Imported to git.

1 files changed, 175 insertions, 0 deletions

diff --git a/src/liblzma/common/raw_common.c b/src/liblzma/common/raw_common.c
new file mode 100644
index 00000000..394903bc
--- /dev/null
+++ b/src/liblzma/common/raw_common.c
@@ -0,0 +1,175 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       raw_common.c
+/// \brief      Stuff shared between raw encoder and raw decoder
+//
+//  Copyright (C) 2007 Lasse Collin
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "raw_common.h"
+
+
+/// \brief      Prepares the filter chain
+///
+/// Prepares the filter chain by setting uncompressed sizes for each filter,
+/// and adding implicit Subblock filter when needed.
+///
+/// \return     true if error occurred, false on success.
+///
+static bool
+prepare(lzma_vli *id, lzma_vli *uncompressed_size, bool implicit)
+{
+	bool needs_end_of_input = false;
+
+	switch (id[0]) {
+	case LZMA_FILTER_COPY:
+	case LZMA_FILTER_X86:
+	case LZMA_FILTER_POWERPC:
+	case LZMA_FILTER_IA64:
+	case LZMA_FILTER_ARM:
+	case LZMA_FILTER_ARMTHUMB:
+	case LZMA_FILTER_SPARC:
+	case LZMA_FILTER_DELTA:
+		uncompressed_size[1] = uncompressed_size[0];
+		needs_end_of_input = true;
+		break;
+
+	case LZMA_FILTER_SUBBLOCK:
+	case LZMA_FILTER_LZMA:
+		// These change the size of the data unpredictably.
+		uncompressed_size[1] = LZMA_VLI_VALUE_UNKNOWN;
+		break;
+
+	case LZMA_FILTER_SUBBLOCK_HELPER:
+		uncompressed_size[1] = uncompressed_size[0];
+		break;
+
+	default:
+		// Unknown filter.
+		return true;
+	}
+
+	// Is this the last filter in the chain?
+	if (id[1] == LZMA_VLI_VALUE_UNKNOWN) {
+		if (!needs_end_of_input || !implicit || uncompressed_size[0]
+				!= LZMA_VLI_VALUE_UNKNOWN)
+			return false;
+
+		// Add implicit Subblock filter.
+		id[1] = LZMA_FILTER_SUBBLOCK;
+		uncompressed_size[1] = LZMA_VLI_VALUE_UNKNOWN;
+		id[2] = LZMA_VLI_VALUE_UNKNOWN;
+	}
+
+	return prepare(id + 1, uncompressed_size + 1, implicit);
+}
+
+
+extern lzma_ret
+lzma_raw_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		const lzma_options_filter *options, lzma_vli uncompressed_size,
+		lzma_init_function (*get_function)(lzma_vli id),
+		bool allow_implicit, bool is_encoder)
+{
+	if (options == NULL || !lzma_vli_is_valid(uncompressed_size))
+		return LZMA_PROG_ERROR;
+
+	// Count the number of filters in the chain.
+	size_t count = 0;
+	while (options[count].id != LZMA_VLI_VALUE_UNKNOWN)
+		++count;
+
+	// Allocate enough space from the stack for IDs and uncompressed
+	// sizes. We need two extra: possible implicit Subblock and end
+	// of array indicator.
+	lzma_vli ids[count + 2];
+	lzma_vli uncompressed_sizes[count + 2];
+	bool using_implicit = false;
+
+	uncompressed_sizes[0] = uncompressed_size;
+
+	if (count == 0) {
+		if (!allow_implicit)
+			return LZMA_PROG_ERROR;
+
+		count = 1;
+		using_implicit = true;
+
+		// Special case: no filters were specified, so an implicit
+		// Copy or Subblock filter is used.
+		if (uncompressed_size == LZMA_VLI_VALUE_UNKNOWN)
+			ids[0] = LZMA_FILTER_SUBBLOCK;
+		else
+			ids[0] = LZMA_FILTER_COPY;
+
+		ids[1] = LZMA_VLI_VALUE_UNKNOWN;
+
+	} else {
+		// Prepare the ids[] and uncompressed_sizes[].
+		for (size_t i = 0; i < count; ++i)
+			ids[i] = options[i].id;
+
+		ids[count] = LZMA_VLI_VALUE_UNKNOWN;
+
+		if (prepare(ids, uncompressed_sizes, allow_implicit))
+			return LZMA_HEADER_ERROR;
+
+		// Check if implicit Subblock filter was added.
+		if (ids[count] != LZMA_VLI_VALUE_UNKNOWN) {
+			assert(ids[count] == LZMA_FILTER_SUBBLOCK);
+			++count;
+			using_implicit = true;
+		}
+	}
+
+	// Set the filter functions, and copy uncompressed sizes and options.
+	lzma_filter_info filters[count + 1];
+	if (is_encoder) {
+		for (size_t i = 0; i < count; ++i) {
+			// The order of the filters is reversed in the
+			// encoder. It allows more efficient handling
+			// of the uncompressed data.
+			const size_t j = count - i - 1;
+
+			filters[j].init = get_function(ids[i]);
+			if (filters[j].init == NULL)
+				return LZMA_HEADER_ERROR;
+
+			filters[j].options = options[i].options;
+			filters[j].uncompressed_size = uncompressed_sizes[i];
+		}
+
+		if (using_implicit)
+			filters[0].options = NULL;
+
+	} else {
+		for (size_t i = 0; i < count; ++i) {
+			filters[i].init = get_function(ids[i]);
+			if (filters[i].init == NULL)
+				return LZMA_HEADER_ERROR;
+
+			filters[i].options = options[i].options;
+			filters[i].uncompressed_size = uncompressed_sizes[i];
+		}
+
+		if (using_implicit)
+			filters[count - 1].options = NULL;
+	}
+
+	// Terminate the array.
+	filters[count].init = NULL;
+
+	// Initialize the filters.
+	return lzma_next_filter_init(next, allocator, filters);
+}