zzip_disk_mmap - turn a filehandle into a mmapped zip disk archive handle

NAME  SYNOPSIS  DESCRIPTION  AUTHOR  COPYRIGHT 

NAME

zzip_disk_mmap, zzip_disk_init, zzip_disk_new, zzip_disk_munmap, zzip_disk_open, zzip_disk_buffer, zzip_disk_close − turn a filehandle into a mmapped zip disk archive handle

SYNOPSIS

#include <zzip/mmapped.h>

zzip__new__ ZZIP_DISK *
zzip_disk_mmap
(int fd)

int
zzip_disk_init
(ZZIP_DISK * disk, void *buffer, zzip_size_t buflen)

zzip__new__ ZZIP_DISK *
zzip_disk_new
(void)

int
zzip_disk_munmap
(ZZIP_DISK * disk)

zzip__new__ ZZIP_DISK *
zzip_disk_open
(char *filename)

zzip__new__ ZZIP_DISK *
zzip_disk_buffer
(void *buffer, size_t buflen)
int
zzip_disk_close
(ZZIP_DISK * disk)

DESCRIPTION

The zzip_disk_mmap function uses the given file-descriptor to detect the length of the file and calls the system mmap(2) to put it in main memory. If it is successful then a newly allocated ZZIP_DISK* is returned with disk->buffer pointing to the mapview of the zipdisk content.

The zzip_disk_mmap function may return null on errors (errno).

The zzip_disk_init function does primary initialization of a disk-buffer struct.

The zzip_disk_init function always returns 0 as success.

The zzip_disk_new function allocates a new disk-buffer with malloc(3)

The zzip_disk_new function may return null on errors (errno).

The zzip_disk_munmap function is the inverse of zzip_disk_mmap and using the system munmap(2) on the buffer area and free(3) on the ZZIP_DISK structure.

The zzip_disk_open function opens the given archive by name and turn the filehandle to zzip_disk_mmap for bringing it to main memory. If it can not be mmap(2)’ed then we slurp the whole file into a newly malloc(2)’ed memory block. Only if that fails too then we return null. Since handling of disk->buffer is ambiguous it should not be snatched away please.

The zzip_disk_open function may return null on errors (errno).

The zzip_disk_buffer function will attach a buffer with a zip image that was acquired from another source than a file. Note that if zzip_disk_mmap fails then zzip_disk_open will fall back and try to read the full file to memory wrapping a ZZIP_DISK around the memory buffer just as the zzip_disk_buffer function will do. Note that the zzip_disk_buffer function will not own the buffer, it will neither be written nor free()d.

The zzip_disk_buffer function may return null (errno).

The zzip_disk_close function will release all data needed to access a (mmapped) zip archive, including any malloc()ed blocks, sharedmem mappings and it dumps the handle struct as well.

The zzip_disk_close function returns 0 on success (or whatever munmap says).

AUTHOR

Guido Draheim <[email protected]>

COPYRIGHT

Copyright (c)Guido Draheim, use under copyleft (LGPL,MPL)


Updated 2024-01-29 - jenkler.se | uex.se