Disk ARchive  2.6.8
Full featured and portable backup and archiving tool
generic_rsync.hpp
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2 // dar - disk archive - a backup/restoration program
3 // Copyright (C) 2002-2020 Denis Corbin
4 //
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21 
25 
26 
27 #ifndef GENERIC_RSYNC_HPP
28 #define GENERIC_RSYNC_HPP
29 
30 #include "../my_config.h"
31 
32 extern "C"
33 {
34 #if HAVE_LIBRSYNC_H
35 #include <librsync.h>
36 #endif
37 }
38 
39 #include "generic_file.hpp"
40 #include "erreurs.hpp"
41 
42 namespace libdar
43 {
44 
47 
49 
50  class generic_rsync : public generic_file
51  {
52  public:
54 
61  generic_rsync(generic_file *signature_storage,
62  U_I signature_block_size,
63  generic_file *below);
64 
66 
78  generic_rsync(generic_file *base_signature,
79  generic_file *below,
80  const infinint & crc_size,
81  const crc **checksum);
82 
84 
93  generic_rsync(generic_file *current_data,
94  generic_file *delta);
95 
96 
97  generic_rsync(const generic_rsync & ref) = delete;
98  generic_rsync(generic_rsync && ref) noexcept = delete;
99  generic_rsync & operator = (const generic_rsync & ref) = delete;
100  generic_rsync & operator = (generic_rsync && ref) noexcept = delete;
101 
102  ~generic_rsync() noexcept(false);
103 
104  // inherited from generic_file
105 
106  virtual bool skippable(skippability direction, const infinint & amount) override { return false; };
107  virtual bool skip(const infinint & pos) override {if(pos != 0 || !initial) throw SRC_BUG; else return true; };
108  virtual bool skip_to_eof() override { throw SRC_BUG; };
109  virtual bool skip_relative(S_I x) override { if(x != 0) throw SRC_BUG; else return true; };
110  virtual infinint get_position() const override { return x_below->get_position(); };
111 
112  protected:
113  virtual void inherited_read_ahead(const infinint & amount) override {};
114  virtual U_I inherited_read(char *a, U_I size) override;
115  virtual void inherited_write(const char *a, U_I size) override;
116  virtual void inherited_sync_write() override {};
117  virtual void inherited_flush_read() override {};
118  virtual void inherited_terminate() override;
119 
120  private:
121  enum { sign, delta, patch } status;
122 
124  generic_file *x_input;
125  generic_file *x_output;
126  bool initial;
127  char *working_buffer;
128  U_I working_size;
129  bool patching_completed;
130  crc *data_crc;
131 
132 #if LIBRSYNC_AVAILABLE
133  rs_job_t *job;
134  rs_signature_t *sumset;
135 
137  static rs_result patch_callback(void *opaque,
138  rs_long_t pos,
139  size_t *len,
140  void **buf);
141 #endif
142 
144 
154  bool step_forward(const char *buffer_in,
155  U_I & avail_in,
156  bool shift_input,
157  char *buffer_out,
158  U_I & avail_out);
159  void free_job();
160  void send_eof();
161  };
162 
164 
165 } // end of namespace
166 
167 #endif
libdar::generic_rsync::inherited_write
virtual void inherited_write(const char *a, U_I size) override
implementation of the write() operation
libdar::generic_rsync::skippable
virtual bool skippable(skippability direction, const infinint &amount) override
whether the implementation is able to skip
Definition: generic_rsync.hpp:106
libdar::infinint
the arbitrary large positive integer class
Definition: real_infinint.hpp:61
libdar::generic_rsync
generic_file interface to librsync
Definition: generic_rsync.hpp:50
libdar::generic_rsync::get_position
virtual infinint get_position() const override
get the current read/write position
Definition: generic_rsync.hpp:110
libdar::generic_rsync::skip_to_eof
virtual bool skip_to_eof() override
skip to the end of file
Definition: generic_rsync.hpp:108
libdar::generic_rsync::skip
virtual bool skip(const infinint &pos) override
skip at the absolute position
Definition: generic_rsync.hpp:107
libdar::saved_status::delta
inode is saved but as delta binary from the content (delta signature) of what was found in the archiv...
libdar::generic_rsync::x_below
generic_file * x_below
underlying layer to read from / write to
Definition: generic_rsync.hpp:123
libdar::generic_rsync::step_forward
bool step_forward(const char *buffer_in, U_I &avail_in, bool shift_input, char *buffer_out, U_I &avail_out)
feed librsync using rs_job_iter
libdar::crc
pure virtual class defining interface of a CRC object
Definition: crc.hpp:46
libdar::generic_rsync::skip_relative
virtual bool skip_relative(S_I x) override
skip relatively to the current position
Definition: generic_rsync.hpp:109
generic_file.hpp
class generic_file is defined here as well as class fichier
libdar::generic_rsync::inherited_read
virtual U_I inherited_read(char *a, U_I size) override
implementation of read() operation
erreurs.hpp
contains all the excetion class thrown by libdar
libdar::generic_rsync::inherited_sync_write
virtual void inherited_sync_write() override
write down any pending data
Definition: generic_rsync.hpp:116
libdar::generic_rsync::inherited_terminate
virtual void inherited_terminate() override
destructor-like call, except that it is allowed to throw exceptions
libdar::generic_file
this is the interface class from which all other data transfer classes inherit
Definition: generic_file.hpp:76
libdar::generic_rsync::inherited_read_ahead
virtual void inherited_read_ahead(const infinint &amount) override
tells the object that several calls to read() will follow to probably obtain at least the given amoun...
Definition: generic_rsync.hpp:113
libdar::generic_rsync::generic_rsync
generic_rsync(generic_file *signature_storage, U_I signature_block_size, generic_file *below)
constructor for "signature" operation
libdar::generic_rsync::inherited_flush_read
virtual void inherited_flush_read() override
reset internal engine, flush caches in order to read the data at current position
Definition: generic_rsync.hpp:117
libdar::generic_file::get_position
virtual infinint get_position() const =0
get the current read/write position
libdar
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:46