1 ///////////////////////////////////////////////////////////////////////////////
4 /// \brief Compresses or uncompresses a file
6 // Author: Lasse Collin
8 // This file has been put into the public domain.
9 // You can do whatever you want with this file.
11 ///////////////////////////////////////////////////////////////////////////////
16 /// Return value type for coder_init().
24 enum operation_mode opt_mode = MODE_COMPRESS;
25 enum format_type opt_format = FORMAT_AUTO;
26 bool opt_auto_adjust = true;
29 /// Stream used to communicate with liblzma
30 static lzma_stream strm = LZMA_STREAM_INIT;
32 /// Filters needed for all encoding all formats, and also decoding in raw data
33 static lzma_filter filters[LZMA_FILTERS_MAX + 1];
35 /// Input and output buffers
37 static io_buf out_buf;
39 /// Number of filters. Zero indicates that we are using a preset.
40 static size_t filters_count = 0;
42 /// Number of the preset (0-9)
43 static size_t preset_number = 6;
45 /// If a preset is used (no custom filter chain) and preset_extreme is true,
46 /// a significantly slower compression is used to achieve slightly better
47 /// compression ratio.
48 static bool preset_extreme = false;
50 /// Integrity check type
51 static lzma_check check;
53 /// This becomes false if the --check=CHECK option is used.
54 static bool check_default = true;
58 coder_set_check(lzma_check new_check)
61 check_default = false;
67 coder_set_preset(size_t new_preset)
69 preset_number = new_preset;
71 // Setting a preset makes us forget a possibly defined custom
73 while (filters_count > 0) {
75 free(filters[filters_count].options);
76 filters[filters_count].options = NULL;
84 coder_set_extreme(void)
86 preset_extreme = true;
92 coder_add_filter(lzma_vli id, void *options)
94 if (filters_count == LZMA_FILTERS_MAX)
95 message_fatal(_("Maximum number of filters is four"));
97 filters[filters_count].id = id;
98 filters[filters_count].options = options;
105 static void lzma_attribute((noreturn))
106 memlimit_too_small(uint64_t memory_usage)
108 message(V_ERROR, _("Memory usage limit is too low for the given "
110 message_mem_needed(V_ERROR, memory_usage);
111 tuklib_exit(E_ERROR, E_ERROR, false);
116 coder_set_compression_settings(void)
118 // Options for LZMA1 or LZMA2 in case we are using a preset.
119 static lzma_options_lzma opt_lzma;
121 if (filters_count == 0) {
122 // We are using a preset. This is not a good idea in raw mode
123 // except when playing around with things. Different versions
124 // of this software may use different options in presets, and
125 // thus make uncompressing the raw data difficult.
126 if (opt_format == FORMAT_RAW) {
127 // The message is shown only if warnings are allowed
128 // but the exit status isn't changed.
129 message(V_WARNING, _("Using a preset in raw mode "
131 message(V_WARNING, _("The exact options of the "
132 "presets may vary between software "
136 // Get the preset for LZMA1 or LZMA2.
138 preset_number |= LZMA_PRESET_EXTREME;
140 if (lzma_lzma_preset(&opt_lzma, preset_number))
143 // Use LZMA2 except with --format=lzma we use LZMA1.
144 filters[0].id = opt_format == FORMAT_LZMA
145 ? LZMA_FILTER_LZMA1 : LZMA_FILTER_LZMA2;
146 filters[0].options = &opt_lzma;
150 // Terminate the filter options array.
151 filters[filters_count].id = LZMA_VLI_UNKNOWN;
153 // If we are using the .lzma format, allow exactly one filter
154 // which has to be LZMA1.
155 if (opt_format == FORMAT_LZMA && (filters_count != 1
156 || filters[0].id != LZMA_FILTER_LZMA1))
157 message_fatal(_("The .lzma format supports only "
158 "the LZMA1 filter"));
160 // If we are using the .xz format, make sure that there is no LZMA1
161 // filter to prevent LZMA_PROG_ERROR.
162 if (opt_format == FORMAT_XZ)
163 for (size_t i = 0; i < filters_count; ++i)
164 if (filters[i].id == LZMA_FILTER_LZMA1)
165 message_fatal(_("LZMA1 cannot be used "
166 "with the .xz format"));
168 // Print the selected filter chain.
