1/////////////////////////////////////////////////////////////////////////////// 2// 3/// \file outqueue.h 4/// \brief Output queue handling in multithreaded coding 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#include "common.h" 14 15 16/// Output buffer for a single thread 17typedef struct { 18 /// Pointer to the output buffer of lzma_outq.buf_size_max bytes 19 uint8_t *buf; 20 21 /// Amount of data written to buf 22 size_t size; 23 24 /// Additional size information 25 lzma_vli unpadded_size; 26 lzma_vli uncompressed_size; 27 28 /// True when no more data will be written into this buffer. 29 /// 30 /// \note This is read by another thread and thus access 31 /// to this variable needs a mutex. 32 bool finished; 33 34} lzma_outbuf; 35 36 37typedef struct { 38 /// Array of buffers that are used cyclically. 39 lzma_outbuf *bufs; 40 41 /// Memory allocated for all the buffers 42 uint8_t *bufs_mem; 43 44 /// Amount of buffer space available in each buffer 45 size_t buf_size_max; 46 47 /// Number of buffers allocated 48 uint32_t bufs_allocated; 49 50 /// Position in the bufs array. The next buffer to be taken 51 /// into use is bufs[bufs_pos]. 52 uint32_t bufs_pos; 53 54 /// Number of buffers in use 55 uint32_t bufs_used; 56 57 /// Position in the buffer in lzma_outq_read() 58 size_t read_pos; 59 60} lzma_outq; 61 62 63/** 64 * \brief Calculate the memory usage of an output queue 65 * 66 * \return Approximate memory usage in bytes or UINT64_MAX on error. 67 */ 68extern uint64_t lzma_outq_memusage(uint64_t buf_size_max, uint32_t threads); 69 70 71/// \brief Initialize an output queue 72/// 73/// \param outq Pointer to an output queue. Before calling 74/// this function the first time, *outq should 75/// have been zeroed with memzero() so that this 76/// function knows that there are no previous 77/// allocations to free. 78/// \param allocator Pointer to allocator or NULL 79/// \param buf_size_max Maximum amount of data that a single buffer 80/// in the queue may need to store. 81/// \param threads Number of buffers that may be in use 82/// concurrently. Note that more than this number 83/// of buffers will actually get allocated to 84/// improve performance when buffers finish 85/// out of order. 86/// 87/// \return - LZMA_OK 88/// - LZMA_MEM_ERROR 89/// 90extern lzma_ret lzma_outq_init( 91 lzma_outq *outq, const lzma_allocator *allocator, 92 uint64_t buf_size_max, uint32_t threads); 93 94 95/// \brief Free the memory associated with the output queue 96extern void lzma_outq_end(lzma_outq *outq, const lzma_allocator *allocator); 97 98 99/// \brief Get a new buffer 100/// 101/// lzma_outq_has_buf() must be used to check that there is a buffer 102/// available before calling lzma_outq_get_buf(). 103/// 104extern lzma_outbuf *lzma_outq_get_buf(lzma_outq *outq); 105 106 107/// \brief Test if there is data ready to be read 108/// 109/// Call to this function must be protected with the same mutex that 110/// is used to protect lzma_outbuf.finished. 111/// 112extern bool lzma_outq_is_readable(const lzma_outq *outq); 113 114 115/// \brief Read finished data 116/// 117/// \param outq Pointer to an output queue 118/// \param out Beginning of the output buffer 119/// \param out_pos The next byte will be written to 120/// out[*out_pos]. 121/// \param out_size Size of the out buffer; the first byte into 122/// which no data is written to is out[out_size]. 123/// \param unpadded_size Unpadded Size from the Block encoder 124/// \param uncompressed_size Uncompressed Size from the Block encoder 125/// 126/// \return - LZMA: All OK. Either no data was available or the buffer 127/// being read didn't become empty yet. 128/// - LZMA_STREAM_END: The buffer being read was finished. 129/// *unpadded_size and *uncompressed_size were set. 130/// 131/// \note This reads lzma_outbuf.finished variables and thus call 132/// to this function needs to be protected with a mutex. 133/// 134extern lzma_ret lzma_outq_read(lzma_outq *restrict outq, 135 uint8_t *restrict out, size_t *restrict out_pos, 136 size_t out_size, lzma_vli *restrict unpadded_size, 137 lzma_vli *restrict uncompressed_size); 138 139 140/// \brief Test if there is at least one buffer free 141/// 142/// This must be used before getting a new buffer with lzma_outq_get_buf(). 143/// 144static inline bool 145lzma_outq_has_buf(const lzma_outq *outq) 146{ 147 return outq->bufs_used < outq->bufs_allocated; 148} 149 150 151/// \brief Test if the queue is completely empty 152static inline bool 153lzma_outq_is_empty(const lzma_outq *outq) 154{ 155 return outq->bufs_used == 0; 156} 157