Ви не можете вибрати більше 25 тем
Теми мають розпочинатися з літери або цифри, можуть містити дефіси (-) і не повинні перевищувати 35 символів.
68 рядки
1.7 KiB
68 рядки
1.7 KiB
// 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.
|
|
|
|
#include "include/iterator.h"
|
|
#include "util/logging.h"
|
|
|
|
namespace leveldb {
|
|
|
|
Iterator::Iterator() {
|
|
cleanup_.function = NULL;
|
|
cleanup_.next = NULL;
|
|
}
|
|
|
|
Iterator::~Iterator() {
|
|
if (cleanup_.function != NULL) {
|
|
(*cleanup_.function)(cleanup_.arg1, cleanup_.arg2);
|
|
for (Cleanup* c = cleanup_.next; c != NULL; ) {
|
|
(*c->function)(c->arg1, c->arg2);
|
|
Cleanup* next = c->next;
|
|
delete c;
|
|
c = next;
|
|
}
|
|
}
|
|
}
|
|
|
|
void Iterator::RegisterCleanup(CleanupFunction func, void* arg1, void* arg2) {
|
|
assert(func != NULL);
|
|
Cleanup* c;
|
|
if (cleanup_.function == NULL) {
|
|
c = &cleanup_;
|
|
} else {
|
|
c = new Cleanup;
|
|
c->next = cleanup_.next;
|
|
cleanup_.next = c;
|
|
}
|
|
c->function = func;
|
|
c->arg1 = arg1;
|
|
c->arg2 = arg2;
|
|
}
|
|
|
|
namespace {
|
|
class EmptyIterator : public Iterator {
|
|
public:
|
|
EmptyIterator(const Status& s) : status_(s) { }
|
|
virtual bool Valid() const { return false; }
|
|
virtual void Seek(const Slice& target) { }
|
|
virtual void SeekToFirst() { }
|
|
virtual void SeekToLast() { }
|
|
virtual void Next() { assert(false); }
|
|
virtual void Prev() { assert(false); }
|
|
Slice key() const { assert(false); return Slice(); }
|
|
Slice value() const { assert(false); return Slice(); }
|
|
virtual Status status() const { return status_; }
|
|
private:
|
|
Status status_;
|
|
};
|
|
}
|
|
|
|
Iterator* NewEmptyIterator() {
|
|
return new EmptyIterator(Status::OK());
|
|
}
|
|
|
|
Iterator* NewErrorIterator(const Status& status) {
|
|
return new EmptyIterator(status);
|
|
}
|
|
|
|
}
|