You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
minio/cmd/fs-helpers.go

91 lines
2.6 KiB

/*
* Minio Cloud Storage, (C) 2016 Minio, 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.
*/
package cmd
import "io"
// Reads from the requested local location uses a staging buffer. Restricts
// reads upto requested range of length and offset. If successful staging
// buffer is written to the incoming stream. Returns errors if any.
func fsReadFile(disk StorageAPI, bucket, object string, writer io.Writer, totalLeft, startOffset int64, buf []byte) (err error) {
bufSize := int64(len(buf))
// Start the read loop until requested range.
for {
// Figure out the right size for the buffer.
curLeft := bufSize
if totalLeft < bufSize {
curLeft = totalLeft
}
// Reads the file at offset.
nr, er := disk.ReadFile(bucket, object, startOffset, buf[:curLeft])
if nr > 0 {
// Write to response writer.
nw, ew := writer.Write(buf[0:nr])
if nw > 0 {
// Decrement whats left to write.
totalLeft -= int64(nw)
// Progress the offset
startOffset += int64(nw)
}
if ew != nil {
err = traceError(ew)
break
}
if nr != int64(nw) {
err = traceError(io.ErrShortWrite)
break
}
}
if er == io.EOF || er == io.ErrUnexpectedEOF {
break
}
if er != nil {
err = traceError(er)
break
}
if totalLeft == 0 {
break
}
}
return err
}
// Reads from input stream until end of file, takes an input buffer for staging reads.
// The staging buffer is then written to the disk. Returns for any error that occurs
// while reading the stream or writing to disk. Caller should cleanup partial files.
// Upon errors total data written will be 0 and returns error, on success returns
// total data written to disk.
func fsCreateFile(disk StorageAPI, reader io.Reader, buf []byte, bucket, object string) (int64, error) {
bytesWritten := int64(0)
// Read the buffer till io.EOF and appends data to path at bucket/object.
for {
n, rErr := reader.Read(buf)
if rErr != nil && rErr != io.EOF {
return 0, traceError(rErr)
}
bytesWritten += int64(n)
wErr := disk.AppendFile(bucket, object, buf[0:n])
if wErr != nil {
return 0, traceError(wErr)
}
if rErr == io.EOF {
break
}
}
return bytesWritten, nil
}