1 files changed, 113 insertions, 0 deletions
diff --git a/src/liblzma/common/auto_decoder.c b/src/liblzma/common/auto_decoder.c
new file mode 100644
index 00000000..7e92df9a
--- /dev/null
+++ b/src/liblzma/common/auto_decoder.c
@@ -0,0 +1,113 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       auto_decoder.c
+/// \brief      Autodetect between .lzma Stream and LZMA_Alone formats
+//
+//  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 "common.h"
+#include "alone_decoder.h"
+
+
+struct lzma_coder_s {
+	lzma_next_coder next;
+
+	lzma_extra **header;
+	lzma_extra **footer;
+	bool initialized;
+};
+
+
+static lzma_ret
+auto_decode(lzma_coder *coder, 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)
+{
+	if (!coder->initialized) {
+		if (*in_pos >= in_size)
+			return LZMA_OK;
+
+		lzma_ret ret;
+
+		if (in[*in_pos] == 0xFF)
+			ret = lzma_stream_decoder_init(&coder->next, allocator,
+					coder->header, coder->footer);
+		else
+			ret = lzma_alone_decoder_init(&coder->next, allocator);
+
+		if (ret != LZMA_OK)
+			return ret;
+
+		coder->initialized = true;
+	}
+
+	return coder->next.code(coder->next.coder, allocator,
+			in, in_pos, in_size, out, out_pos, out_size, action);
+}
+
+
+static void
+auto_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_next_coder_end(&coder->next, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_ret
+auto_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		lzma_extra **header, lzma_extra **footer)
+{
+	if (next->coder == NULL) {
+		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (next->coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		next->code = &auto_decode;
+		next->end = &auto_decoder_end;
+		next->coder->next = LZMA_NEXT_CODER_INIT;
+	}
+
+	next->coder->header = header;
+	next->coder->footer = footer;
+	next->coder->initialized = false;
+
+	return LZMA_OK;
+}
+
+
+/*
+extern lzma_ret
+lzma_auto_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		lzma_extra **header, lzma_extra **footer)
+{
+	lzma_next_coder_init(
+			auto_decoder_init, next, allocator, header, footer);
+}
+*/
+
+
+extern LZMA_API lzma_ret
+lzma_auto_decoder(lzma_stream *strm, lzma_extra **header, lzma_extra **footer)
+{
+	lzma_next_strm_init(strm, auto_decoder_init, header, footer);
+
+	strm->internal->supported_actions[LZMA_RUN] = true;
+	strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true;
+
+	return LZMA_OK;
+}