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authorLasse Collin <lasse.collin@tukaani.org>2009-01-26 14:34:10 +0200
committerLasse Collin <lasse.collin@tukaani.org>2009-01-26 14:34:10 +0200
commit667481f1aad34e1ed15738e7913a9c7e256b4cf5 (patch)
treedc5b1b272885a07b6b0a6c7c94561c3924e3d811 /src/liblzma/common/block_buffer_decoder.c
parentAdd more sanity checks to lzma_stream_buffer_decode(). (diff)
downloadxz-667481f1aad34e1ed15738e7913a9c7e256b4cf5.tar.xz
Add lzma_block_buffer_decode().
Diffstat (limited to 'src/liblzma/common/block_buffer_decoder.c')
-rw-r--r--src/liblzma/common/block_buffer_decoder.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/src/liblzma/common/block_buffer_decoder.c b/src/liblzma/common/block_buffer_decoder.c
new file mode 100644
index 00000000..ec24e44b
--- /dev/null
+++ b/src/liblzma/common/block_buffer_decoder.c
@@ -0,0 +1,87 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file block_buffer_decoder.c
+/// \brief Single-call .xz Block decoder
+//
+// Copyright (C) 2009 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 "block_decoder.h"
+
+
+extern LZMA_API lzma_ret
+lzma_block_buffer_decode(lzma_block *block, lzma_allocator *allocator,
+ const uint8_t *in, size_t *in_pos, size_t in_size,
+ uint8_t *out, size_t *out_pos, size_t out_size)
+{
+ if (in_pos == NULL || (in == NULL && *in_pos != in_size)
+ || *in_pos > in_size || out_pos == NULL
+ || (out == NULL && *out_pos != out_size)
+ || *out_pos > out_size)
+ return LZMA_PROG_ERROR;
+
+ // Initialize the Block decoder.
+ lzma_next_coder block_decoder = LZMA_NEXT_CODER_INIT;
+ lzma_ret ret = lzma_block_decoder_init(
+ &block_decoder, allocator, block);
+
+ if (ret == LZMA_OK) {
+ // Save the positions so that we can restore them in case
+ // an error occurs.
+ const size_t in_start = *in_pos;
+ const size_t out_start = *out_pos;
+
+ // Do the actual decoding.
+ ret = block_decoder.code(block_decoder.coder, allocator,
+ in, in_pos, in_size, out, out_pos, out_size,
+ LZMA_FINISH);
+
+ if (ret == LZMA_STREAM_END) {
+ ret = LZMA_OK;
+ } else {
+ // Something went wrong, restore the positions.
+ *in_pos = in_start;
+ *out_pos = out_start;
+
+ if (ret == LZMA_OK) {
+ // Either the input was truncated or the
+ // output buffer was too small.
+ assert(*in_pos == in_size
+ || *out_pos == out_size);
+
+ // If all the input was consumed, then the
+ // input is truncated, even if the output
+ // buffer is also full. This is because
+ // processing the last byte of the Block
+ // never produces output.
+ //
+ // NOTE: This assumption may break when new
+ // filters are added, if the end marker of
+ // the filter doesn't consume at least one
+ // complete byte.
+ if (*in_pos == in_size)
+ ret = LZMA_DATA_ERROR;
+ else
+ ret = LZMA_BUF_ERROR;
+ }
+ }
+ }
+
+ // Free the decoder memory. This needs to be done even if
+ // initialization fails, because the internal API doesn't
+ // require the initialization function to free its memory on error.
+ lzma_next_end(&block_decoder, allocator);
+
+ return ret;
+}