/
google.go
104 lines (96 loc) · 2.5 KB
/
google.go
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package storage
import (
"io/ioutil"
pathutil "path"
"cloud.google.com/go/storage"
"golang.org/x/net/context"
"google.golang.org/api/iterator"
)
// GoogleCSBackend is a storage backend for Google Cloud Storage
type GoogleCSBackend struct {
Prefix string
Client *storage.BucketHandle
Context context.Context
}
// NewGoogleCSBackend creates a new instance of GoogleCSBackend
func NewGoogleCSBackend(bucket string, prefix string) *GoogleCSBackend {
ctx := context.Background()
client, err := storage.NewClient(ctx)
if err != nil {
panic(err)
}
bucketHandle := client.Bucket(bucket)
prefix = cleanPrefix(prefix)
b := &GoogleCSBackend{
Prefix: prefix,
Client: bucketHandle,
Context: ctx,
}
return b
}
// ListObjects lists all objects in Google Cloud Storage bucket, at prefix
func (b GoogleCSBackend) ListObjects(prefix string) ([]Object, error) {
var objects []Object
prefix = pathutil.Join(b.Prefix, prefix)
listQuery := &storage.Query{
Prefix: prefix,
}
it := b.Client.Objects(b.Context, listQuery)
for {
attrs, err := it.Next()
if err == iterator.Done {
break
}
if err != nil {
return objects, err
}
path := removePrefixFromObjectPath(prefix, attrs.Name)
if objectPathIsInvalid(path) {
continue
}
object := Object{
Path: path,
Content: []byte{},
LastModified: attrs.Updated,
}
objects = append(objects, object)
}
return objects, nil
}
// GetObject retrieves an object from Google Cloud Storage bucket, at prefix
func (b GoogleCSBackend) GetObject(path string) (Object, error) {
var object Object
object.Path = path
objectHandle := b.Client.Object(pathutil.Join(b.Prefix, path))
attrs, err := objectHandle.Attrs(b.Context)
if err != nil {
return object, err
}
object.LastModified = attrs.Updated
rc, err := objectHandle.NewReader(b.Context)
if err != nil {
return object, err
}
content, err := ioutil.ReadAll(rc)
rc.Close()
if err != nil {
return object, err
}
object.Content = content
return object, nil
}
// PutObject uploads an object to Google Cloud Storage bucket, at prefix
func (b GoogleCSBackend) PutObject(path string, content []byte) error {
wc := b.Client.Object(pathutil.Join(b.Prefix, path)).NewWriter(b.Context)
_, err := wc.Write(content)
if err != nil {
return err
}
err = wc.Close()
return err
}
// DeleteObject removes an object from Google Cloud Storage bucket, at prefix
func (b GoogleCSBackend) DeleteObject(path string) error {
err := b.Client.Object(pathutil.Join(b.Prefix, path)).Delete(b.Context)
return err
}