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diff --git a/tensorflow/core/lib/io/format.h b/tensorflow/core/lib/io/format.h
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+++ b/tensorflow/core/lib/io/format.h
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+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef TENSORFLOW_LIB_IO_FORMAT_H_
+#define TENSORFLOW_LIB_IO_FORMAT_H_
+
+#include <string>
+#include <stdint.h>
+#include "tensorflow/core/lib/core/stringpiece.h"
+#include "tensorflow/core/public/status.h"
+#include "tensorflow/core/lib/io/table_builder.h"
+
+namespace tensorflow {
+class RandomAccessFile;
+namespace table {
+
+class Block;
+
+// BlockHandle is a pointer to the extent of a file that stores a data
+// block or a meta block.
+class BlockHandle {
+ public:
+  BlockHandle();
+
+  // The offset of the block in the file.
+  uint64 offset() const { return offset_; }
+  void set_offset(uint64 offset) { offset_ = offset; }
+
+  // The size of the stored block
+  uint64 size() const { return size_; }
+  void set_size(uint64 size) { size_ = size; }
+
+  void EncodeTo(string* dst) const;
+  Status DecodeFrom(StringPiece* input);
+
+  // Maximum encoding length of a BlockHandle
+  enum { kMaxEncodedLength = 10 + 10 };
+
+ private:
+  uint64 offset_;
+  uint64 size_;
+};
+
+// Footer encapsulates the fixed information stored at the tail
+// end of every table file.
+class Footer {
+ public:
+  Footer() {}
+
+  // The block handle for the metaindex block of the table
+  const BlockHandle& metaindex_handle() const { return metaindex_handle_; }
+  void set_metaindex_handle(const BlockHandle& h) { metaindex_handle_ = h; }
+
+  // The block handle for the index block of the table
+  const BlockHandle& index_handle() const { return index_handle_; }
+  void set_index_handle(const BlockHandle& h) { index_handle_ = h; }
+
+  void EncodeTo(string* dst) const;
+  Status DecodeFrom(StringPiece* input);
+
+  // Encoded length of a Footer.  Note that the serialization of a
+  // Footer will always occupy exactly this many bytes.  It consists
+  // of two block handles and a magic number.
+  enum { kEncodedLength = 2 * BlockHandle::kMaxEncodedLength + 8 };
+
+ private:
+  BlockHandle metaindex_handle_;
+  BlockHandle index_handle_;
+};
+
+// kTableMagicNumber was picked by running
+//    echo http://code.google.com/p/leveldb/ | sha1sum
+// and taking the leading 64 bits.
+static const uint64 kTableMagicNumber = 0xdb4775248b80fb57ull;
+
+// 1-byte type + 32-bit crc
+static const size_t kBlockTrailerSize = 5;
+
+struct BlockContents {
+  StringPiece data;     // Actual contents of data
+  bool cachable;        // True iff data can be cached
+  bool heap_allocated;  // True iff caller should delete[] data.data()
+};
+
+// Read the block identified by "handle" from "file".  On failure
+// return non-OK.  On success fill *result and return OK.
+extern Status ReadBlock(RandomAccessFile* file, const BlockHandle& handle,
+                             BlockContents* result);
+
+// Implementation details follow.  Clients should ignore,
+
+inline BlockHandle::BlockHandle()
+    : offset_(~static_cast<uint64>(0)), size_(~static_cast<uint64>(0)) {}
+
+}  // namespace table
+}  // namespace tensorflow
+
+#endif  // TENSORFLOW_LIB_IO_FORMAT_H_