github.com/slspeek/camlistore_namedsearch@v0.0.0-20140519202248-ed6f70f7721a/pkg/blobserver/localdisk/receive.go (about)

     1  /*
     2  Copyright 2011 Google Inc.
     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 localdisk
    18  
    19  import (
    20  	"errors"
    21  	"fmt"
    22  	"io"
    23  	"io/ioutil"
    24  	"log"
    25  	"os"
    26  
    27  	"camlistore.org/pkg/blob"
    28  )
    29  
    30  func (ds *DiskStorage) ReceiveBlob(blobRef blob.Ref, source io.Reader) (ref blob.SizedRef, err error) {
    31  	ds.dirLockMu.RLock()
    32  	defer ds.dirLockMu.RUnlock()
    33  
    34  	hashedDirectory := ds.blobDirectory(blobRef)
    35  	err = os.MkdirAll(hashedDirectory, 0700)
    36  	if err != nil {
    37  		return
    38  	}
    39  
    40  	tempFile, err := ioutil.TempFile(hashedDirectory, blobFileBaseName(blobRef)+".tmp")
    41  	if err != nil {
    42  		return
    43  	}
    44  
    45  	success := false // set true later
    46  	defer func() {
    47  		if !success {
    48  			log.Println("Removing temp file: ", tempFile.Name())
    49  			os.Remove(tempFile.Name())
    50  		}
    51  	}()
    52  
    53  	written, err := io.Copy(tempFile, source)
    54  	if err != nil {
    55  		return
    56  	}
    57  	if err = tempFile.Sync(); err != nil {
    58  		return
    59  	}
    60  	if err = tempFile.Close(); err != nil {
    61  		return
    62  	}
    63  	stat, err := os.Lstat(tempFile.Name())
    64  	if err != nil {
    65  		return
    66  	}
    67  	if stat.Size() != written {
    68  		err = fmt.Errorf("temp file %q size %d didn't match written size %d", tempFile.Name(), stat.Size(), written)
    69  		return
    70  	}
    71  
    72  	fileName := ds.blobPath(blobRef)
    73  	if err = os.Rename(tempFile.Name(), fileName); err != nil {
    74  		if err = mapRenameError(err, tempFile.Name(), fileName); err != nil {
    75  			return
    76  		}
    77  	}
    78  
    79  	stat, err = os.Lstat(fileName)
    80  	if err != nil {
    81  		return
    82  	}
    83  	if stat.Size() != written {
    84  		err = errors.New("Written size didn't match.")
    85  		return
    86  	}
    87  
    88  	success = true // used in defer above
    89  	return blob.SizedRef{Ref: blobRef, Size: uint32(stat.Size())}, nil
    90  }