5094d2d097
Previously, the PrefixIterator() for moss was implemented by comparing the prefix bytes on every Next(). With this optimization, the next larger endKeyExclusive is computed at the iterator's initialization, which allows us to avoid all those prefix comparisons.
127 lines
2.0 KiB
Go
127 lines
2.0 KiB
Go
// Copyright (c) 2016 Couchbase, Inc.
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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
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// License. You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an "AS
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// IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
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// express or implied. See the License for the specific language
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// governing permissions and limitations under the License.
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package moss
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import (
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"bytes"
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"github.com/couchbase/moss"
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)
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type Iterator struct {
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store *Store
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ss moss.Snapshot
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iter moss.Iterator
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start []byte
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end []byte
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done bool
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k []byte
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v []byte
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}
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func (x *Iterator) Seek(seekToKey []byte) {
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x.done = true
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x.k = nil
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x.v = nil
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if bytes.Compare(seekToKey, x.start) < 0 {
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seekToKey = x.start
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}
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iter, err := x.ss.StartIterator(seekToKey, x.end, moss.IteratorOptions{})
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if err != nil {
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x.store.Logf("bleve moss StartIterator err: %v", err)
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return
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}
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err = x.iter.Close()
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if err != nil {
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x.store.Logf("bleve moss iterator.Seek err: %v", err)
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return
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}
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x.iter = iter
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x.checkDone()
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}
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func (x *Iterator) Next() {
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if x.done {
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return
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}
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err := x.iter.Next()
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if err != nil {
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x.done = true
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x.k = nil
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x.v = nil
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return
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}
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x.checkDone()
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}
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func (x *Iterator) Current() ([]byte, []byte, bool) {
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return x.k, x.v, !x.done
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}
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func (x *Iterator) Key() []byte {
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if x.done {
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return nil
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}
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return x.k
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}
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func (x *Iterator) Value() []byte {
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if x.done {
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return nil
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}
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return x.v
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}
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func (x *Iterator) Valid() bool {
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return !x.done
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}
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func (x *Iterator) Close() error {
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var err error
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x.ss = nil
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if x.iter != nil {
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err = x.iter.Close()
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x.iter = nil
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}
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x.done = true
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x.k = nil
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x.v = nil
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return err
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}
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func (x *Iterator) checkDone() {
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k, v, err := x.iter.Current()
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if err != nil {
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x.done = true
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x.k = nil
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x.v = nil
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return
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}
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x.done = false
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x.k = k
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x.v = v
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}
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