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Diffstat (limited to 'src/xz/coder.c')
| -rw-r--r-- | src/xz/coder.c | 1109 |
1 files changed, 1109 insertions, 0 deletions
diff --git a/src/xz/coder.c b/src/xz/coder.c new file mode 100644 index 0000000..91d40ed --- /dev/null +++ b/src/xz/coder.c @@ -0,0 +1,1109 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file coder.c +/// \brief Compresses or uncompresses a file +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "private.h" + + +/// Return value type for coder_init(). +enum coder_init_ret { + CODER_INIT_NORMAL, + CODER_INIT_PASSTHRU, + CODER_INIT_ERROR, +}; + + +enum operation_mode opt_mode = MODE_COMPRESS; +enum format_type opt_format = FORMAT_AUTO; +bool opt_auto_adjust = true; +bool opt_single_stream = false; +uint64_t opt_block_size = 0; +uint64_t *opt_block_list = NULL; + + +/// Stream used to communicate with liblzma +static lzma_stream strm = LZMA_STREAM_INIT; + +/// Filters needed for all encoding all formats, and also decoding in raw data +static lzma_filter filters[LZMA_FILTERS_MAX + 1]; + +/// Input and output buffers +static io_buf in_buf; +static io_buf out_buf; + +/// Number of filters. Zero indicates that we are using a preset. +static uint32_t filters_count = 0; + +/// Number of the preset (0-9) +static uint32_t preset_number = LZMA_PRESET_DEFAULT; + +/// Integrity check type +static lzma_check check; + +/// This becomes false if the --check=CHECK option is used. +static bool check_default = true; + +/// Indicates if unconsumed input is allowed to remain after +/// decoding has successfully finished. This is set for each file +/// in coder_init(). +static bool allow_trailing_input; + +#ifdef MYTHREAD_ENABLED +static lzma_mt mt_options = { + .flags = 0, + .timeout = 300, + .filters = filters, +}; +#endif + + +extern void +coder_set_check(lzma_check new_check) +{ + check = new_check; + check_default = false; + return; +} + + +static void +forget_filter_chain(void) +{ + // Setting a preset makes us forget a possibly defined custom + // filter chain. + while (filters_count > 0) { + --filters_count; + free(filters[filters_count].options); + filters[filters_count].options = NULL; + } + + return; +} + + +extern void +coder_set_preset(uint32_t new_preset) +{ + preset_number &= ~LZMA_PRESET_LEVEL_MASK; + preset_number |= new_preset; + forget_filter_chain(); + return; +} + + +extern void +coder_set_extreme(void) +{ + preset_number |= LZMA_PRESET_EXTREME; + forget_filter_chain(); + return; +} + + +extern void +coder_add_filter(lzma_vli id, void *options) +{ + if (filters_count == LZMA_FILTERS_MAX) + message_fatal(_("Maximum number of filters is four")); + + filters[filters_count].id = id; + filters[filters_count].options = options; + ++filters_count; + + // Setting a custom filter chain makes us forget the preset options. + // This makes a difference if one specifies e.g. "xz -9 --lzma2 -e" + // where the custom filter chain resets the preset level back to + // the default 6, making the example equivalent to "xz -6e". + preset_number = LZMA_PRESET_DEFAULT; + + return; +} + + +tuklib_attr_noreturn +static void +memlimit_too_small(uint64_t memory_usage) +{ + message(V_ERROR, _("Memory usage limit is too low for the given " + "filter setup.")); + message_mem_needed(V_ERROR, memory_usage); + tuklib_exit(E_ERROR, E_ERROR, false); +} + + +extern void +coder_set_compression_settings(void) +{ +#ifdef HAVE_LZIP_DECODER + // .lz compression isn't supported. + assert(opt_format != FORMAT_LZIP); +#endif + + // The default check type is CRC64, but fallback to CRC32 + // if CRC64 isn't supported by the copy of liblzma we are + // using. CRC32 is always supported. + if (check_default) { + check = LZMA_CHECK_CRC64; + if (!lzma_check_is_supported(check)) + check = LZMA_CHECK_CRC32; + } + + // Options for LZMA1 or LZMA2 in case we are using a preset. + static lzma_options_lzma opt_lzma; + + if (filters_count == 