Disk ARchive 2.3.12
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the cache class implements a very basic read/write caching mechanisme More...
#include <cache.hpp>
Inherits libdar::generic_file.
Public Member Functions | |
cache (user_interaction &dialog, generic_file &hidden, U_I initial_size=10240, U_I unused_read_ratio=10, U_I observation_read_number=100, U_I max_size_hit_read_ratio=50, U_I unused_write_ratio=10, U_I observation_write_number=100, U_I max_size_hit_write_ratio=50) | |
bool | skip (const infinint &pos) |
skip at the absolute position | |
bool | skip_to_eof () |
skip to the end of file | |
bool | skip_relative (S_I x) |
skip relatively to the current position | |
infinint | get_position () |
get the current read/write position | |
Protected Member Functions | |
S_I | inherited_read (char *a, size_t size) |
S_I | inherited_write (const char *a, size_t size) |
the cache class implements a very basic read/write caching mechanisme
it is intended to reduce context switches when no compression is used and when reading or writing catalogue through a pipe. The catalogue read and write is done by calling dump/constructor methods of the many objects that a catalogue can contain. This makes a lot of small read or write, which make very poor performances when used over the network through a pipe to ssh. When compression is used, the problem disapears as the compression engine gather these many small read or write into much bigger ones. This in only when there is no compression that that this class is useful (and used).