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Diffstat (limited to 'src/boost/libs/exception/example/example_io.cpp')
| -rw-r--r-- | src/boost/libs/exception/example/example_io.cpp | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/src/boost/libs/exception/example/example_io.cpp b/src/boost/libs/exception/example/example_io.cpp new file mode 100644 index 00000000..f4893328 --- /dev/null +++ b/src/boost/libs/exception/example/example_io.cpp @@ -0,0 +1,209 @@ +//Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc. + +//Distributed under the Boost Software License, Version 1.0. (See accompanying +//file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +//This program simulates errors on copying simple data files. It demonstrates +//typical Boost Exception usage. + +//The output from this program can vary depending on the platform. + +#include <boost/throw_exception.hpp> +#include <boost/exception/info.hpp> +#include <boost/exception/get_error_info.hpp> +#include <boost/exception/diagnostic_information.hpp> +#include <boost/exception/errinfo_file_open_mode.hpp> +#include <boost/exception/errinfo_file_handle.hpp> +#include <boost/exception/errinfo_file_name.hpp> +#include <boost/exception/errinfo_api_function.hpp> +#include <boost/exception/errinfo_errno.hpp> +#include <boost/shared_ptr.hpp> +#include <boost/weak_ptr.hpp> +#include <iostream> + +typedef boost::error_info<struct tag_file_name_src,std::string> errinfo_src_file_name; +typedef boost::error_info<struct tag_file_name_dst,std::string> errinfo_dst_file_name; + +char const data[] = "example"; +size_t const data_size = sizeof(data); + +class +error: //Base for all exception objects we throw. + public virtual std::exception, + public virtual boost::exception + { + public: + + char const * + what() const BOOST_NOEXCEPT_OR_NOTHROW + { + return "example_io error"; + } + + protected: + + ~error() BOOST_NOEXCEPT_OR_NOTHROW + { + } + }; + +struct open_error: virtual error { }; +struct read_error: virtual error { }; +struct write_error: virtual error { }; +struct fopen_error: virtual open_error { }; +struct fread_error: virtual read_error { }; +struct fwrite_error: virtual write_error { }; + +boost::shared_ptr<FILE> +my_fopen( char const * name, char const * mode ) + { + if( FILE * f = ::fopen(name,mode) ) + return boost::shared_ptr<FILE>(f,fclose); + else + BOOST_THROW_EXCEPTION(fopen_error() << + boost::errinfo_errno (errno) << + boost::errinfo_file_name(name) << + boost::errinfo_file_open_mode(mode) << + boost::errinfo_api_function("fopen")); + } + +void +my_fread( void * buffer, size_t size, size_t count, boost::shared_ptr<FILE> const & stream ) + { + assert(stream); + if( count!=fread(buffer,size,count,stream.get()) || ferror(stream.get()) ) + BOOST_THROW_EXCEPTION(fread_error() << + boost::errinfo_api_function("fread") << + boost::errinfo_errno(errno) << + boost::errinfo_file_handle(boost::weak_ptr<FILE>(stream))); + } + +void +my_fwrite( void const * buffer, size_t size, size_t count, boost::shared_ptr<FILE> const & stream ) + { + assert(stream); + if( count!=fwrite(buffer,size,count,stream.get()) || ferror(stream.get()) ) + BOOST_THROW_EXCEPTION(fwrite_error() << + boost::errinfo_api_function("fwrite") << + boost::errinfo_errno(errno) << + boost::errinfo_file_handle(boost::weak_ptr<FILE>(stream))); + } + +void +reset_file( char const * file_name ) + { + (void) my_fopen(file_name,"wb"); + } + +void +create_data( char const * file_name ) + { + boost::shared_ptr<FILE> f = my_fopen(file_name,"wb"); + my_fwrite( data, 1, data_size, f ); + } + +void +copy_data( char const * src_file_name, char const * dst_file_name ) + { + boost::shared_ptr<FILE> src = my_fopen(src_file_name,"rb"); + boost::shared_ptr<FILE> dst = my_fopen(dst_file_name,"wb"); + try + { + char buffer[data_size]; + my_fread( buffer, 1, data_size, src ); + my_fwrite( buffer, 1, data_size, dst ); + } + catch( + boost::exception & x ) + { + if( boost::weak_ptr<FILE> const * f=boost::get_error_info<boost::errinfo_file_handle>(x) ) + if( boost::shared_ptr<FILE> fs = f->lock() ) + { + if( fs==src ) + x << boost::errinfo_file_name(src_file_name); + else if( fs==dst ) + x << boost::errinfo_file_name(dst_file_name); + } + x << + errinfo_src_file_name(src_file_name) << + errinfo_dst_file_name(dst_file_name); + throw; + } + } + +void +dump_copy_info( boost::exception const & x ) + { + if( std::string const * src = boost::get_error_info<errinfo_src_file_name>(x) ) + std::cerr << "Source file name: " << *src << "\n"; + if( std::string const * dst = boost::get_error_info<errinfo_dst_file_name>(x) ) + std::cerr << "Destination file name: " << *dst << "\n"; + } + +void +dump_file_info( boost::exception const & x ) + { + if( std::string const * fn = boost::get_error_info<boost::errinfo_file_name>(x) ) + std::cerr << "File name: " << *fn << "\n"; + } + +void +dump_clib_info( boost::exception const & x ) + { + if( int const * err=boost::get_error_info<boost::errinfo_errno>(x) ) + std::cerr << "OS error: " << *err << "\n"; + if( char const * const * fn=boost::get_error_info<boost::errinfo_api_function>(x) ) + std::cerr << "Failed function: " << *fn << "\n"; + } + +void +dump_all_info( boost::exception const & x ) + { + std::cerr << "-------------------------------------------------\n"; + dump_copy_info(x); + dump_file_info(x); + dump_clib_info(x); + std::cerr << "\nOutput from diagnostic_information():\n"; + std::cerr << diagnostic_information(x); + } + +int +main() + { + try + { + create_data( "tmp1.txt" ); + copy_data( "tmp1.txt", "tmp2.txt" ); //This should succeed. + + reset_file( "tmp1.txt" ); //Creates empty file. + try + { + copy_data( "tmp1.txt", "tmp2.txt" ); //This should fail, tmp1.txt is empty. + } + catch( + read_error & x ) + { + std::cerr << "\nCaught 'read_error' exception.\n"; + dump_all_info(x); + } + + remove( "tmp1.txt" ); + remove( "tmp2.txt" ); + try + { + copy_data( "tmp1.txt", "tmp2.txt" ); //This should fail, tmp1.txt does not exist. + } + catch( + open_error & x ) + { + std::cerr << "\nCaught 'open_error' exception.\n"; + dump_all_info(x); + } + } + catch( + ... ) + { + std::cerr << "\nCaught unexpected exception!\n"; + std::cerr << boost::current_exception_diagnostic_information(); + } + } |