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2.5.2
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the null_file class implements the /dev/null behavior More...
#include <null_file.hpp>
Inherits libdar::generic_file, and libdar::thread_cancellation.
Public Member Functions | |
null_file (gf_mode m) | |
bool | skippable (skippability direction, const infinint &amount) |
bool | skip (const infinint &pos) |
bool | skip_to_eof () |
skip to the end of file | |
bool | skip_relative (signed int x) |
infinint | get_position () const |
get the current read/write position | |
Protected Member Functions | |
void | inherited_read_ahead (const infinint &amount) |
U_I | inherited_read (char *a, U_I size) |
implementation of read() operation | |
void | inherited_write (const char *a, U_I size) |
implementation of the write() operation | |
void | inherited_sync_write () |
write down any pending data | |
void | inherited_flush_read () |
void | inherited_terminate () |
destructor-like call, except that it is allowed to throw exceptions |
the null_file class implements the /dev/null behavior
this is a generic_file implementation that emulate the comportment of the /dev/null special file. all that is writen to is lost, and nothing can be read from it (empty file). This is a completed implementation all call are consistent.
Definition at line 50 of file null_file.hpp.
void libdar::null_file::inherited_flush_read | ( | ) | [inline, protected, virtual] |
reset internal engine, flush caches in order to read the data at current position
Implements libdar::generic_file.
Definition at line 79 of file null_file.hpp.
U_I libdar::null_file::inherited_read | ( | char * | a, |
U_I | size | ||
) | [inline, protected, virtual] |
implementation of read() operation
[in,out] | a | where to put the data to read |
[in] | size | says how much data to read |
Implements libdar::generic_file.
Definition at line 63 of file null_file.hpp.
References libdar::thread_cancellation::check_self_cancellation().
void libdar::null_file::inherited_read_ahead | ( | const infinint & | amount | ) | [inline, protected, virtual] |
tells the object that several calls to read() will follow to probably obtain at least the given amount of data
[in] | amount | is the maximum expected amount of data that is known to be read |
Implements libdar::generic_file.
Definition at line 61 of file null_file.hpp.
void libdar::null_file::inherited_sync_write | ( | ) | [inline, protected, virtual] |
write down any pending data
Implements libdar::generic_file.
Definition at line 78 of file null_file.hpp.
void libdar::null_file::inherited_terminate | ( | ) | [inline, protected, virtual] |
destructor-like call, except that it is allowed to throw exceptions
Implements libdar::generic_file.
Definition at line 80 of file null_file.hpp.
void libdar::null_file::inherited_write | ( | const char * | a, |
U_I | size | ||
) | [inline, protected, virtual] |
implementation of the write() operation
[in] | a | what data to write |
[in] | size | amount of data to write |
Implements libdar::generic_file.
Definition at line 71 of file null_file.hpp.
References libdar::thread_cancellation::check_self_cancellation().
bool libdar::null_file::skip | ( | const infinint & | pos | ) | [inline, virtual] |
skip at the absolute position
[in] | pos | the offset in byte where next read/write operation must start |
Implements libdar::generic_file.
Definition at line 55 of file null_file.hpp.
bool libdar::null_file::skippable | ( | skippability | direction, |
const infinint & | amount | ||
) | [inline, virtual] |
whether the implementation is able to skip
Implements libdar::generic_file.
Definition at line 54 of file null_file.hpp.