1 files changed, 180 insertions, 0 deletions
diff --git a/src/liblzma/common/outqueue.c b/src/liblzma/common/outqueue.c
new file mode 100644
index 00000000..b9eac16d
--- /dev/null
+++ b/src/liblzma/common/outqueue.c
@@ -0,0 +1,180 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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, 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, lzma_allocator *allocator)
+{
+	lzma_free(outq->bufs, allocator);
+	lzma_free(outq->bufs_mem, allocator);
+	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;
+}