Atom feed. Here is a sample of the code for that class. Notice the [Key] attribute on the Id property, which is required by RIA Services to uniquely identify the entity. using System; using System.Collections.Generic; using System.Linq; using System.Runtime.Serialization; using System.ComponentModel.DataAnnotations; namespace EarthquakeLocator.Web.Model { /// <summary> /// Represents an earthquake occurrence and related information. /// </summary> [DataContract] public class Earthquake { /// <summary> /// Gets or sets the id. /// </summary> /// <value>The id.</value> [Key] [DataMember] public string Id { get; set; } /// <summary> /// Gets or sets the title. /// </summary> /// <value>The title.</value> [DataMember] public string Title { get; set; } /// <summary> /// Gets or sets the summary. /// </summary> /// <value>The summary.</value> [DataMember] public string Summary { get; set; } // additional properties omitted } } View Model The recent trend to use the MVVM pattern for WPF and Silverlight provides a great way to separate the data and behavior logic out of the user interface layer of your client applications. I have chosen to use the MVVM Light Toolkit for the Earthquake Locator, but there are other options out there if you prefer another library. That said, I went ahead and created a ViewModel folder in the Silverlight project and added a EarthquakeViewModel class that derives from ViewModelBase. Here is the code: using System; using System.Collections.ObjectModel; using System.ComponentModel.Composition; using System.ComponentModel.Composition.Hosting; using Microsoft.Maps.MapControl; using GalaSoft.MvvmLight; using EarthquakeLocator.Web.Model; using EarthquakeLocator.Web.Services; namespace EarthquakeLocator.ViewModel { /// <summary> /// Provides data for views displaying earthquake information. /// </summary> public class EarthquakeViewModel : ViewModelBase { [Import] public EarthquakeContext Context; /// <summary> /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class. /// </summary> public EarthquakeViewModel() { var catalog = new AssemblyCatalog(GetType().Assembly); var container = new CompositionContainer(catalog); container.ComposeParts(this); Initialize(); } /// <summary> /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class. /// </summary> /// <param name="context">The context.</param> public EarthquakeViewModel(EarthquakeContext context) { Context = context; Initialize(); } private void Initialize() { MapCenter = new Location(20, -170); ZoomLevel = 2; } #region Private Methods private void OnAutoLoadDataChanged() { LoadEarthquakes(); } private void LoadEarthquakes() { var query = Context.GetEarthquakesQuery(); Context.Earthquakes.Clear(); Context.Load(query, (op) => { if ( !op.HasError ) { foreach ( var item in op.Entities ) { Earthquakes.Add(item); } } }, null); } #endregion Private Methods #region Properties private bool autoLoadData; /// <summary> /// Gets or sets a value indicating whether to auto load data. /// </summary> /// <value><c>true</c> if auto loading data; otherwise, <c>false</c>.</value> public bool AutoLoadData { get { return autoLoadData; } set { if ( autoLoadData != value ) { autoLoadData = value; RaisePropertyChanged("AutoLoadData"); OnAutoLoadDataChanged(); } } } private ObservableCollection<Earthquake> earthquakes; /// <summary> /// Gets the collection of earthquakes to display. /// </summary> /// <value>The collection of earthquakes.</value> public ObservableCollection<Earthquake> Earthquakes { get { if ( earthquakes == null ) { earthquakes = new ObservableCollection<Earthquake>(); } return earthquakes; } } private Location mapCenter; /// <summary> /// Gets or sets the map center. /// </summary> /// <value>The map center.</value> public Location MapCenter { get { return mapCenter; } set { if ( mapCenter != value ) { mapCenter = value; RaisePropertyChanged("MapCenter"); } } } private double zoomLevel; /// <summary> /// Gets or sets the zoom level. /// </summary> /// <value>The zoom level.</value> public double ZoomLevel { get { return zoomLevel; } set { if ( zoomLevel != value ) { zoomLevel = value; RaisePropertyChanged("ZoomLevel"); } } } #endregion Properties } } The EarthquakeViewModel class contains all of the properties that will be bound to by the various controls in our views. Be sure to read through the LoadEarthquakes() method, which handles calling the GetEarthquakes() method in our EarthquakeService via the EarthquakeContext proxy, and also transfers the loaded entities into the view model’s Earthquakes collection. Another thing to notice is what’s going on in the default constructor. I chose to use the Managed Extensibility Framework (MEF) for my composition needs, but you can use any dependency injection library or none at all. To allow the EarthquakeContext class to be discoverable by MEF, I added the following partial class so that I could supply the appropriate [Export] attribute: using System; using System.ComponentModel.Composition; namespace EarthquakeLocator.Web.Services { /// <summary> /// The client side proxy for the EarthquakeService class. /// </summary> [Export] public partial class EarthquakeContext { } } One last piece I wanted to point out before moving on to the user interface, I added a client side partial class for the Earthquake entity that contains helper properties that we will bind to later: using System; namespace EarthquakeLocator.Web.Model { /// <summary> /// Represents an earthquake occurrence and related information. /// </summary> public partial class Earthquake { /// <summary> /// Gets the location based on the current Latitude/Longitude. /// </summary> /// <value>The location.</value> public string Location { get { return String.Format("{0},{1}", Latitude, Longitude); } } /// <summary> /// Gets the size based on the Magnitude. /// </summary> /// <value>The size.</value> public double Size { get { return (Magnitude * 3); } } } } View Now the fun part! Usually, I would create a Views folder to place all of my View controls in, but I took the easy way out and added the following XAML code to the default MainPage.xaml file. Be sure to add the bing prefix associating the Microsoft.Maps.MapControl namespace after adding the assembly reference to your project. The MVVM Light Toolkit project templates come with a ViewModelLocator class that you can use via a static resource, but I am instantiating the EarthquakeViewModel directly in my user control. I am setting the AutoLoadData property to true as a way to trigger the LoadEarthquakes() method call. The MapItemsControl found within the <bing:Map> control binds its ItemsSource property to the Earthquakes collection of the view model, and since it is an ObservableCollection<T>, we get the automatic two way data binding via the INotifyCollectionChanged interface. <UserControl x:Class="EarthquakeLocator.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl" xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel" mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480" > <UserControl.Resources> <DataTemplate x:Key="EarthquakeTemplate"> <Ellipse Fill="Red" Stroke="Black" StrokeThickness="1" Width="{Binding Size}" Height="{Binding Size}" bing:MapLayer.Position="{Binding Location}" bing:MapLayer.PositionOrigin="Center"> <ToolTipService.ToolTip> <StackPanel> <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" /> <TextBlock Text="{Binding UtcTime}" /> <TextBlock Text="{Binding LocalTime}" /> <TextBlock Text="{Binding DepthDesc}" /> </StackPanel> </ToolTipService.ToolTip> </Ellipse> </DataTemplate> </UserControl.Resources> <UserControl.DataContext> <vm:EarthquakeViewModel AutoLoadData="True" /> </UserControl.DataContext> <Grid x:Name="LayoutRoot"> <bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--" Center="{Binding MapCenter, Mode=TwoWay}" ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}"> <bing:MapItemsControl ItemsSource="{Binding Earthquakes}" ItemTemplate="{StaticResource EarthquakeTemplate}" /> </bing:Map> </Grid> </UserControl> The EarthquakeTemplate defines the Ellipse that will represent each earthquake, the Width and Height that are determined by the Magnitude, the Position on the map, and also the tooltip that will appear when we mouse over each data point. Running the application will give us the following result (shown with a tooltip example): That concludes this portion of our show but I plan on implementing additional functionality in later blog posts. Be sure to come back soon to see the next installments in this series. Enjoy! Additional Resources USGS Earthquake Data Feeds Brad Abrams shows how RIA Services and MVVM can work together

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Parallelism in .NET – Part 5, Partitioning of Work

