Disk ARchive  2.5.2
Full featured and portable backup and archiving tool
tuyau.hpp
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00001 /*********************************************************************/
00002 // dar - disk archive - a backup/restoration program
00003 // Copyright (C) 2002-2052 Denis Corbin
00004 //
00005 // This program is free software; you can redistribute it and/or
00006 // modify it under the terms of the GNU General Public License
00007 // as published by the Free Software Foundation; either version 2
00008 // of the License, or (at your option) any later version.
00009 //
00010 // This program is distributed in the hope that it will be useful,
00011 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00012 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013 // GNU General Public License for more details.
00014 //
00015 // You should have received a copy of the GNU General Public License
00016 // along with this program; if not, write to the Free Software
00017 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
00018 //
00019 // to contact the author : http://dar.linux.free.fr/email.html
00020 /*********************************************************************/
00021 
00030 
00031 #ifndef TUYAU_HPP
00032 #define TUYAU_HPP
00033 
00034 #include "../my_config.h"
00035 #include "infinint.hpp"
00036 #include "generic_file.hpp"
00037 #include "thread_cancellation.hpp"
00038 #include "mem_ui.hpp"
00039 
00040 namespace libdar
00041 {
00042 
00044 
00046 
00047     class tuyau : public generic_file, public thread_cancellation, protected mem_ui
00048     {
00049     public:
00050         tuyau(const user_interaction & dialog, //< for user interaction
00051           int fd);                         //< fd is the filedescriptor of a pipe extremity already openned
00052         tuyau(const user_interaction & dialog, //< for user interaction
00053           int fd,                          //< fd is the filedescriptor of a pipe extremity already openned
00054           gf_mode mode);                   //< forces the mode if possible
00055         tuyau(const user_interaction & dialog, //< for user interaction
00056           const std::string &filename,     //< named pipe to open
00057           gf_mode mode);                   //< forces the mode if possible
00058     tuyau(const user_interaction & dialog);//< creates a anonymous pipe and bind itself to the writing end. The reading end can be obtained by get_read_side() method
00059         ~tuyau();
00060 
00061         // provides the reading end of the anonymous pipe when the current object has created it (no filedesc, no path given to constructor).
00062         // it cannot be called more than once.
00063     int get_read_fd() const;
00064 
00066 
00070     void close_read_fd();
00071 
00073     void do_not_close_read_fd();
00074 
00075             // inherited from generic_file
00076     bool skippable(skippability direction, const infinint & amount);
00077         bool skip(const infinint & pos);
00078         bool skip_to_eof();
00079         bool skip_relative(signed int x);
00080         infinint get_position() const { return position; };
00081 
00082     bool has_next_to_read();
00083 
00084     protected:
00085     void inherited_read_ahead(const infinint & amount) {}; // relying on the operating system
00086         virtual U_I inherited_read(char *a, U_I size);
00087         virtual void inherited_write(const char *a, U_I size);
00088     void inherited_sync_write() {};
00089     void inherited_flush_read() {};
00090     void inherited_terminate();
00091 
00092     private:
00093     enum
00094     {
00095         pipe_fd,        //< holds a single file descriptor for the pipe
00096         pipe_path,      //< holds a filename to be openned (named pipe)
00097         pipe_both       //< holds a pair of file descriptors
00098     }
00099         pipe_mode;          //< defines how the object's status (which possible values defined by the anonymous enum above)
00100     infinint position;  //< recorded position in the stream
00101     int filedesc;       //< file descriptors of the pipe
00102     int other_end_fd;   //< in pipe_both mode, this holds the reading side of the anonymous pipe
00103         std::string chemin; //< in pipe_path mode only, this holds the named pipe to be open
00104     bool has_one_to_read; //< if true, the next char to read is placed in "next_to_read"
00105     char next_to_read;  //< when has_one_to_read is true, contains the next to read byte
00106 
00107         void ouverture();
00108 
00110 
00113     bool read_and_drop(infinint byte);
00114 
00116     bool read_to_eof();
00117     };
00118 
00119 } // end of namespace
00120 
00121 #endif
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