1 files changed, 94 insertions, 0 deletions
diff --git a/lzuncompress.c b/lzuncompress.c
new file mode 100644
index 000000000000..82ede94614ff
--- /dev/null
+++ b/lzuncompress.c
@@ -0,0 +1,94 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "ficl.h"
+
+
+
+int ficlLzDecodeHeaderField(const unsigned char *data, int *byteOffset)
+	{
+	unsigned char id;
+	int networkOrder;
+	int length;
+
+	id = data[(*byteOffset)++];
+	if (id < 252)
+		return id;
+
+	networkOrder = 0;
+	length = (id == 253) ? 2: 4;
+
+	ficlBitGetString(((unsigned char *)&networkOrder), data,
+		(*byteOffset) * 8,
+		length * 8, sizeof(networkOrder) * 8);
+	(*byteOffset) += length;
+
+	return ficlNetworkUnsigned32(networkOrder);
+	}
+
+
+
+int ficlLzUncompress(const unsigned char *compressed, unsigned char **uncompressed_p, size_t *uncompressedSize_p)
+	{
+	unsigned char *window;
+	unsigned char *buffer;
+	unsigned char *uncompressed;
+	unsigned char *initialWindow;
+
+	int bitstreamLength;
+	int inputPosition;
+	int uncompressedSize;
+
+	*uncompressed_p = NULL;
+
+	inputPosition = 0;
+	bitstreamLength = ficlLzDecodeHeaderField(compressed, &inputPosition);
+	uncompressedSize = ficlLzDecodeHeaderField(compressed, &inputPosition);
+
+	inputPosition <<= 3; /* same as * 8 */
+
+	bitstreamLength += inputPosition;
+
+	uncompressed = (unsigned char *)calloc(uncompressedSize + 1, 1);
+	if (uncompressed == NULL)
+		return -1;
+	window = buffer = uncompressed;
+	initialWindow = buffer + FICL_LZ_WINDOW_SIZE;
+
+	while (inputPosition != bitstreamLength)
+		{
+		int length;
+		int token = ficlBitGet(compressed, inputPosition);
+		inputPosition++;
+
+		if (token)
+			{
+			/* phrase token */
+			int offset = 0;
+			ficlBitGetString((unsigned char *)&offset, compressed, inputPosition, FICL_LZ_PHRASE_BITS - (1 + FICL_LZ_NEXT_BITS), sizeof(offset) * 8);
+			offset = ficlNetworkUnsigned32(offset);
+			inputPosition += FICL_LZ_PHRASE_BITS - (1 + FICL_LZ_NEXT_BITS);
+
+			length = (offset & ((1 << FICL_LZ_LENGTH_BITS) - 1)) + FICL_LZ_MINIMUM_USEFUL_MATCH;
+			offset >>= FICL_LZ_LENGTH_BITS;
+
+			memmove(buffer, window + offset, length);
+			buffer += length;
+			length++;
+			}
+		else
+			length = 1;
+
+		/* symbol token */
+		*buffer = 0;
+		ficlBitGetString(buffer++, compressed, inputPosition, FICL_LZ_NEXT_BITS, sizeof(*buffer) * 8);
+		inputPosition += FICL_LZ_NEXT_BITS;
+		if (buffer > initialWindow)
+			window = buffer - FICL_LZ_WINDOW_SIZE;
+		}
+
+	*uncompressed_p = uncompressed;
+	*uncompressedSize_p = uncompressedSize;
+
+	return 0;
+	}