2015-01-12 20:10:44 +01:00
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// Copyright (c) 2015 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 gtreap provides an in-memory implementation of the
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// KVStore interfaces using the gtreap balanced-binary treap,
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// copy-on-write data structure.
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package gtreap
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import (
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"bytes"
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"fmt"
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"sync"
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"github.com/blevesearch/bleve/index/store"
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"github.com/blevesearch/bleve/registry"
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"github.com/steveyen/gtreap"
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)
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const Name = "gtreap"
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func init() {
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registry.RegisterKVStore(Name, StoreConstructor)
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}
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const MAX_CONCURRENT_WRITERS = 1
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func StoreConstructor(config map[string]interface{}) (store.KVStore, error) {
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s := &Store{
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availableWriters: make(chan bool, MAX_CONCURRENT_WRITERS),
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t: gtreap.NewTreap(itemCompare),
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}
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for i := 0; i < MAX_CONCURRENT_WRITERS; i++ {
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s.availableWriters <- true
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}
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return s, nil
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}
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type Item struct {
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k []byte
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v []byte
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}
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func itemCompare(a, b interface{}) int {
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return bytes.Compare(a.(*Item).k, b.(*Item).k)
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}
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type Store struct {
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availableWriters chan bool
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m sync.Mutex
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t *gtreap.Treap
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2015-04-24 23:11:47 +02:00
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mo store.MergeOperator
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}
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type Writer struct {
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s *Store
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}
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func (s *Store) Open() error {
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return nil
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}
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2015-04-24 23:11:47 +02:00
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func (s *Store) SetMergeOperator(mo store.MergeOperator) {
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s.mo = mo
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}
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func (s *Store) Close() error {
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close(s.availableWriters)
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return nil
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}
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func (s *Store) Reader() (store.KVReader, error) {
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s.m.Lock()
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t := s.t
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s.m.Unlock()
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return &Reader{t: t}, nil
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}
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func (s *Store) Writer() (store.KVWriter, error) {
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available, ok := <-s.availableWriters
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if !ok || !available {
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return nil, fmt.Errorf("no available writers")
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}
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return &Writer{s: s}, nil
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}
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