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36a5f8ed7f
- 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)
65 lines
1.8 KiB
C++
65 lines
1.8 KiB
C++
// 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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//
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// WriteBatch holds a collection of updates to apply atomically to a DB.
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//
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// The updates are applied in the order in which they are added
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// to the WriteBatch. For example, the value of "key" will be "v3"
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// after the following batch is written:
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//
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// batch.Put("key", "v1");
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// batch.Delete("key");
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// batch.Put("key", "v2");
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// batch.Put("key", "v3");
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//
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// Multiple threads can invoke const methods on a WriteBatch without
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// external synchronization, but if any of the threads may call a
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// non-const method, all threads accessing the same WriteBatch must use
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// external synchronization.
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#ifndef STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
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#define STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
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#include <string>
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#include "leveldb/status.h"
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namespace leveldb {
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class Slice;
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class WriteBatch {
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public:
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WriteBatch();
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~WriteBatch();
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// Store the mapping "key->value" in the database.
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void Put(const Slice& key, const Slice& value);
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// If the database contains a mapping for "key", erase it. Else do nothing.
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void Delete(const Slice& key);
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// Clear all updates buffered in this batch.
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void Clear();
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// Support for iterating over the contents of a batch.
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class Handler {
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public:
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virtual ~Handler();
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virtual void Put(const Slice& key, const Slice& value) = 0;
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virtual void Delete(const Slice& key) = 0;
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};
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Status Iterate(Handler* handler) const;
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private:
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friend class WriteBatchInternal;
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std::string rep_; // See comment in write_batch.cc for the format of rep_
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// Intentionally copyable
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};
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} // namespace leveldb
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#endif // STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
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