Move packages http and url

http/response.go

@@ -0,0 +1,52 @@
+// Copyright 2017 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"io"
+	"strings"
+
+	"golang.org/x/net/html/charset"
+)
+
+// Response wraps a server response.
+type Response struct {
+	Body         io.Reader
+	StatusCode   int
+	EffectiveURL string
+	LastModified string
+	ETag         string
+	ContentType  string
+}
+
+// HasServerFailure returns true if the status code represents a failure.
+func (r *Response) HasServerFailure() bool {
+	return r.StatusCode >= 400
+}
+
+// IsModified returns true if the resource has been modified.
+func (r *Response) IsModified(etag, lastModified string) bool {
+	if r.StatusCode == 304 {
+		return false
+	}
+
+	if r.ETag != "" && r.ETag == etag {
+		return false
+	}
+
+	if r.LastModified != "" && r.LastModified == lastModified {
+		return false
+	}
+
+	return true
+}
+
+// NormalizeBodyEncoding make sure the body is encoded in UTF-8.
+func (r *Response) NormalizeBodyEncoding() (io.Reader, error) {
+	if strings.Contains(r.ContentType, "charset=") {
+		return charset.NewReader(r.Body, r.ContentType)
+	}
+	return r.Body, nil
+}