Implement gateway support Google Cloud Storage

vendor/cloud.google.com/go/storage/bucket.go

@@ -0,0 +1,337 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// 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 storage
+
+import (
+	"net/http"
+	"time"
+
+	"golang.org/x/net/context"
+	"google.golang.org/api/googleapi"
+	"google.golang.org/api/iterator"
+	raw "google.golang.org/api/storage/v1"
+)
+
+// Create creates the Bucket in the project.
+// If attrs is nil the API defaults will be used.
+func (b *BucketHandle) Create(ctx context.Context, projectID string, attrs *BucketAttrs) error {
+	var bkt *raw.Bucket
+	if attrs != nil {
+		bkt = attrs.toRawBucket()
+	} else {
+		bkt = &raw.Bucket{}
+	}
+	bkt.Name = b.name
+	req := b.c.raw.Buckets.Insert(projectID, bkt)
+	setClientHeader(req.Header())
+	return runWithRetry(ctx, func() error { _, err := req.Context(ctx).Do(); return err })
+}
+
+// Delete deletes the Bucket.
+func (b *BucketHandle) Delete(ctx context.Context) error {
+	req := b.c.raw.Buckets.Delete(b.name)
+	setClientHeader(req.Header())
+	return runWithRetry(ctx, func() error { return req.Context(ctx).Do() })
+}
+
+// ACL returns an ACLHandle, which provides access to the bucket's access control list.
+// This controls who can list, create or overwrite the objects in a bucket.
+// This call does not perform any network operations.
+func (b *BucketHandle) ACL() *ACLHandle {
+	return &b.acl
+}
+
+// DefaultObjectACL returns an ACLHandle, which provides access to the bucket's default object ACLs.
+// These ACLs are applied to newly created objects in this bucket that do not have a defined ACL.
+// This call does not perform any network operations.
+func (b *BucketHandle) DefaultObjectACL() *ACLHandle {
+	return &b.defaultObjectACL
+}
+
+// Object returns an ObjectHandle, which provides operations on the named object.
+// This call does not perform any network operations.
+//
+// name must consist entirely of valid UTF-8-encoded runes. The full specification
+// for valid object names can be found at:
+//   https://cloud.google.com/storage/docs/bucket-naming
+func (b *BucketHandle) Object(name string) *ObjectHandle {
+	return &ObjectHandle{
+		c:      b.c,
+		bucket: b.name,
+		object: name,
+		acl: ACLHandle{
+			c:      b.c,
+			bucket: b.name,
+			object: name,
+		},
+		gen: -1,
+	}
+}
+
+// Attrs returns the metadata for the bucket.
+func (b *BucketHandle) Attrs(ctx context.Context) (*BucketAttrs, error) {
+	req := b.c.raw.Buckets.Get(b.name).Projection("full")
+	setClientHeader(req.Header())
+	var resp *raw.Bucket
+	var err error
+	err = runWithRetry(ctx, func() error {
+		resp, err = req.Context(ctx).Do()
+		return err
+	})
+	if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
+		return nil, ErrBucketNotExist
+	}
+	if err != nil {
+		return nil, err
+	}
+	return newBucket(resp), nil
+}
+
+// BucketAttrs represents the metadata for a Google Cloud Storage bucket.
+type BucketAttrs struct {
+	// Name is the name of the bucket.
+	Name string
+
+	// ACL is the list of access control rules on the bucket.
+	ACL []ACLRule
+
+	// DefaultObjectACL is the list of access controls to
+	// apply to new objects when no object ACL is provided.
+	DefaultObjectACL []ACLRule
+
+	// Location is the location of the bucket. It defaults to "US".
+	Location string
+
+	// MetaGeneration is the metadata generation of the bucket.
+	MetaGeneration int64
+
+	// StorageClass is the default storage class of the bucket. This defines
+	// how objects in the bucket are stored and determines the SLA
+	// and the cost of storage. Typical values are "MULTI_REGIONAL",
+	// "REGIONAL", "NEARLINE", "COLDLINE", "STANDARD" and
+	// "DURABLE_REDUCED_AVAILABILITY". Defaults to "STANDARD", which
+	// is equivalent to "MULTI_REGIONAL" or "REGIONAL" depending on
+	// the bucket's location settings.
+	StorageClass string
+
+	// Created is the creation time of the bucket.
+	Created time.Time
+
+	// VersioningEnabled reports whether this bucket has versioning enabled.
+	// This field is read-only.
+	VersioningEnabled bool
+}
+
+func newBucket(b *raw.Bucket) *BucketAttrs {
+	if b == nil {
+		return nil
+	}
+	bucket := &BucketAttrs{
+		Name:              b.Name,
+		Location:          b.Location,
+		MetaGeneration:    b.Metageneration,
+		StorageClass:      b.StorageClass,
+		Created:           convertTime(b.TimeCreated),
+		VersioningEnabled: b.Versioning != nil && b.Versioning.Enabled,
+	}
+	acl := make([]ACLRule, len(b.Acl))
+	for i, rule := range b.Acl {
+		acl[i] = ACLRule{
+			Entity: ACLEntity(rule.Entity),
+			Role:   ACLRole(rule.Role),
+		}
+	}
+	bucket.ACL = acl
+	objACL := make([]ACLRule, len(b.DefaultObjectAcl))
+	for i, rule := range b.DefaultObjectAcl {
+		objACL[i] = ACLRule{
+			Entity: ACLEntity(rule.Entity),
+			Role:   ACLRole(rule.Role),
+		}
+	}
+	bucket.DefaultObjectACL = objACL
+	return bucket
+}
+
+// toRawBucket copies the editable attribute from b to the raw library's Bucket type.
