minix/lib/libarchive/archive_write_set_compression_gzip.c

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2010-07-13 21:17:02 +02:00
/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_compression_gzip.c 201081 2009-12-28 02:04:42Z kientzle $");
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <time.h>
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#endif
#include "archive.h"
#include "archive_private.h"
#include "archive_write_private.h"
#ifndef HAVE_ZLIB_H
int
archive_write_set_compression_gzip(struct archive *a)
{
archive_set_error(a, ARCHIVE_ERRNO_MISC,
"gzip compression not supported on this platform");
return (ARCHIVE_FATAL);
}
#else
/* Don't compile this if we don't have zlib. */
struct private_data {
z_stream stream;
#ifndef __minix
int64_t total_in;
#else
ssize_t total_in;
#endif
unsigned char *compressed;
size_t compressed_buffer_size;
unsigned long crc;
};
struct private_config {
int compression_level;
};
/*
* Yuck. zlib.h is not const-correct, so I need this one bit
* of ugly hackery to convert a const * pointer to a non-const pointer.
*/
#define SET_NEXT_IN(st,src) \
(st)->stream.next_in = (Bytef *)(uintptr_t)(const void *)(src)
static int archive_compressor_gzip_finish(struct archive_write *);
static int archive_compressor_gzip_init(struct archive_write *);
static int archive_compressor_gzip_options(struct archive_write *,
const char *, const char *);
static int archive_compressor_gzip_write(struct archive_write *,
const void *, size_t);
static int drive_compressor(struct archive_write *, struct private_data *,
int finishing);
/*
* Allocate, initialize and return a archive object.
*/
int
archive_write_set_compression_gzip(struct archive *_a)
{
struct archive_write *a = (struct archive_write *)_a;
struct private_config *config;
__archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
ARCHIVE_STATE_NEW, "archive_write_set_compression_gzip");
config = malloc(sizeof(*config));
if (config == NULL) {
archive_set_error(&a->archive, ENOMEM, "Out of memory");
return (ARCHIVE_FATAL);
}
a->compressor.config = config;
a->compressor.finish = &archive_compressor_gzip_finish;
config->compression_level = Z_DEFAULT_COMPRESSION;
a->compressor.init = &archive_compressor_gzip_init;
a->compressor.options = &archive_compressor_gzip_options;
a->archive.compression_code = ARCHIVE_COMPRESSION_GZIP;
a->archive.compression_name = "gzip";
return (ARCHIVE_OK);
}
/*
* Setup callback.
*/
static int
archive_compressor_gzip_init(struct archive_write *a)
{
int ret;
struct private_data *state;
struct private_config *config;
time_t t;
config = (struct private_config *)a->compressor.config;
if (a->client_opener != NULL) {
ret = (a->client_opener)(&a->archive, a->client_data);
if (ret != ARCHIVE_OK)
return (ret);
}
/*
* The next check is a temporary workaround until the gzip
* code can be overhauled some. The code should not require
* that compressed_buffer_size == bytes_per_block. Removing
* this assumption will allow us to compress larger chunks at
* a time, which should improve overall performance
* marginally. As a minor side-effect, such a cleanup would
* allow us to support truly arbitrary block sizes.
*/
if (a->bytes_per_block < 10) {
archive_set_error(&a->archive, EINVAL,
"GZip compressor requires a minimum 10 byte block size");
return (ARCHIVE_FATAL);
}
state = (struct private_data *)malloc(sizeof(*state));
if (state == NULL) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate data for compression");
return (ARCHIVE_FATAL);
}
memset(state, 0, sizeof(*state));
/*
* See comment above. We should set compressed_buffer_size to
* max(bytes_per_block, 65536), but the code can't handle that yet.
