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Disk ARchive
2.4.13
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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 | skip (const infinint &pos) |
| skip at the absolute position More... | |
| bool | skip_to_eof () |
| skip to the end of file | |
| bool | skip_relative (signed int x) |
| infinint | get_position () |
| get the current read/write position | |
Public Member Functions inherited from libdar::generic_file | |
| generic_file (gf_mode m) | |
| main constructor | |
| generic_file (const generic_file &ref) | |
| copy constructor | |
| void | terminate () const |
| virtual destructor, this let inherited destructor to be called even from a generic_file pointer to an inherited class More... | |
| const generic_file & | operator= (const generic_file &ref) |
| assignment operator | |
| gf_mode | get_mode () const |
| retreive the openning mode for this object | |
| U_I | read (char *a, U_I size) |
| read data from the generic_file More... | |
| void | write (const char *a, U_I size) |
| write data to the generic_file More... | |
| void | write (const std::string &arg) |
| write a string to the generic_file More... | |
| S_I | read_back (char &a) |
| skip back one char, read on char and skip back one char | |
| S_I | read_forward (char &a) |
| read one char | |
| virtual bool | skip_relative (S_I x)=0 |
| skip relatively to the current position | |
| virtual void | copy_to (generic_file &ref) |
| copy all data from current position to the object in argument | |
| virtual void | copy_to (generic_file &ref, const infinint &crc_size, crc *&value) |
| copy all data from the current position to the object in argument and computes a CRC value of the transmitted data More... | |
| U_32 | copy_to (generic_file &ref, U_32 size) |
| small copy (up to 4GB) with CRC calculation | |
| infinint | copy_to (generic_file &ref, infinint size) |
| copy the given amount to the object in argument | |
| bool | diff (generic_file &f, const infinint &crc_size, crc *&value) |
| compares the contents with the object in argument More... | |
| bool | diff (generic_file &f, const infinint &crc_size, crc *&value, infinint &err_offset) |
| void | reset_crc (const infinint &width) |
| reset CRC on read or writen data More... | |
| bool | crc_status () const |
| to known whether CRC calculation is activated or not | |
| crc * | get_crc () |
| get CRC of the transfered date since last reset More... | |
| void | sync_write () |
| write any pending data | |
Public Member Functions inherited from libdar::thread_cancellation | |
| thread_cancellation () | |
| the constructor | |
| virtual | ~thread_cancellation () |
| the destructor | |
| void | check_self_cancellation () const |
| Checkpoint test : whether the current libdar call must abort or not. More... | |
| void | block_delayed_cancellation (bool mode) |
Protected Member Functions | |
| U_I | inherited_read (char *a, U_I size) |
| implementation of read() operation More... | |
| void | inherited_write (const char *a, U_I size) |
| implementation of the write() operation More... | |
| void | inherited_sync_write () |
| write down any pending data More... | |
| void | inherited_terminate () |
| destructor-like call, except that it is allowed to throw exceptions More... | |
Protected Member Functions inherited from libdar::generic_file | |
| void | set_mode (gf_mode x) |
| bool | is_terminated () const |
Additional Inherited Members | |
Static Public Member Functions inherited from libdar::thread_cancellation | |
| static void | init () |
| mandatory initialization static method More... | |
| static U_I | count () |
| method for debugging/control purposes | |
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.
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inlineprotectedvirtual |
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().
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inlineprotectedvirtual |
write down any pending data
Implements libdar::generic_file.
Definition at line 78 of file null_file.hpp.
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inlineprotectedvirtual |
destructor-like call, except that it is allowed to throw exceptions
Implements libdar::generic_file.
Definition at line 80 of file null_file.hpp.
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inlineprotectedvirtual |
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().
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inlinevirtual |
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 54 of file null_file.hpp.
1.8.6