/usr/include/rocksdb/iterator.h is in librocksdb-dev 5.8.8-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | // Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
// 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.
//
// An iterator yields a sequence of key/value pairs from a source.
// The following class defines the interface. Multiple implementations
// are provided by this library. In particular, iterators are provided
// to access the contents of a Table or a DB.
//
// Multiple threads can invoke const methods on an Iterator without
// external synchronization, but if any of the threads may call a
// non-const method, all threads accessing the same Iterator must use
// external synchronization.
#ifndef STORAGE_ROCKSDB_INCLUDE_ITERATOR_H_
#define STORAGE_ROCKSDB_INCLUDE_ITERATOR_H_
#include <string>
#include "rocksdb/cleanable.h"
#include "rocksdb/slice.h"
#include "rocksdb/status.h"
namespace rocksdb {
class Iterator : public Cleanable {
public:
Iterator() {}
virtual ~Iterator() {}
// An iterator is either positioned at a key/value pair, or
// not valid. This method returns true iff the iterator is valid.
virtual bool Valid() const = 0;
// Position at the first key in the source. The iterator is Valid()
// after this call iff the source is not empty.
virtual void SeekToFirst() = 0;
// Position at the last key in the source. The iterator is
// Valid() after this call iff the source is not empty.
virtual void SeekToLast() = 0;
// Position at the first key in the source that at or past target
// The iterator is Valid() after this call iff the source contains
// an entry that comes at or past target.
virtual void Seek(const Slice& target) = 0;
// Position at the last key in the source that at or before target
// The iterator is Valid() after this call iff the source contains
// an entry that comes at or before target.
virtual void SeekForPrev(const Slice& target) {}
// Moves to the next entry in the source. After this call, Valid() is
// true iff the iterator was not positioned at the last entry in the source.
// REQUIRES: Valid()
virtual void Next() = 0;
// Moves to the previous entry in the source. After this call, Valid() is
// true iff the iterator was not positioned at the first entry in source.
// REQUIRES: Valid()
virtual void Prev() = 0;
// Return the key for the current entry. The underlying storage for
// the returned slice is valid only until the next modification of
// the iterator.
// REQUIRES: Valid()
virtual Slice key() const = 0;
// Return the value for the current entry. The underlying storage for
// the returned slice is valid only until the next modification of
// the iterator.
// REQUIRES: !AtEnd() && !AtStart()
virtual Slice value() const = 0;
// If an error has occurred, return it. Else return an ok status.
// If non-blocking IO is requested and this operation cannot be
// satisfied without doing some IO, then this returns Status::Incomplete().
virtual Status status() const = 0;
// If supported, renew the iterator to represent the latest state. The
// iterator will be invalidated after the call. Not supported if
// ReadOptions.snapshot is given when creating the iterator.
virtual Status Refresh() {
return Status::NotSupported("Refresh() is not supported");
}
// Property "rocksdb.iterator.is-key-pinned":
// If returning "1", this means that the Slice returned by key() is valid
// as long as the iterator is not deleted.
// It is guaranteed to always return "1" if
// - Iterator created with ReadOptions::pin_data = true
// - DB tables were created with
// BlockBasedTableOptions::use_delta_encoding = false.
// Property "rocksdb.iterator.super-version-number":
// LSM version used by the iterator. The same format as DB Property
// kCurrentSuperVersionNumber. See its comment for more information.
virtual Status GetProperty(std::string prop_name, std::string* prop);
private:
// No copying allowed
Iterator(const Iterator&);
void operator=(const Iterator&);
};
// Return an empty iterator (yields nothing).
extern Iterator* NewEmptyIterator();
// Return an empty iterator with the specified status.
extern Iterator* NewErrorIterator(const Status& status);
} // namespace rocksdb
#endif // STORAGE_ROCKSDB_INCLUDE_ITERATOR_H_
|