1*81ad8388SMartin Matuska /////////////////////////////////////////////////////////////////////////////// 2*81ad8388SMartin Matuska // 3*81ad8388SMartin Matuska /// \file block_encoder.h 4*81ad8388SMartin Matuska /// \brief Encodes .xz Blocks 5*81ad8388SMartin Matuska // 6*81ad8388SMartin Matuska // Author: Lasse Collin 7*81ad8388SMartin Matuska // 8*81ad8388SMartin Matuska // This file has been put into the public domain. 9*81ad8388SMartin Matuska // You can do whatever you want with this file. 10*81ad8388SMartin Matuska // 11*81ad8388SMartin Matuska /////////////////////////////////////////////////////////////////////////////// 12*81ad8388SMartin Matuska 13*81ad8388SMartin Matuska #ifndef LZMA_BLOCK_ENCODER_H 14*81ad8388SMartin Matuska #define LZMA_BLOCK_ENCODER_H 15*81ad8388SMartin Matuska 16*81ad8388SMartin Matuska #include "common.h" 17*81ad8388SMartin Matuska 18*81ad8388SMartin Matuska 19*81ad8388SMartin Matuska /// \brief Biggest Compressed Size value that the Block encoder supports 20*81ad8388SMartin Matuska /// 21*81ad8388SMartin Matuska /// The maximum size of a single Block is limited by the maximum size of 22*81ad8388SMartin Matuska /// a Stream, which in theory is 2^63 - 3 bytes (i.e. LZMA_VLI_MAX - 3). 23*81ad8388SMartin Matuska /// While the size is really big and no one should hit it in practice, we 24*81ad8388SMartin Matuska /// take it into account in some places anyway to catch some errors e.g. if 25*81ad8388SMartin Matuska /// application passes insanely big value to some function. 26*81ad8388SMartin Matuska /// 27*81ad8388SMartin Matuska /// We could take into account the headers etc. to determine the exact 28*81ad8388SMartin Matuska /// maximum size of the Compressed Data field, but the complexity would give 29*81ad8388SMartin Matuska /// us nothing useful. Instead, limit the size of Compressed Data so that 30*81ad8388SMartin Matuska /// even with biggest possible Block Header and Check fields the total 31*81ad8388SMartin Matuska /// encoded size of the Block stays as a valid VLI. This doesn't guarantee 32*81ad8388SMartin Matuska /// that the size of the Stream doesn't grow too big, but that problem is 33*81ad8388SMartin Matuska /// taken care outside the Block handling code. 34*81ad8388SMartin Matuska /// 35*81ad8388SMartin Matuska /// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of 36*81ad8388SMartin Matuska /// the Compressed Data field, it will still stay in the proper limit. 37*81ad8388SMartin Matuska /// 38*81ad8388SMartin Matuska /// This constant is in this file because it is needed in both 39*81ad8388SMartin Matuska /// block_encoder.c and block_buffer_encoder.c. 40*81ad8388SMartin Matuska #define COMPRESSED_SIZE_MAX ((LZMA_VLI_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \ 41*81ad8388SMartin Matuska - LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3)) 42*81ad8388SMartin Matuska 43*81ad8388SMartin Matuska 44*81ad8388SMartin Matuska extern lzma_ret lzma_block_encoder_init(lzma_next_coder *next, 45*81ad8388SMartin Matuska lzma_allocator *allocator, lzma_block *block); 46*81ad8388SMartin Matuska 47*81ad8388SMartin Matuska #endif 48