+func (b *BucketAttrs) toRawBucket() *raw.Bucket {
+	var acl []*raw.BucketAccessControl
+	if len(b.ACL) > 0 {
+		acl = make([]*raw.BucketAccessControl, len(b.ACL))
+		for i, rule := range b.ACL {
+			acl[i] = &raw.BucketAccessControl{
+				Entity: string(rule.Entity),
+				Role:   string(rule.Role),
+			}
+		}
+	}
+	dACL := toRawObjectACL(b.DefaultObjectACL)
+	return &raw.Bucket{
+		Name:             b.Name,
+		DefaultObjectAcl: dACL,
+		Location:         b.Location,
+		StorageClass:     b.StorageClass,
+		Acl:              acl,
+	}
+}
+
+// Objects returns an iterator over the objects in the bucket that match the Query q.
+// If q is nil, no filtering is done.
+func (b *BucketHandle) Objects(ctx context.Context, q *Query) *ObjectIterator {
+	it := &ObjectIterator{
+		ctx:    ctx,
+		bucket: b,
+	}
+	it.pageInfo, it.nextFunc = iterator.NewPageInfo(
+		it.fetch,
+		func() int { return len(it.items) },
+		func() interface{} { b := it.items; it.items = nil; return b })
+	if q != nil {
+		it.query = *q
+	}
+	return it
+}
+
+// An ObjectIterator is an iterator over ObjectAttrs.
+type ObjectIterator struct {
+	ctx      context.Context
+	bucket   *BucketHandle
+	query    Query
+	pageInfo *iterator.PageInfo
+	nextFunc func() error
+	items    []*ObjectAttrs
+}
+
+// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
+func (it *ObjectIterator) PageInfo() *iterator.PageInfo { return it.pageInfo }
+
+// Next returns the next result. Its second return value is iterator.Done if
+// there are no more results. Once Next returns iterator.Done, all subsequent
+// calls will return iterator.Done.
+//
+// If Query.Delimiter is non-empty, some of the ObjectAttrs returned by Next will
+// have a non-empty Prefix field, and a zero value for all other fields. These
+// represent prefixes.
+func (it *ObjectIterator) Next() (*ObjectAttrs, error) {
+	if err := it.nextFunc(); err != nil {
+		return nil, err
+	}
+	item := it.items[0]
+	it.items = it.items[1:]
+	return item, nil
+}
+
+func (it *ObjectIterator) fetch(pageSize int, pageToken string) (string, error) {
+	req := it.bucket.c.raw.Objects.List(it.bucket.name)
+	setClientHeader(req.Header())
+	req.Projection("full")
+	req.Delimiter(it.query.Delimiter)
+	req.Prefix(it.query.Prefix)
+	req.Versions(it.query.Versions)
+	req.PageToken(pageToken)
+	if pageSize > 0 {
+		req.MaxResults(int64(pageSize))
+	}
+	var resp *raw.Objects
+	var err error
+	err = runWithRetry(it.ctx, func() error {
+		resp, err = req.Context(it.ctx).Do()
+		return err
+	})
+	if err != nil {
+		if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
+			err = ErrBucketNotExist
+		}
+		return "", err
+	}
+	for _, item := range resp.Items {
+		it.items = append(it.items, newObject(item))
+	}
+	for _, prefix := range resp.Prefixes {
+		it.items = append(it.items, &ObjectAttrs{Prefix: prefix})
+	}
+	return resp.NextPageToken, nil
+}
+
+// TODO(jbd): Add storage.buckets.update.
+
+// Buckets returns an iterator over the buckets in the project. You may
+// optionally set the iterator's Prefix field to restrict the list to buckets
+// whose names begin with the prefix. By default, all buckets in the project
+// are returned.
+func (c *Client) Buckets(ctx context.Context, projectID string) *BucketIterator {
+	it := &BucketIterator{
+		ctx:       ctx,
+		client:    c,
+		projectID: projectID,
+	}
+	it.pageInfo, it.nextFunc = iterator.NewPageInfo(
+		it.fetch,
+		func() int { return len(it.buckets) },
+		func() interface{} { b := it.buckets; it.buckets = nil; return b })
+	return it
+}
+
+// A BucketIterator is an iterator over BucketAttrs.
+type BucketIterator struct {
+	// Prefix restricts the iterator to buckets whose names begin with it.
+	Prefix string
+
+	ctx       context.Context
+	client    *Client
+	projectID string
+	buckets   []*BucketAttrs
+	pageInfo  *iterator.PageInfo
+	nextFunc  func() error
+}
+
+// Next returns the next result. Its second return value is iterator.Done if
+// there are no more results. Once Next returns iterator.Done, all subsequent
+// calls will return iterator.Done.
+func (it *BucketIterator) Next() (*BucketAttrs, error) {
+	if err := it.nextFunc(); err != nil {
+		return nil, err
+	}
+	b := it.buckets[0]
+	it.buckets = it.buckets[1:]
+	return b, nil
+}
+
+// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
+func (it *BucketIterator) PageInfo() *iterator.PageInfo { return it.pageInfo }
+
+func (it *BucketIterator) fetch(pageSize int, pageToken string) (string, error) {
+	req := it.client.raw.Buckets.List(it.projectID)
+	setClientHeader(req.Header())
+	req.Projection("full")
+	req.Prefix(it.Prefix)
+	req.PageToken(pageToken)
+	if pageSize > 0 {
+		req.MaxResults(int64(pageSize))
+	}
+	var resp *raw.Buckets
+	var err error
+	err = runWithRetry(it.ctx, func() error {
+		resp, err = req.Context(it.ctx).Do()
+		return err
+	})
+	if err != nil {
+		return "", err
+	}
+	for _, item := range resp.Items {
+		it.buckets = append(it.buckets, newBucket(item))
+	}
+	return resp.NextPageToken, nil
+}