- by Reed

When parallelizing any routine, we start by decomposing the problem. Once the problem is understood, we need to break our work into separate tasks, so each task can be run on a different processing element. This process is called partitioning. Partitioning our tasks is a challenging feat. There are opposing forces at work here: too many partitions adds overhead, too few partitions leaves processors idle. Trying to work the perfect balance between the two extremes is the goal for which we should aim. Luckily, the Task Parallel Library automatically handles much of this process. However, there are situations where the default partitioning may not be appropriate, and knowledge of our routines may allow us to guide the framework to making better decisions. First off, I’d like to say that this is a more advanced topic. It is perfectly acceptable to use the parallel constructs in the framework without considering the partitioning taking place. The default behavior in the Task Parallel Library is very well-behaved, even for unusual work loads, and should rarely be adjusted. I have found few situations where the default partitioning behavior in the TPL is not as good or better than my own hand-written partitioning routines, and recommend using the defaults unless there is a strong, measured, and profiled reason to avoid using them. However, understanding partitioning, and how the TPL partitions your data, helps in understanding the proper usage of the TPL. I indirectly mentioned partitioning while discussing aggregation. Typically, our systems will have a limited number of Processing Elements (PE), which is the terminology used for hardware capable of processing a stream of instructions. For example, in a standard Intel i7 system, there are four processor cores, each of which has two potential hardware threads due to Hyperthreading. This gives us a total of 8 PEs – theoretically, we can have up to eight operations occurring concurrently within our system. In order to fully exploit this power, we need to partition our work into Tasks. A task is a simple set of instructions that can be run on a PE. Ideally, we want to have at least one task per PE in the system, since fewer tasks means that some of our processing power will be sitting idle. A naive implementation would be to just take our data, and partition it with one element in our collection being treated as one task. When we loop through our collection in parallel, using this approach, we’d just process one item at a time, then reuse that thread to process the next, etc. There’s a flaw in this approach, however. It will tend to be slower than necessary, often slower than processing the data serially. The problem is that there is overhead associated with each task. When we take a simple foreach loop body and implement it using the TPL, we add overhead. First, we change the body from a simple statement to a delegate, which must be invoked. In order to invoke the delegate on a separate thread, the delegate gets added to the ThreadPool’s current work queue, and the ThreadPool must pull this off the queue, assign it to a free thread, then execute it. If our collection had one million elements, the overhead of trying to spawn one million tasks would destroy our performance. The answer, here, is to partition our collection into groups, and have each group of elements treated as a single task. By adding a partitioning step, we can break our total work into small enough tasks to keep our processors busy, but large enough tasks to avoid overburdening the ThreadPool. There are two clear, opposing goals here: Always try to keep each processor working, but also try to keep the individual partitions as large as possible. When using Parallel.For, the partitioning is always handled automatically. At first, partitioning here seems simple. A naive implementation would merely split the total element count up by the number of PEs in the system, and assign a chunk of data to each processor. Many hand-written partitioning schemes work in this exactly manner. This perfectly balanced, static partitioning scheme works very well if the amount of work is constant for each element. However, this is rarely the case. Often, the length of time required to process an element grows as we progress through the collection, especially if we’re doing numerical computations. In this case, the first PEs will finish early, and sit idle waiting on the last chunks to finish. Sometimes, work can decrease as we progress, since previous computations may be used to speed up later computations. In this situation, the first chunks will be working far longer than the last chunks. In order to balance the workload, many implementations create many small chunks, and reuse threads. This adds overhead, but does provide better load balancing, which in turn improves performance. The Task Parallel Library handles this more elaborately. Chunks are determined at runtime, and start small. They grow slowly over time, getting larger and larger. This tends to lead to a near optimum load balancing, even in odd cases such as increasing or decreasing workloads. Parallel.ForEach is a bit more complicated, however. When working with a generic IEnumerable<T>, the number of items required for processing is not known in advance, and must be discovered at runtime. In addition, since we don’t have direct access to each element, the scheduler must enumerate the collection to process it. Since IEnumerable<T> is not thread safe, it must lock on elements as it enumerates, create temporary collections for each chunk to process, and schedule this out. By default, it uses a partitioning method similar to the one described above. We can see this directly by looking at the Visual Partitioning sample shipped by the Task Parallel Library team, and available as part of the Samples for Parallel Programming. When we run the sample, with four cores and the default, Load Balancing partitioning scheme, we see this: The colored bands represent each processing core. You can see that, when we started (at the top), we begin with very small bands of color. As the routine progresses through the Parallel.ForEach, the chunks get larger and larger (seen by larger and larger stripes). Most of the time, this is fantastic behavior, and most likely will out perform any custom written partitioning. However, if your routine is not scaling well, it may be due to a failure in the default partitioning to handle your specific case. With prior knowledge about your work, it may be possible to partition data more meaningfully than the default Partitioner. There is the option to use an overload of Parallel.ForEach which takes a Partitioner<T> instance. The Partitioner<T> class is an abstract class which allows for both static and dynamic partitioning. By overriding Partitioner<T>.SupportsDynamicPartitions, you can specify whether a dynamic approach is available. If not, your custom Partitioner<T> subclass would override GetPartitions(int), which returns a list of IEnumerator<T> instances. These are then used by the Parallel class to split work up amongst processors. When dynamic partitioning is available, GetDynamicPartitions() is used, which returns an IEnumerable<T> for each partition. If you do decide to implement your own Partitioner<T>, keep in mind the goals and tradeoffs of different partitioning strategies, and design appropriately. The Samples for Parallel Programming project includes a ChunkPartitioner class in the ParallelExtensionsExtras project. This provides example code for implementing your own, custom allocation strategies, including a static allocator of a given chunk size. Although implementing your own Partitioner<T> is possible, as I mentioned above, this is rarely required or useful in practice. The default behavior of the TPL is very good, often better than any hand written partitioning strategy.

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Compiling examples for consuming the REST Endpoints for WCF Service using Agatha

- by REA_ANDREW

I recently made two contributions to the Agatha Project by Davy Brion over on Google Code, and one of the things I wanted to follow up with was a post showing examples and some, seemingly required tid bits. The contributions which I made where: To support StructureMap To include REST (JSON and XML) support for the service contract The examples which I have made, I want to format them so they fit in with the current format of examples over on Agatha and hopefully create and submit a third patch which will include these examples to help others who wish to use these additions. Whilst building these examples for both XML and JSON I have learnt a couple of things which I feel are not really well documented, but are extremely good practice and once known make perfect sense. I have chosen a real basic e-commerce context for my example Requests and Responses, and have also made use of the excellent tool AutoMapper, again on Google Code. Setting the scene I have followed the Pipes and Filters Pattern with the IQueryable interface on my Repository and exposed the following methods to query Products: IQueryable<Product> GetProducts(); IQueryable<Product> ByCategoryName(this IQueryable<Product> products, string categoryName) Product ByProductCode(this IQueryable<Product> products, String productCode) I have an interface for the IProductRepository but for the concrete implementation I have simply created a protected getter which populates a private List<Product> with 100 test products with random data. Another good reason for following an interface based approach is that it will demonstrate usage of my first contribution which is the StructureMap support. Finally the two Domain Objects I have made are Product and Category as shown below: public class Product { public String ProductCode { get; set; } public String Name { get; set; } public Decimal Price { get; set; } public Decimal Rrp { get; set; } public Category Category { get; set; } } public class Category { public String Name { get; set; } } Requirements for the REST Support One of the things which you will notice with Agatha is that you do not have to decorate your Request and Response objects with the WCF Service Model Attributes like DataContract, DataMember etc… Unfortunately from what I have seen, these are required if you want the same types to work with your REST endpoint. I have not tried but I assume the same result can be achieved by simply decorating the same classes with the Serializable Attribute. Without this the operation will fail. Another surprising thing I have found is that it did not work until I used the following Attribute parameters: Name Namespace e.g. [DataContract(Name = "GetProductsRequest", Namespace = "AgathaRestExample.Service.Requests")] public class GetProductsRequest : Request { } Although I was surprised by this, things kind of explained themselves when I got round to figuring out the exact construct required for both the XML and the REST. One of the things which you already know and are then reminded of is that each of your Requests and Responses ultimately inherit from an abstract base class respectively. This information needs to be represented in a way native to the format being used. I have seen this in XML but I have not seen the format which is required for the JSON. JSON Consumer Example I have used JQuery to create the example and I simply want to make two requests to the server which as you will know with Agatha are transmitted inside an array to reduce the service calls. I have also used a tool called json2 which is again over at Google Code simply to convert my JSON expression into its string format for transmission. You will notice that I specify the type of Request I am using and the relevant Namespace it belongs to. Also notice that the second request has a parameter so each of these two object are representing an abstract Request and the parameters of the object describe it. <script type="text/javascript"> var bodyContent = $.ajax({ url: "http://localhost:50348/service.svc/json/processjsonrequests", global: false, contentType: "application/json; charset=utf-8", type: "POST", processData: true, data: JSON.stringify([ { __type: "GetProductsRequest:AgathaRestExample.Service.Requests" }, { __type: "GetProductsByCategoryRequest:AgathaRestExample.Service.Requests", CategoryName: "Category1" } ]), dataType: "json", success: function(msg) { alert(msg); } }).responseText; </script> XML Consumer Example For the XML Consumer example I have chosen to use a simple Console Application and make a WebRequest to the service using the XML as a request. I have made a crude static method which simply reads from an XML File, replaces some value with a parameter and returns the formatted XML. I say crude but it simply shows how XML Templates for each type of Request could be made and then have a wrapper utility in whatever language you use to combine the requests which are required. The following XML is the same Request array as shown above but simply in the XML Format. <?xml version="1.0" encoding="utf-8" ?> <ArrayOfRequest xmlns="http://schemas.datacontract.org/2004/07/Agatha.Common" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <Request i:type="a:GetProductsRequest" xmlns:a="AgathaRestExample.Service.Requests"/> <Request i:type="a:GetProductsByCategoryRequest" xmlns:a="AgathaRestExample.Service.Requests"> <a:CategoryName>{CategoryName}</a:CategoryName> </Request> </ArrayOfRequest> It is funny because I remember submitting a question to StackOverflow asking whether there was a REST Client Generation tool similar to what Microsoft used for their RestStarterKit but which could be applied to existing services which have REST endpoints attached. I could not find any but this is now definitely something which I am going to build, as I think it is extremely useful to have but also it should not be too difficult based on the information I now know about the above. Finally I thought that the Strategy Pattern would lend itself really well to this type of thing so it can accommodate for different languages. I think that is about it, I have included the code for the example Console app which I made below incase anyone wants to have a mooch at the code. As I said above I want to reformat these to fit in with the current examples over on the Agatha project, but also now thinking about it, make a Documentation Web method…{brain ticking} :-) Cheers for now and here is the final bit of code: static void Main(string[] args) { var request = WebRequest.Create("http://localhost:50348/service.svc/xml/processxmlrequests"); request.Method = "POST"; request.ContentType = "text/xml"; using(var writer = new StreamWriter(request.GetRequestStream())) { writer.WriteLine(GetExampleRequestsString("Category1")); } var response = request.GetResponse(); using(var reader = new StreamReader(response.GetResponseStream())) { Console.WriteLine(reader.ReadToEnd()); } Console.ReadLine(); } static string GetExampleRequestsString(string categoryName) { var data = File.ReadAllText(Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "ExampleRequests.xml")); data = data.Replace("{CategoryName}", categoryName); return data; } }