169 message_filters_show(V_DEBUG, filters);
171 // If using --format=raw, we can be decoding. The memusage function
172 // also validates the filter chain and the options used for the
174 const uint64_t memory_limit = hardware_memlimit_get(opt_mode);
175 uint64_t memory_usage;
176 if (opt_mode == MODE_COMPRESS)
177 memory_usage = lzma_raw_encoder_memusage(filters);
179 memory_usage = lzma_raw_decoder_memusage(filters);
181 if (memory_usage == UINT64_MAX)
182 message_fatal(_("Unsupported filter chain or filter options"));
184 // Print memory usage info before possible dictionary
185 // size auto-adjusting.
186 message_mem_needed(V_DEBUG, memory_usage);
187 if (opt_mode == MODE_COMPRESS) {
188 const uint64_t decmem = lzma_raw_decoder_memusage(filters);
189 if (decmem != UINT64_MAX)
190 message(V_DEBUG, _("Decompression will need "
191 "%s MiB of memory."), uint64_to_str(
192 round_up_to_mib(decmem), 0));
195 if (memory_usage > memory_limit) {
196 // If --no-auto-adjust was used or we didn't find LZMA1 or
197 // LZMA2 as the last filter, give an error immediately.
198 // --format=raw implies --no-auto-adjust.
199 if (!opt_auto_adjust || opt_format == FORMAT_RAW)
200 memlimit_too_small(memory_usage);
202 assert(opt_mode == MODE_COMPRESS);
204 // Look for the last filter if it is LZMA2 or LZMA1, so
205 // we can make it use less RAM. With other filters we don't
208 while (filters[i].id != LZMA_FILTER_LZMA2
209 && filters[i].id != LZMA_FILTER_LZMA1) {
210 if (filters[i].id == LZMA_VLI_UNKNOWN)
211 memlimit_too_small(memory_usage);
216 // Decrease the dictionary size until we meet the memory
217 // usage limit. First round down to full mebibytes.
218 lzma_options_lzma *opt = filters[i].options;
219 const uint32_t orig_dict_size = opt->dict_size;
220 opt->dict_size &= ~((UINT32_C(1) << 20) - 1);
222 // If it is below 1 MiB, auto-adjusting failed. We
223 // could be more sophisticated and scale it down even
224 // more, but let's see if many complain about this
227 // FIXME: Displays the scaled memory usage instead
229 if (opt->dict_size < (UINT32_C(1) << 20))
230 memlimit_too_small(memory_usage);
232 memory_usage = lzma_raw_encoder_memusage(filters);
233 if (memory_usage == UINT64_MAX)
236 // Accept it if it is low enough.
237 if (memory_usage <= memory_limit)
240 // Otherwise 1 MiB down and try again. I hope this
241 // isn't too slow method for cases where the original
242 // dict_size is very big.
243 opt->dict_size -= UINT32_C(1) << 20;
246 // Tell the user that we decreased the dictionary size.
247 message(V_WARNING, _("Adjusted LZMA%c dictionary size "
248 "from %s MiB to %s MiB to not exceed "
249 "the memory usage limit of %s MiB"),
250 filters[i].id == LZMA_FILTER_LZMA2
252 uint64_to_str(orig_dict_size >> 20, 0),
253 uint64_to_str(opt->dict_size >> 20, 1),
254 uint64_to_str(round_up_to_mib(
259 // Limit the number of worker threads so that memory usage
260 // limit isn't exceeded.
261 assert(memory_usage > 0);
262 size_t thread_limit = memory_limit / memory_usage;
263 if (thread_limit == 0)
266 if (opt_threads > thread_limit)
267 opt_threads = thread_limit;
271 // The default check type is CRC64, but fallback to CRC32
272 // if CRC64 isn't supported by the copy of liblzma we are
273 // using. CRC32 is always supported.
274 check = LZMA_CHECK_CRC64;
275 if (!lzma_check_is_supported(check))
276 check = LZMA_CHECK_CRC32;
283 /// Return true if the data in in_buf seems to be in the .xz format.
287 return strm.avail_in >= 6 && memcmp(in_buf.u8, "\3757zXZ", 6) == 0;
291 /// Return true if the data in in_buf seems to be in the .lzma format.
295 // The .lzma header is 13 bytes.
296 if (strm.avail_in < 13)
299 // Decode the LZMA1 properties.
300 lzma_filter filter = { .id = LZMA_FILTER_LZMA1 };
301 if (lzma_properties_decode(&filter, NULL, in_buf.u8, 5) != LZMA_OK)
304 // A hack to ditch tons of false positives: We allow only dictionary
305 // sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone
306 // created only files with 2^n, but accepts any dictionary size.
307 // If someone complains, this will be reconsidered.
