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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file process.c
+/// \brief Compresses or uncompresses a file
+//
+// Copyright (C) 2007 Lasse Collin
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#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 (1-9)
+static size_t preset_number = 7;
+
+/// Indicate if no preset has been given. In that case, we will auto-adjust
+/// the compression preset so that it doesn't use too much RAM.
+// FIXME
+static bool preset_default = true;
+
+/// Integrity check type
+static lzma_check check = LZMA_CHECK_CRC64;
+
+
+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_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;
+}
+
+
+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 (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_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"));
+
+ // TODO: liblzma probably needs an API to validate the filter chain.
+
+ // If using --format=raw, we can be decoding.
+ uint64_t memory_usage;
+ uint64_t memory_limit;
+ if (opt_mode == MODE_COMPRESS) {
+ memory_usage = lzma_memusage_encoder(filters);
+ memory_limit = hardware_memlimit_encoder();
+ } else {
+ memory_usage = lzma_memusage_decoder(filters);
+ memory_limit = hardware_memlimit_decoder();
+ }
+
+ if (memory_usage == UINT64_MAX)
+ message_bug();
+
+ if (preset_default) {
+ // When no preset was explicitly requested, we use the default
+ // preset only if the memory usage limit allows. Otherwise we
+ // select a lower preset automatically.
+ while (memory_usage > memory_limit) {
+ if (preset_number == 1)
+ message_fatal(_("Memory usage limit is too "
+ "small for any internal "
+ "filter preset"));
+
+ if (lzma_lzma_preset(&opt_lzma, --preset_number))
+ message_bug();
+
+ memory_usage = lzma_memusage_encoder(filters);
+ }
+ } else {
+ if (memory_usage > memory_limit)
+ message_fatal(_("Memory usage limit is too small "
+ "for the given filter setup"));
+ }
+
+ // Limit the number of worked 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_decoder(), flags);
+ break;
+
+ case FORMAT_XZ:
+ ret = lzma_stream_decoder(&strm,
+ hardware_memlimit_decoder(), flags);
+ break;
+
+ case FORMAT_LZMA:
+ ret = lzma_alone_decoder(&strm,
+ hardware_memlimit_decoder());
+ break;
+
+ case FORMAT_RAW:
+ // Memory usage has already been checked in args.c.
+ // FIXME Comment
+ 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_run(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(pair->src_name, in_size);
+
+ lzma_action action = LZMA_RUN;
+ lzma_ret ret;
+
+ 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))
+ return false;
+
+ 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) {
+ // First print the final progress info.
+ // This way the user sees more accurately
+ // where the error occurred. Note that we
+ // print this *before* the possible error
+ // message.
+ //
+ // FIXME: What if something goes wrong
+ // after this?
+ message_progress_end(strm.total_in,
+ strm.total_out,
+ ret == LZMA_STREAM_END);
+
+ // 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))
+ return false;
+ }
+
+ 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
+ || io_read(pair, in_buf, 1)
+ == 0)) {
+ assert(pair->src_eof);
+ return true;
+ }
+
+ // FIXME: What about io_read() failing?
+
+ // 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 would have
+ // actually needed.
+ // TODO
+ }
+
+ if (stop)
+ return false;
+ }
+
+ // Show progress information if --verbose was specified and
+ // stderr is a terminal.
+ message_progress_update(strm.total_in, strm.total_out);
+ }
+
+ return false;
+}
+
+
+extern void
+process_file(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_run(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;
+}