0) { + // We are using a preset. This is not a good idea in raw mode + // except when playing around with things. Different versions + // of this software may use different options in presets, and + // thus make uncompressing the raw data difficult. + if (opt_format == FORMAT_RAW) { + // The message is shown only if warnings are allowed + // but the exit status isn't changed. + message(V_WARNING, _("Using a preset in raw mode " + "is discouraged.")); + message(V_WARNING, _("The exact options of the " + "presets may vary between software " + "versions.")); + } + + // Get the preset for LZMA1 or LZMA2. + if (lzma_lzma_preset(&opt_lzma, preset_number)) + message_bug(); + + // Use LZMA2 except with --format=lzma we use LZMA1. + filters[0].id = opt_format == FORMAT_LZMA + ? LZMA_FILTER_LZMA1 : LZMA_FILTER_LZMA2; + filters[0].options = &opt_lzma; + filters_count = 1; + } + + // Terminate the filter options array. + filters[filters_count].id = LZMA_VLI_UNKNOWN; + + // If we are using the .lzma format, allow exactly one filter + // which has to be LZMA1. + if (opt_format == FORMAT_LZMA && (filters_count != 1 + || filters[0].id != LZMA_FILTER_LZMA1)) + message_fatal(_("The .lzma format supports only " + "the LZMA1 filter")); + + // If we are using the .xz format, make sure that there is no LZMA1 + // filter to prevent LZMA_PROG_ERROR. + if (opt_format == FORMAT_XZ) + for (size_t i = 0; i < filters_count; ++i) + if (filters[i].id == LZMA_FILTER_LZMA1) + message_fatal(_("LZMA1 cannot be used " + "with the .xz format")); + + // Print the selected filter chain. + message_filters_show(V_DEBUG, filters); + + // The --flush-timeout option requires LZMA_SYNC_FLUSH support + // from the filter chain. Currently threaded encoder doesn't support + // LZMA_SYNC_FLUSH so single-threaded mode must be used. + if (opt_mode == MODE_COMPRESS && opt_flush_timeout != 0) { + for (size_t i = 0; i < filters_count; ++i) { + switch (filters[i].id) { + case LZMA_FILTER_LZMA2: + case LZMA_FILTER_DELTA: + break; + + default: + message_fatal(_("The filter chain is " + "incompatible with --flush-timeout")); + } + } + + if (hardware_threads_is_mt()) { + message(V_WARNING, _("Switching to single-threaded " + "mode due to --flush-timeout")); + hardware_threads_set(1); + } + } + + // Get the memory usage. Note that if --format=raw was used, + // we can be decompressing. + // + // If multithreaded .xz compression is done, this value will be + // replaced. + uint64_t memory_limit = hardware_memlimit_get(opt_mode); + uint64_t memory_usage = UINT64_MAX; + if (opt_mode == MODE_COMPRESS) { +#ifdef HAVE_ENCODERS +# ifdef MYTHREAD_ENABLED + if (opt_format == FORMAT_XZ && hardware_threads_is_mt()) { + memory_limit = hardware_memlimit_mtenc_get(); + mt_options.threads = hardware_threads_get(); + mt_options.block_size = opt_block_size; + mt_options.check = check; + memory_usage = lzma_stream_encoder_mt_memusage( + &mt_options); + if (memory_usage != UINT64_MAX) + message(V_DEBUG, _("Using up to %" PRIu32 + " threads."), + mt_options.threads); + } else +# endif + { + memory_usage = lzma_raw_encoder_memusage(filters); + } +#endif + } else { +#ifdef HAVE_DECODERS + memory_usage = lzma_raw_decoder_memusage(filters); +#endif + } + + if (memory_usage == UINT64_MAX) + message_fatal(_("Unsupported filter chain or filter options")); + + // Print memory usage info before possible dictionary + // size auto-adjusting. + // + // NOTE: If only encoder support was built, we cannot show the + // what the decoder memory usage will be. + message_mem_needed(V_DEBUG, memory_usage); +#ifdef HAVE_DECODERS + if (opt_mode == MODE_COMPRESS) { + const uint64_t decmem = lzma_raw_decoder_memusage(filters); + if (decmem != UINT64_MAX) + message(V_DEBUG, _("Decompression will need " + "%s MiB of memory."), uint64_to_str( + round_up_to_mib(decmem), 0)); + } +#endif + + if (memory_usage <= memory_limit) + return; + + // With --format=raw settings