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author | kientzle <kientzle@FreeBSD.org> | 2004-02-09 23:22:54 +0000 |
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committer | kientzle <kientzle@FreeBSD.org> | 2004-02-09 23:22:54 +0000 |
commit | af9413b539628b0758b4af66ffbb879fba49cc6d (patch) | |
tree | 20e1d80fd0a1d288a08af1696ee258bcd08f41d0 /lib/libarchive/archive_write_set_compression_gzip.c | |
parent | 6b6e533f7e91602d4ccb3353351eb9f816c2daf2 (diff) | |
download | FreeBSD-src-af9413b539628b0758b4af66ffbb879fba49cc6d.zip FreeBSD-src-af9413b539628b0758b4af66ffbb879fba49cc6d.tar.gz |
Initial import of libarchive.
What it is:
A library for reading and writing various streaming archive
formats, especially tar and cpio. Being a library, it should
be easy to incorporate into pkg_* tools, sysinstall, and any
other place that needs to read or write such archives.
Features:
* Full automatic detection of both compression and archive format.
* Extensible internal architecture to make it easy to add new formats.
* Support for "pax interchange format," a new POSIX-standard tar format
that eliminates essentially all of the restrictions of historic formats.
* BSD license
Thanks to: jkh for pushing me to start this work, gordon for
encouraging me to commit it, bde for answering endless style
questions, and many others for feedback and encouragement.
Status: Pretty good overall, though there are still a few rough edges and
the library could always use more testing. Feedback eagerly solicited.
Diffstat (limited to 'lib/libarchive/archive_write_set_compression_gzip.c')
-rw-r--r-- | lib/libarchive/archive_write_set_compression_gzip.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/lib/libarchive/archive_write_set_compression_gzip.c b/lib/libarchive/archive_write_set_compression_gzip.c new file mode 100644 index 0000000..7c9ade6 --- /dev/null +++ b/lib/libarchive/archive_write_set_compression_gzip.c @@ -0,0 +1,380 @@ +/*- + * Copyright (c) 2003-2004 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 + * in this position and unchanged. + * 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#ifdef DMALLOC +#include <dmalloc.h> +#endif +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <zlib.h> + +#include "archive.h" +#include "archive_private.h" + +struct private_data { + z_stream stream; + int64_t total_in; + unsigned char *compressed; + size_t compressed_buffer_size; + unsigned long crc; +}; + + +/* + * 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 = (void *)(uintptr_t)(const void *)(src) + +static int archive_compressor_gzip_finish(struct archive *); +static int archive_compressor_gzip_init(struct archive *); +static ssize_t archive_compressor_gzip_write(struct archive *, const void *, + size_t); +static int drive_compressor(struct archive *, struct private_data *, + int finishing); + + +/* + * Allocate, initialize and return a archive object. + */ +int +archive_write_set_compression_gzip(struct archive *a) +{ + archive_check_magic(a, ARCHIVE_WRITE_MAGIC, ARCHIVE_STATE_NEW); + a->compression_init = &archive_compressor_gzip_init; + a->compression_code = ARCHIVE_COMPRESSION_GZIP; + a->compression_name = "gzip"; + return (ARCHIVE_OK); +} + +/* + * Setup callback. + */ +static int +archive_compressor_gzip_init(struct archive *a) +{ + int ret; + struct private_data *state; + time_t t; + + a->compression_code = ARCHIVE_COMPRESSION_GZIP; + a->compression_name = "gzip"; + + if (a->client_opener != NULL) { + ret = (a->client_opener)(a, a->client_data); + if (ret != ARCHIVE_OK) + return (ret); + } + + state = (struct private_data *)malloc(sizeof(*state)); + if (state == NULL) { + archive_set_error(a, ENOMEM, + "Can't allocate data for compression"); + return (ARCHIVE_FATAL); + } + memset(state, 0, sizeof(*state)); + + state->compressed_buffer_size = a->bytes_per_block; + state->compressed = malloc(state->compressed_buffer_size); + state->crc = crc32(0L, NULL, 0); + + if (state->compressed == NULL) { + archive_set_error(a, 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->compression_write = archive_compressor_gzip_write; + a->compression_finish = archive_compressor_gzip_finish; + + /* Initialize compression library. */ + ret = deflateInit2(&(state->stream), + Z_DEFAULT_COMPRESSION, + Z_DEFLATED, + -15 /* < 0 to suppress zlib header */, + 8, + Z_DEFAULT_STRATEGY); + + if (ret == Z_OK) { + a->compression_data = state; + return (0); + } + + /* Library setup failed: clean up. */ + archive_set_error(a, -1, "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, EINVAL, "Internal error initializing " + "compression library: invalid setup parameter"); + break; + case Z_MEM_ERROR: + archive_set_error(a, ENOMEM, "Internal error initializing " + "compression library"); + break; + case Z_VERSION_ERROR: + archive_set_error(a, -1, "Internal error initializing " + "compression library: invalid library version"); + break; + } + + return (ARCHIVE_FATAL); +} + +/* + * Write data to the compressed stream. + */ +static ssize_t +archive_compressor_gzip_write(struct archive *a, const void *buff, + size_t length) +{ + struct private_data *state; + int ret; + + state = a->compression_data; + if (!a->client_writer) { + archive_set_error(a, EDOOFUS, + "No write callback is registered? " + "This is probably an internal programming error."); + return (ARCHIVE_FATAL); + } + + /* Update statistics */ + state->crc = crc32(state->crc, 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); + + return (length); +} + + +/* + * Finish the compression... + */ +static int +archive_compressor_gzip_finish(struct archive *a) +{ + ssize_t block_length, target_block_length; + int ret; + struct private_data *state; + unsigned tocopy; + unsigned char trailer[8]; + + state = a->compression_data; + ret = 0; + if (a->client_writer == NULL) { + archive_set_error(a, EDOOFUS, + "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) { + ret = (a->client_writer)(a, a->client_data, state->compressed, + state->compressed_buffer_size); + 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. */ + target_block_length = block_length; + 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 */ + ret = (a->client_writer)(a, a->client_data, state->compressed, + block_length); + + /* Cleanup: shut down compressor, release memory, etc. */ +cleanup: + switch (deflateEnd(&(state->stream))) { + case Z_OK: + break; + default: + archive_set_error(a, -1, "Failed to clean up compressor"); + ret = ARCHIVE_FATAL; + } + free(state->compressed); + free(state); + + /* Close the output */ + if (a->client_closer != NULL) + (a->client_closer)(a, a->client_data); + + 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 *a, struct private_data *state, int finishing) +{ + size_t ret; + + for (;;) { + if (state->stream.avail_out == 0) { + ret = (a->client_writer)(a, a->client_data, + state->compressed, state->compressed_buffer_size); + if (ret <= 0) { + /* TODO: Handle this write failure */ + return (ARCHIVE_FATAL); + } else if (ret < state->compressed_buffer_size) { + /* Short write: Move remaining to + * front of block and keep filling */ + memmove(state->compressed, + state->compressed + ret, + state->compressed_buffer_size - ret); + } + + state->stream.next_out + = state->compressed + + state->compressed_buffer_size - ret; + state->stream.avail_out = ret; + } + + 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, -1, "GZip compression failed"); + return (ARCHIVE_FATAL); + } + } +} |