Switch WebHTTPBody and WebDragData to implement copy-on-write behavior. This

allows me to return a copyable instance of these wrapper classes while
preventing a consumer from modifying the WebCore objects being wrapped.  A
modification will just modify a copy.  This is going to be especially helpful
when it comes to wrapping HistoryItem.

Note how this simplifies WebURLRequest a bit since it doesn't have to carry a
WebHTTPBody member.

The copy-on-write behavior is implemented in an ensureMutable method.

This CL depends on https://bugs.webkit.org/show_bug.cgi?id=26622

BUG=none
TEST=none
R=dglazkov

Review URL: http://codereview.chromium.org/141062

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19103 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 48 insertions, 21 deletions

diff --git a/webkit/api/src/WebDragData.cpp b/webkit/api/src/WebDragData.cpp
index 044c6ea..facbcd2 100644
--- a/webkit/api/src/WebDragData.cpp
+++ b/webkit/api/src/WebDragData.cpp
@@ -71,7 +71,7 @@ WebURL WebDragData::url() const
 
 void WebDragData::setURL(const WebURL& url)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->url = url;
 }
 
@@ -83,7 +83,7 @@ WebString WebDragData::urlTitle() const
 
 void WebDragData::setURLTitle(const WebString& urlTitle)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->urlTitle = urlTitle;
 }
 
@@ -95,7 +95,7 @@ WebString WebDragData::fileExtension() const
 
 void WebDragData::setFileExtension(const WebString& fileExtension)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->fileExtension = fileExtension;
 }
 
@@ -113,14 +113,14 @@ void WebDragData::fileNames(WebVector<WebString>& fileNames) const
 
 void WebDragData::setFileNames(const WebVector<WebString>& fileNames)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->filenames.clear();
     m_private->filenames.append(fileNames.data(), fileNames.size());
 }
 
 void WebDragData::appendToFileNames(const WebString& fileName)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->filenames.append(fileName);
 }
 
@@ -132,7 +132,7 @@ WebString WebDragData::plainText() const
 
 void WebDragData::setPlainText(const WebString& plainText)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->plainText = plainText;
 }
 
@@ -144,7 +144,7 @@ WebString WebDragData::htmlText() const
 
 void WebDragData::setHTMLText(const WebString& htmlText)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->textHtml = htmlText;
 }
 
@@ -156,7 +156,7 @@ WebURL WebDragData::htmlBaseURL() const
 
 void WebDragData::setHTMLBaseURL(const WebURL& htmlBaseURL)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->htmlBaseUrl = htmlBaseURL;
 }
 
@@ -168,7 +168,7 @@ WebString WebDragData::fileContentFileName() const
 
 void WebDragData::setFileContentFileName(const WebString& fileName)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->fileContentFilename = fileName;
 }
 
@@ -180,7 +180,7 @@ WebData WebDragData::fileContent() const
 
 void WebDragData::setFileContent(const WebData& fileContent)
 {
-    ASSERT(!isNull());
+    ensureMutable();
     m_private->fileContent = fileContent;
 }
 
@@ -208,4 +208,11 @@ void WebDragData::assign(WebDragDataPrivate* p)
     m_private = p;
 }
 
+void WebDragData::ensureMutable()
+{
+    ASSERT(!isNull());
+    if (!m_private->hasOneRef())
+        assign(static_cast<WebDragDataPrivate*>(m_private->copy().releaseRef()));
+}
+
 } // namespace WebKit
diff --git a/webkit/api/src/WebHTTPBody.cpp b/webkit/api/src/WebHTTPBody.cpp
index 69875e7..bd66b08 100644
--- a/webkit/api/src/WebHTTPBody.cpp
+++ b/webkit/api/src/WebHTTPBody.cpp
@@ -50,13 +50,23 @@ void WebHTTPBody::reset()
     assign(0);
 }
 
+void WebHTTPBody::assign(const WebHTTPBody& other)
+{
+    WebHTTPBodyPrivate* p = const_cast<WebHTTPBodyPrivate*>(other.m_private);
+    p->ref();
+    assign(p);
+}
+
 size_t WebHTTPBody::elementCount() const
 {
+    ASSERT(!isNull());
     return m_private->elements().size();
 }
 
 bool WebHTTPBody::elementAt(size_t index, Element& result) const
 {
+    ASSERT(!isNull());
+
     if (index >= m_private->elements().size())
         return false;
 
