| 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
|
|
|
|
|