are never adjusted to meet + // the memory usage limit. + if (opt_format == FORMAT_RAW) + memlimit_too_small(memory_usage); + + assert(opt_mode == MODE_COMPRESS); + +#ifdef HAVE_ENCODERS +# ifdef MYTHREAD_ENABLED + if (opt_format == FORMAT_XZ && hardware_threads_is_mt()) { + // Try to reduce the number of threads before + // adjusting the compression settings down. + while (mt_options.threads > 1) { + // Reduce the number of threads by one and check + // the memory usage. + --mt_options.threads; + memory_usage = lzma_stream_encoder_mt_memusage( + &mt_options); + if (memory_usage == UINT64_MAX) + message_bug(); + + if (memory_usage <= memory_limit) { + // The memory usage is now low enough. + message(V_WARNING, _("Reduced the number of " + "threads from %s to %s to not exceed " + "the memory usage limit of %s MiB"), + uint64_to_str( + hardware_threads_get(), 0), + uint64_to_str(mt_options.threads, 1), + uint64_to_str(round_up_to_mib( + memory_limit), 2)); + return; + } + } + + // If the memory usage limit is only a soft limit (automatic + // number of threads and no --memlimit-compress), the limit + // is only used to reduce the number of threads and once at + // just one thread, the limit is completely ignored. This + // way -T0 won't use insane amount of memory but at the same + // time the soft limit will never make xz fail and never make + // xz change settings that would affect the compressed output. + if (hardware_memlimit_mtenc_is_default()) { + message(V_WARNING, _("Reduced the number of threads " + "from %s to one. The automatic memory usage " + "limit of %s MiB is still being exceeded. " + "%s MiB of memory is required. " + "Continuing anyway."), + uint64_to_str(hardware_threads_get(), 0), + uint64_to_str( + round_up_to_mib(memory_limit), 1), + uint64_to_str( + round_up_to_mib(memory_usage), 2)); + return; + } + + // If --no-adjust was used, we cannot drop to single-threaded + // mode since it produces different compressed output. + // + // NOTE: In xz 5.2.x, --no-adjust also prevented reducing + // the number of threads. This changed in 5.3.3alpha. + if (!opt_auto_adjust) + memlimit_too_small(memory_usage); + + // Switch to single-threaded mode. It uses + // less memory than using one thread in + // the multithreaded mode but the output + // is also different. + hardware_threads_set(1); + memory_usage = lzma_raw_encoder_memusage(filters); + message(V_WARNING, _("Switching to single-threaded mode " + "to not exceed the memory usage limit of %s MiB"), + uint64_to_str(round_up_to_mib(memory_limit), 0)); + } +# endif + + if (memory_usage <= memory_limit) + return; + + // Don't adjust LZMA2 or LZMA1 dictionary size if --no-adjust + // was specified as that would change the compressed output. + if (!opt_auto_adjust) + memlimit_too_small(memory_usage); + + // Look for the last filter if it is LZMA2 or LZMA1, so we can make + // it use less RAM. With other filters we don't know what to do. + size_t i = 0; + while (filters[i].id != LZMA_FILTER_LZMA2 + && filters[i].id != LZMA_FILTER_LZMA1) { + if (filters[i].id == LZMA_VLI_UNKNOWN) + memlimit_too_small(memory_usage); + + ++i; + } + + // Decrease the dictionary size until we meet the memory + // usage limit. First round down to full mebibytes. + lzma_options_lzma *opt = filters[i].options; + const uint32_t orig_dict_size = opt->dict_size; + opt->dict_size &= ~((UINT32_C(1) << 20) - 1); + while (true) { + // If it is below 1 MiB, auto-adjusting failed. We could be + // more sophisticated and scale it down even more, but let's + // see if many complain about this version. + // + // FIXME: Displays the scaled memory usage instead + // of the original. + if (opt->dict_size < (UINT32_C(1) << 20)) + memlimit_too_small(memory_usage); + + memory_usage = lzma_raw_encoder_memusage(filters); + if (memory_usage == UINT64_MAX) + message_bug(); + + // Accept it if it is low enough. + if (memory_usage <= memory_limit) + break; + + // Otherwise 