github.com/slspeek/camlistore_namedsearch@v0.0.0-20140519202248-ed6f70f7721a/pkg/blobserver/mongo/enumerate.go (about) 1 /* 2 Copyright 2014 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 mongo 18 19 import ( 20 "log" 21 22 "camlistore.org/pkg/blob" 23 "camlistore.org/pkg/context" 24 "camlistore.org/third_party/labix.org/v2/mgo/bson" 25 ) 26 27 func (m *mongoStorage) EnumerateBlobs(ctx *context.Context, dest chan<- blob.SizedRef, after string, limit int) error { 28 defer close(dest) 29 30 var b blobDoc 31 var qry bson.M 32 if after != "" { 33 qry = bson.M{"key": bson.M{"$gt": after}} 34 } 35 iter := m.c.Find(qry).Limit(limit).Select(bson.M{"key": 1, "size": 1}).Sort("key").Iter() 36 37 for iter.Next(&b) { 38 br, ok := blob.Parse(b.Key) 39 if !ok { 40 continue 41 } 42 select { 43 case dest <- blob.SizedRef{Ref: br, Size: uint32(b.Size)}: 44 case <-ctx.Done(): 45 // Close the iterator but ignore the error value since we are already cancelling 46 if err := iter.Close(); err != nil { 47 log.Printf("Error closing iterator after enumerating: %v", err) 48 } 49 return context.ErrCanceled 50 } 51 } 52 53 if err := iter.Close(); err != nil { 54 return err 55 } 56 57 return nil 58 }