diff options
Diffstat (limited to '3rd-party/zisofs_tools/compress.c')
| -rw-r--r-- | 3rd-party/zisofs_tools/compress.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/3rd-party/zisofs_tools/compress.c b/3rd-party/zisofs_tools/compress.c new file mode 100644 index 0000000..56f0af0 --- /dev/null +++ b/3rd-party/zisofs_tools/compress.c @@ -0,0 +1,155 @@ +/* + * This file has been modified for the cdrkit suite. + * + * The behaviour and appearence of the program code below can differ to a major + * extent from the version distributed by the original author(s). + * + * For details, see Changelog file distributed with the cdrkit package. If you + * received this file from another source then ask the distributing person for + * a log of modifications. + * + */ + +/* $Id: compress.c,v 1.4 2006/07/04 04:57:42 hpa Exp $ */ +/* ----------------------------------------------------------------------- * + * + * Copyright 2001-2006 H. Peter Anvin - All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139, + * USA; either version 2 of the License, or (at your option) any later + * version; incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +#include "mkzftree.h" /* Must be included first! */ + +#include <stdlib.h> +#include <stdio.h> +#include <utime.h> +#include <unistd.h> +#include <zlib.h> + +#include "iso9660.h" + + +int block_compress_file(FILE *input, FILE *output, off_t size) +{ + struct compressed_file_header hdr; + Bytef inbuf[CBLOCK_SIZE], outbuf[2*CBLOCK_SIZE]; + size_t bytes, pointer_bytes, nblocks, block; + uLong cbytes; /* uLong is a zlib datatype */ + char *pointer_block, *curptr; + off_t position; + int i; + int force_compress = opt.force; + int zerr; + int err = EX_SOFTWARE; + + if ( (sizeof hdr) & 3 ) { + fputs("INTERNAL ERROR: header is not a multiple of 4\n", stderr); + abort(); + } + + memset(&hdr, 0, sizeof hdr); + memcpy(&hdr.magic, zisofs_magic, sizeof zisofs_magic); + hdr.header_size = (sizeof hdr) >> 2; + hdr.block_size = CBLOCK_SIZE_LG2; + set_731(&hdr.uncompressed_len, size); + + if ( fwrite(&hdr, sizeof hdr, 1, output) != 1 ) + return EX_CANTCREAT; + + nblocks = (size+CBLOCK_SIZE-1) >> CBLOCK_SIZE_LG2; + pointer_bytes = 4*(nblocks+1); + pointer_block = xmalloc(pointer_bytes); + memset(pointer_block, 0, pointer_bytes); + + if ( fseek(output, pointer_bytes, SEEK_CUR) == -1 ) { + err = EX_CANTCREAT; + goto free_ptr_bail; + } + + curptr = pointer_block; + position = sizeof hdr + pointer_bytes; + + block = 0; + while ( (bytes = fread(inbuf, 1, CBLOCK_SIZE, input)) > 0 ) { + if ( bytes < CBLOCK_SIZE && block < nblocks-1 ) { + err = EX_IOERR; + goto free_ptr_bail; + } + + /* HACK: If the file has our magic number, always compress */ + if ( block == 0 && bytes >= sizeof zisofs_magic ) { + if ( !memcmp(inbuf, zisofs_magic, sizeof zisofs_magic) ) + force_compress = 1; + } + + set_731(curptr, position); curptr += 4; + + /* We have two special cases: a zero-length block is defined as all zero, + and a block the length of which is equal to the block size is unencoded. */ + + for ( i = 0 ; i < (int)CBLOCK_SIZE ; i++ ) { + if ( inbuf[i] ) break; + } + + if ( i == CBLOCK_SIZE ) { + /* All-zero block. No output */ + } else { + cbytes = 2*CBLOCK_SIZE; + if ( (zerr = compress2(outbuf, &cbytes, inbuf, bytes, opt.level)) + != Z_OK ) { + err = (zerr == Z_MEM_ERROR) ? EX_OSERR : EX_SOFTWARE; + goto free_ptr_bail; /* Compression failure */ + } + if ( fwrite(outbuf, 1, cbytes, output) != cbytes ) { + err = EX_CANTCREAT; + goto free_ptr_bail; + } + position += cbytes; + } + block++; + } + + /* Set pointer to the end of the final block */ + set_731(curptr, position); + + /* Now write the pointer table */ + if ( fseek(output, sizeof hdr, SEEK_SET) == -1 || + fwrite(pointer_block, 1, pointer_bytes, output) != pointer_bytes ) { + err = EX_CANTCREAT; + goto free_ptr_bail; + } + + free(pointer_block); + + /* Now make sure that this was actually the right thing to do */ + if ( !force_compress && position >= size ) { + /* Incompressible file, just copy it */ + rewind(input); + rewind(output); + + position = 0; + while ( (bytes = fread(inbuf, 1, CBLOCK_SIZE, input)) > 0 ) { + if ( fwrite(inbuf, 1, bytes, output) != bytes ) + return EX_CANTCREAT; + position += bytes; + } + + /* Truncate the file to the correct size */ + fflush(output); + ftruncate(fileno(output), position); + } + + /* If we get here, we're done! */ + return 0; + + /* Common bailout code */ + free_ptr_bail: + free(pointer_block); + return err; +} + |