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67 righe
1.7 KiB
67 righe
1.7 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_.function = NULL;
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cleanup_.next = NULL;
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}
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Iterator::~Iterator() {
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if (cleanup_.function != NULL) {
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(*cleanup_.function)(cleanup_.arg1, cleanup_.arg2);
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for (Cleanup* c = cleanup_.next; c != NULL; ) {
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(*c->function)(c->arg1, c->arg2);
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Cleanup* next = c->next;
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delete c;
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c = next;
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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 != NULL);
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Cleanup* c;
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if (cleanup_.function == NULL) {
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c = &cleanup_;
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} else {
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c = new Cleanup;
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c->next = cleanup_.next;
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cleanup_.next = c;
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}
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c->function = func;
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c->arg1 = arg1;
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c->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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virtual bool Valid() const { return false; }
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virtual void Seek(const Slice& target) { }
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virtual void SeekToFirst() { }
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virtual void SeekToLast() { }
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virtual void Next() { assert(false); }
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virtual void Prev() { assert(false); }
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Slice key() const { assert(false); return Slice(); }
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Slice value() const { assert(false); return Slice(); }
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virtual Status status() const { 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() {
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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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