Import relocation packer from chromium repo
Bug: 18051137
Change-Id: Ia67fa11da8247e3f86f70a8ce99e6695f2c05423
diff --git a/tools/relocation_packer/src/leb128.h b/tools/relocation_packer/src/leb128.h
new file mode 100644
index 0000000..6cc2d7c
--- /dev/null
+++ b/tools/relocation_packer/src/leb128.h
@@ -0,0 +1,74 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// LEB128 encoder and decoder for packed relative relocations.
+//
+// Run-length encoded relative relocations consist of a large number
+// of pairs of relatively small positive integer values. Encoding these as
+// LEB128 saves space.
+//
+// For more on LEB128 see http://en.wikipedia.org/wiki/LEB128.
+
+#ifndef TOOLS_RELOCATION_PACKER_SRC_LEB128_H_
+#define TOOLS_RELOCATION_PACKER_SRC_LEB128_H_
+
+#include <stdint.h>
+#include <vector>
+
+#include "elf_traits.h"
+
+namespace relocation_packer {
+
+// Encode packed words as a LEB128 byte stream.
+class Leb128Encoder {
+ public:
+ // Explicit (but empty) constructor and destructor, for chromium-style.
+ Leb128Encoder();
+ ~Leb128Encoder();
+
+ // Add a value to the encoding stream.
+ // |value| is the unsigned int to add.
+ void Enqueue(ELF::Xword value);
+
+ // Add a vector of values to the encoding stream.
+ // |values| is the vector of unsigned ints to add.
+ void EnqueueAll(const std::vector<ELF::Xword>& values);
+
+ // Retrieve the encoded representation of the values.
+ // |encoding| is the returned vector of encoded data.
+ void GetEncoding(std::vector<uint8_t>* encoding) { *encoding = encoding_; }
+
+ private:
+ // Growable vector holding the encoded LEB128 stream.
+ std::vector<uint8_t> encoding_;
+};
+
+// Decode a LEB128 byte stream to produce packed words.
+class Leb128Decoder {
+ public:
+ // Create a new decoder for the given encoded stream.
+ // |encoding| is the vector of encoded data.
+ explicit Leb128Decoder(const std::vector<uint8_t>& encoding);
+
+ // Explicit (but empty) destructor, for chromium-style.
+ ~Leb128Decoder();
+
+ // Retrieve the next value from the encoded stream.
+ ELF::Xword Dequeue();
+
+ // Retrieve all remaining values from the encoded stream.
+ // |values| is the vector of decoded data.
+ void DequeueAll(std::vector<ELF::Xword>* values);
+
+ private:
+ // Encoded LEB128 stream.
+ std::vector<uint8_t> encoding_;
+
+ // Cursor indicating the current stream retrieval point.
+ size_t cursor_;
+};
+
+} // namespace relocation_packer
+
+#endif // TOOLS_RELOCATION_PACKER_SRC_LEB128_H_