Adding upstream version 5.6.1+really5.4.5.upstream/5.6.1+really5.4.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 292 insertions, 0 deletions

diff --git a/src/liblzma/simple/simple_coder.c b/src/liblzma/simple/simple_coder.c
new file mode 100644
index 0000000..ed2d7fb
--- /dev/null
+++ b/src/liblzma/simple/simple_coder.c
@@ -0,0 +1,292 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       simple_coder.c
+/// \brief      Wrapper for simple filters
+///
+/// Simple filters don't change the size of the data i.e. number of bytes
+/// in equals the number of bytes out.
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "simple_private.h"
+
+
+/// Copied or encodes/decodes more data to out[].
+static lzma_ret
+copy_or_code(lzma_simple_coder *coder, const lzma_allocator *allocator,
+		const uint8_t *restrict in, size_t *restrict in_pos,
+		size_t in_size, uint8_t *restrict out,
+		size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+	assert(!coder->end_was_reached);
+
+	if (coder->next.code == NULL) {
+		lzma_bufcpy(in, in_pos, in_size, out, out_pos, out_size);
+
+		// Check if end of stream was reached.
+		if (coder->is_encoder && action == LZMA_FINISH
+				&& *in_pos == in_size)
+			coder->end_was_reached = true;
+
+	} else {
+		// Call the next coder in the chain to provide us some data.
+		const lzma_ret ret = coder->next.code(
+				coder->next.coder, allocator,
+				in, in_pos, in_size,
+				out, out_pos, out_size, action);
+
+		if (ret == LZMA_STREAM_END) {
+			assert(!coder->is_encoder
+					|| action == LZMA_FINISH);
+			coder->end_was_reached = true;
+
+		} else if (ret != LZMA_OK) {
+			return ret;
+		}
+	}
+
+	return LZMA_OK;
+}
+
+
+static size_t
+call_filter(lzma_simple_coder *coder, uint8_t *buffer, size_t size)
+{
+	const size_t filtered = coder->filter(coder->simple,
+			coder->now_pos, coder->is_encoder,
+			buffer, size);
+	coder->now_pos += filtered;
+	return filtered;
+}
+
+
+static lzma_ret
+simple_code(void *coder_ptr, const lzma_allocator *allocator,
+		const uint8_t *restrict in, size_t *restrict in_pos,
+		size_t in_size, uint8_t *restrict out,
+		size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+	lzma_simple_coder *coder = coder_ptr;
+
+	// TODO: Add partial support for LZMA_SYNC_FLUSH. We can support it
+	// in cases when the filter is able to filter everything. With most
+	// simple filters it can be done at offset that is a multiple of 2,
+	// 4, or 16. With x86 filter, it needs good luck, and thus cannot
+	// be made to work predictably.
+	if (action == LZMA_SYNC_FLUSH)
+		return LZMA_OPTIONS_ERROR;
+
+	// Flush already filtered data from coder->buffer[] to out[].
+	if (coder->pos < coder->filtered) {
+		lzma_bufcpy(coder->buffer, &coder->pos, coder->filtered,
+				out, out_pos, out_size);
+
+		// If we couldn't flush all the filtered data, return to
+		// application immediately.
+		if (coder->pos < coder->filtered)
+			return LZMA_OK;
+
+		if (coder->end_was_reached) {
+			assert(coder->filtered == coder->size);
+			return LZMA_STREAM_END;
+		}
+	}
+
+	// If we get here, there is no filtered data left in the buffer.
+	coder->filtered = 0;
+
+	assert(!coder->end_was_reached);
+
+	// If there is more output space left than there is unfiltered data
+	// in coder->buffer[], flush coder->buffer[] to out[], and copy/code
+	// more data to out[] hopefully filling it completely. Then filter
+	// the data in out[]. This step is where most of the data gets
+	// filtered if the buffer sizes used by the application are reasonable.
+	const size_t out_avail = out_size - *out_pos;
+	const size_t buf_avail = coder->size - coder->pos;
+	if (out_avail > buf_avail || buf_avail == 0) {
+		// Store the old position so that we know from which byte
+		// to start filtering.
+		const size_t out_start = *out_pos;
+
+		// Flush data from coder->buffer[] to out[], but don't reset
+		// coder->pos and coder->size yet. This way the coder can be
+		// restarted if the next filter in the chain returns e.g.
+		// LZMA_MEM_ERROR.
+		//
+		// Do the memcpy() conditionally because out can be NULL
+		// (in which case buf_avail is always 0). Calling memcpy()
+		// with a null-pointer is undefined even if the third
+		// argument is 0.
+		if (buf_avail > 0)
+			memcpy(out + *out_pos, coder->buffer + coder->pos,
+					buf_avail);
+
+		*out_pos += buf_avail;
+
+		// Copy/Encode/Decode more data to out[].
+		{
+			const lzma_ret ret = copy_or_code(coder, allocator,
+					in, in_pos, in_size,
+					out, out_pos, out_size, action);
+			assert(ret != LZMA_STREAM_END);
+			if (ret != LZMA_OK)
+				return ret;
+		}
+
+		// Filter out[] unless there is nothing to filter.
