rocksdb/table/iterator.cc
Hans Wennborg 36a5f8ed7f A number of fixes:
- Replace raw slice comparison with a call to user comparator.
  Added test for custom comparators.

- Fix end of namespace comments.

- Fixed bug in picking inputs for a level-0 compaction.

  When finding overlapping files, the covered range may expand
  as files are added to the input set.  We now correctly expand
  the range when this happens instead of continuing to use the
  old range.  For example, suppose L0 contains files with the
  following ranges:

      F1: a .. d
      F2:    c .. g
      F3:       f .. j

  and the initial compaction target is F3.  We used to search
  for range f..j which yielded {F2,F3}.  However we now expand
  the range as soon as another file is added.  In this case,
  when F2 is added, we expand the range to c..j and restart the
  search.  That picks up file F1 as well.

  This change fixes a bug related to deleted keys showing up
  incorrectly after a compaction as described in Issue 44.

(Sync with upstream @25072954)
2011-10-31 17:22:06 +00:00

68 lines
1.7 KiB
C++

// 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