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Dependency Injection in ASP.NET Web API using Autofac

- by shiju

In this post, I will demonstrate how to use Dependency Injection in ASP.NET Web API using Autofac in an ASP.NET MVC 4 app. The new ASP.NET Web API is a great framework for building HTTP services. The Autofac IoC container provides the better integration with ASP.NET Web API for applying dependency injection. The NuGet package Autofac.WebApi provides the Dependency Injection support for ASP.NET Web API services. Using Autofac in ASP.NET Web API The following command in the Package Manager console will install Autofac.WebApi package into your ASP.NET Web API application. PM > Install-Package Autofac.WebApi The following code block imports the necessary namespaces for using Autofact.WebApi using Autofac; using Autofac.Integration.WebApi; .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The following code in the Bootstrapper class configures the Autofac. 1: public static class Bootstrapper 2: { 3: public static void Run() 4: { 5: SetAutofacWebAPI(); 6: } 7: private static void SetAutofacWebAPI() 8: { 9: var configuration = GlobalConfiguration.Configuration; 10: var builder = new ContainerBuilder(); 11: // Configure the container 12: builder.ConfigureWebApi(configuration); 13: // Register API controllers using assembly scanning. 14: builder.RegisterApiControllers(Assembly.GetExecutingAssembly()); 15: builder.RegisterType<DefaultCommandBus>().As<ICommandBus>() 16: .InstancePerApiRequest(); 17: builder.RegisterType<UnitOfWork>().As<IUnitOfWork>() 18: .InstancePerApiRequest(); 19: builder.RegisterType<DatabaseFactory>().As<IDatabaseFactory>() 20: .InstancePerApiRequest(); 21: builder.RegisterAssemblyTypes(typeof(CategoryRepository) 22: .Assembly).Where(t => t.Name.EndsWith("Repository")) 23: .AsImplementedInterfaces().InstancePerApiRequest(); 24: var services = Assembly.Load("EFMVC.Domain"); 25: builder.RegisterAssemblyTypes(services) 26: .AsClosedTypesOf(typeof(ICommandHandler<>)) 27: .InstancePerApiRequest(); 28: builder.RegisterAssemblyTypes(services) 29: .AsClosedTypesOf(typeof(IValidationHandler<>)) 30: .InstancePerApiRequest(); 31: var container = builder.Build(); 32: // Set the WebApi dependency resolver. 33: var resolver = new AutofacWebApiDependencyResolver(container); 34: configuration.ServiceResolver.SetResolver(resolver); 35: } 36: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The RegisterApiControllers method will scan the given assembly and register the all ApiController classes. This method will look for types that derive from IHttpController with name convention end with “Controller”. The InstancePerApiRequest method specifies the life time of the component for once per API controller invocation. The GlobalConfiguration.Configuration provides a ServiceResolver class which can be use set dependency resolver for ASP.NET Web API. In our example, we are using AutofacWebApiDependencyResolver class provided by Autofac.WebApi to set the dependency resolver. The Run method of Bootstrapper class is calling from Application_Start method of Global.asax.cs. 1: protected void Application_Start() 2: { 3: AreaRegistration.RegisterAllAreas(); 4: RegisterGlobalFilters(GlobalFilters.Filters); 5: RegisterRoutes(RouteTable.Routes); 6: BundleTable.Bundles.RegisterTemplateBundles(); 7: //Call Autofac DI configurations 8: Bootstrapper.Run(); 9: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Autofac.Mvc4 The Autofac framework’s integration with ASP.NET MVC has updated for ASP.NET MVC 4. The NuGet package Autofac.Mvc4 provides the dependency injection support for ASP.NET MVC 4. There is not any syntax change between Autofac.Mvc3 and Autofac.Mvc4 Source Code I have updated my EFMVC app with Autofac.WebApi for applying dependency injection for it’s ASP.NET Web API services. EFMVC app also updated to Autofac.Mvc4 for it’s ASP.NET MVC 4 web app. The above code sample is taken from the EFMVC app. You can download the source code of EFMVC app from http://efmvc.codeplex.com/

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Do not use “using” in WCF Client

- by oazabir

You know that any IDisposable object must be disposed using using. So, you have been using using to wrap WCF service’s ChannelFactory and Clients like this: using(var client = new SomeClient()) {. ..} Or, if you are doing it the hard and slow way (without really knowing why), then: using(var factory = new ChannelFactory<ISomeService>()) {var channel= factory.CreateChannel();...} That’s what we have all learnt in school right? We have learnt it wrong! When there’s a network related error or the connection is broken, or the call is timed out before Dispose is called by the using keyword, then it results in the following exception when the using keyword tries to dispose the channel: failed: System.ServiceModel.CommunicationObjectFaultedException : The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state. Server stack trace: at System.ServiceModel.Channels.CommunicationObject.Close(TimeSpan timeout) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout) at System.ServiceModel.ClientBase`1.System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout) at System.ServiceModel.ClientBase`1.Close() at System.ServiceModel.ClientBase`1.System.IDisposable.Dispose() There are various reasons for which the underlying connection can be at broken state before the using block is completed and the .Dispose() is called. Common problems like network connection dropping, IIS doing an app pool recycle at that moment, some proxy sitting between you and the service dropping the connection for various reasons and so on. The point is, it might seem like a corner case, but it’s a likely corner case. If you are building a highly available client, you need to treat this properly before you go-live. So, do NOT use using on WCF Channel/Client/ChannelFactory. Instead you need to use an alternative. Here’s what you can do: First create an extension method. public static class WcfExtensions{ public static void Using<T>(this T client, Action<T> work) where T : ICommunicationObject { try { work(client); client.Close(); } catch (CommunicationException e) { client.Abort(); } catch (TimeoutException e) { client.Abort(); } catch (Exception e) { client.Abort(); throw; } }} Then use this instead of the using keyword: new SomeClient().Using(channel => { channel.Login(username, password);}); Or if you are using ChannelFactory then: new ChannelFactory<ISomeService>().Using(channel => { channel.Login(username, password);}); Enjoy!

