2 * Copyright (c) 2008 Joerg Sonnenberger
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 * Copyright (c) 1985, 1986, 1992, 1993
28 * The Regents of the University of California. All rights reserved.
30 * This code is derived from software contributed to Berkeley by
31 * Diomidis Spinellis and James A. Woods, derived from original
32 * work by Spencer Thomas and Joseph Orost.
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
37 * 1. Redistributions of source code must retain the above copyright
38 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in the
41 * documentation and/or other materials provided with the distribution.
42 * 3. Neither the name of the University nor the names of its contributors
43 * may be used to endorse or promote products derived from this software
44 * without specific prior written permission.
46 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 #include "archive_platform.h"
61 __FBSDID("$FreeBSD: src/lib/libarchive/archive_write_set_compression_compress.c,v 1.1 2008/03/14 20:35:37 kientzle Exp $");
74 #include "archive_private.h"
75 #include "archive_write_private.h"
77 #define HSIZE 69001 /* 95% occupancy */
78 #define HSHIFT 8 /* 8 - trunc(log2(HSIZE / 65536)) */
79 #define CHECK_GAP 10000 /* Ratio check interval. */
81 #define MAXCODE(bits) ((1 << (bits)) - 1)
84 * the next two codes should not be changed lightly, as they must not
85 * lie within the contiguous general code space.
87 #define FIRST 257 /* First free entry. */
88 #define CLEAR 256 /* Table clear output code. */
91 off_t in_count, out_count, checkpoint;
93 int code_len; /* Number of bits/code. */
94 int cur_maxcode; /* Maximum code, given n_bits. */
95 int max_maxcode; /* Should NEVER generate this code. */
97 unsigned short codetab [HSIZE];
98 int first_free; /* First unused entry. */
101 int cur_code, cur_fcode;
104 unsigned char bit_buf;
106 unsigned char *compressed;
107 size_t compressed_buffer_size;
108 size_t compressed_offset;
111 static int archive_compressor_compress_finish(struct archive_write *);
112 static int archive_compressor_compress_init(struct archive_write *);
113 static int archive_compressor_compress_write(struct archive_write *,
114 const void *, size_t);
117 * Allocate, initialize and return a archive object.
120 archive_write_set_compression_compress(struct archive *_a)
122 struct archive_write *a = (struct archive_write *)_a;
123 __archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
124 ARCHIVE_STATE_NEW, "archive_write_set_compression_compress");
125 a->compressor.init = &archive_compressor_compress_init;
126 a->archive.compression_code = ARCHIVE_COMPRESSION_COMPRESS;
127 a->archive.compression_name = "compress";
135 archive_compressor_compress_init(struct archive_write *a)
138 struct private_data *state;
140 a->archive.compression_code = ARCHIVE_COMPRESSION_COMPRESS;
141 a->archive.compression_name = "compress";
143 if (a->bytes_per_block < 4) {
144 archive_set_error(&a->archive, EINVAL,
145 "Can't write Compress header as single block");
146 return (ARCHIVE_FATAL);
149 if (a->client_opener != NULL) {
150 ret = (a->client_opener)(&a->archive, a->client_data);
151 if (ret != ARCHIVE_OK)
155 state = (struct private_data *)malloc(sizeof(*state));
157 archive_set_error(&a->archive, ENOMEM,
158 "Can't allocate data for compression");
159 return (ARCHIVE_FATAL);
161 memset(state, 0, sizeof(*state));
163 state->compressed_buffer_size = a->bytes_per_block;
164 state->compressed = malloc(state->compressed_buffer_size);
166 if (state->compressed == NULL) {
167 archive_set_error(&a->archive, ENOMEM,
168 "Can't allocate data for compression buffer");
170 return (ARCHIVE_FATAL);
173 a->compressor.write = archive_compressor_compress_write;
174 a->compressor.finish = archive_compressor_compress_finish;
176 state->max_maxcode = 0x10000; /* Should NEVER generate this code. */
177 state->in_count = 0; /* Length of input. */
179 state->bit_offset = 0;
180 state->out_count = 3; /* Includes 3-byte header mojo. */
181 state->compress_ratio = 0;
182 state->checkpoint = CHECK_GAP;
184 state->cur_maxcode = MAXCODE(state->code_len);
185 state->first_free = FIRST;
187 memset(state->hashtab, 0xff, sizeof(state->hashtab));
189 /* Prime output buffer with a gzip header. */
190 state->compressed[0] = 0x1f; /* Compress */
191 state->compressed[1] = 0x9d;
192 state->compressed[2] = 0x90; /* Block mode, 16bit max */
193 state->compressed_offset = 3;
195 a->compressor.data = state;
200 * Output the given code.
202 * code: A n_bits-bit integer. If == -1, then EOF. This assumes
203 * that n_bits =< (long)wordsize - 1.
205 * Outputs code to the file.
207 * Chars are 8 bits long.
209 * Maintain a BITS character long buffer (so that 8 codes will
210 * fit in it exactly). Use the VAX insv instruction to insert each
211 * code in turn. When the buffer fills up empty it and start over.
