forked from apache/beam
-
Notifications
You must be signed in to change notification settings - Fork 0
/
gcs.go
126 lines (108 loc) · 3.5 KB
/
gcs.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You 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 gcs contains a Google Cloud Storage (GCS) implementation of the
// Beam file system.
package gcs
import (
"context"
"fmt"
"io"
"path/filepath"
"strings"
"cloud.google.com/go/storage"
"github.com/apache/beam/sdks/go/pkg/beam/internal/errors"
"github.com/apache/beam/sdks/go/pkg/beam/io/filesystem"
"github.com/apache/beam/sdks/go/pkg/beam/log"
"github.com/apache/beam/sdks/go/pkg/beam/util/gcsx"
"google.golang.org/api/iterator"
"google.golang.org/api/option"
)
func init() {
filesystem.Register("gs", New)
}
type fs struct {
client *storage.Client
}
// New creates a new Google Cloud Storage filesystem using application
// default credentials. If it fails, it falls back to unauthenticated
// access.
func New(ctx context.Context) filesystem.Interface {
client, err := storage.NewClient(ctx, option.WithScopes(storage.ScopeReadWrite))
if err != nil {
log.Warnf(ctx, "Warning: falling back to unauthenticated GCS access: %v", err)
client, err = storage.NewClient(ctx, option.WithoutAuthentication())
if err != nil {
panic(errors.Wrapf(err, "failed to create GCS client"))
}
}
return &fs{client: client}
}
func (f *fs) Close() error {
return f.client.Close()
}
func (f *fs) List(ctx context.Context, glob string) ([]string, error) {
bucket, object, err := gcsx.ParseObject(glob)
if err != nil {
return nil, err
}
var candidates []string
if index := strings.Index(object, "*"); index > 0 {
// We handle globs by list all candidates and matching them here.
// For now, we assume * is the first matching character to make a
// prefix listing and not list the entire bucket.
it := f.client.Bucket(bucket).Objects(ctx, &storage.Query{
Prefix: object[:index],
})
for {
obj, err := it.Next()
if err == iterator.Done {
break
}
if err != nil {
return nil, err
}
match, err := filepath.Match(object, obj.Name)
if err != nil {
return nil, err
}
if match {
candidates = append(candidates, obj.Name)
}
}
} else {
// Single object.
candidates = []string{object}
}
var ret []string
for _, obj := range candidates {
ret = append(ret, fmt.Sprintf("gs://%v/%v", bucket, obj))
}
return ret, nil
}
func (f *fs) OpenRead(ctx context.Context, filename string) (io.ReadCloser, error) {
bucket, object, err := gcsx.ParseObject(filename)
if err != nil {
return nil, err
}
return f.client.Bucket(bucket).Object(object).NewReader(ctx)
}
// TODO(herohde) 7/12/2017: should we create the bucket in OpenWrite? For now, "no".
func (f *fs) OpenWrite(ctx context.Context, filename string) (io.WriteCloser, error) {
bucket, object, err := gcsx.ParseObject(filename)
if err != nil {
return nil, err
}
return f.client.Bucket(bucket).Object(object).NewWriter(ctx), nil
}