12940b44dSPeter Avalos /////////////////////////////////////////////////////////////////////////////// 22940b44dSPeter Avalos // 32940b44dSPeter Avalos /// \file block_encoder.h 42940b44dSPeter Avalos /// \brief Encodes .xz Blocks 52940b44dSPeter Avalos // 62940b44dSPeter Avalos // Author: Lasse Collin 72940b44dSPeter Avalos // 82940b44dSPeter Avalos // This file has been put into the public domain. 92940b44dSPeter Avalos // You can do whatever you want with this file. 102940b44dSPeter Avalos // 112940b44dSPeter Avalos /////////////////////////////////////////////////////////////////////////////// 122940b44dSPeter Avalos 132940b44dSPeter Avalos #ifndef LZMA_BLOCK_ENCODER_H 142940b44dSPeter Avalos #define LZMA_BLOCK_ENCODER_H 152940b44dSPeter Avalos 162940b44dSPeter Avalos #include "common.h" 172940b44dSPeter Avalos 182940b44dSPeter Avalos 192940b44dSPeter Avalos /// \brief Biggest Compressed Size value that the Block encoder supports 202940b44dSPeter Avalos /// 212940b44dSPeter Avalos /// The maximum size of a single Block is limited by the maximum size of 222940b44dSPeter Avalos /// a Stream, which in theory is 2^63 - 3 bytes (i.e. LZMA_VLI_MAX - 3). 232940b44dSPeter Avalos /// While the size is really big and no one should hit it in practice, we 242940b44dSPeter Avalos /// take it into account in some places anyway to catch some errors e.g. if 252940b44dSPeter Avalos /// application passes insanely big value to some function. 262940b44dSPeter Avalos /// 272940b44dSPeter Avalos /// We could take into account the headers etc. to determine the exact 282940b44dSPeter Avalos /// maximum size of the Compressed Data field, but the complexity would give 292940b44dSPeter Avalos /// us nothing useful. Instead, limit the size of Compressed Data so that 302940b44dSPeter Avalos /// even with biggest possible Block Header and Check fields the total 312940b44dSPeter Avalos /// encoded size of the Block stays as a valid VLI. This doesn't guarantee 322940b44dSPeter Avalos /// that the size of the Stream doesn't grow too big, but that problem is 332940b44dSPeter Avalos /// taken care outside the Block handling code. 342940b44dSPeter Avalos /// 352940b44dSPeter Avalos /// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of 362940b44dSPeter Avalos /// the Compressed Data field, it will still stay in the proper limit. 372940b44dSPeter Avalos /// 382940b44dSPeter Avalos /// This constant is in this file because it is needed in both 392940b44dSPeter Avalos /// block_encoder.c and block_buffer_encoder.c. 402940b44dSPeter Avalos #define COMPRESSED_SIZE_MAX ((LZMA_VLI_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \ 412940b44dSPeter Avalos - LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3)) 422940b44dSPeter Avalos 432940b44dSPeter Avalos 442940b44dSPeter Avalos extern lzma_ret lzma_block_encoder_init(lzma_next_coder *next, 45*15ab8c86SJohn Marino const lzma_allocator *allocator, lzma_block *block); 462940b44dSPeter Avalos 472940b44dSPeter Avalos #endif 48