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-rw-r--r--vendor/google.golang.org/cloud/internal/cloud.go128
1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/google.golang.org/cloud/internal/cloud.go b/vendor/google.golang.org/cloud/internal/cloud.go
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+++ b/vendor/google.golang.org/cloud/internal/cloud.go
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+// 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 internal provides support for the cloud packages.
+//
+// Users should not import this package directly.
+package internal
+
+import (
+ "fmt"
+ "net/http"
+ "sync"
+
+ "golang.org/x/net/context"
+)
+
+type contextKey struct{}
+
+func WithContext(parent context.Context, projID string, c *http.Client) context.Context {
+ if c == nil {
+ panic("nil *http.Client passed to WithContext")
+ }
+ if projID == "" {
+ panic("empty project ID passed to WithContext")
+ }
+ return context.WithValue(parent, contextKey{}, &cloudContext{
+ ProjectID: projID,
+ HTTPClient: c,
+ })
+}
+
+const userAgent = "gcloud-golang/0.1"
+
+type cloudContext struct {
+ ProjectID string
+ HTTPClient *http.Client
+
+ mu sync.Mutex // guards svc
+ svc map[string]interface{} // e.g. "storage" => *rawStorage.Service
+}
+
+// Service returns the result of the fill function if it's never been
+// called before for the given name (which is assumed to be an API
+// service name, like "datastore"). If it has already been cached, the fill
+// func is not run.
+// It's safe for concurrent use by multiple goroutines.
+func Service(ctx context.Context, name string, fill func(*http.Client) interface{}) interface{} {
+ return cc(ctx).service(name, fill)
+}
+
+func (c *cloudContext) service(name string, fill func(*http.Client) interface{}) interface{} {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+
+ if c.svc == nil {
+ c.svc = make(map[string]interface{})
+ } else if v, ok := c.svc[name]; ok {
+ return v
+ }
+ v := fill(c.HTTPClient)
+ c.svc[name] = v
+ return v
+}
+
+// Transport is an http.RoundTripper that appends
+// Google Cloud client's user-agent to the original
+// request's user-agent header.
+type Transport struct {
+ // Base is the actual http.RoundTripper
+ // requests will use. It must not be nil.
+ Base http.RoundTripper
+}
+
+// RoundTrip appends a user-agent to the existing user-agent
+// header and delegates the request to the base http.RoundTripper.
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+ req = cloneRequest(req)
+ ua := req.Header.Get("User-Agent")
+ if ua == "" {
+ ua = userAgent
+ } else {
+ ua = fmt.Sprintf("%s %s", ua, userAgent)
+ }
+ req.Header.Set("User-Agent", ua)
+ return t.Base.RoundTrip(req)
+}
+
+// cloneRequest returns a clone of the provided *http.Request.
+// The clone is a shallow copy of the struct and its Header map.
+func cloneRequest(r *http.Request) *http.Request {
+ // shallow copy of the struct
+ r2 := new(http.Request)
+ *r2 = *r
+ // deep copy of the Header
+ r2.Header = make(http.Header)
+ for k, s := range r.Header {
+ r2.Header[k] = s
+ }
+ return r2
+}
+
+func ProjID(ctx context.Context) string {
+ return cc(ctx).ProjectID
+}
+
+func HTTPClient(ctx context.Context) *http.Client {
+ return cc(ctx).HTTPClient
+}
+
+// cc returns the internal *cloudContext (cc) state for a context.Context.
+// It panics if the user did it wrong.
+func cc(ctx context.Context) *cloudContext {
+ if c, ok := ctx.Value(contextKey{}).(*cloudContext); ok {
+ return c
+ }
+ panic("invalid context.Context type; it should be created with cloud.NewContext")
+}