1 MiB down and try again. I hope this + // isn't too slow method for cases where the original + // dict_size is very big. + opt->dict_size -= UINT32_C(1) << 20; + } + + // Tell the user that we decreased the dictionary size. + message(V_WARNING, _("Adjusted LZMA%c dictionary size " + "from %s MiB to %s MiB to not exceed " + "the memory usage limit of %s MiB"), + filters[i].id == LZMA_FILTER_LZMA2 + ? '2' : '1', + uint64_to_str(orig_dict_size >> 20, 0), + uint64_to_str(opt->dict_size >> 20, 1), + uint64_to_str(round_up_to_mib(memory_limit), 2)); +#endif + + return; +} + + +#ifdef HAVE_DECODERS +/// Return true if the data in in_buf seems to be in the .xz format. +static bool +is_format_xz(void) +{ + // Specify the magic as hex to be compatible with EBCDIC systems. + static const uint8_t magic[6] = { 0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00 }; + return strm.avail_in >= sizeof(magic) + && memcmp(in_buf.u8, magic, sizeof(magic)) == 0; +} + + +/// Return true if the data in in_buf seems to be in the .lzma format. +static bool +is_format_lzma(void) +{ + // The .lzma header is 13 bytes. + if (strm.avail_in < 13) + return false; + + // Decode the LZMA1 properties. + lzma_filter filter = { .id = LZMA_FILTER_LZMA1 }; + if (lzma_properties_decode(&filter, NULL, in_buf.u8, 5) != LZMA_OK) + return false; + + // A hack to ditch tons of false positives: We allow only dictionary + // sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone + // created only files with 2^n, but accepts any dictionary size. + // If someone complains, this will be reconsidered. + lzma_options_lzma *opt = filter.options; + const uint32_t dict_size = opt->dict_size; + free(opt); + + if (dict_size != UINT32_MAX) { + uint32_t d = dict_size - 1; + d |= d >> 2; + d |= d >> 3; + d |= d >> 4; + d |= d >> 8; + d |= d >> 16; + ++d; + if (d != dict_size || dict_size == 0) + return false; + } + + // Another hack to ditch false positives: Assume that if the + // uncompressed size is known, it must be less than 256 GiB. + // Again, if someone complains, this will be reconsidered. + uint64_t uncompressed_size = 0; + for (size_t i = 0; i < 8; ++i) + uncompressed_size |= (uint64_t)(in_buf.u8[5 + i]) << (i * 8); + + if (uncompressed_size != UINT64_MAX + && uncompressed_size > (UINT64_C(1) << 38)) + return false; + + return true; +} + + +#ifdef HAVE_LZIP_DECODER +/// Return true if the data in in_buf seems to be in the .lz format. +static bool +is_format_lzip(void) +{ + static const uint8_t magic[4] = { 0x4C, 0x5A, 0x49, 0x50 }; + return strm.avail_in >= sizeof(magic) + && memcmp(in_buf.u8, magic, sizeof(magic)) == 0; +} +#endif +#endif + + +/// Detect the input file type (for now, this done only when decompressing), +/// and initialize an appropriate coder. Return value indicates if a normal +/// liblzma-based coder was initialized (CODER_INIT_NORMAL), if passthru +/// mode should be used (CODER_INIT_PASSTHRU), or if an error occurred +/// (CODER_INIT_ERROR). +static enum coder_init_ret +coder_init(file_pair *pair) +{ + lzma_ret ret = LZMA_PROG_ERROR; + + // In most cases if there is input left when coding finishes, + // something has gone wrong. Exceptions are --single-stream + // and decoding .lz files which can contain trailing non-.lz data. + // These will be handled later in this function. + allow_trailing_input = false; + + if (opt_mode == MODE_COMPRESS) { +#ifdef HAVE_ENCODERS + switch (opt_format) { + case FORMAT_AUTO: + // args.c ensures this. + assert(0); + break; + + case FORMAT_XZ: +# ifdef MYTHREAD_ENABLED + if (hardware_threads_is_mt()) + ret = lzma_stream_encoder_mt( + &strm, &mt_options); + else +# endif + ret = lzma_stream_encoder( + &strm, filters, check); + break; + + case FORMAT_LZMA: + ret = lzma_alone_encoder(&strm, filters[0].options); + break; + +# ifdef HAVE_LZIP_DECODER + case FORMAT_LZIP: + // args.c should disallow this. + assert(0); + ret = LZMA_PROG_ERROR; + break; +# endif + + case FORMAT_RAW: + ret = lzma_raw_encoder(&strm, filters); + break; + } +#endif + } else { +#ifdef HAVE_DECODERS + uint32_t flags = 0; + + // It seems silly to warn about unsupported check if the + // check won't be verified anyway due to --ignore-check. + if (opt_ignore_check) + flags |= LZMA_IGNORE_CHECK; + else + flags |= LZMA_TELL_UNSUPPORTED_CHECK; + + if (opt_single_stream) + allow_trailing_input = true; + else + flags |= LZMA_CONCATENATED; + + // We abuse FORMAT_AUTO to indicate unknown file format, + // for which we may consider passthru mode. + enum format_type init_format = FORMAT_AUTO; + + switch (opt_format) { + case FORMAT_AUTO: + // .lz is checked before .lzma since .lzma detection + // is more complicated (no magic bytes). + if (is_format_xz()) + init_format = FORMAT_XZ; +# ifdef HAVE_LZIP_DECODER + else if (is_format_lzip()) + init_format = FORMAT_LZIP; +# endif + else if (is_format_lzma()) + init_format = FORMAT_LZMA; + break; + + case FORMAT_XZ: + if (is_format_xz()) + init_format = FORMAT_XZ; + break; + + case FORMAT_LZMA: + if (is_format_lzma()) + init_format = FORMAT_LZMA; + break; + +# ifdef HAVE_LZIP_DECODER + case FORMAT_LZIP: + if (is_format_lzip()) + init_format = FORMAT_LZIP; + break; +# endif + + case FORMAT_RAW: + init_format = FORMAT_RAW; + break; + } + + switch (init_format) { + case FORMAT_AUTO: + // Unknown file format. If --decompress --stdout + // --force have been given, then we copy the input + // as is to stdout. Checking for MODE_DECOMPRESS + // is needed, because we don't want to do use + // passthru mode with --test. + if (opt_mode == MODE_DECOMPRESS + && opt_stdout && opt_force) { + // These are needed for progress info. + strm.total_in = 0; + strm.total_out = 0; + return CODER_INIT_PASSTHRU; + } + + ret = LZMA_FORMAT_ERROR; + break; + + case FORMAT_XZ: +# ifdef MYTHREAD_ENABLED + mt_options.flags = flags; + + mt_options.threads = hardware_threads_get(); + mt_options.memlimit_stop + = hardware_memlimit_get(MODE_DECOMPRESS); + + // If single-threaded mode was requested, set the + // memlimit for threading to zero. This forces the + // decoder to use single-threaded mode which matches + // the behavior of lzma_stream_decoder(). + // + // Otherwise use the limit for threaded decompression + // which has a sane default (users are still free to + // make it insanely high though). + mt_options.memlimit_threading + = mt_options.threads == 1 + ? 0 : hardware_memlimit_mtdec_get(); + + ret = lzma_stream_decoder_mt(&strm, &mt_options); +# else + ret = lzma_stream_decoder(&strm, + hardware_memlimit_get( + MODE_DECOMPRESS), flags); +# endif + break; + + case FORMAT_LZMA: + ret = lzma_alone_decoder(&strm, + hardware_memlimit_get( + MODE_DECOMPRESS)); + break; + +# ifdef HAVE_LZIP_DECODER + case FORMAT_LZIP: + allow_trailing_input = true; + ret = lzma_lzip_decoder(&strm, + hardware_memlimit_get( + MODE_DECOMPRESS), flags); + break; +# endif + + case FORMAT_RAW: + // Memory usage has already been checked in + // coder_set_compression_settings(). + ret = lzma_raw_decoder(&strm, filters); + break; + } + + // Try to decode the headers. This will catch too low + // memory usage limit in case it happens in the first + // Block of the first Stream, which is where it very + // probably will happen if it is going to happen. + // + // This will also catch unsupported check type which + // we treat as a warning only. If there are empty + // concatenated Streams with unsupported check type then + // the message can be shown more than once here. The loop + // is used in case there is first a warning about + // unsupported check type and then the first Block + // would exceed the memlimit. + if (ret == LZMA_OK && init_format != FORMAT_RAW) { + strm.next_out = NULL; + strm.avail_out = 0; + while ((ret = lzma_code(&strm, LZMA_RUN)) + == LZMA_UNSUPPORTED_CHECK) + message_warning(_("%s: %s"), pair->src_name, + message_strm(ret)); + + // With --single-stream lzma_code won't wait for + // LZMA_FINISH and thus it can return LZMA_STREAM_END + // if the file has no uncompressed data inside. + // So treat LZMA_STREAM_END as LZMA_OK here. + // When lzma_code() is called again in coder_normal() + // it will return LZMA_STREAM_END again. + if (ret == LZMA_STREAM_END) + ret = LZMA_OK; + } +#endif + } + + if (ret != LZMA_OK) { + message_error(_("%s: %s"), pair->src_name, message_strm(ret)); + if (ret == LZMA_MEMLIMIT_ERROR) + message_mem_needed(V_ERROR, lzma_memusage(&strm)); + + return CODER_INIT_ERROR; + } + + return CODER_INIT_NORMAL; +} + + +/// Resolve conflicts between opt_block_size and opt_block_list in single +/// threaded mode. We want to default to opt_block_list, except when it is +/// larger than opt_block_size. If this is the case for the current Block +/// at *list_pos, then we break into smaller Blocks. Otherwise advance +/// to the next Block in opt_block_list, and break apart if needed. +static void +split_block(uint64_t *block_remaining, + uint64_t *next_block_remaining, + size_t *list_pos) +{ + if (*next_block_remaining > 0) { + // The Block at *list_pos has previously been split up. + assert(!hardware_threads_is_mt()); + assert(opt_block_size > 0); + assert(opt_block_list != NULL); + + if (*next_block_remaining > opt_block_size) { + // We have to split the current Block at *list_pos + // into another opt_block_size length Block. + *block_remaining = opt_block_size; + } else { + // This is the last remaining split Block for the + // Block at *list_pos. + *block_remaining = *next_block_remaining; + } + + *next_block_remaining -= *block_remaining; + + } else { + // The Block at *list_pos has been finished. Go to the next + // entry in the list. If the end of the list has been reached, + // reuse the size of the last Block. + if (opt_block_list[*list_pos + 1] != 0) + ++*list_pos; + + *block_remaining = opt_block_list[*list_pos]; + + // If in single-threaded mode, split up the Block if needed. + // This is not needed in multi-threaded mode because liblzma + // will do this due to how threaded encoding works. + if (!hardware_threads_is_mt() && opt_block_size > 0 + && *block_remaining > opt_block_size) { + *next_block_remaining + = *block_remaining - opt_block_size; + *block_remaining = opt_block_size; + } + } +} + + +static bool +coder_write_output(file_pair *pair) +{ + if (opt_mode != MODE_TEST) { + if (io_write(pair, &out_buf, IO_BUFFER_SIZE - strm.avail_out)) + return true; + } + + strm.next_out = out_buf.u8; + strm.avail_out = IO_BUFFER_SIZE; + return false; +} + + +/// Compress or decompress using liblzma. +static bool +coder_normal(file_pair *pair) +{ + // Encoder needs to know when we have given all the input to it. + // The decoders need to know it too when we are using + // LZMA_CONCATENATED. We need to check for src_eof here, because + // the first input chunk has been already read if decompressing, + // and that may have been the only chunk we will read. + lzma_action action = pair->src_eof ? LZMA_FINISH : LZMA_RUN; + + lzma_ret ret; + + // Assume that something goes wrong. + bool success = false; + + // block_remaining indicates how many input bytes to encode before + // finishing the current .xz Block. The Block size is set with + // --block-size=SIZE and --block-list. They have an effect only when + // compressing to the .xz format. If block_remaining == UINT64_MAX, + // only a single block is created. + uint64_t block_remaining = UINT64_MAX; + + // next_block_remaining for when we are in single-threaded mode and + // the Block in --block-list is larger than the --block-size=SIZE. + uint64_t next_block_remaining = 0; + + // Position in opt_block_list. Unused if --block-list wasn't used. + size_t list_pos = 0; + + // Handle --block-size for single-threaded mode and the first step + // of --block-list. + if (opt_mode == MODE_COMPRESS && opt_format == FORMAT_XZ) { + // --block-size