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authorNiall Sheridan <nsheridan@gmail.com>2016-06-06 00:55:30 +0100
committerNiall Sheridan <nsheridan@gmail.com>2016-06-06 00:55:30 +0100
commita18a13fb09eac00cdacf1f74080524182b7243de (patch)
treebcf982d0054f0b86c01f93fe095633568aacfea8 /vendor/go4.org/wkfs/gcs
parentb8af9fe60f27353bdd5933ed37508b30d4290046 (diff)
update vendor
Diffstat (limited to 'vendor/go4.org/wkfs/gcs')
-rw-r--r--vendor/go4.org/wkfs/gcs/gcs.go196
1 files changed, 196 insertions, 0 deletions
diff --git a/vendor/go4.org/wkfs/gcs/gcs.go b/vendor/go4.org/wkfs/gcs/gcs.go
new file mode 100644
index 0000000..21f2551
--- /dev/null
+++ b/vendor/go4.org/wkfs/gcs/gcs.go
@@ -0,0 +1,196 @@
+/*
+Copyright 2014 The Camlistore Authors
+
+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 gcs registers a Google Cloud Storage filesystem at the
+// well-known /gcs/ filesystem path if the current machine is running
+// on Google Compute Engine.
+//
+// It was initially only meant for small files, and as such, it can only
+// read files smaller than 1MB for now.
+package gcs // import "go4.org/wkfs/gcs"
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "path"
+ "strings"
+ "time"
+
+ "go4.org/wkfs"
+ "golang.org/x/net/context"
+ "golang.org/x/oauth2"
+ "golang.org/x/oauth2/google"
+ "google.golang.org/cloud"
+ "google.golang.org/cloud/compute/metadata"
+ "google.golang.org/cloud/storage"
+)
+
+// Max size for all files read, because we use a bytes.Reader as our file
+// reader, instead of storage.NewReader. This is because we get all wkfs.File
+// methods for free by embedding a bytes.Reader. This filesystem was only supposed
+// to be for configuration data only, so this is ok for now.
+const maxSize = 1 << 20
+
+func init() {
+ if !metadata.OnGCE() {
+ return
+ }
+ hc, err := google.DefaultClient(oauth2.NoContext)
+ if err != nil {
+ registerBrokenFS(fmt.Errorf("could not get http client for context: %v", err))
+ return
+ }
+ projID, err := metadata.ProjectID()
+ if projID == "" || err != nil {
+ registerBrokenFS(fmt.Errorf("could not get GCE project ID: %v", err))
+ return
+ }
+ ctx := cloud.NewContext(projID, hc)
+ sc, err := storage.NewClient(ctx)
+ if err != nil {
+ registerBrokenFS(fmt.Errorf("could not get cloud storage client: %v", err))
+ return
+ }
+ wkfs.RegisterFS("/gcs/", &gcsFS{
+ ctx: ctx,
+ sc: sc,
+ })
+}
+
+type gcsFS struct {
+ ctx context.Context
+ sc *storage.Client
+ err error // sticky error
+}
+
+func registerBrokenFS(err error) {
+ wkfs.RegisterFS("/gcs/", &gcsFS{
+ err: err,
+ })
+}
+
+func (fs *gcsFS) parseName(name string) (bucket, fileName string, err error) {
+ if fs.err != nil {
+ return "", "", fs.err
+ }
+ name = strings.TrimPrefix(name, "/gcs/")
+ i := strings.Index(name, "/")
+ if i < 0 {
+ return name, "", nil
+ }
+ return name[:i], name[i+1:], nil
+}
+
+// Open opens the named file for reading. It returns an error if the file size
+// is larger than 1 << 20.
+func (fs *gcsFS) Open(name string) (wkfs.File, error) {
+ bucket, fileName, err := fs.parseName(name)
+ if err != nil {
+ return nil, err
+ }
+ obj := fs.sc.Bucket(bucket).Object(fileName)
+ attrs, err := obj.Attrs(fs.ctx)
+ if err != nil {
+ return nil, err
+ }
+ size := attrs.Size
+ if size > maxSize {
+ return nil, fmt.Errorf("file %s too large (%d bytes) for /gcs/ filesystem", name, size)
+ }
+ rc, err := obj.NewReader(fs.ctx)
+ if err != nil {
+ return nil, err
+ }
+ defer rc.Close()
+
+ slurp, err := ioutil.ReadAll(io.LimitReader(rc, size))
+ if err != nil {
+ return nil, err
+ }
+ return &file{
+ name: name,
+ Reader: bytes.NewReader(slurp),
+ }, nil
+}
+
+func (fs *gcsFS) Stat(name string) (os.FileInfo, error) { return fs.Lstat(name) }
+func (fs *gcsFS) Lstat(name string) (os.FileInfo, error) {
+ bucket, fileName, err := fs.parseName(name)
+ if err != nil {
+ return nil, err
+ }
+ attrs, err := fs.sc.Bucket(bucket).Object(fileName).Attrs(fs.ctx)
+ if err == storage.ErrObjectNotExist {
+ return nil, os.ErrNotExist
+ }
+ if err != nil {
+ return nil, err
+ }
+ return &statInfo{
+ name: attrs.Name,
+ size: attrs.Size,
+ }, nil
+}
+
+func (fs *gcsFS) MkdirAll(path string, perm os.FileMode) error { return nil }
+
+func (fs *gcsFS) OpenFile(name string, flag int, perm os.FileMode) (wkfs.FileWriter, error) {
+ bucket, fileName, err := fs.parseName(name)
+ if err != nil {
+ return nil, err
+ }
+ switch flag {
+ case os.O_WRONLY | os.O_CREATE | os.O_EXCL:
+ case os.O_WRONLY | os.O_CREATE | os.O_TRUNC:
+ default:
+ return nil, fmt.Errorf("Unsupported OpenFlag flag mode %d on Google Cloud Storage", flag)
+ }
+ if flag&os.O_EXCL != 0 {
+ if _, err := fs.Stat(name); err == nil {
+ return nil, os.ErrExist
+ }
+ }
+ // TODO(mpl): consider adding perm to the object's ObjectAttrs.Metadata
+ return fs.sc.Bucket(bucket).Object(fileName).NewWriter(fs.ctx), nil
+}
+
+type statInfo struct {
+ name string
+ size int64
+ isDir bool
+ modtime time.Time
+}
+
+func (si *statInfo) IsDir() bool { return si.isDir }
+func (si *statInfo) ModTime() time.Time { return si.modtime }
+func (si *statInfo) Mode() os.FileMode { return 0644 }
+func (si *statInfo) Name() string { return path.Base(si.name) }
+func (si *statInfo) Size() int64 { return si.size }
+func (si *statInfo) Sys() interface{} { return nil }
+
+type file struct {
+ name string
+ *bytes.Reader
+}
+
+func (*file) Close() error { return nil }
+func (f *file) Name() string { return path.Base(f.name) }
+func (f *file) Stat() (os.FileInfo, error) {
+ panic("Stat not implemented on /gcs/ files yet")
+}