308 lzma_options_lzma *opt = filter.options;
309 const uint32_t dict_size = opt->dict_size;
312 if (dict_size != UINT32_MAX) {
313 uint32_t d = dict_size - 1;
320 if (d != dict_size || dict_size == 0)
324 // Another hack to ditch false positives: Assume that if the
325 // uncompressed size is known, it must be less than 256 GiB.
326 // Again, if someone complains, this will be reconsidered.
327 uint64_t uncompressed_size = 0;
328 for (size_t i = 0; i < 8; ++i)
329 uncompressed_size |= (uint64_t)(in_buf.u8[5 + i]) << (i * 8);
331 if (uncompressed_size != UINT64_MAX
332 && uncompressed_size > (UINT64_C(1) << 38))
339 /// Detect the input file type (for now, this done only when decompressing),
340 /// and initialize an appropriate coder. Return value indicates if a normal
341 /// liblzma-based coder was initialized (CODER_INIT_NORMAL), if passthru
342 /// mode should be used (CODER_INIT_PASSTHRU), or if an error occurred
343 /// (CODER_INIT_ERROR).
344 static enum coder_init_ret
345 coder_init(file_pair *pair)
347 lzma_ret ret = LZMA_PROG_ERROR;
349 if (opt_mode == MODE_COMPRESS) {
350 switch (opt_format) {
352 // args.c ensures this.
357 ret = lzma_stream_encoder(&strm, filters, check);
361 ret = lzma_alone_encoder(&strm, filters[0].options);
365 ret = lzma_raw_encoder(&strm, filters);
369 const uint32_t flags = LZMA_TELL_UNSUPPORTED_CHECK
372 // We abuse FORMAT_AUTO to indicate unknown file format,
373 // for which we may consider passthru mode.
374 enum format_type init_format = FORMAT_AUTO;
376 switch (opt_format) {
379 init_format = FORMAT_XZ;
380 else if (is_format_lzma())
381 init_format = FORMAT_LZMA;
386 init_format = FORMAT_XZ;
390 if (is_format_lzma())
391 init_format = FORMAT_LZMA;
395 init_format = FORMAT_RAW;
399 switch (init_format) {
401 // Uknown file format. If --decompress --stdout
402 // --force have been given, then we copy the input
403 // as is to stdout. Checking for MODE_DECOMPRESS
404 // is needed, because we don't want to do use
405 // passthru mode with --test.
406 if (opt_mode == MODE_DECOMPRESS
407 && opt_stdout && opt_force)
408 return CODER_INIT_PASSTHRU;
410 ret = LZMA_FORMAT_ERROR;
414 ret = lzma_stream_decoder(&strm,
415 hardware_memlimit_get(
416 MODE_DECOMPRESS), flags);
420 ret = lzma_alone_decoder(&strm,
421 hardware_memlimit_get(
426 // Memory usage has already been checked in
427 // coder_set_compression_settings().
428 ret = lzma_raw_decoder(&strm, filters);
432 // Try to decode the headers. This will catch too low
433 // memory usage limit in case it happens in the first
434 // Block of the first Stream, which is where it very
435 // probably will happen if it is going to happen.
436 if (ret == LZMA_OK && init_format != FORMAT_RAW) {
437 strm.next_out = NULL;
439 ret = lzma_code(&strm, LZMA_RUN);
443 if (ret != LZMA_OK) {
444 message_error("%s: %s", pair->src_name, message_strm(ret));
445 if (ret == LZMA_MEMLIMIT_ERROR)
446 message_mem_needed(V_ERROR, lzma_memusage(&strm));
448 return CODER_INIT_ERROR;
451 return CODER_INIT_NORMAL;
455 /// Compress or decompress using liblzma.
457 coder_normal(file_pair *pair)
459 // Encoder needs to know when we have given all the input to it.
460 // The decoders need to know it too when we are using
461 // LZMA_CONCATENATED. We need to check for src_eof here, because
462 // the first input chunk has been already read, and that may
463 // have been the only chunk we will read.
464 lzma_action action = pair->src_eof ? LZMA_FINISH : LZMA_RUN;
468 // Assume that something goes wrong.
469 bool success = false;
471 strm.next_out = out_buf.u8;
472 strm.avail_out = IO_BUFFER_SIZE;
474 while (!user_abort) {
475 // Fill the input buffer if it is empty and we haven't reached
477 if (strm.avail_in == 0 && !pair->src_eof) {
478 strm.next_in = in_buf.u8;
479 strm.avail_in = io_read(
480 pair, &in_buf, IO_BUFFER_SIZE);
482 if (strm.avail_in == SIZE_MAX)
486 action = LZMA_FINISH;
489 // Let liblzma do the actual work.
