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Disk ARchive 2.7.18
Full featured and portable backup and archiving tool
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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) | |
| null_file (const null_file &ref)=default | |
| null_file (null_file &&ref) noexcept=default | |
| null_file & | operator= (const null_file &ref)=default |
| null_file & | operator= (null_file &&ref) noexcept=default |
| virtual bool | skippable (skippability direction, const infinint &amount) override |
| whether the implementation is able to skip | |
| virtual bool | skip (const infinint &pos) override |
| skip at the absolute position | |
| virtual bool | skip_to_eof () override |
| skip to the end of file | |
| virtual bool | skip_relative (signed int x) override |
| virtual bool | truncatable (const infinint &pos) const override |
| whether the implementation is able to truncate to the given position | |
| virtual infinint | get_position () const override |
| 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 | |
| generic_file (generic_file &&ref) noexcept | |
| move constructor | |
| generic_file & | operator= (const generic_file &ref) |
| assignment operator | |
| generic_file & | operator= (generic_file &&ref) noexcept |
| move operator | |
| ~generic_file () noexcept(false) | |
| virtual destructor, | |
| void | terminate () |
| destructor-like call, except that it is allowed to throw exceptions | |
| bool | operator== (generic_file &ref) |
| bool | operator!= (generic_file &ref) |
| gf_mode | get_mode () const |
| retreive the openning mode for this object | |
| void | read_ahead (const infinint &amount) |
| void | ignore_read_ahead (bool mode) |
| virtual U_I | read (char *a, U_I size) override |
| read data from the generic_file inherited from proto_generic_file | |
| virtual void | write (const char *a, U_I size) override |
| write data to the generic_file inherited from proto_generic_file | |
| void | write (const std::string &arg) |
| write a string to the generic_file | |
| 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 | truncate (const infinint &pos) |
| truncate file at the given offset | |
| 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 | |
| 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 &me_read_ahead, const infinint &you_read_ahead, const infinint &crc_size, crc *&value) |
| compares the contents with the object in argument | |
| bool | diff (generic_file &f, const infinint &me_read_ahead, const infinint &you_read_ahead, const infinint &crc_size, crc *&value, infinint &err_offset) |
| void | reset_crc (const infinint &width) |
| reset CRC on read or writen data | |
| 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 | |
| void | sync_write () |
| write any pending data | |
| void | flush_read () |
| be ready to read at current position, reseting all pending data for reading, cached and in compression engine for example | |
Public Member Functions inherited from libdar::proto_generic_file | |
| proto_generic_file (const proto_generic_file &ref)=default | |
| copy constructor | |
| proto_generic_file (proto_generic_file &&ref) noexcept=default | |
| move constructor | |
| proto_generic_file & | operator= (const proto_generic_file &ref)=default |
| assignment operator | |
| proto_generic_file & | operator= (proto_generic_file &&ref) noexcept=default |
| move operator | |
| virtual | ~proto_generic_file () noexcept(false) |
| virtual destructor | |
Public Member Functions inherited from libdar::thread_cancellation | |
| thread_cancellation () | |
| the constructor | |
| thread_cancellation (const thread_cancellation &ref)=default | |
| copy constructor | |
| thread_cancellation (thread_cancellation &&ref) noexcept=default | |
| move constructor | |
| thread_cancellation & | operator= (const thread_cancellation &ref)=default |
| assignment operator | |
| thread_cancellation & | operator= (thread_cancellation &&ref) noexcept=default |
| move operator | |
| virtual | ~thread_cancellation () noexcept(false) |
| the destructor | |
| void | check_self_cancellation () const |
| Checkpoint test : whether the current libdar call must abort or not. | |
| void | block_delayed_cancellation (bool mode) |
Protected Member Functions | |
| 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 amount of data | |
| virtual U_I | inherited_read (char *a, U_I size) override |
| implementation of read() operation | |
| virtual void | inherited_write (const char *a, U_I siz) override |
| implementation of the write() operation | |
| virtual void | inherited_truncate (const infinint &pos) override |
| truncate file at the give offset | |
| virtual void | inherited_sync_write () override |
| write down any pending data | |
| virtual void | inherited_flush_read () override |
| reset internal engine, flush caches in order to read the data at current position | |
| virtual void | inherited_terminate () override |
| destructor-like call, except that it is allowed to throw exceptions | |
Protected Member Functions inherited from libdar::generic_file | |
| void | set_mode (gf_mode x) |
| bool | is_terminated () const |
Private Member Functions | |
| void | set_offset (const infinint &x) |
| bool | set_rel_offset (signed int x) |
Private Attributes | |
| infinint | offset |
| infinint | max_offset |
Additional Inherited Members | |
Public Types inherited from libdar::generic_file | |
| enum | skippability { skip_backward , skip_forward } |
Static Public Member Functions inherited from libdar::thread_cancellation | |
| 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 49 of file null_file.hpp.
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inline |
Definition at line 52 of file null_file.hpp.
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inlineoverridevirtual |
get the current read/write position
Implements libdar::generic_file.
Definition at line 64 of file null_file.hpp.
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inlineoverrideprotectedvirtual |
reset internal engine, flush caches in order to read the data at current position
Implements libdar::generic_file.
Definition at line 87 of file null_file.hpp.
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inlineoverrideprotectedvirtual |
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 69 of file null_file.hpp.
References libdar::thread_cancellation::check_self_cancellation().
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inlineoverrideprotectedvirtual |
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 67 of file null_file.hpp.
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inlineoverrideprotectedvirtual |
write down any pending data
Implements libdar::generic_file.
Definition at line 86 of file null_file.hpp.
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inlineoverrideprotectedvirtual |
destructor-like call, except that it is allowed to throw exceptions
Implements libdar::generic_file.
Definition at line 88 of file null_file.hpp.
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inlineoverrideprotectedvirtual |
truncate file at the give offset
Implements libdar::generic_file.
Definition at line 85 of file null_file.hpp.
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inlineoverrideprotectedvirtual |
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 77 of file null_file.hpp.
References libdar::thread_cancellation::check_self_cancellation().
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inlineprivate |
Definition at line 94 of file null_file.hpp.
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inlineprivate |
Definition at line 101 of file null_file.hpp.
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inlineoverridevirtual |
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 60 of file null_file.hpp.
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inlineoverridevirtual |
Definition at line 62 of file null_file.hpp.
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inlineoverridevirtual |
skip to the end of file
Implements libdar::generic_file.
Definition at line 61 of file null_file.hpp.
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inlineoverridevirtual |
whether the implementation is able to skip
Implements libdar::generic_file.
Definition at line 59 of file null_file.hpp.
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inlineoverridevirtual |
whether the implementation is able to truncate to the given position
Implements libdar::generic_file.
Definition at line 63 of file null_file.hpp.
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private |
Definition at line 92 of file null_file.hpp.
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private |
Definition at line 91 of file null_file.hpp.