github.com/olivere/camlistore@v0.0.0-20140121221811-1b7ac2da0199/pkg/index/kvfile/kvfile.go (about)

     1  /*
     2  Copyright 2013 The Camlistore Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8       http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // Package kvfile implements the Camlistore index storage abstraction
    18  // on top of a single mutable database file on disk using
    19  // github.com/cznic/kv.
    20  package kvfile
    21  
    22  import (
    23  	"camlistore.org/pkg/blobserver"
    24  	"camlistore.org/pkg/index"
    25  	"camlistore.org/pkg/jsonconfig"
    26  	"camlistore.org/pkg/sorted/kvfile"
    27  )
    28  
    29  func init() {
    30  	blobserver.RegisterStorageConstructor("kvfileindexer",
    31  		blobserver.StorageConstructor(newFromConfig))
    32  }
    33  
    34  func newFromConfig(ld blobserver.Loader, config jsonconfig.Obj) (blobserver.Storage, error) {
    35  	blobPrefix := config.RequiredString("blobSource")
    36  	kv, err := kvfile.NewKeyValue(config)
    37  	if err != nil {
    38  		return nil, err
    39  	}
    40  
    41  	ix := index.New(kv)
    42  	sto, err := ld.GetStorage(blobPrefix)
    43  	if err != nil {
    44  		ix.Close()
    45  		return nil, err
    46  	}
    47  	ix.BlobSource = sto
    48  
    49  	// Good enough, for now:
    50  	ix.KeyFetcher = ix.BlobSource
    51  
    52  	return ix, err
    53  }