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Toorcon14

- by danx

Toorcon 2012 Information Security Conference San Diego, CA, http://www.toorcon.org/ Dan Anderson, October 2012 It's almost Halloween, and we all know what that means—yes, of course, it's time for another Toorcon Conference! Toorcon is an annual conference for people interested in computer security. This includes the whole range of hackers, computer hobbyists, professionals, security consultants, press, law enforcement, prosecutors, FBI, etc. We're at Toorcon 14—see earlier blogs for some of the previous Toorcon's I've attended (back to 2003). This year's "con" was held at the Westin on Broadway in downtown San Diego, California. The following are not necessarily my views—I'm just the messenger—although I could have misquoted or misparaphrased the speakers. Also, I only reviewed some of the talks, below, which I attended and interested me. MalAndroid—the Crux of Android Infections, Aditya K. Sood Programming Weird Machines with ELF Metadata, Rebecca "bx" Shapiro Privacy at the Handset: New FCC Rules?, Valkyrie Hacking Measured Boot and UEFI, Dan Griffin You Can't Buy Security: Building the Open Source InfoSec Program, Boris Sverdlik What Journalists Want: The Investigative Reporters' Perspective on Hacking, Dave Maas & Jason Leopold Accessibility and Security, Anna Shubina Stop Patching, for Stronger PCI Compliance, Adam Brand McAfee Secure & Trustmarks — a Hacker's Best Friend, Jay James & Shane MacDougall MalAndroid—the Crux of Android Infections Aditya K. Sood, IOActive, Michigan State PhD candidate Aditya talked about Android smartphone malware. There's a lot of old Android software out there—over 50% Gingerbread (2.3.x)—and most have unpatched vulnerabilities. Of 9 Android vulnerabilities, 8 have known exploits (such as the old Gingerbread Global Object Table exploit). Android protection includes sandboxing, security scanner, app permissions, and screened Android app market. The Android permission checker has fine-grain resource control, policy enforcement. Android static analysis also includes a static analysis app checker (bouncer), and a vulnerablity checker. What security problems does Android have? User-centric security, which depends on the user to grant permission and make smart decisions. But users don't care or think about malware (the're not aware, not paranoid). All they want is functionality, extensibility, mobility Android had no "proper" encryption before Android 3.0 No built-in protection against social engineering and web tricks Alternative Android app markets are unsafe. Simply visiting some markets can infect Android Aditya classified Android Malware types as: Type A—Apps. These interact with the Android app framework. For example, a fake Netflix app. Or Android Gold Dream (game), which uploads user files stealthy manner to a remote location. Type K—Kernel. Exploits underlying Linux libraries or kernel Type H—Hybrid. These use multiple layers (app framework, libraries, kernel). These are most commonly used by Android botnets, which are popular with Chinese botnet authors What are the threats from Android malware? These incude leak info (contacts), banking fraud, corporate network attacks, malware advertising, malware "Hackivism" (the promotion of social causes. For example, promiting specific leaders of the Tunisian or Iranian revolutions. Android malware is frequently "masquerated". That is, repackaged inside a legit app with malware. To avoid detection, the hidden malware is not unwrapped until runtime. The malware payload can be hidden in, for example, PNG files. Less common are Android bootkits—there's not many around. What they do is hijack the Android init framework—alteering system programs and daemons, then deletes itself. For example, the DKF Bootkit (China). Android App Problems: no code signing! all self-signed native code execution permission sandbox — all or none alternate market places no robust Android malware detection at network level delayed patch process Programming Weird Machines with ELF Metadata Rebecca "bx" Shapiro, Dartmouth College, NH https://github.com/bx/elf-bf-tools @bxsays on twitter Definitions. "ELF" is an executable file format used in linking and loading executables (on UNIX/Linux-class machines). "Weird machine" uses undocumented computation sources (I think of them as unintended virtual machines). Some examples of "weird machines" are those that: return to weird location, does SQL injection, corrupts the heap. Bx then talked about using ELF metadata as (an uintended) "weird machine". Some ELF background: A compiler takes source code and generates a ELF object file (hello.o). A static linker makes an ELF executable from the object file. A runtime linker and loader takes ELF executable and loads and relocates it in memory. The ELF file has symbols to relocate functions and variables. ELF has two relocation tables—one at link time and another one at loading time: .rela.dyn (link time) and .dynsym (dynamic table). GOT: Global Offset Table of addresses for dynamically-linked functions. PLT: Procedure Linkage Tables—works with GOT. The memory layout of a process (not the ELF file) is, in order: program (+ heap), dynamic libraries, libc, ld.so, stack (which includes the dynamic table loaded into memory) For ELF, the "weird machine" is found and exploited in the loader. ELF can be crafted for executing viruses, by tricking runtime into executing interpreted "code" in the ELF symbol table. One can inject parasitic "code" without modifying the actual ELF code portions. Think of the ELF symbol table as an "assembly language" interpreter. It has these elements: instructions: Add, move, jump if not 0 (jnz) Think of symbol table entries as "registers" symbol table value is "contents" immediate values are constants direct values are addresses (e.g., 0xdeadbeef) move instruction: is a relocation table entry add instruction: relocation table "addend" entry jnz instruction: takes multiple relocation table entries The ELF weird machine exploits the loader by relocating relocation table entries. The loader will go on forever until told to stop. It stores state on stack at "end" and uses IFUNC table entries (containing function pointer address). The ELF weird machine, called "Brainfu*k" (BF) has: 8 instructions: pointer inc, dec, inc indirect, dec indirect, jump forward, jump backward, print. Three registers - 3 registers Bx showed example BF source code that implemented a Turing machine printing "hello, world". More interesting was the next demo, where bx modified ping. Ping runs suid as root, but quickly drops privilege. BF modified the loader to disable the library function call dropping privilege, so it remained as root. Then BF modified the ping -t argument to execute the -t filename as root. It's best to show what this modified ping does with an example: $ whoami bx $ ping localhost -t backdoor.sh # executes backdoor $ whoami root $ The modified code increased from 285948 bytes to 290209 bytes. A BF tool compiles "executable" by modifying the symbol table in an existing ELF executable. The tool modifies .dynsym and .rela.dyn table, but not code or data. Privacy at the Handset: New FCC Rules? "Valkyrie" (Christie Dudley, Santa Clara Law JD candidate) Valkyrie talked about mobile handset privacy. Some background: Senator Franken (also a comedian) became alarmed about CarrierIQ, where the carriers track their customers. Franken asked the FCC to find out what obligations carriers think they have to protect privacy. The carriers' response was that they are doing just fine with self-regulation—no worries! Carriers need to collect data, such as missed calls, to maintain network quality. But carriers also sell data for marketing. Verizon sells customer data and enables this with a narrow privacy policy (only 1 month to opt out, with difficulties). The data sold is not individually identifiable and is aggregated. But Verizon recommends, as an aggregation workaround to "recollate" data to other databases to identify customers indirectly. The FCC has regulated telephone privacy since 1934 and mobile network privacy since 2007. Also, the carriers say mobile phone privacy is a FTC responsibility (not FCC). FTC is trying to improve mobile app privacy, but FTC has no authority over carrier / customer relationships. As a side note, Apple iPhones are unique as carriers have extra control over iPhones they don't have with other smartphones. As a result iPhones may be more regulated. Who are the consumer advocates? Everyone knows EFF, but EPIC (Electrnic Privacy Info Center), although more obsecure, is more relevant. What to do? Carriers must be accountable. Opt-in and opt-out at any time. Carriers need incentive to grant users control for those who want it, by holding them liable and responsible for breeches on their clock. Location information should be added current CPNI privacy protection, and require "Pen/trap" judicial order to obtain (and would still be a lower standard than 4th Amendment). Politics are on a pro-privacy swing now, with many senators and the Whitehouse. There will probably be new regulation soon, and enforcement will be a problem, but consumers will still have some benefit. Hacking Measured Boot and UEFI Dan Griffin, JWSecure, Inc., Seattle, @JWSdan Dan talked about hacking measured UEFI boot. First some terms: UEFI is a boot technology that is replacing BIOS (has whitelisting and blacklisting). UEFI protects devices against rootkits. TPM - hardware security device to store hashs and hardware-protected keys "secure boot" can control at firmware level what boot images can boot "measured boot" OS feature that tracks hashes (from BIOS, boot loader, krnel, early drivers). "remote attestation" allows remote validation and control based on policy on a remote attestation server. Microsoft pushing TPM (Windows 8 required), but Google is not. Intel TianoCore is the only open source for UEFI. Dan has Measured Boot Tool at http://mbt.codeplex.com/ with a demo where you can also view TPM data. TPM support already on enterprise-class machines. UEFI Weaknesses. UEFI toolkits are evolving