Vendor main dependencies.

vendor/google.golang.org/cloud/internal/cloud.go

@@ -0,0 +1,128 @@
+// 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 represents the actual http.RoundTripper
+	// the requests will be delegated to.
+	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")
+}