mirror of https://github.com/facebook/rocksdb.git
135 lines
4.3 KiB
C++
135 lines
4.3 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "rocksdb/iterator.h"
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#include "memory/arena.h"
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#include "table/internal_iterator.h"
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#include "table/iterator_wrapper.h"
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namespace ROCKSDB_NAMESPACE {
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Status Iterator::GetProperty(std::string prop_name, std::string* prop) {
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if (prop == nullptr) {
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return Status::InvalidArgument("prop is nullptr");
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}
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if (prop_name == "rocksdb.iterator.is-key-pinned") {
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*prop = "0";
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return Status::OK();
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}
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if (prop_name == "rocksdb.iterator.is-value-pinned") {
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*prop = "0";
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return Status::OK();
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}
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return Status::InvalidArgument("Unidentified property.");
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}
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namespace {
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class EmptyIterator : public Iterator {
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public:
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explicit EmptyIterator(const Status& s) : status_(s) {}
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bool Valid() const override { return false; }
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void Seek(const Slice& /*target*/) override {}
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void SeekForPrev(const Slice& /*target*/) override {}
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void SeekToFirst() override {}
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void SeekToLast() override {}
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void Next() override { assert(false); }
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void Prev() override { assert(false); }
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Slice key() const override {
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assert(false);
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return Slice();
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}
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Slice value() const override {
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assert(false);
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return Slice();
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}
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Status status() const override { return status_; }
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private:
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Status status_;
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};
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template <class TValue = Slice>
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class EmptyInternalIterator : public InternalIteratorBase<TValue> {
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public:
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explicit EmptyInternalIterator(const Status& s) : status_(s) {}
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bool Valid() const override { return false; }
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void Seek(const Slice& /*target*/) override {}
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void SeekForPrev(const Slice& /*target*/) override {}
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void SeekToFirst() override {}
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void SeekToLast() override {}
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void Next() override { assert(false); }
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void Prev() override { assert(false); }
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Slice key() const override {
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assert(false);
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return Slice();
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}
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TValue value() const override {
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assert(false);
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return TValue();
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}
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Status status() const override { return status_; }
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private:
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Status status_;
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};
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} // namespace
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Iterator* NewEmptyIterator() { return new EmptyIterator(Status::OK()); }
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Iterator* NewErrorIterator(const Status& status) {
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return new EmptyIterator(status);
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}
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template <class TValue>
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InternalIteratorBase<TValue>* NewErrorInternalIterator(const Status& status) {
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return new EmptyInternalIterator<TValue>(status);
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}
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template InternalIteratorBase<IndexValue>* NewErrorInternalIterator(
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const Status& status);
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template InternalIteratorBase<Slice>* NewErrorInternalIterator(
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const Status& status);
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template <class TValue>
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InternalIteratorBase<TValue>* NewErrorInternalIterator(const Status& status,
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Arena* arena) {
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if (arena == nullptr) {
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return NewErrorInternalIterator<TValue>(status);
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} else {
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auto mem = arena->AllocateAligned(sizeof(EmptyInternalIterator<TValue>));
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return new (mem) EmptyInternalIterator<TValue>(status);
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}
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}
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template InternalIteratorBase<IndexValue>* NewErrorInternalIterator(
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const Status& status, Arena* arena);
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template InternalIteratorBase<Slice>* NewErrorInternalIterator(
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const Status& status, Arena* arena);
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template <class TValue>
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InternalIteratorBase<TValue>* NewEmptyInternalIterator() {
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return new EmptyInternalIterator<TValue>(Status::OK());
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}
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template InternalIteratorBase<IndexValue>* NewEmptyInternalIterator();
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template InternalIteratorBase<Slice>* NewEmptyInternalIterator();
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template <class TValue>
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InternalIteratorBase<TValue>* NewEmptyInternalIterator(Arena* arena) {
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if (arena == nullptr) {
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return NewEmptyInternalIterator<TValue>();
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} else {
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auto mem = arena->AllocateAligned(sizeof(EmptyInternalIterator<TValue>));
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return new (mem) EmptyInternalIterator<TValue>(Status::OK());
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}
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}
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template InternalIteratorBase<IndexValue>* NewEmptyInternalIterator(
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Arena* arena);
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template InternalIteratorBase<Slice>* NewEmptyInternalIterator(Arena* arena);
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} // namespace ROCKSDB_NAMESPACE
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