rapidly, but UEFI has weaknesses: assume user is an ally trust TPM implicitly, and attached to computer hibernate file is unprotected (disk encryption protects against this) protection migrating from hardware to firmware delays in patching and whitelist updates will UEFI really be adopted by the mainstream (smartphone hardware support, bank support, apathetic consumer support) You Can't Buy Security: Building the Open Source InfoSec Program Boris Sverdlik, ISDPodcast.com co-host Boris talked about problems typical with current security audits. "IT Security" is an oxymoron—IT exists to enable buiness, uptime, utilization, reporting, but don't care about security—IT has conflict of interest. There's no Magic Bullet ("blinky box"), no one-size-fits-all solution (e.g., Intrusion Detection Systems (IDSs)). Regulations don't make you secure. The cloud is not secure (because of shared data and admin access). Defense and pen testing is not sexy. Auditors are not solution (security not a checklist)—what's needed is experience and adaptability—need soft skills. Step 1: First thing is to Google and learn the company end-to-end before you start. Get to know the management team (not IT team), meet as many people as you can. Don't use arbitrary values such as CISSP scores. Quantitive risk assessment is a myth (e.g. AV*EF-SLE). Learn different Business Units, legal/regulatory obligations, learn the business and where the money is made, verify company is protected from script kiddies (easy), learn sensitive information (IP, internal use only), and start with low-hanging fruit (customer service reps and social engineering). Step 2: Policies. Keep policies short and relevant. Generic SANS "security" boilerplate policies don't make sense and are not followed. Focus on acceptable use, data usage, communications, physical security. Step 3: Implementation: keep it simple stupid. Open source, although useful, is not free (implementation cost). Access controls with authentication & authorization for local and remote access. MS Windows has it, otherwise use OpenLDAP, OpenIAM, etc. Application security Everyone tries to reinvent the wheel—use existing static analysis tools. Review high-risk apps and major revisions. Don't run different risk level apps on same system. Assume host/client compromised and use app-level security control. Network security VLAN != segregated because there's too many workarounds. Use explicit firwall rules, active and passive network monitoring (snort is free), disallow end user access to production environment, have a proxy instead of direct Internet access. Also, SSL certificates are not good two-factor auth and SSL does not mean "safe." Operational Controls Have change, patch, asset, & vulnerability management (OSSI is free). For change management, always review code before pushing to production For logging, have centralized security logging for business-critical systems, separate security logging from administrative/IT logging, and lock down log (as it has everything). Monitor with OSSIM (open source). Use intrusion detection, but not just to fulfill a checkbox: build rules from a whitelist perspective (snort). OSSEC has 95% of what you need. Vulnerability management is a QA function when done right: OpenVas and Seccubus are free. Security awareness The reality is users will always click everything. Build real awareness, not compliance driven checkbox, and have it integrated into the culture. Pen test by crowd sourcing—test with logging COSSP http://www.cossp.org/ - Comprehensive Open Source Security Project What Journalists Want: The Investigative Reporters' Perspective on Hacking Dave Maas, San Diego CityBeat Jason Leopold, Truthout.org The difference between hackers and investigative journalists: For hackers, the motivation varies, but method is same, technological specialties. For investigative journalists, it's about one thing—The Story, and they need broad info-gathering skills. J-School in 60 Seconds: Generic formula: Person or issue of pubic interest, new info, or angle. Generic criteria: proximity, prominence, timeliness, human interest, oddity, or consequence. Media awareness of hackers and trends: journalists becoming extremely aware of hackers with congressional debates (privacy, data breaches), demand for data-mining Journalists, use of coding and web development for Journalists, and Journalists busted for hacking (Murdock). Info gathering by investigative journalists include Public records laws. Federal Freedom of Information Act (FOIA) is good, but slow. California Public Records Act is a lot stronger. FOIA takes forever because of foot-dragging—it helps to be specific. Often need to sue (especially FBI). CPRA is faster, and requests can be vague. Dumps and leaks (a la Wikileaks) Journalists want: leads, protecting ourselves, our sources, and adapting tools for news gathering (Google hacking). Anonomity is important to whistleblowers. They want no digital footprint left behind (e.g., email, web log). They don't trust encryption, want to feel safe and secure. Whistleblower laws are very weak—there's no upside for whistleblowers—they have to be very passionate to do it. Accessibility and Security or: How I Learned to Stop Worrying and Love the Halting Problem Anna Shubina, Dartmouth College Anna talked about how accessibility and security are related. Accessibility of digital content (not real world accessibility). mostly refers to blind users and screenreaders, for our purpose. Accessibility is about parsing documents, as are many security issues. "Rich" executable content causes accessibility to fail, and often causes security to fail. For example MS Word has executable format—it's not a document exchange format—more dangerous than PDF or HTML. Accessibility is often the first and maybe only sanity check with parsing. They have no choice because someone may want to read what you write. Google, for example, is very particular about web browser you use and are bad at supporting other browsers. Uses JavaScript instead of links, often requiring mouseover to display content. PDF is a security nightmare. Executible format, embedded flash, JavaScript, etc. 15 million lines of code. Google Chrome doesn't handle PDF correctly, causing several security bugs. PDF has an accessibility checker and PDF tagging, to help with accessibility. But no PDF checker checks for incorrect tags, untagged content, or validates lists or tables. None check executable content at all. The "Halting Problem" is: can one decide whether a program will ever stop? The answer, in general, is no (Rice's theorem). The same holds true for accessibility checkers. Language-theoretic Security says complicated data formats are hard to parse and cannot be solved due to the Halting Problem. W3C Web Accessibility Guidelines: "Perceivable, Operable, Understandable, Robust" Not much help though, except for "Robust", but here's some gems: * all information should be parsable (paraphrasing) * if not parsable, cannot be converted to alternate formats * maximize compatibility in new document formats Executible webpages are bad for security and accessibility. They say it's for a better web experience. But is it necessary to stuff web pages with JavaScript for a better experience? A good example is The Drudge Report—it has hand-written HTML with no JavaScript, yet drives a lot of web traffic due to good content. A bad example is Google News—hidden scrollbars, guessing user input. Solutions: Accessibility and security problems come from same source Expose "better user experience" myth Keep your corner of Internet parsable Remember "Halting Problem"—recognize false solutions (checking and verifying tools) Stop Patching, for Stronger PCI Compliance Adam Brand, protiviti @adamrbrand, http://www.picfun.com/ Adam talked about PCI compliance for retail sales. Take an example: for PCI compliance, 50% of Brian's time (a IT guy), 960 hours/year was spent patching POSs in 850 restaurants. Often applying some patches make no sense (like fixing a browser vulnerability on a server). "Scanner worship" is overuse of vulnerability scanners—it gives a warm and fuzzy and it's simple (red or green results—fix reds). Scanners give a false sense of security. In reality, breeches from missing patches are uncommon—more common problems are: default passwords, cleartext authentication, misconfiguration (firewall ports open). Patching Myths: Myth 1: install within 30 days of patch release (but PCI Â§6.1 allows a "risk-based approach" instead). Myth 2: vendor decides what's critical (also PCI Â§6.1). But Â§6.2 requires user ranking of vulnerabilities instead. Myth 3: scan and rescan until it passes. But PCI Â§11.2.1b says this applies only to high-risk vulnerabilities. Adam says good recommendations come from NIST 800-40. Instead use sane patching and focus on what's really important. From NIST 800-40: Proactive: Use a proactive vulnerability management process: use change control, configuration management, monitor file integrity. Monitor: start with NVD and other vulnerability alerts, not scanner results. Evaluate: public-facing system? workstation? internal server? (risk rank) Decide:on action and timeline Test: pre-test patches (stability, functionality, rollback) for change control Install: notify, change control, tickets McAfee Secure & Trustmarks — a Hacker's Best Friend Jay James, Shane MacDougall, Tactical Intelligence Inc., Canada "McAfee Secure Trustmark" is a website seal marketed by McAfee. A website gets this badge if they pass their remote scanning. The problem is a removal of trustmarks act as flags that you're vulnerable. Easy to view status change by viewing McAfee list on website or on Google. "Secure TrustGuard" is similar to McAfee. Jay and Shane wrote Perl scripts to gather sites from McAfee and search engines. If their certification image changes to a 1x1 pixel image, then they are longer certified. Their scripts take deltas of scans to see what changed daily. The bottom line is change in TrustGuard status is a flag for hackers to attack your site. Entire idea of seals is silly—you're raising a flag saying if you're vulnerable.

