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-rw-r--r--src/liblzma/subblock/subblock_decoder_helper.c80
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
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+++ b/src/liblzma/subblock/subblock_decoder_helper.c
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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;
+}