diff options
Diffstat (limited to 'contrib/xz/src/liblzma/common/outqueue.c')
| -rw-r--r-- | contrib/xz/src/liblzma/common/outqueue.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/contrib/xz/src/liblzma/common/outqueue.c b/contrib/xz/src/liblzma/common/outqueue.c new file mode 100644 index 0000000..2dc8a38 --- /dev/null +++ b/contrib/xz/src/liblzma/common/outqueue.c @@ -0,0 +1,184 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file outqueue.c +/// \brief Output queue handling in multithreaded coding +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "outqueue.h" + + +/// This is to ease integer overflow checking: We may allocate up to +/// 2 * LZMA_THREADS_MAX buffers and we need some extra memory for other +/// data structures (that's the second /2). +#define BUF_SIZE_MAX (UINT64_MAX / LZMA_THREADS_MAX / 2 / 2) + + +static lzma_ret +get_options(uint64_t *bufs_alloc_size, uint32_t *bufs_count, + uint64_t buf_size_max, uint32_t threads) +{ + if (threads > LZMA_THREADS_MAX || buf_size_max > BUF_SIZE_MAX) + return LZMA_OPTIONS_ERROR; + + // The number of buffers is twice the number of threads. + // This wastes RAM but keeps the threads busy when buffers + // finish out of order. + // + // NOTE: If this is changed, update BUF_SIZE_MAX too. + *bufs_count = threads * 2; + *bufs_alloc_size = *bufs_count * buf_size_max; + + return LZMA_OK; +} + + +extern uint64_t +lzma_outq_memusage(uint64_t buf_size_max, uint32_t threads) +{ + uint64_t bufs_alloc_size; + uint32_t bufs_count; + + if (get_options(&bufs_alloc_size, &bufs_count, buf_size_max, threads) + != LZMA_OK) + return UINT64_MAX; + + return sizeof(lzma_outq) + bufs_count * sizeof(lzma_outbuf) + + bufs_alloc_size; +} + + +extern lzma_ret +lzma_outq_init(lzma_outq *outq, const lzma_allocator *allocator, + uint64_t buf_size_max, uint32_t threads) +{ + uint64_t bufs_alloc_size; + uint32_t bufs_count; + + // Set bufs_count and bufs_alloc_size. + return_if_error(get_options(&bufs_alloc_size, &bufs_count, + buf_size_max, threads)); + + // Allocate memory if needed. + if (outq->buf_size_max != buf_size_max + || outq->bufs_allocated != bufs_count) { + lzma_outq_end(outq, allocator); + +#if SIZE_MAX < UINT64_MAX + if (bufs_alloc_size > SIZE_MAX) + return LZMA_MEM_ERROR; +#endif + + outq->bufs = lzma_alloc(bufs_count * sizeof(lzma_outbuf), + allocator); + outq->bufs_mem = lzma_alloc((size_t)(bufs_alloc_size), + allocator); + + if (outq->bufs == NULL || outq->bufs_mem == NULL) { + lzma_outq_end(outq, allocator); + return LZMA_MEM_ERROR; + } + } + + // Initialize the rest of the main structure. Initialization of + // outq->bufs[] is done when they are actually needed. + outq->buf_size_max = (size_t)(buf_size_max); + outq->bufs_allocated = bufs_count; + outq->bufs_pos = 0; + outq->bufs_used = 0; + outq->read_pos = 0; + + return LZMA_OK; +} + + +extern void +lzma_outq_end(lzma_outq *outq, const lzma_allocator *allocator) +{ + lzma_free(outq->bufs, allocator); + outq->bufs = NULL; + + lzma_free(outq->bufs_mem, allocator); + outq->bufs_mem = NULL; + + return; +} + + +extern lzma_outbuf * +lzma_outq_get_buf(lzma_outq *outq) +{ + // Caller must have checked it with lzma_outq_has_buf(). + assert(outq->bufs_used < outq->bufs_allocated); + + // Initialize the new buffer. + lzma_outbuf *buf = &outq->bufs[outq->bufs_pos]; + buf->buf = outq->bufs_mem + outq->bufs_pos * outq->buf_size_max; + buf->size = 0; + buf->finished = false; + + // Update the queue state. + if (++outq->bufs_pos == outq->bufs_allocated) + outq->bufs_pos = 0; + + ++outq->bufs_used; + + return buf; +} + + +extern bool +lzma_outq_is_readable(const lzma_outq *outq) +{ + uint32_t i = outq->bufs_pos - outq->bufs_used; + if (outq->bufs_pos < outq->bufs_used) + i += outq->bufs_allocated; + + return outq->bufs[i].finished; +} + + +extern lzma_ret +lzma_outq_read(lzma_outq *restrict outq, uint8_t *restrict out, + size_t *restrict out_pos, size_t out_size, + lzma_vli *restrict unpadded_size, + lzma_vli *restrict uncompressed_size) +{ + // There must be at least one buffer from which to read. + if (outq->bufs_used == 0) + return LZMA_OK; + + // Get the buffer. + uint32_t i = outq->bufs_pos - outq->bufs_used; + if (outq->bufs_pos < outq->bufs_used) + i += outq->bufs_allocated; + + lzma_outbuf *buf = &outq->bufs[i]; + + // If it isn't finished yet, we cannot read from it. + if (!buf->finished) + return LZMA_OK; + + // Copy from the buffer to output. + lzma_bufcpy(buf->buf, &outq->read_pos, buf->size, + out, out_pos, out_size); + + // Return if we didn't get all the data from the buffer. + if (outq->read_pos < buf->size) + return LZMA_OK; + + // The buffer was finished. Tell the caller its size information. + *unpadded_size = buf->unpadded_size; + *uncompressed_size = buf->uncompressed_size; + + // Free this buffer for further use. + --outq->bufs_used; + outq->read_pos = 0; + + return LZMA_STREAM_END; +} |
