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-rw-r--r--src/xz/coder.c488
1 files changed, 488 insertions, 0 deletions
diff --git a/src/xz/coder.c b/src/xz/coder.c
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file process.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"
+
+
+enum operation_mode opt_mode = MODE_COMPRESS;
+
+enum format_type opt_format = FORMAT_AUTO;
+
+
+/// 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];
+
+/// 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;
+
+/// True if we should auto-adjust the compression settings to use less memory
+/// if memory usage limit is too low for the original settings.
+static bool auto_adjust = true;
+
+/// 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
+#ifdef HAVE_CHECK_CRC64
+static lzma_check check = LZMA_CHECK_CRC64;
+#else
+static lzma_check check = LZMA_CHECK_CRC32;
+#endif
+
+
+extern void
+coder_set_check(lzma_check new_check)
+{
+ check = new_check;
+ 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, uint64_t memory_limit)
+{
+ message_fatal(_("Memory usage limit (%" PRIu64 " MiB) is too small "
+ "for the given filter setup (%" PRIu64 " MiB)"),
+ memory_limit >> 20, memory_usage >> 20);
+}
+
+
+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_Alone format, allow exactly one filter
+ // which has to be LZMA.
+ if (opt_format == FORMAT_LZMA && (filters_count != 1
+ || filters[0].id != LZMA_FILTER_LZMA1))
+ message_fatal(_("With --format=lzma only the LZMA1 filter "
+ "is supported"));
+
+ // Print the selected filter chain.
+ message_filters(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.
+ message(V_DEBUG, _("%s MiB (%s B) of memory is required per thread, "
+ "limit is %s MiB (%s B)"),
+ uint64_to_str(memory_usage >> 20, 0),
+ uint64_to_str(memory_usage, 1),
+ uint64_to_str(memory_limit >> 20, 2),
+ uint64_to_str(memory_limit, 3));
+
+ 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 immediatelly.
+ // --format=raw implies --no-auto-adjust.
+ if (!auto_adjust || opt_format == FORMAT_RAW)
+ memlimit_too_small(memory_usage, memory_limit);
+
+ 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, memory_limit);
+
+ ++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_limit);
+
+ 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(memory_limit >> 20, 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;
+*/
+
+ return;
+}
+
+
+static bool
+coder_init(void)
+{
+ 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;
+
+ switch (opt_format) {
+ case FORMAT_AUTO:
+ ret = lzma_auto_decoder(&strm,
+ hardware_memlimit_get(), flags);
+ 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;
+ }
+ }
+
+ if (ret != LZMA_OK) {
+ if (ret == LZMA_MEM_ERROR)
+ message_error("%s", message_strm(LZMA_MEM_ERROR));
+ else
+ message_bug();
+
+ return true;
+ }
+
+ return false;
+}
+
+
+static bool
+coder_main(file_pair *pair)
+{
+ // Buffers to hold input and output data.
+ uint8_t in_buf[IO_BUFFER_SIZE];
+ uint8_t out_buf[IO_BUFFER_SIZE];
+
+ // Initialize the progress indicator.
+ const uint64_t in_size = pair->src_st.st_size <= (off_t)(0)
+ ? 0 : (uint64_t)(pair->src_st.st_size);
+ message_progress_start(&strm, pair->src_name, in_size);
+
+ lzma_action action = LZMA_RUN;
+ lzma_ret ret;
+ bool success = false; // Assume that something goes wrong.
+
+ strm.avail_in = 0;
+ strm.next_out = out_buf;
+ 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;
+ strm.avail_in = io_read(pair, in_buf, IO_BUFFER_SIZE);
+
+ if (strm.avail_in == SIZE_MAX)
+ break;
+
+ // 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.
+ 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;
+ 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) {
+ // Figure out how much memory it would have
+ // actually needed.
+ uint64_t memusage = lzma_memusage(&strm);
+ uint64_t memlimit = hardware_memlimit_get();
+
+ // Round the memory limit down and usage up.
+ // This way we don't display a ridiculous
+ // message like "Limit was 9 MiB, but 9 MiB
+ // would have been needed".
+ memusage = (memusage + 1024 * 1024 - 1)
+ / (1024 * 1024);
+ memlimit /= 1024 * 1024;
+
+ message_error(_("Limit was %s MiB, "
+ "but %s MiB would "
+ "have been needed"),
+ uint64_to_str(memlimit, 0),
+ uint64_to_str(memusage, 1));
+ }
+
+ if (stop)
+ break;
+ }
+
+ // Show progress information under certain conditions.
+ message_progress_update();
+ }
+
+ message_progress_end(success);
+
+ return success;
+}
+
+
+extern void
+coder_run(const char *filename)
+{
+ // First try initializing the coder. If it fails, it's useless to try
+ // opening the file. Check also for user_abort just in case if we had
+ // got a signal while initializing the coder.
+ if (coder_init() || user_abort)
+ return;
+
+ // Try to open the input and output files.
+ file_pair *pair = io_open(filename);
+ if (pair == NULL)
+ return;
+
+ // Do the actual coding.
+ const bool success = coder_main(pair);
+
+ // 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;
+}
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