/* -*- 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