Disk ARchive  2.7.4
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) 2002-2022 Denis Corbin
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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 bool truncatable(const infinint & pos) const override { return pos == get_position(); };
111  virtual infinint get_position() const override { return x_below->get_position(); };
112 
113  protected:
114  virtual void inherited_read_ahead(const infinint & amount) override {};
115  virtual U_I inherited_read(char *a, U_I size) override;
116  virtual void inherited_write(const char *a, U_I size) override;
117  virtual void inherited_truncate(const infinint & pos) override { if(pos != get_position()) throw SRC_BUG; };
118  virtual void inherited_sync_write() override {};
119  virtual void inherited_flush_read() override {};
120  virtual void inherited_terminate() override;
121 
122  private:
123  enum { sign, delta, patch } status;
124 
126  generic_file *x_input;
127  generic_file *x_output;
128  bool initial;
129  char *working_buffer;
130  U_I working_size;
131  bool patching_completed;
132  crc *data_crc;
133 
134 #if LIBRSYNC_AVAILABLE
135  rs_job_t *job;
136  rs_signature_t *sumset;
137 
139  static rs_result patch_callback(void *opaque,
140  rs_long_t pos,
141  size_t *len,
142  void **buf);
143 #endif
144 
146 
156  bool step_forward(const char *buffer_in,
157  U_I & avail_in,
158  bool shift_input,
159  char *buffer_out,
160  U_I & avail_out);
161  void free_job();
162  void send_eof();
163  };
164 
166 
167 } // end of namespace
168 
169 #endif
pure virtual class defining interface of a CRC object
Definition: crc.hpp:47
this is the interface class from which all other data transfer classes inherit
virtual infinint get_position() const =0
get the current read/write position
generic_file interface to librsync
virtual void inherited_flush_read() override
reset internal engine, flush caches in order to read the data at current position
virtual void inherited_truncate(const infinint &pos) override
truncate file at the give offset
virtual void inherited_terminate() override
destructor-like call, except that it is allowed to throw exceptions
virtual bool skippable(skippability direction, const infinint &amount) override
whether the implementation is able to skip
virtual infinint get_position() const override
get the current read/write position
generic_rsync(generic_file *signature_storage, U_I signature_block_size, generic_file *below)
constructor for "signature" operation
virtual bool skip(const infinint &pos) override
skip at the absolute position
virtual void inherited_sync_write() override
write down any pending data
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...
generic_rsync(generic_file *current_data, generic_file *delta)
constructor for "patch" operation
generic_rsync(generic_file *base_signature, generic_file *below, const infinint &crc_size, const crc **checksum)
constructor for "delta" operation
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
virtual U_I inherited_read(char *a, U_I size) override
implementation of read() operation
virtual bool skip_to_eof() override
skip to the end of file
virtual void inherited_write(const char *a, U_I size) override
implementation of the write() operation
virtual bool skip_relative(S_I x) override
skip relatively to the current position
generic_file * x_below
underlying layer to read from / write to
virtual bool truncatable(const infinint &pos) const override
whether the implementation is able to truncate to the given position
the arbitrary large positive integer class
contains all the excetion class thrown by libdar
class generic_file is defined here as well as class fichier
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:47