filesystem::huge_file Class Reference
Supports reading and writing to very large files, > 4 gigabytes. More...
#include <huge_file.h>
Public Types | |
| enum | outcomes { OKAY = basis::common::OKAY, FAILURE = basis::common::FAILURE, ACCESS_DENIED = basis::common::ACCESS_DENIED, BAD_INPUT = basis::common::BAD_INPUT } |
Public Member Functions | |
| huge_file (const basis::astring &filename, const basis::astring &permissions) | |
| opens "filename" for access, where it presumably is a very large file. | |
| virtual | ~huge_file () |
| DEFINE_CLASS_NAME ("huge_file") | |
| bool | good () const |
| reports if the file was opened successfully. | |
| bool | eof () const |
| reports when the file pointer has reached the end of the file. | |
| double | length () |
| expensive operation accesses the file to find length. | |
| double | file_pointer () const |
| returns where we currently are in the file. | |
| basis::outcome | seek (double new_position, byte_filer::origins origin=byte_filer::FROM_CURRENT) |
| move the file pointer to "new_position" if possible. | |
| basis::outcome | move_to (double absolute_posn) |
| simpler seek just goes from current location to "absolute_posn". | |
| basis::outcome | read (basis::byte_array &to_fill, int desired_size, int &size_read) |
| reads "desired_size" into "to_fill" if possible. | |
| basis::outcome | write (const basis::byte_array &to_write, int &size_written) |
| stores the array "to_write" into the file. | |
| bool | truncate () |
| truncates the file after the current position. | |
| void | flush () |
| forces any pending writes to actually be saved to the file. | |
Detailed Description
Supports reading and writing to very large files, > 4 gigabytes.
The standard file I/O functions only handle files up to 4 gigabytes. This class extends the range to essentially unlimited sizes, as long as the operating system can accurately do relative seeks and can read/write to files of the size needed.
Definition at line 35 of file huge_file.h.
Member Enumeration Documentation
Definition at line 46 of file huge_file.h.
Constructor & Destructor Documentation
| filesystem::huge_file::huge_file | ( | const basis::astring & | filename, | |
| const basis::astring & | permissions | |||
| ) |
opens "filename" for access, where it presumably is a very large file.
see byte filer for a description of the permissions.
Definition at line 34 of file huge_file.cpp.
| filesystem::huge_file::~huge_file | ( | ) | [virtual] |
Definition at line 40 of file huge_file.cpp.
References basis::WHACK().
Member Function Documentation
| filesystem::huge_file::DEFINE_CLASS_NAME | ( | "huge_file" | ) |
| bool filesystem::huge_file::eof | ( | ) | const |
reports when the file pointer has reached the end of the file.
Definition at line 175 of file huge_file.cpp.
References filesystem::byte_filer::eof().
Referenced by filesystem::heavy_file_operations::copy_file().
| double filesystem::huge_file::file_pointer | ( | ) | const [inline] |
returns where we currently are in the file.
Definition at line 62 of file huge_file.h.
| void filesystem::huge_file::flush | ( | ) |
forces any pending writes to actually be saved to the file.
Definition at line 45 of file huge_file.cpp.
References filesystem::byte_filer::flush().
| bool filesystem::huge_file::good | ( | ) | const |
reports if the file was opened successfully.
Definition at line 173 of file huge_file.cpp.
References filesystem::byte_filer::good().
Referenced by filesystem::heavy_file_operations::buffer_files(), filesystem::heavy_file_operations::copy_file(), and filesystem::heavy_file_operations::write_file_chunk().
| double filesystem::huge_file::length | ( | ) |
expensive operation accesses the file to find length.
Definition at line 49 of file huge_file.cpp.
References filesystem::byte_filer::eof(), filesystem::byte_filer::file_size_limit(), filesystem::byte_filer::filename(), filesystem::byte_filer::FROM_CURRENT, filesystem::byte_filer::FROM_START, FUNCDEF, filesystem::byte_filer::length(), LOG, OKAY, filesystem::byte_filer::read(), seek(), and filesystem::byte_filer::seek().
Referenced by filesystem::heavy_file_operations::buffer_files(), seek(), and filesystem::heavy_file_operations::write_file_chunk().
| outcome filesystem::huge_file::move_to | ( | double | absolute_posn | ) |
simpler seek just goes from current location to "absolute_posn".
Definition at line 177 of file huge_file.cpp.
References basis::absolute_value(), FAILURE, filesystem::byte_filer::file_size_limit(), filesystem::byte_filer::FROM_CURRENT, FUNCDEF, LOG, basis::minimum(), OKAY, and filesystem::byte_filer::seek().
Referenced by seek().
| outcome filesystem::huge_file::read | ( | basis::byte_array & | to_fill, | |
| int | desired_size, | |||
| int & | size_read | |||
| ) |
reads "desired_size" into "to_fill" if possible.
"size_read" reports how many bytes were actually read.
Definition at line 255 of file huge_file.cpp.
References FAILURE, OKAY, and filesystem::byte_filer::read().
Referenced by filesystem::heavy_file_operations::buffer_files(), and filesystem::heavy_file_operations::copy_file().
| outcome filesystem::huge_file::seek | ( | double | new_position, | |
| byte_filer::origins | origin = byte_filer::FROM_CURRENT | |||
| ) |
move the file pointer to "new_position" if possible.
the relative seek is the easiest type of seek to accomplish with a huge file. the other types are also supported, but take a bit more to implement.
Definition at line 223 of file huge_file.cpp.
References BAD_INPUT, FAILURE, filesystem::byte_filer::FROM_CURRENT, filesystem::byte_filer::FROM_END, filesystem::byte_filer::FROM_START, FUNCDEF, length(), LOG, move_to(), and filesystem::byte_filer::seek().
Referenced by filesystem::heavy_file_operations::buffer_files(), length(), and filesystem::heavy_file_operations::write_file_chunk().
| bool filesystem::huge_file::truncate | ( | ) |
truncates the file after the current position.
Definition at line 47 of file huge_file.cpp.
References filesystem::byte_filer::truncate().
Referenced by filesystem::heavy_file_operations::write_file_chunk().
| outcome filesystem::huge_file::write | ( | const basis::byte_array & | to_write, | |
| int & | size_written | |||
| ) |
stores the array "to_write" into the file.
"size_written" reports how many bytes got written.
Definition at line 267 of file huge_file.cpp.
References FAILURE, OKAY, and filesystem::byte_filer::write().
Referenced by filesystem::heavy_file_operations::copy_file(), and filesystem::heavy_file_operations::write_file_chunk().
The documentation for this class was generated from the following files:
- /var/www/hoople2/source/core/library/filesystem/huge_file.h
- /var/www/hoople2/source/core/library/filesystem/huge_file.cpp
