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