From a18a13fb09eac00cdacf1f74080524182b7243de Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Mon, 6 Jun 2016 00:55:30 +0100 Subject: update vendor --- vendor/go4.org/wkfs/gcs/gcs.go | 196 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 vendor/go4.org/wkfs/gcs/gcs.go (limited to 'vendor/go4.org/wkfs/gcs/gcs.go') 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") +} -- cgit v1.2.3