1 files changed, 57 insertions, 0 deletions
diff --git a/tensorflow/core/lib/io/block_builder.h b/tensorflow/core/lib/io/block_builder.h
new file mode 100644
index 0000000000..e07a647805
--- /dev/null
+++ b/tensorflow/core/lib/io/block_builder.h
@@ -0,0 +1,57 @@
+// 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_BLOCK_BUILDER_H_
+#define TENSORFLOW_LIB_IO_BLOCK_BUILDER_H_
+
+#include <vector>
+
+#include <stdint.h>
+#include "tensorflow/core/lib/core/stringpiece.h"
+
+namespace tensorflow {
+namespace table {
+
+struct Options;
+
+class BlockBuilder {
+ public:
+  explicit BlockBuilder(const Options* options);
+
+  // Reset the contents as if the BlockBuilder was just constructed.
+  void Reset();
+
+  // REQUIRES: Finish() has not been called since the last call to Reset().
+  // REQUIRES: key is larger than any previously added key
+  void Add(const StringPiece& key, const StringPiece& value);
+
+  // Finish building the block and return a slice that refers to the
+  // block contents.  The returned slice will remain valid for the
+  // lifetime of this builder or until Reset() is called.
+  StringPiece Finish();
+
+  // Returns an estimate of the current (uncompressed) size of the block
+  // we are building.
+  size_t CurrentSizeEstimate() const;
+
+  // Return true iff no entries have been added since the last Reset()
+  bool empty() const { return buffer_.empty(); }
+
+ private:
+  const Options* options_;
+  string buffer_;                 // Destination buffer
+  std::vector<uint32> restarts_;  // Restart points
+  int counter_;                   // Number of entries emitted since restart
+  bool finished_;                 // Has Finish() been called?
+  string last_key_;
+
+  // No copying allowed
+  BlockBuilder(const BlockBuilder&);
+  void operator=(const BlockBuilder&);
+};
+
+}  // namespace table
+}  // namespace tensorflow
+
+#endif  // TENSORFLOW_LIB_IO_BLOCK_BUILDER_H_