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bleve/index/store/cznicb/cznicb.go
Marty Schoch a9c07acbfa refactor of kvstore api to support native merge in rocksdb
refactor to share code in emulated batch
refactor to share code in emulated merge
refactor index kvstore benchmarks to share more code
refactor index kvstore benchmarks to be more repeatable
2015-04-24 17:13:50 -04:00

113 lines
2.5 KiB
Go

// Copyright (c) 2015 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.
// +build go1.4
// Package cznicb provides an in-memory implementation of the KVStore
// interfaces using the cznic/b in-memory btree. Of note: this
// implementation does not have reader isolation.
package cznicb
import (
"bytes"
"fmt"
"sync"
"github.com/blevesearch/bleve/index/store"
"github.com/blevesearch/bleve/registry"
"github.com/cznic/b"
)
const Name = "cznicb"
const MAX_CONCURRENT_WRITERS = 1
func init() {
registry.RegisterKVStore(Name, StoreConstructor)
}
func StoreConstructor(config map[string]interface{}) (store.KVStore, error) {
s := &Store{
t: b.TreeNew(itemCompare),
availableWriters: make(chan bool, MAX_CONCURRENT_WRITERS),
}
for i := 0; i < MAX_CONCURRENT_WRITERS; i++ {
s.availableWriters <- true
}
return s, nil
}
func itemCompare(a, b interface{}) int {
return bytes.Compare(a.([]byte), b.([]byte))
}
type Store struct {
availableWriters chan bool
m sync.RWMutex
t *b.Tree
mo store.MergeOperator
}
func (s *Store) Open() error {
return nil
}
func (s *Store) SetMergeOperator(mo store.MergeOperator) {
s.mo = mo
}
func (s *Store) Reader() (store.KVReader, error) {
return &Reader{s: s}, nil
}
func (s *Store) Writer() (store.KVWriter, error) {
available, ok := <-s.availableWriters
if !ok || !available {
return nil, fmt.Errorf("no available writers")
}
return &Writer{s: s, r: &Reader{s: s}}, nil
}
func (s *Store) Close() error {
return nil
}
func (s *Store) get(k []byte) ([]byte, error) {
s.m.RLock()
defer s.m.RUnlock()
v, ok := s.t.Get(k)
if !ok || v == nil {
return nil, nil
}
return v.([]byte), nil
}
func (s *Store) iterator(k []byte) store.KVIterator {
iter := &Iterator{s: s}
iter.Seek(k)
return iter
}
func (s *Store) set(k, v []byte) (err error) {
s.m.Lock()
defer s.m.Unlock()
s.t.Set(k, v)
return nil
}
func (s *Store) delete(k []byte) (err error) {
s.m.Lock()
defer s.m.Unlock()
s.t.Delete(k)
return nil
}