*/
state->compressed_buffer_size = a->bytes_per_block;
state->compressed = (unsigned char *)malloc(state->compressed_buffer_size);
state->crc = crc32(0L, NULL, 0);
if (state->compressed == NULL) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate data for compression buffer");
free(state);
return (ARCHIVE_FATAL);
}
state->stream.next_out = state->compressed;
state->stream.avail_out = state->compressed_buffer_size;
/* Prime output buffer with a gzip header. */
t = time(NULL);
state->compressed[0] = 0x1f; /* GZip signature bytes */
state->compressed[1] = 0x8b;
state->compressed[2] = 0x08; /* "Deflate" compression */
state->compressed[3] = 0; /* No options */
state->compressed[4] = (t)&0xff; /* Timestamp */
state->compressed[5] = (t>>8)&0xff;
state->compressed[6] = (t>>16)&0xff;
state->compressed[7] = (t>>24)&0xff;
state->compressed[8] = 0; /* No deflate options */
state->compressed[9] = 3; /* OS=Unix */
state->stream.next_out += 10;
state->stream.avail_out -= 10;
a->compressor.write = archive_compressor_gzip_write;
/* Initialize compression library. */
ret = deflateInit2(&(state->stream),
config->compression_level,
Z_DEFLATED,
-15 /* < 0 to suppress zlib header */,
8,
Z_DEFAULT_STRATEGY);
if (ret == Z_OK) {
a->compressor.data = state;
return (0);
}
/* Library setup failed: clean up. */
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Internal error "
"initializing compression library");
free(state->compressed);
free(state);
/* Override the error message if we know what really went wrong. */
switch (ret) {
case Z_STREAM_ERROR:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Internal error initializing "
"compression library: invalid setup parameter");
break;
case Z_MEM_ERROR:
archive_set_error(&a->archive, ENOMEM, "Internal error initializing "
"compression library");
break;
case Z_VERSION_ERROR:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Internal error initializing "
"compression library: invalid library version");
break;
}
return (ARCHIVE_FATAL);
}
/*
* Set write options.
*/
static int
archive_compressor_gzip_options(struct archive_write *a, const char *key,
const char *value)
{
struct private_config *config;
config = (struct private_config *)a->compressor.config;
if (strcmp(key, "compression-level") == 0) {
if (value == NULL || !(value[0] >= '0' && value[0] <= '9') ||
value[1] != '\0')
return (ARCHIVE_WARN);
config->compression_level = value[0] - '0';
return (ARCHIVE_OK);
}
return (ARCHIVE_WARN);
}
/*
* Write data to the compressed stream.
*/
static int
archive_compressor_gzip_write(struct archive_write *a, const void *buff,
size_t length)
{
struct private_data *state;
int ret;
state = (struct private_data *)a->compressor.data;
if (a->client_writer == NULL) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"No write callback is registered? "
"This is probably an internal programming error.");
return (ARCHIVE_FATAL);
}
/* Update statistics */
state->crc = crc32(state->crc, (const Bytef *)buff, length);
state->total_in += length;
/* Compress input data to output buffer */
SET_NEXT_IN(state, buff);
state->stream.avail_in = length;
if ((ret = drive_compressor(a, state, 0)) != ARCHIVE_OK)
return (ret);
a->archive.file_position += length;
return (ARCHIVE_OK);
}
/*
* Finish the compression...
*/
static int
archive_compressor_gzip_finish(struct archive_write *a)
{
ssize_t block_length, target_block_length, bytes_written;
int ret;
struct private_data *state;
unsigned tocopy;
unsigned char trailer[8];
state = (struct private_data *)a->compressor.data;
ret = 0;
if (state != NULL) {
if (a->client_writer == NULL) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"No write callback is registered? "
"This is probably an internal programming error.");
ret = ARCHIVE_FATAL;
goto cleanup;
}
/* By default, always pad the uncompressed data. */
if (a->pad_uncompressed) {
tocopy = a->bytes_per_block -
(state->total_in % a->bytes_per_block);
while (tocopy > 0 && tocopy < (unsigned)a->bytes_per_block) {
SET_NEXT_IN(state, a->nulls);
state->stream.avail_in = tocopy < a->null_length ?
