// Read the contents of the latest generation of the object with the supplied
// name.
func ReadObject(
ctx context.Context,
bucket gcs.Bucket,
name string) (contents []byte, err error) {
// Call the bucket.
req := &gcs.ReadObjectRequest{
Name: name,
}
rc, err := bucket.NewReader(ctx, req)
if err != nil {
return
}
// Don't forget to close.
defer func() {
closeErr := rc.Close()
if closeErr != nil && err == nil {
err = fmt.Errorf("Close: %v", closeErr)
}
}()
// Read the contents.
contents, err = ioutil.ReadAll(rc)
if err != nil {
err = fmt.Errorf("ReadAll: %v", err)
return
}
return
}
func readOnce(
ctx context.Context,
o *gcs.Object,
bucket gcs.Bucket) (r result, err error) {
// Is the object large enough?
if o.Size < *fSize {
err = fmt.Errorf(
"Object of size %d not large enough for read size %d",
o.Size,
*fSize)
return
}
// Set up an appropriate request.
req := &gcs.ReadObjectRequest{
Name: o.Name,
Generation: o.Generation,
Range: &gcs.ByteRange{},
}
req.Range.Start = uint64(rand.Int63n(int64(o.Size - *fSize)))
req.Range.Limit = req.Range.Start + *fSize
// Create the reader.
start := time.Now()
rc, err := bucket.NewReader(ctx, req)
if err != nil {
err = fmt.Errorf("NewReader: %v", err)
return
}
defer func() {
closeErr := rc.Close()
if err == nil && closeErr != nil {
err = fmt.Errorf("Close: %v", closeErr)
}
}()
// Measure the time to first byte.
_, err = rc.Read([]byte{0})
if err != nil {
err = fmt.Errorf("Read: %v", err)
return
}
r.FirstByteLatency = time.Since(start)
// And the time to read everything.
n, err := io.Copy(ioutil.Discard, rc)
if err != nil {
err = fmt.Errorf("Copy: %v", err)
return
}
r.FullBodyDuration = time.Since(start)
r.BytesRead = int(n + 1)
return
}