Index: content/renderer/unique_name_helper.h |
diff --git a/content/renderer/unique_name_helper.h b/content/renderer/unique_name_helper.h |
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+// Copyright 2017 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+// |
+// Description of the current unique name format |
+// --------------------------------------------- |
+// |
+// Changing the format of unique name is undesirable, because it breaks |
+// backcompatibility of session history (which stores unique names |
+// generated in the past on user's disk). This incremental, |
+// backcompatibility-aware approach has resulted so far in the following |
+// rather baroque format... : |
+// |
+// uniqueName ::= <nullForMainFrame> | <assignedName> | <generatedName> |
+// (generatedName is used if assignedName is |
+// non-unique / conflicts with other frame's unique name. |
+// |
+// assignedName ::= value of iframe's name attribute |
+// or value assigned to window.name (*before* the first |
+// real commit - afterwards unique name stays immutable). |
+// |
+// generatedName ::= oldGeneratedName newUniqueSuffix? |
+// (newUniqueSuffix is only present if oldGeneratedName was |
+// not unique after all) |
+// |
+// oldGeneratedName ::= "<!--framePath //" ancestorChain |
+// "/<!--frame" childCount "-->-->" |
+// (oldGeneratedName is generated by |
+// generateUniqueNameCandidate method). |
+// |
+// childCount ::= current number of siblings |
+// |
+// ancestorChain ::= concatenated unique names of ancestor chain, |
+// terminated on the first ancestor (if any) starting with |
+// "<!--framePath"; each ancestor's unique name is |
+// separated by "/" character |
+// ancestorChain example1: "grandparent/parent" |
+// (ancestor's unique names : #1--^ | #2-^ ) |
+// ancestorChain example2: |
+// "<!--framePath //foo/bar/<!--frame42-->-->/blah/foobar" |
+// (ancestor's unique names: |
+// ^--#1--^ | #2 | #3-^ ) |
+// |
+// newUniqueSuffix ::= "<!--framePosition" framePosition "/" retryNumber |
+// "-->" |
+// |
+// framePosition ::= "-" numberOfSiblingsBeforeChild |
+// [ framePosition-forParent? ] |
+// |
+// retryNumber ::= smallest non-negative integer resulting in unique name |
+ |
+#ifndef CONTENT_RENDERER_UNIQUE_NAME_HELPER_H_ |
+#define CONTENT_RENDERER_UNIQUE_NAME_HELPER_H_ |
+ |
+#include <string> |
+ |
+#include "base/macros.h" |
+ |
+namespace blink { |
+class WebFrame; |
+class WebLocalFrame; |
+} // namespace blink |
+ |
+namespace content { |
+ |
+class RenderFrameImpl; |
+ |
+class UniqueNameHelper { |
+ public: |
+ explicit UniqueNameHelper(RenderFrameImpl* render_frame); |
+ ~UniqueNameHelper(); |
+ |
+ const std::string& value() const { return unique_name_; } |
+ |
+ void set_from_replicated_state(const std::string& unique_name) { |
+ unique_name_ = unique_name; |
+ } |
+ |
+ // Note: |parent| needs to be plumbed in for new child frames, since the |
+ // unique name needs to be calculated before the new child RenderFrameImpl is |
+ // created. |
+ static std::string GenerateNameForNewChildFrame(blink::WebFrame* parent, |
+ const std::string& name); |
+ |
+ void UpdateName(const std::string& name); |
+ |
+ private: |
+ blink::WebLocalFrame* GetWebFrame() const; |
+ |
+ RenderFrameImpl* const render_frame_; |
+ std::string unique_name_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(UniqueNameHelper); |
+}; |
+ |
+} // namespace content |
+ |
+#endif // CONTENT_RENDERER_UNIQUE_NAME_HELPER_H_ |