Squashed 'src/rocksdb/' content from commit 224932d

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include/rocksdb/slice_transform.h

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+// Copyright (c) 2013, Facebook, Inc.  All rights reserved.
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree. An additional grant
+// of patent rights can be found in the PATENTS file in the same directory.
+// Copyright (c) 2012 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.
+//
+// Class for specifying user-defined functions which perform a
+// transformation on a slice.  It is not required that every slice
+// belong to the domain and/or range of a function.  Subclasses should
+// define InDomain and InRange to determine which slices are in either
+// of these sets respectively.
+
+#ifndef STORAGE_ROCKSDB_INCLUDE_SLICE_TRANSFORM_H_
+#define STORAGE_ROCKSDB_INCLUDE_SLICE_TRANSFORM_H_
+
+#include <string>
+
+namespace rocksdb {
+
+class Slice;
+
+class SliceTransform {
+ public:
+  virtual ~SliceTransform() {};
+
+  // Return the name of this transformation.
+  virtual const char* Name() const = 0;
+
+  // transform a src in domain to a dst in the range
+  virtual Slice Transform(const Slice& src) const = 0;
+
+  // determine whether this is a valid src upon the function applies
+  virtual bool InDomain(const Slice& src) const = 0;
+
+  // determine whether dst=Transform(src) for some src
+  virtual bool InRange(const Slice& dst) const = 0;
+};
+
+extern const SliceTransform* NewFixedPrefixTransform(size_t prefix_len);
+
+extern const SliceTransform* NewNoopTransform();
+
+}
+
+#endif  // STORAGE_ROCKSDB_INCLUDE_SLICE_TRANSFORM_H_