490 ret = lzma_code(&strm, action);
492 // Write out if the output buffer became full.
493 if (strm.avail_out == 0) {
494 if (opt_mode != MODE_TEST && io_write(pair, &out_buf,
495 IO_BUFFER_SIZE - strm.avail_out))
498 strm.next_out = out_buf.u8;
499 strm.avail_out = IO_BUFFER_SIZE;
502 if (ret != LZMA_OK) {
503 // Determine if the return value indicates that we
504 // won't continue coding.
505 const bool stop = ret != LZMA_NO_CHECK
506 && ret != LZMA_UNSUPPORTED_CHECK;
509 // Write the remaining bytes even if something
510 // went wrong, because that way the user gets
511 // as much data as possible, which can be good
512 // when trying to get at least some useful
513 // data out of damaged files.
514 if (opt_mode != MODE_TEST && io_write(pair,
515 &out_buf, IO_BUFFER_SIZE
520 if (ret == LZMA_STREAM_END) {
521 // Check that there is no trailing garbage.
522 // This is needed for LZMA_Alone and raw
524 if (strm.avail_in == 0 && !pair->src_eof) {
525 // Try reading one more byte.
526 // Hopefully we don't get any more
527 // input, and thus pair->src_eof
529 strm.avail_in = io_read(
531 if (strm.avail_in == SIZE_MAX)
534 assert(strm.avail_in == 0
535 || strm.avail_in == 1);
538 if (strm.avail_in == 0) {
539 assert(pair->src_eof);
544 // We hadn't reached the end of the file.
545 ret = LZMA_DATA_ERROR;
549 // If we get here and stop is true, something went
550 // wrong and we print an error. Otherwise it's just
551 // a warning and coding can continue.
553 message_error("%s: %s", pair->src_name,
556 message_warning("%s: %s", pair->src_name,
559 // When compressing, all possible errors set
561 assert(opt_mode != MODE_COMPRESS);
564 if (ret == LZMA_MEMLIMIT_ERROR) {
565 // Display how much memory it would have
567 message_mem_needed(V_ERROR,
568 lzma_memusage(&strm));
575 // Show progress information under certain conditions.
576 message_progress_update();
583 /// Copy from input file to output file without processing the data in any
584 /// way. This is used only when trying to decompress unrecognized files
585 /// with --decompress --stdout --force, so the output is always stdout.
587 coder_passthru(file_pair *pair)
589 while (strm.avail_in != 0) {
593 if (io_write(pair, &in_buf, strm.avail_in))
596 strm.total_in += strm.avail_in;
597 strm.total_out = strm.total_in;
598 message_progress_update();
600 strm.avail_in = io_read(pair, &in_buf, IO_BUFFER_SIZE);
601 if (strm.avail_in == SIZE_MAX)
610 coder_run(const char *filename)
612 // Set and possibly print the filename for the progress message.
613 message_filename(filename);
615 // Try to open the input file.
616 file_pair *pair = io_open_src(filename);
620 // Assume that something goes wrong.
621 bool success = false;
623 // Read the first chunk of input data. This is needed to detect
624 // the input file type (for now, only for decompression).
625 strm.next_in = in_buf.u8;
626 strm.avail_in = io_read(pair, &in_buf, IO_BUFFER_SIZE);
628 if (strm.avail_in != SIZE_MAX) {
629 // Initialize the coder. This will detect the file format
630 // and, in decompression or testing mode, check the memory
631 // usage of the first Block too. This way we don't try to
632 // open the destination file if we see that coding wouldn't
633 // work at all anyway. This also avoids deleting the old
634 // "target" file if --force was used.
635 const enum coder_init_ret init_ret = coder_init(pair);
637 if (init_ret != CODER_INIT_ERROR && !user_abort) {
638 // Don't open the destination file when --test
640 if (opt_mode == MODE_TEST || !io_open_dest(pair)) {
641 // Initialize the progress indicator.
642 const uint64_t in_size
643 = pair->src_st.st_size <= 0
644 ? 0 : pair->src_st.st_size;
645 message_progress_start(&strm, in_size);
647 // Do the actual coding or passthru.
648 if (init_ret == CODER_INIT_NORMAL)
649 success = coder_normal(pair);
651 success = coder_passthru(pair);
653 message_progress_end(success);
658 // Close the file pair. It needs to know if coding was successful to
659 // know if the source or target file should be unlinked.
660 io_close(pair, success);