/////////////////////////////////////////////////////////////////////////////// // /// \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