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")
+}