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Unified Diff: xz/src/liblzma/common/block_header_encoder.c

Issue 2869016: Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/deps/third_party/
Patch Set: Created 10 years, 6 months ago
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Index: xz/src/liblzma/common/block_header_encoder.c
===================================================================
--- xz/src/liblzma/common/block_header_encoder.c (revision 0)
+++ xz/src/liblzma/common/block_header_encoder.c (revision 0)
@@ -0,0 +1,132 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file block_header_encoder.c
+/// \brief Encodes Block Header for .xz files
+//
+// Author: Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "common.h"
+#include "check.h"
+
+
+extern LZMA_API(lzma_ret)
+lzma_block_header_size(lzma_block *block)
+{
+ if (block->version != 0)
+ return LZMA_OPTIONS_ERROR;
+
+ // Block Header Size + Block Flags + CRC32.
+ uint32_t size = 1 + 1 + 4;
+
+ // Compressed Size
+ if (block->compressed_size != LZMA_VLI_UNKNOWN) {
+ const uint32_t add = lzma_vli_size(block->compressed_size);
+ if (add == 0 || block->compressed_size == 0)
+ return LZMA_PROG_ERROR;
+
+ size += add;
+ }
+
+ // Uncompressed Size
+ if (block->uncompressed_size != LZMA_VLI_UNKNOWN) {
+ const uint32_t add = lzma_vli_size(block->uncompressed_size);
+ if (add == 0)
+ return LZMA_PROG_ERROR;
+
+ size += add;
+ }
+
+ // List of Filter Flags
+ if (block->filters == NULL || block->filters[0].id == LZMA_VLI_UNKNOWN)
+ return LZMA_PROG_ERROR;
+
+ for (size_t i = 0; block->filters[i].id != LZMA_VLI_UNKNOWN; ++i) {
+ // Don't allow too many filters.
+ if (i == LZMA_FILTERS_MAX)
+ return LZMA_PROG_ERROR;
+
+ uint32_t add;
+ return_if_error(lzma_filter_flags_size(&add,
+ block->filters + i));
+
+ size += add;
+ }
+
+ // Pad to a multiple of four bytes.
+ block->header_size = (size + 3) & ~UINT32_C(3);
+
+ // NOTE: We don't verify that the encoded size of the Block stays
+ // within limits. This is because it is possible that we are called
+ // with exaggerated Compressed Size (e.g. LZMA_VLI_MAX) to reserve
+ // space for Block Header, and later called again with lower,
+ // real values.
+
+ return LZMA_OK;
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_block_header_encode(const lzma_block *block, uint8_t *out)
+{
+ // Validate everything but filters.
+ if (lzma_block_unpadded_size(block) == 0
+ || !lzma_vli_is_valid(block->uncompressed_size))
+ return LZMA_PROG_ERROR;
+
+ // Indicate the size of the buffer _excluding_ the CRC32 field.
+ const size_t out_size = block->header_size - 4;
+
+ // Store the Block Header Size.
+ out[0] = out_size / 4;
+
+ // We write Block Flags in pieces.
+ out[1] = 0x00;
+ size_t out_pos = 2;
+
+ // Compressed Size
+ if (block->compressed_size != LZMA_VLI_UNKNOWN) {
+ return_if_error(lzma_vli_encode(block->compressed_size, NULL,
+ out, &out_pos, out_size));
+
+ out[1] |= 0x40;
+ }
+
+ // Uncompressed Size
+ if (block->uncompressed_size != LZMA_VLI_UNKNOWN) {
+ return_if_error(lzma_vli_encode(block->uncompressed_size, NULL,
+ out, &out_pos, out_size));
+
+ out[1] |= 0x80;
+ }
+
+ // Filter Flags
+ if (block->filters == NULL || block->filters[0].id == LZMA_VLI_UNKNOWN)
+ return LZMA_PROG_ERROR;
+
+ size_t filter_count = 0;
+ do {
+ // There can be a maximum of four filters.
+ if (filter_count == LZMA_FILTERS_MAX)
+ return LZMA_PROG_ERROR;
+
+ return_if_error(lzma_filter_flags_encode(
+ block->filters + filter_count,
+ out, &out_pos, out_size));
+
+ } while (block->filters[++filter_count].id != LZMA_VLI_UNKNOWN);
+
+ out[1] |= filter_count - 1;
+
+ // Padding
+ memzero(out + out_pos, out_size - out_pos);
+
+ // CRC32
+ unaligned_write32le(out + out_size, lzma_crc32(out, out_size, 0));
+
+ return LZMA_OK;
+}
Property changes on: xz/src/liblzma/common/block_header_encoder.c
___________________________________________________________________
Added: svn:eol-style
+ LF
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