aboutsummaryrefslogtreecommitdiff
path: root/src/leveldb/table/iterator.cc
blob: 3d1c87fdece73d4c1ef16a0a762f70059b9443e6 (plain)
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
// 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 "leveldb/iterator.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_;
};
}  // namespace

Iterator* NewEmptyIterator() {
  return new EmptyIterator(Status::OK());
}

Iterator* NewErrorIterator(const Status& status) {
  return new EmptyIterator(status);
}

}  // namespace leveldb