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How to create item in SharePoint2010 document library using SharePoint Web service

- by ybbest

Today, I’d like to show you how to create item in SharePoint2010 document library using SharePoint Web service. Originally, I thought I could use the WebSvcLists(list.asmx) that provides methods for working with lists and list data. However, after a bit Googling , I realize that I need to use the WebSvcCopy (copy.asmx).Here are the code used private const string siteUrl = "http://ybbest"; private static void Main(string[] args) { using (CopyWSProxyWrapper copyWSProxyWrapper = new CopyWSProxyWrapper(siteUrl)) { copyWSProxyWrapper.UploadFile("TestDoc2.pdf", new[] {string.Format("{0}/Shared Documents/TestDoc2.pdf", siteUrl)}, Resource.TestDoc, GetFieldInfos().ToArray()); } } private static List<FieldInformation> GetFieldInfos() { var fieldInfos = new List<FieldInformation>(); //The InternalName , DisplayName and FieldType are both required to make it work fieldInfos.Add(new FieldInformation { InternalName = "Title", Value = "TestDoc2.pdf", DisplayName = "Title", Type = FieldType.Text }); return fieldInfos; } Here is the code for the proxy wrapper. public class CopyWSProxyWrapper : IDisposable { private readonly string siteUrl; public CopyWSProxyWrapper(string siteUrl) { this.siteUrl = siteUrl; } private readonly CopySoapClient proxy = new CopySoapClient(); public void UploadFile(string testdoc2Pdf, string[] destinationUrls, byte[] testDoc, FieldInformation[] fieldInformations) { using (CopySoapClient proxy = new CopySoapClient()) { proxy.Endpoint.Address = new EndpointAddress(String.Format("{0}/_vti_bin/copy.asmx", siteUrl)); proxy.ClientCredentials.Windows.ClientCredential = CredentialCache.DefaultNetworkCredentials; proxy.ClientCredentials.Windows.AllowedImpersonationLevel = TokenImpersonationLevel.Impersonation; CopyResult[] copyResults = null; try { proxy.CopyIntoItems(testdoc2Pdf, destinationUrls, fieldInformations, testDoc, out copyResults); } catch (Exception e) { System.Console.WriteLine(e); } if (copyResults != null) System.Console.WriteLine(copyResults[0].ErrorMessage); System.Console.ReadLine(); } } public void Dispose() { proxy.Close(); } } You can download the source code here . ******Update********** It seems to be a bug that , you can not set the contentType when create a document item using Copy.asmx. In sp2007 the field type was Choice, however, in sp2010 it is actually Computed. I have tried using the Computed field type with no luck. I have also tried sending the ContentTypeId and this does not work.You might have to write your own web services to handle this.You can check my previous blog on how to get started with you own custom WCF in SP2010 here. References: SharePoint 2010 Web Services SharePoint2007 Web Services SharePoint MSDN Forum

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ESB Toolkit 2.0 EndPointConfig (HTTPS with WCF-BasicHttp and the ESB Toolkit 2.0)

- by Andy Morrison

Earlier this week I had an ESB endpoint (Off-Ramp in ESB parlance) that I was sending to over http using WCF-BasicHttp. I needed to switch the protocol to https: which I did by changing my UDDI Binding over to https: No problem from a management perspective; however, when I tried to run the process I saw this exception: Event Type: Error Event Source: BizTalk Server 2009 Event Category: BizTalk Server 2009 Event ID: 5754 Date: 3/10/2010 Time: 2:58:23 PM User: N/A Computer: XXXXXXXXX Description: A message sent to adapter "WCF-BasicHttp" on send port "SPDynamic.XXX.SR" with URI "https://XXXXXXXXX.com/XXXXXXX/whatever.asmx" is suspended. Error details: System.ArgumentException: The provided URI scheme 'https' is invalid; expected 'http'. Parameter name: via at System.ServiceModel.Channels.TransportChannelFactory`1.ValidateScheme(Uri via) at System.ServiceModel.Channels.HttpChannelFactory.ValidateCreateChannelParameters(EndpointAddress remoteAddress, Uri via) at System.ServiceModel.Channels.HttpChannelFactory.OnCreateChannel(EndpointAddress remoteAddress, Uri via) at System.ServiceModel.Channels.ChannelFactoryBase`1.InternalCreateChannel(EndpointAddress address, Uri via) at System.ServiceModel.Channels.ChannelFactoryBase`1.CreateChannel(EndpointAddress address, Uri via) at System.ServiceModel.Channels.ServiceChannelFactory.ServiceChannelFactoryOverRequest.CreateInnerChannelBinder(EndpointAddress to, Uri via) at System.ServiceModel.Channels.ServiceChannelFactory.CreateServiceChannel(EndpointAddress address, Uri via) at System.ServiceModel.Channels.ServiceChannelFactory.CreateChannel(Type channelType, EndpointAddress address, Uri via) at System.ServiceModel.ChannelFactory`1.CreateChannel(EndpointAddress address, Uri via) at System.ServiceModel.ChannelFactory`1.CreateChannel() at Microsoft.BizTalk.Adapter.Wcf.Runtime.WcfClient`2.GetChannel[TChannel](IBaseMessage bizTalkMessage, ChannelFactory`1& cachedFactory) at Microsoft.BizTalk.Adapter.Wcf.Runtime.WcfClient`2.SendMessage(IBaseMessage bizTalkMessage) MessageId: {1170F4ED-550F-4F7E-B0E0-1EE92A25AB10} InstanceID: {1640C6C6-CA9C-4746-AEB0-584FDF7BB61E} I knew from a previous experience that I likely needed to set the SecurityMode setting for my Send Port. But how do you do this for a Dynamic port (which I was using since this is an ESB solution)? Within the UDDI portal you have to add an additional Instance Info to your Binding named: EndPointConfig Then you have to set its value to: SecurityMode=Transport Like this: The EndPointConfig is how the ESB Toolkit 2.0 provides extensibility for the various transports. To see what the key-value pair options are for a given transport, open up an itinerary and change one of your resolvers to a “static” resolver by setting the “Resolver Implementation” to Static. Then select a “Transport Name” ”, for instance to WCF-BasicHttp. At this point you can then click on the “EndPoint Configuration” property for to see an adapter/ramp specific properties dialog (key-value pairs.) Here’s the dialog that popped up for WCF-BasicHttp: I simply set the SecurityMode to Transport. Please note that you will get different properties within the window depending on the Transport Name you select for the resolver. When you are done with your settings, export the itinerary to disk and find that xml; then find that resolver’s xml within that file. It will look like endpointConfig=SecurityMode=Transport in this case. Note that if you set additional properties you will have additional key-value pairs after endpointConfig= Copy that string and paste it into the UDDI portal for you Binding’s EndPointConfig Instance Info value.

