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Diffstat (limited to 'Build/source/libs/zziplib/zzipwrap/wrap.c')
| -rw-r--r-- | Build/source/libs/zziplib/zzipwrap/wrap.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/Build/source/libs/zziplib/zzipwrap/wrap.c b/Build/source/libs/zziplib/zzipwrap/wrap.c new file mode 100644 index 00000000000..2bea0c39e5b --- /dev/null +++ b/Build/source/libs/zziplib/zzipwrap/wrap.c @@ -0,0 +1,223 @@ + +/* Wrapper interface for zziplib's file IO functions. + * + * -- In memory-access IO function -- + * Provides default fileio functions open/read/lseek/close and functions + * that enable blocked, memory buffered IO. + * + * (c) A. Schiffler, aschiffler@home.com + * Released under same license as zziplib (LGPL), Oct 2001 + * + * modified 2002 to use new plugin_io interface by Guido Draheim + */ + +#include <zzip/conf.h> +#include <zzip/plugin.h> +/* #incl <zzip/wrap.h> */ +#include "wrap.h" + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#ifdef ZZIP_HAVE_UNISTD_H +#include <unistd.h> +#endif +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +/* Some globals that we use for operation */ + +static int zzip_memory_blocksize=0; +static zzipwrap_pfn_t zzip_memory_callback=NULL; +static void *zzip_memory_callbackdata=NULL; +static char *zzip_memory_buffer=NULL; +static int zzip_memory_bufferblock=0; +static int zzip_memory_fd=-1; +static int zzip_memory_pos=0; +static int zzip_memory_size=0; + +/* at the moment, we do not export the five handlers of zzip_memry plugin_io */ +#define ZZIP_memory static + +ZZIP_memory void zzip_memory_reset(void) +{ + zzip_memory_buffer=NULL; + zzip_memory_bufferblock=0; + zzip_memory_pos=0; + zzip_memory_size=0; + zzip_memory_fd=-1; +} + +ZZIP_memory int zzip_memory_read(int fd, char *buf, size_t count) +{ + int requested_block; + int transfer_start; + int transfer_bytes; + int bytes_read; + int bytes_to_write; + int bytes_written; + + /* Check file descriptor */ + if (fd!=zzip_memory_fd) { + return(-1); + } + + if ((int)count<0) + return -1; + + /* Work out how many bytes we have to read based */ + /* on filepos and requested buffersize. */ + bytes_to_write=zzip_memory_size-zzip_memory_pos; + if (bytes_to_write>=(int)count) { + bytes_to_write=(int)count; + } + + /* Read/transfer loop */ + bytes_written=0; + while (bytes_to_write>0) { + /* Check which block we are reading from */ + requested_block=zzip_memory_pos/zzip_memory_blocksize; + /* Check if we have this block available */ + if (zzip_memory_bufferblock!=requested_block) { + /* Read this block */ + lseek(fd,requested_block*zzip_memory_blocksize,SEEK_SET); + bytes_read=read(fd,zzip_memory_buffer,zzip_memory_blocksize); + /* Clear unused bytes */ + if ((bytes_read>=0) && (bytes_read<zzip_memory_blocksize)) { + memset(&zzip_memory_buffer[bytes_read],0,zzip_memory_blocksize-bytes_read); + } + /* Set current block pos */ + zzip_memory_bufferblock=requested_block; + /* Process buffer if callback is set */ + if (zzip_memory_callback) { + zzip_memory_callback(zzip_memory_buffer,zzip_memory_blocksize,zzip_memory_callbackdata); + } + } else { + bytes_read=zzip_memory_blocksize; + } + /* Check if we have read any data */ + if (bytes_read > 0) { + /* Copy data to output buffer */ + transfer_start=zzip_memory_pos-zzip_memory_bufferblock*zzip_memory_blocksize; + transfer_bytes=zzip_memory_blocksize-transfer_start; + if (transfer_bytes>bytes_to_write) { + transfer_bytes=bytes_to_write; + } + memcpy (&buf[bytes_written], &zzip_memory_buffer[transfer_start],transfer_bytes); + zzip_memory_pos += transfer_bytes; + bytes_written += transfer_bytes; + bytes_to_write -= transfer_bytes; + } else { + /* Exit on error during read */ + bytes_to_write=0; + } + } + return(bytes_written); +} + +ZZIP_memory int zzip_memory_open(const char *pathname, int flags) +{ + int fd; + struct stat stat_buffer; + + /* Deallocate any memory buffer laying around */ + if (zzip_memory_buffer) { + free(zzip_memory_buffer); + } + /* Reset variables */ + zzip_memory_reset(); + /* Open file */ + fd=open(pathname, flags); + if (fd<0) { + return(-1); + } else { + /* Get filesize */ + if (fstat(fd, &stat_buffer)<0) { + return(-1); + } + if (stat_buffer.st_size<1) { + return(-1); + } + /* Store filesize */ + zzip_memory_size = stat_buffer.st_size; + /* Allocate readbuffer */ + zzip_memory_buffer = malloc(zzip_memory_blocksize); + /* Invalidate buffer block */ + zzip_memory_bufferblock = -1; + /* Store file descriptor */ + zzip_memory_fd=fd; + /* Return file descriptor */ + return(fd); + } +} + +ZZIP_memory int zzip_memory_close(int fd) +{ + /* Check file descriptor */ + if (fd!=zzip_memory_fd) { + return(-1); + } + /* Clear any memory buffer that might be laying around */ + if (zzip_memory_buffer) { + free(zzip_memory_buffer); + } + /* Reset variables */ + zzip_memory_reset(); + /* Close file */ + return(close(fd)); +} + +ZZIP_memory off_t zzip_memory_lseek(int fildes, off_t offset, int whence) +{ + /* Check file descriptor */ + if (fildes!=zzip_memory_fd) { + return(-1); + } + /* Change position pointer */ + switch (whence) { + case SEEK_SET: + zzip_memory_pos=offset; + break; + case SEEK_CUR: + zzip_memory_pos += offset; + break; + case SEEK_END: + zzip_memory_pos = zzip_memory_size-1; + break; + } + /* Limit position to the last byte of the file */ + if (zzip_memory_pos>(zzip_memory_size-1)) { + zzip_memory_pos=zzip_memory_size-1; + } + /* Return current position */ + return(zzip_memory_pos); +} + +/* -------- Control wrapper usage */ + + +zzip_plugin_io_t +zzipwrap_use_memory_io(int blocksize, + zzipwrap_pfn_t callback, void *callbackdata) +{ + static const struct zzip_plugin_io zzip_memory_io = + { + (void *) zzip_memory_open, + (void *) zzip_memory_close, + (void *) zzip_memory_read, + (void *) zzip_memory_lseek, + (void *) zzip_filesize, + 0 + }; + + /* Store blocksize and block-processing callback data */ + + zzip_memory_blocksize = blocksize; + zzip_memory_callback = callback; + zzip_memory_callbackdata = callbackdata; + + return (zzip_plugin_io_t) &zzip_memory_io; +} + |