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authorLasse Collin <lasse.collin@tukaani.org>2008-08-28 22:53:15 +0300
committerLasse Collin <lasse.collin@tukaani.org>2008-08-28 22:53:15 +0300
commit3b34851de1eaf358cf9268922fa0eeed8278d680 (patch)
tree7bab212af647541df64227a8d350d17a2e789f6b /src/liblzma/lzma/lzma2_decoder.c
parentFix test_filter_flags to match the new restriction of lc+lp. (diff)
downloadxz-3b34851de1eaf358cf9268922fa0eeed8278d680.tar.xz
Sort of garbage collection commit. :-| Many things are still
broken. API has changed a lot and it will still change a little more here and there. The command line tool doesn't have all the required changes to reflect the API changes, so it's easy to get "internal error" or trigger assertions.
Diffstat (limited to '')
-rw-r--r--src/liblzma/lzma/lzma2_decoder.c318
1 files changed, 318 insertions, 0 deletions
diff --git a/src/liblzma/lzma/lzma2_decoder.c b/src/liblzma/lzma/lzma2_decoder.c
new file mode 100644
index 00000000..b16c40ce
--- /dev/null
+++ b/src/liblzma/lzma/lzma2_decoder.c
@@ -0,0 +1,318 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lzma2_decoder.c
+/// \brief LZMA2 decoder
+//
+// Copyright (C) 1999-2008 Igor Pavlov
+// Copyright (C) 2008 Lasse Collin
+//
+// This library 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 library 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 "lzma2_decoder.h"
+#include "lz_decoder.h"
+#include "lzma_decoder.h"
+
+
+struct lzma_coder_s {
+ enum sequence {
+ SEQ_CONTROL,
+ SEQ_UNCOMPRESSED_1,
+ SEQ_UNCOMPRESSED_2,
+ SEQ_COMPRESSED_0,
+ SEQ_COMPRESSED_1,
+ SEQ_PROPERTIES,
+ SEQ_LZMA,
+ SEQ_COPY,
+ } sequence;
+
+ /// Sequence after the size fields have been decoded.
+ enum sequence next_sequence;
+
+ /// LZMA decoder
+ lzma_lz_decoder lzma;
+
+ /// Uncompressed size of LZMA chunk
+ size_t uncompressed_size;
+
+ /// Compressed size of the chunk (naturally equals to uncompressed
+ /// size of uncompressed chunk)
+ size_t compressed_size;
+
+ /// True if properties are needed. This is false before the
+ /// first LZMA chunk.
+ bool need_properties;
+
+ /// True if dictionary reset is needed. This is false before the
+ /// first chunk (LZMA or uncompressed).
+ bool need_dictionary_reset;
+
+ lzma_options_lzma options;
+};
+
+
+static lzma_ret
+lzma2_decode(lzma_coder *restrict coder, lzma_dict *restrict dict,
+ const uint8_t *restrict in, size_t *restrict in_pos,
+ size_t in_size)
+{
+ // With SEQ_LZMA it is possible that no new input is needed to do
+ // some progress. The rest of the sequences assume that there is
+ // at least one byte of input.
+ while (*in_pos < in_size || coder->sequence == SEQ_LZMA)
+ switch (coder->sequence) {
+ case SEQ_CONTROL:
+ if (in[*in_pos] & 0x80) {
+ // Get the highest five bits of uncompressed size.
+ coder->uncompressed_size
+ = (uint32_t)(in[*in_pos] & 0x1F) << 16;
+ coder->sequence = SEQ_UNCOMPRESSED_1;
+
+ // See if we need to reset dictionary or state.
+ switch ((in[(*in_pos)++] >> 5) & 3) {
+ case 3:
+ dict_reset(dict);
+ coder->need_dictionary_reset = false;
+
+ // Fall through
+
+ case 2:
+ if (coder->need_dictionary_reset)
+ return LZMA_DATA_ERROR;
+
+ coder->need_properties = false;
+ coder->next_sequence = SEQ_PROPERTIES;
+ break;
+
+ case 1:
+ if (coder->need_properties)
+ return LZMA_DATA_ERROR;
+
+ coder->lzma.reset(coder->lzma.coder,
+ &coder->options);
+
+ coder->next_sequence = SEQ_LZMA;
+ break;
+
+ case 0:
+ if (coder->need_properties)
+ return LZMA_DATA_ERROR;
+
+ coder->next_sequence = SEQ_LZMA;
+ break;
+ }
+
+ } else {
+ switch (in[(*in_pos)++]) {
+ case 0:
+ // End of payload marker
+ return LZMA_STREAM_END;
+
+ case 1:
+ // Dictionary reset
+ dict_reset(dict);
+ coder->need_dictionary_reset = false;
+
+ // Fall through
+
+ case 2:
+ if (coder->need_dictionary_reset)
+ return LZMA_DATA_ERROR;
+
+ // Uncompressed chunk; we need to read total
+ // size first.