doesn't do anything here in threaded mode, + // because the threaded encoder will take care of splitting + // to fixed-sized Blocks. + if (!hardware_threads_is_mt() && opt_block_size > 0) + block_remaining = opt_block_size; + + // If --block-list was used, start with the first size. + // + // For threaded case, --block-size specifies how big Blocks + // the encoder needs to be prepared to create at maximum + // and --block-list will simultaneously cause new Blocks + // to be started at specified intervals. To keep things + // logical, the same is done in single-threaded mode. The + // output is still not identical because in single-threaded + // mode the size info isn't written into Block Headers. + if (opt_block_list != NULL) { + if (block_remaining < opt_block_list[list_pos]) { + assert(!hardware_threads_is_mt()); + next_block_remaining = opt_block_list[list_pos] + - block_remaining; + } else { + block_remaining = opt_block_list[list_pos]; + } + } + } + + strm.next_out = out_buf.u8; + strm.avail_out = IO_BUFFER_SIZE; + + while (!user_abort) { + // Fill the input buffer if it is empty and we aren't + // flushing or finishing. + if (strm.avail_in == 0 && action == LZMA_RUN) { + strm.next_in = in_buf.u8; + strm.avail_in = io_read(pair, &in_buf, + my_min(block_remaining, + IO_BUFFER_SIZE)); + + if (strm.avail_in == SIZE_MAX) + break; + + if (pair->src_eof) { + action = LZMA_FINISH; + + } else if (block_remaining != UINT64_MAX) { + // Start a new Block after every + // opt_block_size bytes of input. + block_remaining -= strm.avail_in; + if (block_remaining == 0) + action = LZMA_FULL_BARRIER; + } + + if (action == LZMA_RUN && pair->flush_needed) + action = LZMA_SYNC_FLUSH; + } + + // Let liblzma do the actual work. + ret = lzma_code(&strm, action); + + // Write out if the output buffer became full. + if (strm.avail_out == 0) { + if (coder_write_output(pair)) + break; + } + + if (ret == LZMA_STREAM_END && (action == LZMA_SYNC_FLUSH + || action == LZMA_FULL_BARRIER)) { + if (action == LZMA_SYNC_FLUSH) { + // Flushing completed. Write the pending data + // out immediately so that the reading side + // can decompress everything compressed so far. + if (coder_write_output(pair)) + break; + + // Mark that we haven't seen any new input + // since the previous flush. + pair->src_has_seen_input = false; + pair->flush_needed = false; + } else { + // Start a new Block after LZMA_FULL_BARRIER. + if (opt_block_list == NULL) { + assert(!hardware_threads_is_mt()); + assert(opt_block_size > 0); + block_remaining = opt_block_size; + } else { + split_block(&block_remaining, + &next_block_remaining, + &list_pos); + } + } + + // Start a new Block after LZMA_FULL_FLUSH or continue + // the same block after LZMA_SYNC_FLUSH. + action = LZMA_RUN; + + } else if (ret != LZMA_OK) { + // Determine if the return value indicates that we + // won't continue coding. LZMA_NO_CHECK would be + // here too if LZMA_TELL_ANY_CHECK was used. + const bool stop = ret != LZMA_UNSUPPORTED_CHECK; + + if (stop) { + // Write the remaining bytes even if something + // went wrong, because that way the user gets + // as much data as possible, which can be good + // when trying to get at least some useful + // data out of damaged files. + if (coder_write_output(pair)) + break; + } + + if (ret == LZMA_STREAM_END) { + if (allow_trailing_input) { + io_fix_src_pos(pair, strm.avail_in); + success = true; + break; + } + + // Check that there is no trailing garbage. + // This is needed for LZMA_Alone and raw + // streams. This is *not* done with .lz files + // as that format specifically requires + // allowing trailing garbage. + if (strm.avail_in == 0 && !pair->src_eof) { + // Try reading one more byte. + // Hopefully we don't get any more + // input, and thus pair->src_eof + // becomes true. + strm.avail_in = io_read( + pair, &in_buf, 1); + if (strm.avail_in == SIZE_MAX) + break; + + assert(strm.avail_in == 0 + || strm.avail_in == 1); + } + + if (strm.avail_in == 0) { + assert(pair->src_eof); + success = true; + break; + } + + // We hadn't reached the end of the file. + ret = LZMA_DATA_ERROR; + assert(stop); + } + + // If we get here and stop is true, something went + // wrong and we print an error. Otherwise it's just + // a warning and coding can continue. + if (stop) { + message_error(_("%s: %s"), pair->src_name, + message_strm(ret)); + } else { + message_warning(_("%s: %s"), pair->src_name, + message_strm(ret)); + + // When compressing, all possible errors set + // stop to true. + assert(opt_mode != MODE_COMPRESS); + } + + if (ret == LZMA_MEMLIMIT_ERROR) { + // Display how much memory it would have + // actually needed. + message_mem_needed(V_ERROR, + lzma_memusage(&strm)); + } + + if (stop) + break; + } + + // Show progress information under certain conditions. + message_progress_update(); + } + + return success; +} + + +/// Copy from input file to output file without processing the data in any +/// way. This is used only when trying to decompress unrecognized files +/// with --decompress --stdout --force, so the output is always stdout. +static bool +coder_passthru(file_pair *pair) +{ + while (strm.avail_in != 0) { + if (user_abort) + return false; + + if (io_write(pair, &in_buf, strm.avail_in)) + return false; + + strm.total_in += strm.avail_in; + strm.total_out = strm.total_in; + message_progress_update(); + + strm.avail_in = io_read(pair, &in_buf, IO_BUFFER_SIZE); + if (strm.avail_in == SIZE_MAX) + return false; + } + + return true; +} + + +extern void +coder_run(const char *filename) +{ + // Set and possibly print the filename for the progress message. + message_filename(filename); + + // Try to open the input file. + file_pair *pair = io_open_src(filename); + if (pair == NULL) + return; + + // Assume that something goes wrong. + bool success = false; + + if (opt_mode == MODE_COMPRESS) { + strm.next_in = NULL; + strm.avail_in = 0; + } else { + // Read the first chunk of input data. This is needed + // to detect the input file type. + strm.next_in = in_buf.u8; + strm.avail_in = io_read(pair, &in_buf, IO_BUFFER_SIZE); + } + + if (strm.avail_in != SIZE_MAX) { + // Initialize the coder. This will detect the file format + // and, in decompression or testing mode, check the memory + // usage of the first Block too. This way we don't try to + // open the destination file if we see that coding wouldn't + // work at all anyway. This also avoids deleting the old + // "target" file if --force was used. + const enum coder_init_ret init_ret = coder_init(pair); + + if (init_ret != CODER_INIT_ERROR && !user_abort) { + // Don't open the destination file when --test + // is used. + if (opt_mode == MODE_TEST || !io_open_dest(pair)) { + // Remember the current time. It is needed + // for progress indicator. + mytime_set_start_time(); + + // Initialize the progress indicator. + // + // NOTE: When reading from stdin, fstat() + // isn't called on it and thus src_st.st_size + // is zero. If stdin pointed to a regular + // file, it would still be possible to know + // the file size but then we would also need + // to take into account the current reading + // position since with stdin it isn't + // necessarily at the beginning of the file. + const bool is_passthru = init_ret + == CODER_INIT_PASSTHRU; + const uint64_t in_size + = pair->src_st.st_size <= 0 + ? 0 : (uint64_t)(pair->src_st.st_size); + message_progress_start(&strm, + is_passthru, in_size); + + // Do the actual coding or passthru. + if (is_passthru) + success = coder_passthru(pair); + else + success = coder_normal(pair); + + message_progress_end(success); + } + } + } + + // Close the file pair. It needs to know if coding was successful to + // know if the source or target file should be unlinked. + io_close(pair, success); + + return; +} + + +#ifndef NDEBUG +extern void +coder_free(void) +{ + lzma_end(&strm); + return; +} +#endif |