1 files changed, 80 insertions, 0 deletions
diff --git a/src/liblzma/subblock/subblock_decoder_helper.c b/src/liblzma/subblock/subblock_decoder_helper.c
new file mode 100644
index 00000000..5ff24431
--- /dev/null
+++ b/src/liblzma/subblock/subblock_decoder_helper.c
@@ -0,0 +1,80 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       subblock_decoder_helper.c
+/// \brief      Helper filter for the Subblock decoder
+///
+/// This filter is used to indicate End of Input for subfilters needing it.
+//
+//  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 "subblock_decoder_helper.h"
+
+
+struct lzma_coder_s {
+	const lzma_options_subblock_helper *options;
+};
+
+
+static lzma_ret
+helper_decode(lzma_coder *coder,
+		lzma_allocator *allocator lzma_attribute((unused)),
+		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_attribute((unused)))
+{
+	// If end_was_reached is true, we cannot have any input.
+	assert(!coder->options->end_was_reached || *in_pos == in_size);
+
+	// We can safely copy as much as possible, because we are never
+	// given more data than a single Subblock Data field.
+	bufcpy(in, in_pos, in_size, out, out_pos, out_size);
+
+	// Return LZMA_STREAM_END when instructed so by the Subblock decoder.
+	return coder->options->end_was_reached ? LZMA_STREAM_END : LZMA_OK;
+}
+
+
+static void
+helper_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+extern lzma_ret
+lzma_subblock_decoder_helper_init(lzma_next_coder *next,
+		lzma_allocator *allocator, const lzma_filter_info *filters)
+{
+	// This is always the last filter in the chain.
+	assert(filters[1].init == NULL);
+
+	// We never know uncompressed size.
+	assert(filters[0].uncompressed_size == LZMA_VLI_VALUE_UNKNOWN);
+
+	if (next->coder == NULL) {
+		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (next->coder == NULL)
+			return LZMA_MEM_ERROR;
+		
+		next->code = &helper_decode;
+		next->end = helper_end;
+	}
+
+	next->coder->options = filters[0].options;
+
+	return LZMA_OK;
+}