1 files changed, 81 insertions, 0 deletions
diff --git a/src/liblzma/common/vli_encoder.c b/src/liblzma/common/vli_encoder.c
new file mode 100644
index 00000000..1ecdb0d2
--- /dev/null
+++ b/src/liblzma/common/vli_encoder.c
@@ -0,0 +1,81 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       vli_encoder.c
+/// \brief      Encodes variable-length integers
+//
+//  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"
+
+
+extern LZMA_API lzma_ret
+lzma_vli_encode(lzma_vli vli, size_t *restrict vli_pos, size_t vli_size,
+		uint8_t *restrict out, size_t *restrict out_pos,
+		size_t out_size)
+{
+	if (vli > LZMA_VLI_VALUE_MAX || *vli_pos >= 9 || vli_size > 9
+			|| (vli != 0 && (vli >> (7 * *vli_pos)) == 0))
+		return LZMA_PROG_ERROR;
+
+	if (*out_pos >= out_size)
+		return LZMA_BUF_ERROR;
+
+	if (*vli_pos == 0) {
+		*vli_pos = 1;
+
+		if (vli <= 0x7F && *vli_pos >= vli_size) {
+			// Single-byte integer
+			out[(*out_pos)++] = vli;
+			return LZMA_STREAM_END;
+		}
+
+		// First byte of a multibyte integer
+		out[(*out_pos)++] = (vli & 0x7F) | 0x80;
+	}
+
+	while (*out_pos < out_size) {
+		const lzma_vli b = vli >> (7 * *vli_pos);
+		++*vli_pos;
+
+		if (b <= 0x7F && *vli_pos >= vli_size) {
+			// Last byte of a multibyte integer
+			out[(*out_pos)++] = (b & 0xFF) | 0x80;
+			return LZMA_STREAM_END;
+		}
+
+		// Middle byte of a multibyte integer
+		out[(*out_pos)++] = b & 0x7F;
+	}
+
+	// vli is not yet completely written out.
+	return LZMA_OK;
+}
+
+
+extern LZMA_API size_t
+lzma_vli_size(lzma_vli vli)
+{
+	if (vli > LZMA_VLI_VALUE_MAX)
+		return 0;
+
+	size_t i = 0;
+	do {
+		vli >>= 7;
+		++i;
+	} while (vli != 0);
+
+	assert(i <= 9);
+	return i;
+}