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72 lines
1.8 KiB
72 lines
1.8 KiB
// 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 "leveldb/iterator.h"
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namespace leveldb {
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Iterator::Iterator() {
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cleanup_head_.function = nullptr;
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cleanup_head_.next = nullptr;
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}
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Iterator::~Iterator() {
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if (!cleanup_head_.IsEmpty()) {
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cleanup_head_.Run();
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for (CleanupNode* node = cleanup_head_.next; node != nullptr; ) {
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node->Run();
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CleanupNode* next_node = node->next;
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delete node;
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node = next_node;
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}
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}
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}
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void Iterator::RegisterCleanup(CleanupFunction func, void* arg1, void* arg2) {
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assert(func != nullptr);
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CleanupNode* node;
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if (cleanup_head_.IsEmpty()) {
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node = &cleanup_head_;
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} else {
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node = new CleanupNode();
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node->next = cleanup_head_.next;
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cleanup_head_.next = node;
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}
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node->function = func;
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node->arg1 = arg1;
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node->arg2 = arg2;
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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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EmptyIterator(const Status& s) : status_(s) { }
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~EmptyIterator() override = default;
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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 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 { assert(false); return Slice(); }
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Slice value() const override { assert(false); return Slice(); }
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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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} // anonymous namespace
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Iterator* NewEmptyIterator() {
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return new EmptyIterator(Status::OK());
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}
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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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} // namespace leveldb
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