214 static unsigned char rmask[9] =
215 {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
218 output_byte(struct archive_write *a, unsigned char c)
220 struct private_data *state = a->compressor.data;
221 ssize_t bytes_written;
223 state->compressed[state->compressed_offset++] = c;
226 if (state->compressed_buffer_size == state->compressed_offset) {
227 bytes_written = (a->client_writer)(&a->archive,
229 state->compressed, state->compressed_buffer_size);
230 if (bytes_written <= 0)
231 return ARCHIVE_FATAL;
232 a->archive.raw_position += bytes_written;
233 state->compressed_offset = 0;
240 output_code(struct archive_write *a, int ocode)
242 struct private_data *state = a->compressor.data;
243 int bits, ret, clear_flg, bit_offset;
245 clear_flg = ocode == CLEAR;
246 bits = state->code_len;
249 * Since ocode is always >= 8 bits, only need to mask the first
252 bit_offset = state->bit_offset % 8;
253 state->bit_buf |= (ocode << bit_offset) & 0xff;
254 output_byte(a, state->bit_buf);
256 bits = state->code_len - (8 - bit_offset);
257 ocode >>= 8 - bit_offset;
258 /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
260 output_byte(a, ocode & 0xff);
265 state->bit_offset += state->code_len;
266 state->bit_buf = ocode & rmask[bits];
267 if (state->bit_offset == state->code_len * 8)
268 state->bit_offset = 0;
271 * If the next entry is going to be too big for the ocode size,
272 * then increase it, if possible.
274 if (clear_flg || state->first_free > state->cur_maxcode) {
276 * Write the whole buffer, because the input side won't
277 * discover the size increase until after it has read it.
279 if (state->bit_offset > 0) {
280 while (state->bit_offset < state->code_len * 8) {
281 ret = output_byte(a, state->bit_buf);
282 if (ret != ARCHIVE_OK)
284 state->bit_offset += 8;
289 state->bit_offset = 0;
293 state->cur_maxcode = MAXCODE(state->code_len);
296 if (state->code_len == 16)
297 state->cur_maxcode = state->max_maxcode;
299 state->cur_maxcode = MAXCODE(state->code_len);
307 output_flush(struct archive_write *a)
309 struct private_data *state = a->compressor.data;
312 /* At EOF, write the rest of the buffer. */
313 if (state->bit_offset % 8) {
314 state->code_len = (state->bit_offset % 8 + 7) / 8;
315 ret = output_byte(a, state->bit_buf);
316 if (ret != ARCHIVE_OK)
324 * Write data to the compressed stream.
327 archive_compressor_compress_write(struct archive_write *a, const void *buff,
330 struct private_data *state;
334 const unsigned char *bp;
336 state = (struct private_data *)a->compressor.data;
337 if (a->client_writer == NULL) {
338 archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
339 "No write callback is registered? "
340 "This is probably an internal programming error.");
341 return (ARCHIVE_FATAL);
349 if (state->in_count == 0) {
350 state->cur_code = *bp++;
358 state->cur_fcode = (c << 16) + state->cur_code;
359 i = ((c << HSHIFT) ^ state->cur_code); /* Xor hashing. */
361 if (state->hashtab[i] == state->cur_fcode) {
362 state->cur_code = state->codetab[i];
365 if (state->hashtab[i] < 0) /* Empty slot. */
367 /* Secondary hash (after G. Knott). */
376 if (state->hashtab[i] == state->cur_fcode) {
377 state->cur_code = state->codetab[i];
380 if (state->hashtab[i] >= 0)
383 ret = output_code(a, state->cur_code);
384 if (ret != ARCHIVE_OK)
387 if (state->first_free < state->max_maxcode) {
388 state->codetab[i] = state->first_free++; /* code -> hashtable */
389 state->hashtab[i] = state->cur_fcode;
392 if (state->in_count < state->checkpoint)
395 state->checkpoint = state->in_count + CHECK_GAP;
397 if (state->in_count <= 0x007fffff)
398 ratio = state->in_count * 256 / state->out_count;
399 else if ((ratio = state->out_count / 256) == 0)
402 ratio = state->in_count / ratio;
404 if (ratio > state->compress_ratio)
405 state->compress_ratio = ratio;
407 state->compress_ratio = 0;
408 memset(state->hashtab, 0xff, sizeof(state->hashtab));
409 state->first_free = FIRST;
410 ret = output_code(a, CLEAR);
411 if (ret != ARCHIVE_OK)
421 * Finish the compression...
424 archive_compressor_compress_finish(struct archive_write *a)
426 ssize_t block_length, target_block_length, bytes_written;
428 struct private_data *state;
431 state = (struct private_data *)a->compressor.data;
433 if (a->client_writer == NULL) {
434 archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
435 "No write callback is registered? "
436 "This is probably an internal programming error.");
441 /* By default, always pad the uncompressed data. */
442 if (a->pad_uncompressed) {
443 while (state->in_count % a->bytes_per_block != 0) {
444 tocopy = a->bytes_per_block -
445 (state->in_count % a->bytes_per_block);
446 if (tocopy > a->null_length)
447 tocopy = a->null_length;
448 ret = archive_compressor_compress_write(a, a->nulls,
450 if (ret != ARCHIVE_OK)
455 ret = output_code(a, state->cur_code);
456 if (ret != ARCHIVE_OK)
458 ret = output_flush(a);
459 if (ret != ARCHIVE_OK)
462 /* Optionally, pad the final compressed block. */
463 block_length = state->compressed_offset;
465 /* Tricky calculation to determine size of last block. */
466 if (a->bytes_in_last_block <= 0)
467 /* Default or Zero: pad to full block */
468 target_block_length = a->bytes_per_block;
470 /* Round length to next multiple of bytes_in_last_block. */
471 target_block_length = a->bytes_in_last_block *
472 ( (block_length + a->bytes_in_last_block - 1) /
473 a->bytes_in_last_block);
474 if (target_block_length > a->bytes_per_block)
475 target_block_length = a->bytes_per_block;
476 if (block_length < target_block_length) {
477 memset(state->compressed + state->compressed_offset, 0,
478 target_block_length - block_length);
479 block_length = target_block_length;
482 /* Write the last block */
483 bytes_written = (a->client_writer)(&a->archive, a->client_data,
484 state->compressed, block_length);
485 if (bytes_written <= 0)
488 a->archive.raw_position += bytes_written;
491 free(state->compressed);