X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=lzma%2Fcommon%2Fblock_encoder.h;fp=lzma%2Fcommon%2Fblock_encoder.h;h=bd97c186e503027e75c9baf956c928d980a052c6;hb=32b8a6b26ed8843828e03e505d2256960bda0980;hp=0000000000000000000000000000000000000000;hpb=d48fc23a4bcf8ca3c406d6e8c8a6f8c6b0fa2f1e;p=zpackage diff --git a/lzma/common/block_encoder.h b/lzma/common/block_encoder.h new file mode 100644 index 0000000..bd97c18 --- /dev/null +++ b/lzma/common/block_encoder.h @@ -0,0 +1,47 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file block_encoder.h +/// \brief Encodes .xz Blocks +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_BLOCK_ENCODER_H +#define LZMA_BLOCK_ENCODER_H + +#include "common.h" + + +/// \brief Biggest Compressed Size value that the Block encoder supports +/// +/// The maximum size of a single Block is limited by the maximum size of +/// a Stream, which in theory is 2^63 - 3 bytes (i.e. LZMA_VLI_MAX - 3). +/// While the size is really big and no one should hit it in practice, we +/// take it into account in some places anyway to catch some errors e.g. if +/// application passes insanely big value to some function. +/// +/// We could take into account the headers etc. to determine the exact +/// maximum size of the Compressed Data field, but the complexity would give +/// us nothing useful. Instead, limit the size of Compressed Data so that +/// even with biggest possible Block Header and Check fields the total +/// encoded size of the Block stays as a valid VLI. This doesn't guarantee +/// that the size of the Stream doesn't grow too big, but that problem is +/// taken care outside the Block handling code. +/// +/// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of +/// the Compressed Data field, it will still stay in the proper limit. +/// +/// This constant is in this file because it is needed in both +/// block_encoder.c and block_buffer_encoder.c. +#define COMPRESSED_SIZE_MAX ((LZMA_VLI_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \ + - LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3)) + + +extern lzma_ret lzma_block_encoder_init(lzma_next_coder *next, + const lzma_allocator *allocator, lzma_block *block); + +#endif