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-rw-r--r--src/liblzma/common/outqueue.h155
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file outqueue.h
+/// \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 "common.h"
+
+
+/// Output buffer for a single thread
+typedef struct {
+ /// Pointer to the output buffer of lzma_outq.buf_size_max bytes
+ uint8_t *buf;
+
+ /// Amount of data written to buf
+ size_t size;
+
+ /// Additional size information
+ lzma_vli unpadded_size;
+ lzma_vli uncompressed_size;
+
+ /// True when no more data will be written into this buffer.
+ ///
+ /// \note This is read by another thread and thus access
+ /// to this variable needs a mutex.
+ bool finished;
+
+} lzma_outbuf;
+
+
+typedef struct {
+ /// Array of buffers that are used cyclically.
+ lzma_outbuf *bufs;
+
+ /// Memory allocated for all the buffers
+ uint8_t *bufs_mem;
+
+ /// Amount of buffer space available in each buffer
+ size_t buf_size_max;
+
+ /// Number of buffers allocated
+ uint32_t bufs_allocated;
+
+ /// Position in the bufs array. The next buffer to be taken
+ /// into use is bufs[bufs_pos].
+ uint32_t bufs_pos;
+
+ /// Number of buffers in use
+ uint32_t bufs_used;
+
+ /// Position in the buffer in lzma_outq_read()
+ size_t read_pos;
+
+} lzma_outq;
+
+
+/**
+ * \brief Calculate the memory usage of an output queue
+ *
+ * \return Approximate memory usage in bytes or UINT64_MAX on error.
+ */
+extern uint64_t lzma_outq_memusage(uint64_t buf_size_max, uint32_t threads);
+
+
+/// \brief Initialize an output queue
+///
+/// \param outq Pointer to an output queue. Before calling
+/// this function the first time, *outq should
+/// have been zeroed with memzero() so that this
+/// function knows that there are no previous
+/// allocations to free.
+/// \param allocator Pointer to allocator or NULL
+/// \param buf_size_max Maximum amount of data that a single buffer
+/// in the queue may need to store.
+/// \param threads Number of buffers that may be in use
+/// concurrently. Note that more than this number
+/// of buffers will actually get allocated to
+/// improve performance when buffers finish
+/// out of order.
+///
+/// \return - LZMA_OK
+/// - LZMA_MEM_ERROR
+///
+extern lzma_ret lzma_outq_init(lzma_outq *outq, lzma_allocator *allocator,
+ uint64_t buf_size_max, uint32_t threads);
+
+
+/// \brief Free the memory associated with the output queue
+extern void lzma_outq_end(lzma_outq *outq, lzma_allocator *allocator);
+
+
+/// \brief Get a new buffer
+///
+/// lzma_outq_has_buf() must be used to check that there is a buffer
+/// available before calling lzma_outq_get_buf().
+///
+extern lzma_outbuf *lzma_outq_get_buf(lzma_outq *outq);
+
+
+/// \brief Test if there is data ready to be read
+///
+/// Call to this function must be protected with the same mutex that
+/// is used to protect lzma_outbuf.finished.
+///
+extern bool lzma_outq_is_readable(const lzma_outq *outq);
+
+
+/// \brief Read finished data
+///
+/// \param outq Pointer to an output queue
+/// \param out Beginning of the output buffer
+/// \param out_pos The next byte will be written to
+/// out[*out_pos].
+/// \param out_size Size of the out buffer; the first byte into
+/// which no data is written to is out[out_size].
+/// \param unpadded_size Unpadded Size from the Block encoder
+/// \param uncompressed_size Uncompressed Size from the Block encoder
+///
+/// \return - LZMA: All OK. Either no data was available or the buffer
+/// being read didn't become empty yet.
+/// - LZMA_STREAM_END: The buffer being read was finished.
+/// *unpadded_size and *uncompressed_size were set.
+///
+/// \note This reads lzma_outbuf.finished variables and thus call
+/// to this function needs to be protected with a mutex.
+///
+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);
+
+
+/// \brief Test if there is at least one buffer free
+///
+/// This must be used before getting a new buffer with lzma_outq_get_buf().
+///
+static inline bool
+lzma_outq_has_buf(const lzma_outq *outq)
+{
+ return outq->bufs_used < outq->bufs_allocated;
+}
+
+
+/// \brief Test if the queue is completely empty
+static inline bool
+lzma_outq_is_empty(const lzma_outq *outq)
+{
+ return outq->bufs_used == 0;
+}