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 // Specify the magic as hex to be compatible with EBCDIC systems.
288 static const uint8_t magic[6] = { 0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00 };
289 return strm.avail_in >= sizeof(magic)
290 && memcmp(in_buf.u8, magic, sizeof(magic)) == 0;
294 /// Return true if the data in in_buf seems to be in the .lzma format.
298 // The .lzma header is 13 bytes.
299 if (strm.avail_in < 13)
302 // Decode the LZMA1 properties.
303 lzma_filter filter = { .id = LZMA_FILTER_LZMA1 };
304 if (lzma_properties_decode(&filter, NULL, in_buf.u8, 5) != LZMA_OK)
307 // A hack to ditch tons of false positives: We allow only dictionary
308 // sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone
309 // created only files with 2^n, but accepts any dictionary size.
310 // If someone complains, this will be reconsidered.
311 lzma_options_lzma *opt = filter.options;
312 const uint32_t dict_size = opt->dict_size;
315 if (dict_size != UINT32_MAX) {
316 uint32_t d = dict_size - 1;
323 if (d != dict_size || dict_size == 0)
327 // Another hack to ditch false positives: Assume that if the
328 // uncompressed size is known, it must be less than 256 GiB.
329 // Again, if someone complains, this will be reconsidered.
330 uint64_t uncompressed_size = 0;
331 for (size_t i = 0; i < 8; ++i)
332 uncompressed_size |= (uint64_t)(in_buf.u8[5 + i]) << (i * 8);
334 if (uncompressed_size != UINT64_MAX
335 && uncompressed_size > (UINT64_C(1) << 38))
342 /// Detect the input file type (for now, this done only when decompressing),
343 /// and initialize an appropriate coder. Return value indicates if a normal
344 /// liblzma-based coder was initialized (CODER_INIT_NORMAL), if passthru
345 /// mode should be used (CODER_INIT_PASSTHRU), or if an error occurred
346 /// (CODER_INIT_ERROR).
347 static enum coder_init_ret
348 coder_init(file_pair *pair)
350 lzma_ret ret = LZMA_PROG_ERROR;
352 if (opt_mode == MODE_COMPRESS) {
353 switch (opt_format) {
355 // args.c ensures this.
360 ret = lzma_stream_encoder(&strm, filters, check);
364 ret = lzma_alone_encoder(&strm, filters[0].options);
368 ret = lzma_raw_encoder(&strm, filters);
372 const uint32_t flags = LZMA_TELL_UNSUPPORTED_CHECK
375 // We abuse FORMAT_AUTO to indicate unknown file format,
376 // for which we may consider passthru mode.
377 enum format_type init_format = FORMAT_AUTO;
379 switch (opt_format) {
382 init_format = FORMAT_XZ;
383 else if (is_format_lzma())
384 init_format = FORMAT_LZMA;
389 init_format = FORMAT_XZ;
393 if (is_format_lzma())
394 init_format = FORMAT_LZMA;
398 init_format = FORMAT_RAW;
402 switch (init_format) {
404 // Uknown file format. If --decompress --stdout
405 // --force have been given, then we copy the input
406 // as is to stdout. Checking for MODE_DECOMPRESS
407 // is needed, because we don't want to do use
408 // passthru mode with --test.
409 if (opt_mode == MODE_DECOMPRESS
410 && opt_stdout && opt_force)
411 return CODER_INIT_PASSTHRU;
413 ret = LZMA_FORMAT_ERROR;
417 ret = lzma_stream_decoder(&strm,
418 hardware_memlimit_get(
419 MODE_DECOMPRESS), flags);
423 ret = lzma_alone_decoder(&strm,
424 hardware_memlimit_get(
429 // Memory usage has already been checked in
430 // coder_set_compression_settings().
431 ret = lzma_raw_decoder(&strm, filters);
435 // Try to decode the headers. This will catch too low
436 // memory usage limit in case it happens in the first
437 // Block of the first Stream, which is where it very
438 // probably will happen if it is going to happen.
439 if (ret == LZMA_OK && init_format != FORMAT_RAW) {
440 strm.next_out = NULL;
442 ret = lzma_code(&strm, LZMA_RUN);
446 if (ret != LZMA_OK) {
447 message_error("%s: %s", pair->src_name, message_strm(ret));
448 if (ret == LZMA_MEMLIMIT_ERROR)
449 message_mem_needed(V_ERROR, lzma_memusage(&strm));
451 return CODER_INIT_ERROR;
454 return CODER_INIT_NORMAL;
458 /// Compress or decompress using liblzma.
460 coder_normal(file_pair *pair)
462 // Encoder needs to know when we have given all the input to it.
463 // The decoders need to know it too when we are using
464 // LZMA_CONCATENATED. We need to check for src_eof here, because
465 // the first input chunk has been already read, and that may
466 // have been the only chunk we will read.
467 lzma_action action = pair->src_eof ? LZMA_FINISH : LZMA_RUN;
471 // Assume that something goes wrong.