tocopy : a->null_length;
state->crc = crc32(state->crc, a->nulls,
state->stream.avail_in);
state->total_in += state->stream.avail_in;
tocopy -= state->stream.avail_in;
ret = drive_compressor(a, state, 0);
if (ret != ARCHIVE_OK)
goto cleanup;
}
}
/* Finish compression cycle */
if (((ret = drive_compressor(a, state, 1))) != ARCHIVE_OK)
goto cleanup;
/* Build trailer: 4-byte CRC and 4-byte length. */
trailer[0] = (state->crc)&0xff;
trailer[1] = (state->crc >> 8)&0xff;
trailer[2] = (state->crc >> 16)&0xff;
trailer[3] = (state->crc >> 24)&0xff;
trailer[4] = (state->total_in)&0xff;
trailer[5] = (state->total_in >> 8)&0xff;
trailer[6] = (state->total_in >> 16)&0xff;
trailer[7] = (state->total_in >> 24)&0xff;
/* Add trailer to current block. */
tocopy = 8;
if (tocopy > state->stream.avail_out)
tocopy = state->stream.avail_out;
memcpy(state->stream.next_out, trailer, tocopy);
state->stream.next_out += tocopy;
state->stream.avail_out -= tocopy;
/* If it overflowed, flush and start a new block. */
if (tocopy < 8) {
bytes_written = (a->client_writer)(&a->archive, a->client_data,
state->compressed, state->compressed_buffer_size);
if (bytes_written <= 0) {
ret = ARCHIVE_FATAL;
goto cleanup;
}
a->archive.raw_position += bytes_written;
state->stream.next_out = state->compressed;
state->stream.avail_out = state->compressed_buffer_size;
memcpy(state->stream.next_out, trailer + tocopy, 8-tocopy);
state->stream.next_out += 8-tocopy;
state->stream.avail_out -= 8-tocopy;
}
/* Optionally, pad the final compressed block. */
block_length = state->stream.next_out - state->compressed;
/* Tricky calculation to determine size of last block. */
if (a->bytes_in_last_block <= 0)
/* Default or Zero: pad to full block */
target_block_length = a->bytes_per_block;
else
/* Round length to next multiple of bytes_in_last_block. */
target_block_length = a->bytes_in_last_block *
( (block_length + a->bytes_in_last_block - 1) /
a->bytes_in_last_block);
if (target_block_length > a->bytes_per_block)
target_block_length = a->bytes_per_block;
if (block_length < target_block_length) {
memset(state->stream.next_out, 0,
target_block_length - block_length);
block_length = target_block_length;
}
/* Write the last block */
bytes_written = (a->client_writer)(&a->archive, a->client_data,
state->compressed, block_length);
if (bytes_written <= 0) {
ret = ARCHIVE_FATAL;
goto cleanup;
}
a->archive.raw_position += bytes_written;
/* Cleanup: shut down compressor, release memory, etc. */
cleanup:
switch (deflateEnd(&(state->stream))) {
case Z_OK:
break;
default:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Failed to clean up compressor");
ret = ARCHIVE_FATAL;
}
free(state->compressed);
free(state);
}
/* Clean up config area even if we never initialized. */
free(a->compressor.config);
a->compressor.config = NULL;
return (ret);
}
/*
* Utility function to push input data through compressor,
* writing full output blocks as necessary.
*
* Note that this handles both the regular write case (finishing ==
* false) and the end-of-archive case (finishing == true).
*/
static int
drive_compressor(struct archive_write *a, struct private_data *state, int finishing)
{
ssize_t bytes_written;
int ret;
for (;;) {
if (state->stream.avail_out == 0) {
bytes_written = (a->client_writer)(&a->archive,
a->client_data, state->compressed,
state->compressed_buffer_size);
if (bytes_written <= 0) {
/* TODO: Handle this write failure */
return (ARCHIVE_FATAL);
} else if ((size_t)bytes_written < state->compressed_buffer_size) {
/* Short write: Move remaining to
* front of block and keep filling */
memmove(state->compressed,
state->compressed + bytes_written,
state->compressed_buffer_size - bytes_written);
}
a->archive.raw_position += bytes_written;
state->stream.next_out
= state->compressed +
state->compressed_buffer_size - bytes_written;
state->stream.avail_out = bytes_written;
}
/* If there's nothing to do, we're done. */
if (!finishing && state->stream.avail_in == 0)
return (ARCHIVE_OK);
ret = deflate(&(state->stream),
finishing ? Z_FINISH : Z_NO_FLUSH );
switch (ret) {
case Z_OK:
/* In non-finishing case, check if compressor
* consumed everything */
if (!finishing && state->stream.avail_in == 0)
return (ARCHIVE_OK);
/* In finishing case, this return always means
* there's more work */
break;
case Z_STREAM_END:
/* This return can only occur in finishing case. */
return (ARCHIVE_OK);
default:
/* Any other return value indicates an error. */
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"GZip compression failed:"
" deflate() call returned status %d",
ret);
return (ARCHIVE_FATAL);
}
}
}
#endif /* HAVE_ZLIB_H */