+		// This way we avoid null pointer + 0 (undefined behavior)
+		// when out == NULL.
+		const size_t size = *out_pos - out_start;
+		const size_t filtered = size == 0 ? 0 : call_filter(
+				coder, out + out_start, size);
+
+		const size_t unfiltered = size - filtered;
+		assert(unfiltered <= coder->allocated / 2);
+
+		// Now we can update coder->pos and coder->size, because
+		// the next coder in the chain (if any) was successful.
+		coder->pos = 0;
+		coder->size = unfiltered;
+
+		if (coder->end_was_reached) {
+			// The last byte has been copied to out[] already.
+			// They are left as is.
+			coder->size = 0;
+
+		} else if (unfiltered > 0) {
+			// There is unfiltered data left in out[]. Copy it to
+			// coder->buffer[] and rewind *out_pos appropriately.
+			*out_pos -= unfiltered;
+			memcpy(coder->buffer, out + *out_pos, unfiltered);
+		}
+	} else if (coder->pos > 0) {
+		memmove(coder->buffer, coder->buffer + coder->pos, buf_avail);
+		coder->size -= coder->pos;
+		coder->pos = 0;
+	}
+
+	assert(coder->pos == 0);
+
+	// If coder->buffer[] isn't empty, try to fill it by copying/decoding
+	// more data. Then filter coder->buffer[] and copy the successfully
+	// filtered data to out[]. It is probable, that some filtered and
+	// unfiltered data will be left to coder->buffer[].
+	if (coder->size > 0) {
+		{
+			const lzma_ret ret = copy_or_code(coder, allocator,
+					in, in_pos, in_size,
+					coder->buffer, &coder->size,
+					coder->allocated, action);
+			assert(ret != LZMA_STREAM_END);
+			if (ret != LZMA_OK)
+				return ret;
+		}
+
+		coder->filtered = call_filter(
+				coder, coder->buffer, coder->size);
+
+		// Everything is considered to be filtered if coder->buffer[]
+		// contains the last bytes of the data.
+		if (coder->end_was_reached)
+			coder->filtered = coder->size;
+
+		// Flush as much as possible.
+		lzma_bufcpy(coder->buffer, &coder->pos, coder->filtered,
+				out, out_pos, out_size);
+	}
+
+	// Check if we got everything done.
+	if (coder->end_was_reached && coder->pos == coder->size)
+		return LZMA_STREAM_END;
+
+	return LZMA_OK;
+}
+
+
+static void
+simple_coder_end(void *coder_ptr, const lzma_allocator *allocator)
+{
+	lzma_simple_coder *coder = coder_ptr;
+	lzma_next_end(&coder->next, allocator);
+	lzma_free(coder->simple, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_ret
+simple_coder_update(void *coder_ptr, const lzma_allocator *allocator,
+		const lzma_filter *filters_null lzma_attribute((__unused__)),
+		const lzma_filter *reversed_filters)
+{
+	lzma_simple_coder *coder = coder_ptr;
+
+	// No update support, just call the next filter in the chain.
+	return lzma_next_filter_update(
+			&coder->next, allocator, reversed_filters + 1);
+}
+
+
+extern lzma_ret
+lzma_simple_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+		const lzma_filter_info *filters,
+		size_t (*filter)(void *simple, uint32_t now_pos,
+			bool is_encoder, uint8_t *buffer, size_t size),
+		size_t simple_size, size_t unfiltered_max,
+		uint32_t alignment, bool is_encoder)
+{
+	// Allocate memory for the lzma_simple_coder structure if needed.
+	lzma_simple_coder *coder = next->coder;
+	if (coder == NULL) {
+		// Here we allocate space also for the temporary buffer. We
+		// need twice the size of unfiltered_max, because then it
+		// is always possible to filter at least unfiltered_max bytes
+		// more data in coder->buffer[] if it can be filled completely.
+		coder = lzma_alloc(sizeof(lzma_simple_coder)
+				+ 2 * unfiltered_max, allocator);
+		if (coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		next->coder = coder;
+		next->code = &simple_code;
+		next->end = &simple_coder_end;
+		next->update = &simple_coder_update;
+
+		coder->next = LZMA_NEXT_CODER_INIT;
+		coder->filter = filter;
+		coder->allocated = 2 * unfiltered_max;
+
+		// Allocate memory for filter-specific data structure.
+		if (simple_size > 0) {
+			coder->simple = lzma_alloc(simple_size, allocator);
+			if (coder->simple == NULL)
+				return LZMA_MEM_ERROR;
+		} else {
+			coder->simple = NULL;
+		}
+	}
+
+	if (filters[0].options != NULL) {
+		const lzma_options_bcj *simple = filters[0].options;
+		coder->now_pos = simple->start_offset;
+		if (coder->now_pos & (alignment - 1))
+			return LZMA_OPTIONS_ERROR;
+	} else {
+		coder->now_pos = 0;
+	}
+
+	// Reset variables.
+	coder->is_encoder = is_encoder;
+	coder->end_was_reached = false;
+	coder->pos = 0;
+	coder->filtered = 0;
+	coder->size = 0;
+
+	return lzma_next_filter_init(&coder->next, allocator, filters + 1);
+}