472 bool success = false;
474 strm.next_out = out_buf.u8;
475 strm.avail_out = IO_BUFFER_SIZE;
477 while (!user_abort) {
478 // Fill the input buffer if it is empty and we haven't reached
480 if (strm.avail_in == 0 && !pair->src_eof) {
481 strm.next_in = in_buf.u8;
482 strm.avail_in = io_read(
483 pair, &in_buf, IO_BUFFER_SIZE);
485 if (strm.avail_in == SIZE_MAX)
489 action = LZMA_FINISH;
492 // Let liblzma do the actual work.
493 ret = lzma_code(&strm, action);
495 // Write out if the output buffer became full.
496 if (strm.avail_out == 0) {
497 if (opt_mode != MODE_TEST && io_write(pair, &out_buf,
498 IO_BUFFER_SIZE - strm.avail_out))
501 strm.next_out = out_buf.u8;
502 strm.avail_out = IO_BUFFER_SIZE;
505 if (ret != LZMA_OK) {
506 // Determine if the return value indicates that we
507 // won't continue coding.
508 const bool stop = ret != LZMA_NO_CHECK
509 && ret != LZMA_UNSUPPORTED_CHECK;
512 // Write the remaining bytes even if something
513 // went wrong, because that way the user gets
514 // as much data as possible, which can be good
515 // when trying to get at least some useful
516 // data out of damaged files.
517 if (opt_mode != MODE_TEST && io_write(pair,
518 &out_buf, IO_BUFFER_SIZE
523 if (ret == LZMA_STREAM_END) {
524 // Check that there is no trailing garbage.
525 // This is needed for LZMA_Alone and raw
527 if (strm.avail_in == 0 && !pair->src_eof) {
528 // Try reading one more byte.
529 // Hopefully we don't get any more
530 // input, and thus pair->src_eof
532 strm.avail_in = io_read(
534 if (strm.avail_in == SIZE_MAX)
537 assert(strm.avail_in == 0
538 || strm.avail_in == 1);
541 if (strm.avail_in == 0) {
542 assert(pair->src_eof);
547 // We hadn't reached the end of the file.
548 ret = LZMA_DATA_ERROR;
552 // If we get here and stop is true, something went
553 // wrong and we print an error. Otherwise it's just
554 // a warning and coding can continue.
556 message_error("%s: %s", pair->src_name,
559 message_warning("%s: %s", pair->src_name,
562 // When compressing, all possible errors set
564 assert(opt_mode != MODE_COMPRESS);
567 if (ret == LZMA_MEMLIMIT_ERROR) {
568 // Display how much memory it would have
570 message_mem_needed(V_ERROR,
571 lzma_memusage(&strm));
578 // Show progress information under certain conditions.
579 message_progress_update();
586 /// Copy from input file to output file without processing the data in any
587 /// way. This is used only when trying to decompress unrecognized files
588 /// with --decompress --stdout --force, so the output is always stdout.
590 coder_passthru(file_pair *pair)
592 while (strm.avail_in != 0) {
596 if (io_write(pair, &in_buf, strm.avail_in))
599 strm.total_in += strm.avail_in;
600 strm.total_out = strm.total_in;
601 message_progress_update();
603 strm.avail_in = io_read(pair, &in_buf, IO_BUFFER_SIZE);
604 if (strm.avail_in == SIZE_MAX)
613 coder_run(const char *filename)
615 // Set and possibly print the filename for the progress message.
616 message_filename(filename);
618 // Try to open the input file.
619 file_pair *pair = io_open_src(filename);
623 // Assume that something goes wrong.
624 bool success = false;
626 // Read the first chunk of input data. This is needed to detect
627 // the input file type (for now, only for decompression).
628 strm.next_in = in_buf.u8;
629 strm.avail_in = io_read(pair, &in_buf, IO_BUFFER_SIZE);
631 if (strm.avail_in != SIZE_MAX) {
632 // Initialize the coder. This will detect the file format
633 // and, in decompression or testing mode, check the memory
634 // usage of the first Block too. This way we don't try to
635 // open the destination file if we see that coding wouldn't
636 // work at all anyway. This also avoids deleting the old
637 // "target" file if --force was used.
638 const enum coder_init_ret init_ret = coder_init(pair);
640 if (init_ret != CODER_INIT_ERROR && !user_abort) {
641 // Don't open the destination file when --test
643 if (opt_mode == MODE_TEST || !io_open_dest(pair)) {
644 // Initialize the progress indicator.
645 const uint64_t in_size
646 = pair->src_st.st_size <= 0
647 ? 0 : pair->src_st.st_size;
648 message_progress_start(&strm, in_size);
650 // Do the actual coding or passthru.
651 if (init_ret == CODER_INIT_NORMAL)
652 success = coder_normal(pair);
654 success = coder_passthru(pair);
656 message_progress_end(success);
661 // Close the file pair. It needs to know if coding was successful to
662 // know if the source or target file should be unlinked.
663 io_close(pair, success);