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

xz/src/liblzma/common/block_decoder.c

Index: xz/src/liblzma/common/block_decoder.c
===================================================================
--- xz/src/liblzma/common/block_decoder.c	(revision 0)
+++ xz/src/liblzma/common/block_decoder.c	(revision 0)
@@ -0,0 +1,242 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       block_decoder.c
+/// \brief      Decodes .xz Blocks
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "block_decoder.h"
+#include "filter_decoder.h"
+#include "check.h"
+
+
+struct lzma_coder_s {
+	enum {
+		SEQ_CODE,
+		SEQ_PADDING,
+		SEQ_CHECK,
+	} sequence;
+
+	/// The filters in the chain; initialized with lzma_raw_decoder_init().
+	lzma_next_coder next;
+
+	/// Decoding options; we also write Compressed Size and Uncompressed
+	/// Size back to this structure when the decoding has been finished.
+	lzma_block *block;
+
+	/// Compressed Size calculated while decoding
+	lzma_vli compressed_size;
+
+	/// Uncompressed Size calculated while decoding
+	lzma_vli uncompressed_size;
+
+	/// Maximum allowed Compressed Size; this takes into account the
+	/// size of the Block Header and Check fields when Compressed Size
+	/// is unknown.
+	lzma_vli compressed_limit;
+
+	/// Position when reading the Check field
+	size_t check_pos;
+
+	/// Check of the uncompressed data
+	lzma_check_state check;
+};
+
+
+static inline bool
+update_size(lzma_vli *size, lzma_vli add, lzma_vli limit)
+{
+	if (limit > LZMA_VLI_MAX)
+		limit = LZMA_VLI_MAX;
+
+	if (limit < *size || limit - *size < add)
+		return true;
+
+	*size += add;
+
+	return false;
+}
+
+
+static inline bool
+is_size_valid(lzma_vli size, lzma_vli reference)
+{
+	return reference == LZMA_VLI_UNKNOWN || reference == size;
+}
+
+
+static lzma_ret
+block_decode(lzma_coder *coder, lzma_allocator *allocator,
+		const uint8_t *restrict in, size_t *restrict in_pos,
+		size_t in_size, uint8_t *restrict out,
+		size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+	switch (coder->sequence) {
+	case SEQ_CODE: {
+		const size_t in_start = *in_pos;
+		const size_t out_start = *out_pos;
+
+		const lzma_ret ret = coder->next.code(coder->next.coder,
+				allocator, in, in_pos, in_size,
+				out, out_pos, out_size, action);
+
+		const size_t in_used = *in_pos - in_start;
+		const size_t out_used = *out_pos - out_start;
+
+		// NOTE: We compare to compressed_limit here, which prevents
+		// the total size of the Block growing past LZMA_VLI_MAX.
+		if (update_size(&coder->compressed_size, in_used,
+					coder->compressed_limit)
+				|| update_size(&coder->uncompressed_size,
+					out_used,
+					coder->block->uncompressed_size))
+			return LZMA_DATA_ERROR;
+
+		lzma_check_update(&coder->check, coder->block->check,
+				out + out_start, out_used);
+
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		// Compressed and Uncompressed Sizes are now at their final
+		// values. Verify that they match the values given to us.
+		if (!is_size_valid(coder->compressed_size,
+					coder->block->compressed_size)
+				|| !is_size_valid(coder->uncompressed_size,
+					coder->block->uncompressed_size))
+			return LZMA_DATA_ERROR;
+
+		// Copy the values into coder->block. The caller
+		// may use this information to construct Index.
+		coder->block->compressed_size = coder->compressed_size;
+		coder->block->uncompressed_size = coder->uncompressed_size;
+
+		coder->sequence = SEQ_PADDING;
+	}
+
+	// Fall through
+
+	case SEQ_PADDING:
+		// Compressed Data is padded to a multiple of four bytes.
+		while (coder->compressed_size & 3) {
+			if (*in_pos >= in_size)
+				return LZMA_OK;
+
+			// We use compressed_size here just get the Padding
+			// right. The actual Compressed Size was stored to
+			// coder->block already, and won't be modified by
+			// us anymore.
+			++coder->compressed_size;
+
+			if (in[(*in_pos)++] != 0x00)
+				return LZMA_DATA_ERROR;
+		}
+
+		if (coder->block->check == LZMA_CHECK_NONE)
+			return LZMA_STREAM_END;
+
+		lzma_check_finish(&coder->check, coder->block->check);
+		coder->sequence = SEQ_CHECK;
+
+	// Fall through
+
+	case SEQ_CHECK: {
+		const size_t check_size = lzma_check_size(coder->block->check);
+		lzma_bufcpy(in, in_pos, in_size, coder->block->raw_check,
+				&coder->check_pos, check_size);
+		if (coder->check_pos < check_size)
+			return LZMA_OK;
+
+		// Validate the Check only if we support it.
+		// coder->check.buffer may be uninitialized
+		// when the Check ID is not supported.
+		if (lzma_check_is_supported(coder->block->check)
+				&& memcmp(coder->block->raw_check,
+					coder->check.buffer.u8,
+					check_size) != 0)
+			return LZMA_DATA_ERROR;
+
+		return LZMA_STREAM_END;
+	}
+	}
+
+	return LZMA_PROG_ERROR;
+}
+
+
+static void
+block_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_next_end(&coder->next, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+extern lzma_ret
+lzma_block_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		lzma_block *block)
+{
+	lzma_next_coder_init(&lzma_block_decoder_init, next, allocator);
+
+	// Validate the options. lzma_block_unpadded_size() does that for us
+	// except for Uncompressed Size and filters. Filters are validated
+	// by the raw decoder.
+	if (lzma_block_unpadded_size(block) == 0
+			|| !lzma_vli_is_valid(block->uncompressed_size))
+		return LZMA_PROG_ERROR;
+
+	// Allocate and initialize *next->coder if needed.
+	if (next->coder == NULL) {
+		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (next->coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		next->code = &block_decode;
+		next->end = &block_decoder_end;
+		next->coder->next = LZMA_NEXT_CODER_INIT;
+	}
+
+	// Basic initializations
+	next->coder->sequence = SEQ_CODE;
+	next->coder->block = block;
+	next->coder->compressed_size = 0;
+	next->coder->uncompressed_size = 0;
+
+	// If Compressed Size is not known, we calculate the maximum allowed
+	// value so that encoded size of the Block (including Block Padding)
+	// is still a valid VLI and a multiple of four.
+	next->coder->compressed_limit
+			= block->compressed_size == LZMA_VLI_UNKNOWN
+				? (LZMA_VLI_MAX & ~LZMA_VLI_C(3))
+					- block->header_size
+					- lzma_check_size(block->check)
+				: block->compressed_size;
+
+	// Initialize the check. It's caller's problem if the Check ID is not
+	// supported, and the Block decoder cannot verify the Check field.
+	// Caller can test lzma_check_is_supported(block->check).
+	next->coder->check_pos = 0;
+	lzma_check_init(&next->coder->check, block->check);
+
+	// Initialize the filter chain.
+	return lzma_raw_decoder_init(&next->coder->next, allocator,
+			block->filters);
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_block_decoder(lzma_stream *strm, lzma_block *block)
+{
+	lzma_next_strm_init(lzma_block_decoder_init, strm, block);
+
+	strm->internal->supported_actions[LZMA_RUN] = true;
+	strm->internal->supported_actions[LZMA_FINISH] = true;
+
+	return LZMA_OK;
+}
Property changes on: xz/src/liblzma/common/block_decoder.c
___________________________________________________________________
Added: svn:eol-style
   + LF