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MVC Portable Areas – Web Application Projects

- by Steve Michelotti

This is the first post in a series related to build and deployment considerations as I’ve been exploring MVC Portable Areas: #1 – Using Web Application Project to build portable areas #2 – Conventions for deploying portable area static files #3 – Portable area static files as embedded resources Portable Areas is a relatively new feature available in MvcContrib that builds upon the new feature called Areas that was introduced in MVC 2. In short, portable areas provide a way to distribute MVC binary components as simple .NET assemblies rather than an assembly along with all the physical files for the views. At the heart of portable areas is a custom view engine that delivers the *.aspx pages by pulling them from embedded resources rather than from the physical file system. A portable area can be something as small as a tiny snippet of html that eventually gets rendered on a page, to something as large as an entire MVC web application. You should read this 4-part series to get up to speed on what portable areas are. Web Application Project In most of the posts to date, portable areas are shown being created with a simple C# class library. This is cool and it serves as an effective way to illustrate the simplicity of portable areas. However, the problem with that is that the developer loses out on the normal developer experience with the various tooling/scaffolding options that we’ve come to expect in visual studio like the ability to add controllers, views, etc. easily: I’ve had good results just using a normal web application project (rather than a class library) to develop portable areas and get the normal vs.net benefits. However, one gotcha that comes as a result is that it’s easy to forget to set the file to “Embedded Resource” every time you add a new aspx page. To mitigate this, simply add this MSBuild snippet shown below to your *.csproj file and all *.aspx, *ascx will automatically be set as embedded resources when your project compiles: 1: <Target Name="BeforeBuild"> 2: <ItemGroup> 3: <EmbeddedResource Include="**\*.aspx;**\*.ascx" /> 4: </ItemGroup> 5: </Target> Also, you should remove the Global.asax from this web application as it is not the host. Being able to have the normal tooling experience we’ve come to expect from Visual Studio makes creating portable areas quite simple. This even allows us to do things like creating a project template such as “MVC Portable Area Web Application” that would come pre-configured with routes set up in the PortableAreaRegistration and no Global.asax file.

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Basic Spatial Data with SQL Server and Entity Framework 5.0

