Reduce string copies in GURL creation

third_party/WebKit/public/platform/WebStringUTF8Adaptor.h

 /*
- * Copyright (C) 2012 Google Inc. All rights reserved.
+ * Copyright (C) 2016 Google Inc. All rights reserved.

[haraken, 2016/01/12 23:44:37]

Ditto. You can use the 3-line copyright.

  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebRTCVoidRequest_h
-#define WebRTCVoidRequest_h
+#ifndef WebStringUTF8Adaptor_h
+#define WebStringUTF8Adaptor_h
 
 #include "WebCommon.h"
-#include "WebNonCopyable.h"
 #include "WebPrivatePtr.h"
-#include "WebString.h"
+#include "base/strings/string_piece.h"
+
+namespace WTF {
+class CStringBuffer;
+}
 
 namespace blink {
 
-class RTCVoidRequest;
+class WebString;
 
-class WebRTCVoidRequest {
+// This class lets you get UTF-8 data out of a String without mallocing a
+// separate buffer to hold the data if the String happens to be 8 bit and
+// contain only ASCII characters.
+//
+// The string passed to the constructor must outlive this class since the
+// returned StringPiece might point into it (which is the whole point).
+class BLINK_COMMON_EXPORT WebStringUTF8Adaptor {
 public:
-    WebRTCVoidRequest() { }
-    WebRTCVoidRequest(const WebRTCVoidRequest& other) { assign(other); }
-    ~WebRTCVoidRequest() { reset(); }
+    WebStringUTF8Adaptor(const WebString&);

[haraken, 2016/01/12 23:44:37]

Is it intentional that we don't have an explicit on the constructor?

[esprehn, 2016/01/13 02:02:32]

explicit

+    ~WebStringUTF8Adaptor();
 
-    WebRTCVoidRequest& operator=(const WebRTCVoidRequest& other)
-    {
-        assign(other);
-        return *this;
-    }
-
-    BLINK_PLATFORM_EXPORT void assign(const WebRTCVoidRequest&);
-
-    BLINK_PLATFORM_EXPORT void reset();
-    bool isNull() const { return m_private.isNull(); }
-
-    BLINK_PLATFORM_EXPORT void requestSucceeded() const;
-    BLINK_PLATFORM_EXPORT void requestFailed(const WebString& error) const;
-
-#if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebRTCVoidRequest(RTCVoidRequest*);
-#endif
+    base::StringPiece asStringPiece() const { return m_stringPiece; }
 
 private:
-    WebPrivatePtr<RTCVoidRequest> m_private;
+    base::StringPiece m_stringPiece;
+
+    // Holds the UTF-8 buffer backing the string piece if conversion was necessary.
+    WebPrivatePtr<WTF::CStringBuffer> m_utf8Buffer;
 };
 
 } // namespace blink
 
-#endif // WebRTCVoidRequest_h
+#endif