github.com/cayleygraph/cayley@v0.7.7/graph/kv/leveldb/leveldb.go (about)

     1  // Copyright 2017 The Cayley Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package leveldb
    16  
    17  import (
    18  	"os"
    19  
    20  	"github.com/cayleygraph/cayley/graph"
    21  	hkv "github.com/hidal-go/hidalgo/kv"
    22  	"github.com/hidal-go/hidalgo/kv/flat"
    23  	"github.com/hidal-go/hidalgo/kv/flat/leveldb"
    24  	"github.com/syndtr/goleveldb/leveldb/opt"
    25  )
    26  
    27  const (
    28  	Type = leveldb.Name
    29  )
    30  
    31  func Create(path string, m graph.Options) (hkv.KV, error) {
    32  	err := os.MkdirAll(path, 0700)
    33  	if err != nil {
    34  		return nil, err
    35  	}
    36  	db, err := leveldb.Open(path, &opt.Options{
    37  		ErrorIfExist: true,
    38  	})
    39  	if os.IsExist(err) {
    40  		return nil, graph.ErrDatabaseExists
    41  	} else if err != nil {
    42  		return nil, err
    43  	}
    44  	nosync, _ := m.BoolKey("nosync", false)
    45  	db.SetWriteOptions(&opt.WriteOptions{
    46  		Sync: !nosync,
    47  	})
    48  	return flat.Upgrade(db), nil
    49  }
    50  
    51  func Open(path string, m graph.Options) (hkv.KV, error) {
    52  	db, err := leveldb.Open(path, &opt.Options{
    53  		ErrorIfMissing: true,
    54  	})
    55  	if err != nil {
    56  		return nil, err
    57  	}
    58  	nosync, _ := m.BoolKey("nosync", false)
    59  	db.SetWriteOptions(&opt.WriteOptions{
    60  		Sync: !nosync,
    61  	})
    62  	return flat.Upgrade(db), nil
    63  }