- by Rick Strahl

In my most recent project we needed to do a bit of geo-spatial referencing. While spatial features have been in SQL Server for a while using those features inside of .NET applications hasn't been as straight forward as could be, because .NET natively doesn't support spatial types. There are workarounds for this with a few custom project like SharpMap or a hack using the Sql Server specific Geo types found in the Microsoft.SqlTypes assembly that ships with SQL server. While these approaches work for manipulating spatial data from .NET code, they didn't work with database access if you're using Entity Framework. Other ORM vendors have been rolling their own versions of spatial integration. In Entity Framework 5.0 running on .NET 4.5 the Microsoft ORM finally adds support for spatial types as well. In this post I'll describe basic geography features that deal with single location and distance calculations which is probably the most common usage scenario. SQL Server Transact-SQL Syntax for Spatial Data Before we look at how things work with Entity framework, lets take a look at how SQL Server allows you to use spatial data to get an understanding of the underlying semantics. The following SQL examples should work with SQL 2008 and forward. Let's start by creating a test table that includes a Geography field and also a pair of Long/Lat fields that demonstrate how you can work with the geography functions even if you don't have geography/geometry fields in the database. Here's the CREATE command:CREATE TABLE [dbo].[Geo]( [id] [int] IDENTITY(1,1) NOT NULL, [Location] [geography] NULL, [Long] [float] NOT NULL, [Lat] [float] NOT NULL ) Now using plain SQL you can insert data into the table using geography::STGeoFromText SQL CLR function:insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.527200 45.712113)', 4326), -121.527200, 45.712113 ) insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.517265 45.714240)', 4326), -121.517265, 45.714240 ) insert into Geo( Location , long, lat ) values ( geography::STGeomFromText ('POINT(-121.511536 45.714825)', 4326), -121.511536, 45.714825) The STGeomFromText function accepts a string that points to a geometric item (a point here but can also be a line or path or polygon and many others). You also need to provide an SRID (Spatial Reference System Identifier) which is an integer value that determines the rules for how geography/geometry values are calculated and returned. For mapping/distance functionality you typically want to use 4326 as this is the format used by most mapping software and geo-location libraries like Google and Bing. The spatial data in the Location field is stored in binary format which looks something like this: Once the location data is in the database you can query the data and do simple distance computations very easily. For example to calculate the distance of each of the values in the database to another spatial point is very easy to calculate. Distance calculations compare two points in space using a direct line calculation. For our example I'll compare a new point to all the points in the database. Using the Location field the SQL looks like this:-- create a source point DECLARE @s geography SET @s = geography:: STGeomFromText('POINT(-121.527200 45.712113)' , 4326); --- return the ids select ID, Location as Geo , Location .ToString() as Point , @s.STDistance( Location) as distance from Geo order by distance The code defines a new point which is the base point to compare each of the values to. You can also compare values from the database directly, but typically you'll want to match a location to another location and determine the difference for which you can use the geography::STDistance function. This query produces the following output: The STDistance function returns the straight line distance between the passed in point and the point in the database field. The result for SRID 4326 is always in meters. Notice that the first value passed was the same point so the difference is 0. The other two points are two points here in town in Hood River a little ways away - 808 and 1256 meters respectively. Notice also that you can order the result by the resulting distance, which effectively gives you results that are ordered radially out from closer to further away. This is great for searches of points of interest near a central location (YOU typically!). These geolocation functions are also available to you if you don't use the Geography/Geometry types, but plain float values. It's a little more work, as each point has to be created in the query using the string syntax, but the following code doesn't use a geography field but produces the same result as the previous query.--- using float fields select ID, geography::STGeomFromText ('POINT(' + STR (long, 15,7 ) + ' ' + Str(lat ,15, 7) + ')' , 4326), geography::STGeomFromText ('POINT(' + STR (long, 15,7 ) + ' ' + Str(lat ,15, 7) + ')' , 4326). ToString(), @s.STDistance( geography::STGeomFromText ('POINT(' + STR(long ,15, 7) + ' ' + Str(lat ,15, 7) + ')' , 4326)) as distance from geo order by distance Spatial Data in the Entity Framework Prior to Entity Framework 5.0 on .NET 4.5 consuming of the data above required using stored procedures or raw SQL commands to access the spatial data. In Entity Framework 5 however, Microsoft introduced the new DbGeometry and DbGeography types. These immutable location types provide a bunch of functionality for manipulating spatial points using geometry functions which in turn can be used to do common spatial queries like I described in the SQL syntax above. The DbGeography/DbGeometry types are immutable, meaning that you can't write to them once they've been created. They are a bit odd in that you need to use factory methods in order to instantiate them - they have no constructor() and you can't assign to properties like Latitude and Longitude. Creating a Model with Spatial Data Let's start by creating a simple Entity Framework model that includes a Location property of type DbGeography: public class GeoLocationContext : DbContext { public DbSet<GeoLocation> Locations { get; set; } } public class GeoLocation { public int Id { get; set; } public DbGeography Location { get; set; } public string Address { get; set; } } That's all there's to it. When you run this now against SQL Server, you get a Geography field for the Location property, which looks the same as the Location field in the SQL examples earlier. Adding Spatial Data to the Database Next let's add some data to the table that includes some latitude and longitude data. An easy way to find lat/long locations is to use Google Maps to pinpoint your location, then right click and click on What's Here. Click on the green marker to get the GPS coordinates. To add the actual geolocation data create an instance of the GeoLocation type and use the DbGeography.PointFromText() factory method to create a new point to assign to the Location property:[TestMethod] public void AddLocationsToDataBase() { var context = new GeoLocationContext(); // remove all context.Locations.ToList().ForEach( loc => context.Locations.Remove(loc)); context.SaveChanges(); var location = new GeoLocation() { // Create a point using native DbGeography Factory method Location = DbGeography.PointFromText( string.Format("POINT({0} {1})", -121.527200,45.712113) ,4326), Address = "301 15th Street, Hood River" }; context.Locations.Add(location); location = new GeoLocation() { Location = CreatePoint(45.714240, -121.517265), Address = "The Hatchery, Bingen" }; context.Locations.Add(location); location = new GeoLocation() { // Create a point using a helper function (lat/long) Location = CreatePoint(45.708457, -121.514432), Address = "Kaze Sushi, Hood River" }; context.Locations.Add(location); location = new GeoLocation() { Location = CreatePoint(45.722780, -120.209227), Address = "Arlington, OR" }; context.Locations.Add(location); context.SaveChanges(); } As promised, a DbGeography object has to be created with one of the static factory methods provided on the type as the Location.Longitude and Location.Latitude properties are read only. Here I'm using PointFromText() which uses a "Well Known Text" format to specify spatial data. In the first example I'm specifying to create a Point from a longitude and latitude value, using an SRID of 4326 (just like earlier in the SQL examples). You'll probably want to create a helper method to make the creation of Points easier to avoid that string format and instead just pass in a couple of double values. Here's my helper called CreatePoint that's used for all but the first point creation in the sample above:public static DbGeography CreatePoint(double latitude, double longitude) { var text = string.Format(CultureInfo.InvariantCulture.NumberFormat, "POINT({0} {1})", longitude, latitude); // 4326 is most common coordinate system used by GPS/Maps return DbGeography.PointFromText(text, 4326); } Using the helper the syntax becomes a bit cleaner, requiring only a latitude and longitude respectively. Note that my method intentionally swaps the parameters around because Latitude and Longitude is the common format I've seen with mapping libraries (especially Google Mapping/Geolocation APIs with their LatLng type). When the context is changed the data is written into the database using the SQL Geography type which looks the same as in the earlier SQL examples shown. Querying Once you have some location data in the database it's now super easy to query the data and find out the distance between locations. A common query is to ask for a number of locations that are near a fixed point - typically your current location and order it by distance. Using LINQ to Entities a query like this is easy to construct:[TestMethod] public void QueryLocationsTest() { var sourcePoint = CreatePoint(45.712113, -121.527200); var context = new GeoLocationContext(); // find any locations within 5 kilometers ordered by distance var matches = context.Locations .Where(loc => loc.Location.Distance(sourcePoint) < 5000) .OrderBy( loc=> loc.Location.Distance(sourcePoint) ) .Select( loc=> new { Address = loc.Address, Distance = loc.Location.Distance(sourcePoint) }); Assert.IsTrue(matches.Count() > 0); foreach (var location in matches) { Console.WriteLine("{0} ({1:n0} meters)", location.Address, location.Distance); } } This example produces: 301 15th Street, Hood River (0 meters)The Hatchery, Bingen (809 meters)Kaze Sushi, Hood River (1,074 meters) The first point in the database is the same as my source point I'm comparing against so the distance is 0. The other two are within the 5 mile radius, while the Arlington location which is 65 miles or so out is not returned. The result is ordered by distance from closest to furthest away. In the code, I first create a source point that is the basis for comparison. The LINQ query then selects all locations that are within 5km of the source point using the Location.Distance() function, which takes a source point as a parameter. You can either use a pre-defined value as I'm doing here, or compare against another database DbGeography property (say when you have to points in the same database for things like routes). What's nice about this query syntax is that it's very clean and easy to read and understand. You can calculate the distance and also easily order by the distance to provide a result that shows locations from closest to furthest away which is a common scenario for any application that places a user in the context of several locations. It's now super easy to accomplish this. Meters vs. Miles As with the SQL Server functions, the Distance() method returns data in meters, so if you need to work with miles or feet you need to do some conversion. Here are a couple of helpers that might be useful (can be found in GeoUtils.cs of the sample project):/// <summary> /// Convert meters to miles /// </summary> /// <param name="meters"></param> /// <returns></returns> public static double MetersToMiles(double? meters) { if (meters == null) return 0F; return meters.Value * 0.000621371192; } /// <summary> /// Convert miles to meters /// </summary> /// <param name="miles"></param> /// <returns></returns> public static double MilesToMeters(double? miles) { if (miles == null) return 0; return miles.Value * 1609.344; } Using these two helpers you can query on miles like this:[TestMethod] public void QueryLocationsMilesTest() { var sourcePoint = CreatePoint(45.712113, -121.527200); var context = new GeoLocationContext(); // find any locations within 5 miles ordered by distance var fiveMiles = GeoUtils.MilesToMeters(5); var matches = context.Locations .Where(loc => loc.Location.Distance(sourcePoint) <= fiveMiles) .OrderBy(loc => loc.Location.Distance(sourcePoint)) .Select(loc => new { Address = loc.Address, Distance = loc.Location.Distance(sourcePoint) }); Assert.IsTrue(matches.Count() > 0); foreach (var location in matches) { Console.WriteLine("{0} ({1:n1} miles)", location.Address, GeoUtils.MetersToMiles(location.Distance)); } } which produces: 301 15th Street, Hood River (0.0 miles)The Hatchery, Bingen (0.5 miles)Kaze Sushi, Hood River (0.7 miles) Nice 'n simple. .NET 4.5 Only Note that DbGeography and DbGeometry are exclusive to Entity Framework 5.0 (not 4.4 which ships in the same NuGet package or installer) and requires .NET 4.5. That's because the new DbGeometry and DbGeography (and related) types are defined in the 4.5 version of System.Data.Entity which is a CLR assembly and is only updated by major versions of .NET. Why this decision was made to add these types to System.Data.Entity rather than to the frequently updated EntityFramework assembly that would have possibly made this work in .NET 4.0 is beyond me, especially given that there are no native .NET framework spatial types to begin with. I find it also odd that there is no native CLR spatial type. The DbGeography and DbGeometry types are specific to Entity Framework and live on those assemblies. They will also work for general purpose, non-database spatial data manipulation, but then you are forced into having a dependency on System.Data.Entity, which seems a bit silly. There's also a System.Spatial assembly that's apparently part of WCF Data Services which in turn don't work with Entity framework. Another example of multiple teams at Microsoft not communicating and implementing the same functionality (differently) in several different places. Perplexed as a I may be, for EF specific code the Entity framework specific types are easy to use and work well. Working with pre-.NET 4.5 Entity Framework and Spatial Data If you can't go to .NET 4.5 just yet you can also still use spatial features in Entity Framework, but it's a lot more work as you can't use the DbContext directly to manipulate the location data. You can still run raw SQL statements to write data into the database and retrieve results using the same TSQL syntax I showed earlier using Context.Database.ExecuteSqlCommand(). Here's code that you can use to add location data into the database:[TestMethod] public void RawSqlEfAddTest() { string sqlFormat = @"insert into GeoLocations( Location, Address) values ( geography::STGeomFromText('POINT({0} {1})', 4326),@p0 )"; var sql = string.Format(sqlFormat,-121.527200, 45.712113); Console.WriteLine(sql); var context = new GeoLocationContext(); Assert.IsTrue(context.Database.ExecuteSqlCommand(sql,"301 N. 15th Street") > 0); } Here I'm using the STGeomFromText() function to add the location data. Note that I'm using string.Format here, which usually would be a bad practice but is required here. I was unable to use ExecuteSqlCommand() and its named parameter syntax as the longitude and latitude parameters are embedded into a string. Rest assured it's required as the following does not work:string sqlFormat = @"insert into GeoLocations( Location, Address) values ( geography::STGeomFromText('POINT(@p0 @p1)', 4326),@p2 )";context.Database.ExecuteSqlCommand(sql, -121.527200, 45.712113, "301 N. 15th Street") Explicitly assigning the point value with string.format works however. There are a number of ways to query location data. You can't get the location data directly, but you can retrieve the point string (which can then be parsed to get Latitude and Longitude) and you can return calculated values like distance. Here's an example of how to retrieve some geo data into a resultset using EF's and SqlQuery method:[TestMethod] public void RawSqlEfQueryTest() { var sqlFormat = @" DECLARE @s geography SET @s = geography:: STGeomFromText('POINT({0} {1})' , 4326); SELECT Address, Location.ToString() as GeoString, @s.STDistance( Location) as Distance FROM GeoLocations ORDER BY Distance"; var sql = string.Format(sqlFormat, -121.527200, 45.712113); var context = new GeoLocationContext(); var locations = context.Database.SqlQuery<ResultData>(sql); Assert.IsTrue(locations.Count() > 0); foreach (var location in locations) { Console.WriteLine(location.Address + " " + location.GeoString + " " + location.Distance); } } public class ResultData { public string GeoString { get; set; } public double Distance { get; set; } public string Address { get; set; } } Hopefully you don't have to resort to this approach as it's fairly limited. Using the new DbGeography/DbGeometry types makes this sort of thing so much easier. When I had to use code like this before I typically ended up retrieving data pks only and then running another query with just the PKs to retrieve the actual underlying DbContext entities. This was very inefficient and tedious but it did work. Summary For the current project I'm working on we actually made the switch to .NET 4.5 purely for the spatial features in EF 5.0. This app heavily relies on spatial queries and it was worth taking a chance with pre-release code to get this ease of integration as opposed to manually falling back to stored procedures or raw SQL string queries to return spatial specific queries. Using native Entity Framework code makes life a lot easier than the alternatives. It might be a late addition to Entity Framework, but it sure makes location calculations and storage easy. Where do you want to go today? ;-) Resources Download Sample Project© Rick Strahl, West Wind Technologies, 2005-2012Posted in ADO.NET Sql Server .NET Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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