// 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_