ed4826b189
The optimization to byte-copy all the storedDocs for a given segment during merging kicks in when the fields are the same across all segments and when there are no deletions for that given segment. This can happen, for example, during data loading or insert-only scenarios. As part of this commit, the Segment.copyStoredDocs() method was added, which uses a single Write() call to copy all the stored docs bytes of a segment to a writer in one shot. And, getDocStoredMetaAndCompressed() was refactored into a related helper function, getDocStoredOffsets(), which provides the storedDocs metadata (offsets & lengths) for a doc.
44 lines
1.4 KiB
Go
44 lines
1.4 KiB
Go
// Copyright (c) 2017 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package zap
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import "encoding/binary"
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func (s *SegmentBase) getDocStoredMetaAndCompressed(docNum uint64) ([]byte, []byte) {
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_, storedOffset, n, metaLen, dataLen := s.getDocStoredOffsets(docNum)
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meta := s.mem[storedOffset+n : storedOffset+n+metaLen]
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data := s.mem[storedOffset+n+metaLen : storedOffset+n+metaLen+dataLen]
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return meta, data
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}
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func (s *SegmentBase) getDocStoredOffsets(docNum uint64) (
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uint64, uint64, uint64, uint64, uint64) {
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indexOffset := s.storedIndexOffset + (8 * docNum)
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storedOffset := binary.BigEndian.Uint64(s.mem[indexOffset : indexOffset+8])
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var n uint64
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metaLen, read := binary.Uvarint(s.mem[storedOffset : storedOffset+binary.MaxVarintLen64])
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n += uint64(read)
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dataLen, read := binary.Uvarint(s.mem[storedOffset+n : storedOffset+n+binary.MaxVarintLen64])
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n += uint64(read)
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return indexOffset, storedOffset, n, metaLen, dataLen
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}
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