Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/xz/coder.c

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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;
+
+
+/// 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 size_t filters_count = 0;
+
+/// Number of the preset (0-9)
+static size_t preset_number = 6;
+
+/// Indicate if no preset has been explicitly given. In that case, if we need
+/// to auto-adjust for lower memory usage, we won't print a warning.
+static bool preset_default = true;
+
+/// If a preset is used (no custom filter chain) and preset_extreme is true,
+/// a significantly slower compression is used to achieve slightly better
+/// compression ratio.
+static bool preset_extreme = false;
+
+/// Integrity check type
+static lzma_check check;
+
+/// This becomes false if the --check=CHECK option is used.
+static bool check_default = true;
+
+
+extern void
+coder_set_check(lzma_check new_check)
+{
+        check = new_check;
+        check_default = false;
+        return;
+}
+
+
+extern void
+coder_set_preset(size_t new_preset)
+{
+        preset_number = new_preset;
+        preset_default = false;
+        return;
+}
+
+
+extern void
+coder_set_extreme(void)
+{
+        preset_extreme = true;
+        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;
+
+        return;
+}
+
+
+static void lzma_attribute((noreturn))
+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)
+{
+        // 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 (preset_extreme)
+                        preset_number |= LZMA_PRESET_EXTREME;
+
+                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;
+        } else {
+                preset_default = false;
+        }
+
+        // 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);
+
+        // If using --format=raw, we can be decoding. The memusage function
+        // also validates the filter chain and the options used for the
+        // filters.
+        const uint64_t memory_limit = hardware_memlimit_get();
+        uint64_t memory_usage;
+        if (opt_mode == MODE_COMPRESS)
+                memory_usage = lzma_raw_encoder_memusage(filters);
+        else
+                memory_usage = lzma_raw_decoder_memusage(filters);
+
+        if (memory_usage == UINT64_MAX)
+                message_fatal(_("Unsupported filter chain or filter options"));
+
+        // Print memory usage info before possible dictionary
+        // size auto-adjusting.
+        message_mem_needed(V_DEBUG, memory_usage);
+
+        if (memory_usage > memory_limit) {
+                // If --no-auto-adjust was used or we didn't find LZMA1 or
+                // LZMA2 as the last filter, give an error immediately.
+                // --format=raw implies --no-auto-adjust.
+                if (!opt_auto_adjust || opt_format == FORMAT_RAW)
+                        memlimit_too_small(memory_usage);
+
+                assert(opt_mode == MODE_COMPRESS);
+
+                // 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.
+                // However, omit the message if no preset or custom chain
+                // was given. FIXME: Always warn?
+                if (!preset_default)
+                        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));
+        }
+
+/*
+        // Limit the number of worker threads so that memory usage
+        // limit isn't exceeded.
+        assert(memory_usage > 0);
+        size_t thread_limit = memory_limit / memory_usage;
+        if (thread_limit == 0)
+                thread_limit = 1;
+
+        if (opt_threads > thread_limit)
+                opt_threads = thread_limit;
+*/
+
+        if (check_default) {
+                // 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.
+                check = LZMA_CHECK_CRC64;
+                if (!lzma_check_is_supported(check))
+                        check = LZMA_CHECK_CRC32;
+        }
+
+        return;
+}
+
+
+/// Return true if the data in in_buf seems to be in the .xz format.
+static bool
+is_format_xz(void)
+{
+        return strm.avail_in >= 6 && memcmp(in_buf.u8, "\3757zXZ", 6) == 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;
+}
+
+
+/// 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;
+
+        if (opt_mode == MODE_COMPRESS) {
+                switch (opt_format) {
+                case FORMAT_AUTO:
+                        // args.c ensures this.
+                        assert(0);
+                        break;
+
+                case FORMAT_XZ:
+                        ret = lzma_stream_encoder(&strm, filters, check);
+                        break;
+
+                case FORMAT_LZMA:
+                        ret = lzma_alone_encoder(&strm, filters[0].options);
+                        break;
+
+                case FORMAT_RAW:
+                        ret = lzma_raw_encoder(&strm, filters);
+                        break;
+                }
+        } else {
+                const uint32_t flags = LZMA_TELL_UNSUPPORTED_CHECK
+                                | 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:
+                        if (is_format_xz())
+                                init_format = FORMAT_XZ;
+                        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;
+
+                case FORMAT_RAW:
+                        init_format = FORMAT_RAW;
+                        break;
+                }
+
+                switch (init_format) {
+                case FORMAT_AUTO:
+                        // Uknown 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)
+                                return CODER_INIT_PASSTHRU;
+
+                        ret = LZMA_FORMAT_ERROR;
+                        break;
+
+                case FORMAT_XZ:
+                        ret = lzma_stream_decoder(&strm,
+                                        hardware_memlimit_get(), flags);
+                        break;
+
+                case FORMAT_LZMA:
+                        ret = lzma_alone_decoder(&strm,
+                                        hardware_memlimit_get());
+                        break;
+
+                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.
+                if (ret == LZMA_OK && init_format != FORMAT_RAW) {
+                        strm.next_out = NULL;
+                        strm.avail_out = 0;
+                        ret = lzma_code(&strm, LZMA_RUN);
+                }
+        }
+
+        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;
+}
+
+
+/// 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, 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;
+
+        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 haven't reached
+                // end of file yet.
+                if (strm.avail_in == 0 && !pair->src_eof) {
+                        strm.next_in = in_buf.u8;
+                        strm.avail_in = io_read(
+                                        pair, &in_buf, IO_BUFFER_SIZE);
+
+                        if (strm.avail_in == SIZE_MAX)
+                                break;
+
+                        if (pair->src_eof)
+                                action = LZMA_FINISH;
+                }
+
+                // 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 (opt_mode != MODE_TEST && io_write(pair, &out_buf,
+                                        IO_BUFFER_SIZE - strm.avail_out))
+                                break;
+
+                        strm.next_out = out_buf.u8;
+                        strm.avail_out = IO_BUFFER_SIZE;
+                }
+
+                if (ret != LZMA_OK) {
+                        // Determine if the return value indicates that we
+                        // won't continue coding.
+                        const bool stop = ret != LZMA_NO_CHECK
+                                        && 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 (opt_mode != MODE_TEST && io_write(pair,
+                                                &out_buf, IO_BUFFER_SIZE
+                                                        - strm.avail_out))
+                                        break;
+                        }
+
+                        if (ret == LZMA_STREAM_END) {
+                                // Check that there is no trailing garbage.
+                                // This is needed for LZMA_Alone and raw
+                                // streams.
+                                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;
+
+        // Read the first chunk of input data. This is needed to detect
+        // the input file type (for now, only for decompression).
+        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)) {
+                                // Initialize the progress indicator.
+                                const uint64_t in_size
+                                                = pair->src_st.st_size <= 0
+                                                ? 0 : pair->src_st.st_size;
+                                message_progress_start(&strm, in_size);
+
+                                // Do the actual coding or passthru.
+                                if (init_ret == CODER_INIT_NORMAL)
+                                        success = coder_normal(pair);
+                                else
+                                        success = coder_passthru(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;
+}