forked from couchbase/moss
/
util_merge.go
51 lines (43 loc) · 1.5 KB
/
util_merge.go
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// Copyright (c) 2016 Couchbase, Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the
// License. You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an "AS
// IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
// express or implied. See the License for the specific language
// governing permissions and limitations under the License.
package moss
import (
"sync"
)
// MergeOperatorStringAppend implements a simple merger that appends
// strings. It was originally built for testing and sample purposes.
type MergeOperatorStringAppend struct {
Sep string // The separator string between operands.
m sync.Mutex
numFull int
numPartial int
}
func (mo *MergeOperatorStringAppend) Name() string {
return "MergeOperatorStringAppend"
}
func (mo *MergeOperatorStringAppend) FullMerge(key, existingValue []byte,
operands [][]byte) ([]byte, bool) {
mo.m.Lock()
mo.numFull++
mo.m.Unlock()
s := string(existingValue)
for _, operand := range operands {
s = s + mo.Sep + string(operand)
}
return []byte(s), true
}
func (mo *MergeOperatorStringAppend) PartialMerge(key,
leftOperand, rightOperand []byte) ([]byte, bool) {
mo.m.Lock()
mo.numPartial++
mo.m.Unlock()
return []byte(string(leftOperand) + mo.Sep + string(rightOperand)), true
}