@@ -83,6 +93,7 @@ bool WebHTTPBody::elementAt(size_t index, Element& result) const
 
 void WebHTTPBody::appendData(const WebData& data)
 {
+    ensureMutable();
     // FIXME: FormDataElement::m_data should be a SharedBuffer<char>.  Then we
     // could avoid this buffer copy.
     m_private->appendData(data.data(), data.size());
@@ -90,22 +101,31 @@ void WebHTTPBody::appendData(const WebData& data)
 
 void WebHTTPBody::appendFile(const WebString& filePath)
 {
+    ensureMutable();
     m_private->appendFile(filePath);
 }
 
 long long WebHTTPBody::identifier() const
 {
+    ASSERT(!isNull());
     return m_private->identifier();
 }
 
 void WebHTTPBody::setIdentifier(long long identifier)
 {
+    ensureMutable();
     return m_private->setIdentifier(identifier);
 }
 
-void WebHTTPBody::rebind(PassRefPtr<FormData> formData)
+WebHTTPBody::WebHTTPBody(const PassRefPtr<FormData>& data)
+    : m_private(static_cast<WebHTTPBodyPrivate*>(data.releaseRef()))
+{
+}
+
+WebHTTPBody& WebHTTPBody::operator=(const PassRefPtr<FormData>& data)
 {
-    assign(static_cast<WebHTTPBodyPrivate*>(formData.releaseRef()));
+    assign(static_cast<WebHTTPBodyPrivate*>(data.releaseRef()));
+    return *this;
 }
 
 WebHTTPBody::operator PassRefPtr<FormData>() const
@@ -121,4 +141,11 @@ void WebHTTPBody::assign(WebHTTPBodyPrivate* p)
     m_private = p;
 }
 
+void WebHTTPBody::ensureMutable()
+{
+    ASSERT(!isNull());
+    if (!m_private->hasOneRef())
+        assign(static_cast<WebHTTPBodyPrivate*>(m_private->copy().releaseRef()));
+}
+
 } // namespace WebKit
diff --git a/webkit/api/src/WebURLRequest.cpp b/webkit/api/src/WebURLRequest.cpp
index b62206c..6c92e7f 100644
--- a/webkit/api/src/WebURLRequest.cpp
+++ b/webkit/api/src/WebURLRequest.cpp
@@ -147,16 +147,14 @@ void WebURLRequest::visitHTTPHeaderFields(WebHTTPHeaderVisitor* visitor) const
         visitor->visitHeader(String(it->first), it->second);
 }
 
-const WebHTTPBody& WebURLRequest::httpBody() const
+WebHTTPBody WebURLRequest::httpBody() const
 {
-    m_private->m_httpBody.rebind(m_private->m_resourceRequest->httpBody());
-    return m_private->m_httpBody;
+    return m_private->m_resourceRequest->httpBody();
 }
 
 void WebURLRequest::setHTTPBody(const WebHTTPBody& httpBody)
 {
     m_private->m_resourceRequest->setHTTPBody(httpBody);
-    m_private->m_httpBody.rebind(0); // Free memory of the old body
 }
 
 bool WebURLRequest::reportUploadProgress() const
diff --git a/webkit/api/src/WebURLRequestPrivate.h b/webkit/api/src/WebURLRequestPrivate.h
index a2b0187..5c95a6f 100644
--- a/webkit/api/src/WebURLRequestPrivate.h
+++ b/webkit/api/src/WebURLRequestPrivate.h
@@ -31,10 +31,6 @@
 #ifndef WebURLRequestPrivate_h
 #define WebURLRequestPrivate_h
 
-// FIXME: This relative path is a temporary hack to support using this
-// header from webkit/glue.
-#include "../public/WebHTTPBody.h"
-
 namespace WebCore { struct ResourceRequest; }
 
 namespace WebKit {
@@ -47,7 +43,6 @@ namespace WebKit {
         virtual void dispose() = 0;
 
         WebCore::ResourceRequest* m_resourceRequest;
-        WebHTTPBody m_httpBody;
     };
 
 } // namespace WebKit