+ coder->sequence = SEQ_COMPRESSED_0;
+ coder->next_sequence = SEQ_COPY;
+ break;
+
+ default:
+ return LZMA_DATA_ERROR;
+ }
+ }
+
+ break;
+
+ case SEQ_UNCOMPRESSED_1:
+ coder->uncompressed_size += (uint32_t)(in[(*in_pos)++]) << 8;
+ coder->sequence = SEQ_UNCOMPRESSED_2;
+ break;
+
+ case SEQ_UNCOMPRESSED_2:
+ coder->uncompressed_size += in[(*in_pos)++] + 1;
+ coder->sequence = SEQ_COMPRESSED_0;
+ coder->lzma.set_uncompressed(coder->lzma.coder,
+ coder->uncompressed_size);
+ break;
+
+ case SEQ_COMPRESSED_0:
+ coder->compressed_size = (uint32_t)(in[(*in_pos)++]) << 8;
+ coder->sequence = SEQ_COMPRESSED_1;
+ break;
+
+ case SEQ_COMPRESSED_1:
+ coder->compressed_size += in[(*in_pos)++] + 1;
+ coder->sequence = coder->next_sequence;
+ break;
+
+ case SEQ_PROPERTIES:
+ if (lzma_lzma_lclppb_decode(&coder->options, in[(*in_pos)++]))
+ return LZMA_DATA_ERROR;
+
+ coder->lzma.reset(coder->lzma.coder, &coder->options);
+
+ coder->sequence = SEQ_LZMA;
+ break;
+
+ case SEQ_LZMA: {
+ // Store the start offset so that we can update
+ // coder->compressed_size later.
+ const size_t in_start = *in_pos;
+
+ // Decode from in[] to *dict.
+ const lzma_ret ret = coder->lzma.code(coder->lzma.coder,
+ dict, in, in_pos, in_size);
+
+ // Validate and update coder->compressed_size.
+ const size_t in_used = *in_pos - in_start;
+ if (in_used > coder->compressed_size)
+ return LZMA_DATA_ERROR;
+
+ coder->compressed_size -= in_used;
+
+ // Return if we didn't finish the chunk, or an error occurred.
+ if (ret != LZMA_STREAM_END)
+ return ret;
+
+ // The LZMA decoder must have consumed the whole chunk now.
+ // We don't need to worry about uncompressed size since it
+ // is checked by the LZMA decoder.
+ if (coder->compressed_size != 0)
+ return LZMA_DATA_ERROR;
+
+ coder->sequence = SEQ_CONTROL;
+ break;
+ }
+
+ case SEQ_COPY: {
+ // Copy from input to the dictionary as is.
+ // FIXME Can copy too much?
+ dict_write(dict, in, in_pos, in_size, &coder->compressed_size);
+ if (coder->compressed_size != 0)
+ return LZMA_OK;
+
+ coder->sequence = SEQ_CONTROL;
+ break;
+ }
+
+ default:
+ assert(0);
+ return LZMA_PROG_ERROR;
+ }
+
+ return LZMA_OK;
+}
+
+
+static void
+lzma2_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+ assert(coder->lzma.end == NULL);
+ lzma_free(coder->lzma.coder, allocator);
+
+ lzma_free(coder, allocator);
+
+ return;
+}
+
+
+static lzma_ret
+lzma2_decoder_init(lzma_lz_decoder *lz, lzma_allocator *allocator,
+ const void *options, size_t *dict_size)
+{
+ if (lz->coder == NULL) {
+ lz->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+ if (lz->coder == NULL)
+ return LZMA_MEM_ERROR;
+
+ lz->code = &lzma2_decode;
+ lz->end = &lzma2_decoder_end;
+
+ lz->coder->lzma = LZMA_LZ_DECODER_INIT;
+ }
+
+ lz->coder->sequence = SEQ_CONTROL;
+ lz->coder->need_properties = true;
+ lz->coder->need_dictionary_reset = true;
+
+ return lzma_lzma_decoder_create(&lz->coder->lzma,
+ allocator, options, dict_size);
+}
+
+
+extern lzma_ret
+lzma_lzma2_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+ const lzma_filter_info *filters)
+{
+ // LZMA2 can only be the last filter in the chain. This is enforced
+ // by the raw_decoder initialization.
+ assert(filters[1].init == NULL);
+
+ return lzma_lz_decoder_init(next, allocator, filters,
+ &lzma2_decoder_init);
+}
+
+
+extern uint64_t
+lzma_lzma2_decoder_memusage(const void *options)
+{
+ const uint64_t lzma_memusage = lzma_lzma_decoder_memusage(options);
+ if (lzma_memusage == UINT64_MAX)
+ return UINT64_MAX;
+
+ return sizeof(lzma_coder) + lzma_memusage;
+}
+
+
+extern lzma_ret
+lzma_lzma2_props_decode(void **options, lzma_allocator *allocator,
+ const uint8_t *props, size_t props_size)
+{
+ if (props_size != 1)
+ return LZMA_HEADER_ERROR;
+
+ // Check that reserved bits are unset.
+ if (props[0] & 0xC0)
+ return LZMA_HEADER_ERROR;
+
+ // Decode the dictionary size.
+ if (props[0] > 40)
+ return LZMA_HEADER_ERROR;
+
+ lzma_options_lzma *opt = lzma_alloc(
+ sizeof(lzma_options_lzma), allocator);
+ if (opt == NULL)
+ return LZMA_MEM_ERROR;
+
+ if (props[0] == 40) {
+ opt->dictionary_size = UINT32_MAX;
+ } else {
+ opt->dictionary_size = 2 | (props[0] & 1);
+ opt->dictionary_size <<= props[0] / 2 + 11;
+ }
+
+ opt->preset_dictionary = NULL;
+ opt->preset_dictionary_size = 0;
+
+ *options = opt;
+
+ return LZMA_OK;
+}