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-rw-r--r--dom/xhr/XMLHttpRequestString.h161
1 files changed, 161 insertions, 0 deletions
diff --git a/dom/xhr/XMLHttpRequestString.h b/dom/xhr/XMLHttpRequestString.h
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+++ b/dom/xhr/XMLHttpRequestString.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_XMLHttpRequestString_h
+#define mozilla_dom_XMLHttpRequestString_h
+
+#include "nsString.h"
+
+namespace mozilla {
+
+class Mutex;
+
+namespace dom {
+
+class DOMString;
+class XMLHttpRequestStringBuffer;
+class XMLHttpRequestStringSnapshot;
+class XMLHttpRequestStringWriterHelper;
+class XMLHttpRequestStringSnapshotReaderHelper;
+
+// We want to avoid the dup of strings when XHR in workers has access to
+// responseText for events dispatched during the loading state. For this reason
+// we use this class, able to create snapshots of the current size of itself
+// without making extra copies.
+class XMLHttpRequestString final
+{
+ friend class XMLHttpRequestStringWriterHelper;
+
+public:
+ XMLHttpRequestString();
+ ~XMLHttpRequestString();
+
+ void Truncate();
+
+ uint32_t Length() const;
+
+ void Append(const nsAString& aString);
+
+ // This method should be called only when the string is really needed because
+ // it can cause the duplication of the strings in case the loading of the XHR
+ // is not completed yet.
+ MOZ_MUST_USE bool GetAsString(nsAString& aString) const;
+
+ size_t SizeOfThis(MallocSizeOf aMallocSizeOf) const;
+
+ const char16_t* Data() const;
+
+ bool IsEmpty() const;
+
+ void CreateSnapshot(XMLHttpRequestStringSnapshot& aSnapshot);
+
+private:
+ XMLHttpRequestString(const XMLHttpRequestString&) = delete;
+ XMLHttpRequestString& operator=(const XMLHttpRequestString&) = delete;
+ XMLHttpRequestString& operator=(const XMLHttpRequestString&&) = delete;
+
+ RefPtr<XMLHttpRequestStringBuffer> mBuffer;
+};
+
+// This class locks the buffer and allows the callee to write data into it.
+class MOZ_STACK_CLASS XMLHttpRequestStringWriterHelper final
+{
+public:
+ explicit XMLHttpRequestStringWriterHelper(XMLHttpRequestString& aString);
+
+ bool
+ AddCapacity(int32_t aCapacity);
+
+ char16_t*
+ EndOfExistingData();
+
+ void
+ AddLength(int32_t aLength);
+
+private:
+ XMLHttpRequestStringWriterHelper(const XMLHttpRequestStringWriterHelper&) = delete;
+ XMLHttpRequestStringWriterHelper& operator=(const XMLHttpRequestStringWriterHelper&) = delete;
+ XMLHttpRequestStringWriterHelper& operator=(const XMLHttpRequestStringWriterHelper&&) = delete;
+
+ RefPtr<XMLHttpRequestStringBuffer> mBuffer;
+ MutexAutoLock mLock;
+};
+
+// This class is the internal XMLHttpRequestStringBuffer of the
+// XMLHttpRequestString plus the current length. GetAsString will return the
+// string with that particular length also if the XMLHttpRequestStringBuffer is
+// grown in the meantime.
+class XMLHttpRequestStringSnapshot final
+{
+ friend class XMLHttpRequestStringBuffer;
+ friend class XMLHttpRequestStringSnapshotReaderHelper;
+
+public:
+ XMLHttpRequestStringSnapshot();
+ ~XMLHttpRequestStringSnapshot();
+
+ XMLHttpRequestStringSnapshot& operator=(const XMLHttpRequestStringSnapshot&);
+
+ void Reset()
+ {
+ ResetInternal(false /* isVoid */);
+ }
+
+ void SetVoid()
+ {
+ ResetInternal(true /* isVoid */);
+ }
+
+ bool IsVoid() const
+ {
+ return mVoid;
+ }
+
+ bool IsEmpty() const
+ {
+ return !mLength;
+ }
+
+ MOZ_MUST_USE bool GetAsString(DOMString& aString) const;
+
+private:
+ XMLHttpRequestStringSnapshot(const XMLHttpRequestStringSnapshot&) = delete;
+ XMLHttpRequestStringSnapshot& operator=(const XMLHttpRequestStringSnapshot&&) = delete;
+
+ void Set(XMLHttpRequestStringBuffer* aBuffer, uint32_t aLength);
+
+ void ResetInternal(bool aIsVoid);
+
+ RefPtr<XMLHttpRequestStringBuffer> mBuffer;
+ uint32_t mLength;
+ bool mVoid;
+};
+
+// This class locks the buffer and allows the callee to read data from it.
+class MOZ_STACK_CLASS XMLHttpRequestStringSnapshotReaderHelper final
+{
+public:
+ explicit XMLHttpRequestStringSnapshotReaderHelper(XMLHttpRequestStringSnapshot& aSnapshot);
+
+ const char16_t*
+ Buffer() const;
+
+ uint32_t
+ Length() const;
+
+private:
+ XMLHttpRequestStringSnapshotReaderHelper(const XMLHttpRequestStringSnapshotReaderHelper&) = delete;
+ XMLHttpRequestStringSnapshotReaderHelper& operator=(const XMLHttpRequestStringSnapshotReaderHelper&) = delete;
+ XMLHttpRequestStringSnapshotReaderHelper& operator=(const XMLHttpRequestStringSnapshotReaderHelper&&) = delete;
+
+ RefPtr<XMLHttpRequestStringBuffer> mBuffer;
+ MutexAutoLock mLock;
+};
+
+} // dom namespace
+} // mozilla namespace
+
+#endif // mozilla_dom_XMLHttpRequestString_h