integrate request builder into HTTP client for googleapis support (#157)

builder/path_template_cache.go

@@ -0,0 +1,21 @@
+package builder
+
+import "sync"
+
+var (
+	pathTemplateCache   = make(map[string]*pathTemplate)
+	pathTemplateCacheMu sync.RWMutex
+)
+
+func getCachedPathTemplate(path string) (*pathTemplate, bool) {
+	pathTemplateCacheMu.RLock()
+	defer pathTemplateCacheMu.RUnlock()
+	tmpl, ok := pathTemplateCache[path]
+	return tmpl, ok
+}
+
+func setPathTemplateCache(path string, tmpl *pathTemplate) {
+	pathTemplateCacheMu.Lock()
+	defer pathTemplateCacheMu.Unlock()
+	pathTemplateCache[path] = tmpl
+}