1 files changed, 267 insertions, 0 deletions
diff --git a/dom/xhr/XMLHttpRequestString.cpp b/dom/xhr/XMLHttpRequestString.cpp
new file mode 100644
index 000000000..c668b94f6
--- /dev/null
+++ b/dom/xhr/XMLHttpRequestString.cpp
@@ -0,0 +1,267 @@
+/* -*- 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/. */
+
+#include "XMLHttpRequestString.h"
+#include "mozilla/Mutex.h"
+#include "nsISupportsImpl.h"
+#include "mozilla/dom/DOMString.h"
+
+namespace mozilla {
+namespace dom {
+
+class XMLHttpRequestStringBuffer final
+{
+  friend class XMLHttpRequestStringWriterHelper;
+  friend class XMLHttpRequestStringSnapshotReaderHelper;
+
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(XMLHttpRequestStringBuffer)
+  NS_DECL_OWNINGTHREAD
+
+  XMLHttpRequestStringBuffer()
+    : mMutex("XMLHttpRequestStringBuffer::mMutex")
+  {
+  }
+
+  uint32_t
+  Length()
+  {
+    MutexAutoLock lock(mMutex);
+    return mData.Length();
+  }
+
+  uint32_t
+  UnsafeLength() const
+  {
+    return mData.Length();
+  }
+
+  void
+  Append(const nsAString& aString)
+  {
+    NS_ASSERT_OWNINGTHREAD(XMLHttpRequestStringBuffer);
+
+    MutexAutoLock lock(mMutex);
+    mData.Append(aString);
+  }
+
+  MOZ_MUST_USE bool
+  GetAsString(nsAString& aString)
+  {
+    MutexAutoLock lock(mMutex);
+    return aString.Assign(mData, mozilla::fallible);
+  }
+
+  size_t
+  SizeOfThis(MallocSizeOf aMallocSizeOf) const
+  {
+    return mData.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+  }
+
+  MOZ_MUST_USE bool
+  GetAsString(DOMString& aString, uint32_t aLength)
+  {
+    MutexAutoLock lock(mMutex);
+    MOZ_ASSERT(aLength <= mData.Length());
+    nsStringBuffer* buf = nsStringBuffer::FromString(mData);
+    if (buf) {
+      // We have to use SetEphemeralStringBuffer, because once we release our
+      // mutex mData can get mutated from some other thread while the DOMString
+      // is still alive.
+      aString.SetEphemeralStringBuffer(buf, aLength);
+      return true;
+    }
+
+    // We can get here if mData is empty.  In that case it won't have an
+    // nsStringBuffer....
+    MOZ_ASSERT(mData.IsEmpty());
+    return aString.AsAString().Assign(mData.BeginReading(), aLength,
+                                      mozilla::fallible);
+  }
+
+  void
+  CreateSnapshot(XMLHttpRequestStringSnapshot& aSnapshot)
+  {
+    MutexAutoLock lock(mMutex);
+    aSnapshot.Set(this, mData.Length());
+  }
+
+private:
+  ~XMLHttpRequestStringBuffer()
+  {}
+
+  nsString& UnsafeData()
+  {
+    return mData;
+  }
+
+  Mutex mMutex;
+
+  // The following member variable is protected by mutex.
+  nsString mData;
+};
+
+// ---------------------------------------------------------------------------
+// XMLHttpRequestString
+
+XMLHttpRequestString::XMLHttpRequestString()
+  : mBuffer(new XMLHttpRequestStringBuffer())
+{
+}
+
+XMLHttpRequestString::~XMLHttpRequestString()
+{
+}
+
+void
+XMLHttpRequestString::Truncate()
+{
+  mBuffer = new XMLHttpRequestStringBuffer();
+}
+
+uint32_t
+XMLHttpRequestString::Length() const
+{
+  return mBuffer->Length();
+}
+
+void
+XMLHttpRequestString::Append(const nsAString& aString)
+{
+  mBuffer->Append(aString);
+}
+
+bool
+XMLHttpRequestString::GetAsString(nsAString& aString) const
+{
+  return mBuffer->GetAsString(aString);
+}
+
+size_t
+XMLHttpRequestString::SizeOfThis(MallocSizeOf aMallocSizeOf) const
+{
+  return mBuffer->SizeOfThis(aMallocSizeOf);
+}
+
+bool
+XMLHttpRequestString::IsEmpty() const
+{
+  return !mBuffer->Length();
+}
+
+void
+XMLHttpRequestString::CreateSnapshot(XMLHttpRequestStringSnapshot& aSnapshot)
+{
+  mBuffer->CreateSnapshot(aSnapshot);
+}
+
+// ---------------------------------------------------------------------------
+// XMLHttpRequestStringSnapshot
+
+XMLHttpRequestStringSnapshot::XMLHttpRequestStringSnapshot()
+  : mLength(0)
+  , mVoid(false)
+{
+}
+
+XMLHttpRequestStringSnapshot::~XMLHttpRequestStringSnapshot()
+{
+}
+
+XMLHttpRequestStringSnapshot&
+XMLHttpRequestStringSnapshot::operator=(const XMLHttpRequestStringSnapshot& aOther)
+{
+  mBuffer = aOther.mBuffer;
+  mLength = aOther.mLength;
+  mVoid = aOther.mVoid;
+  return *this;
+}
+
+void
+XMLHttpRequestStringSnapshot::ResetInternal(bool aIsVoid)
+{
+  mBuffer = nullptr;
+  mLength = 0;
+  mVoid = aIsVoid;
+}
+
+void
+XMLHttpRequestStringSnapshot::Set(XMLHttpRequestStringBuffer* aBuffer,
+                                  uint32_t aLength)
+{
+  MOZ_ASSERT(aBuffer);
+  MOZ_ASSERT(aLength <= aBuffer->UnsafeLength());
+
+  mBuffer = aBuffer;
+  mLength = aLength;
+  mVoid = false;
+}
+
+bool
+XMLHttpRequestStringSnapshot::GetAsString(DOMString& aString) const
+{
+  if (mBuffer) {
+    MOZ_ASSERT(!mVoid);
+    return mBuffer->GetAsString(aString, mLength);
+  }
+
+  if (mVoid) {
+    aString.SetNull();
+  }
+
+  return true;
+}
+
+// ---------------------------------------------------------------------------
+// XMLHttpRequestStringWriterHelper
+
+XMLHttpRequestStringWriterHelper::XMLHttpRequestStringWriterHelper(XMLHttpRequestString& aString)
+  : mBuffer(aString.mBuffer)
+  , mLock(aString.mBuffer->mMutex)
+{
+}
+
+bool
+XMLHttpRequestStringWriterHelper::AddCapacity(int32_t aCapacity)
+{
+  return mBuffer->UnsafeData().SetCapacity(mBuffer->UnsafeLength() + aCapacity, fallible);
+}
+
+char16_t*
+XMLHttpRequestStringWriterHelper::EndOfExistingData()
+{
+  return mBuffer->UnsafeData().BeginWriting() + mBuffer->UnsafeLength();
+}
+
+void
+XMLHttpRequestStringWriterHelper::AddLength(int32_t aLength)
+{
+  mBuffer->UnsafeData().SetLength(mBuffer->UnsafeLength() + aLength);
+}
+
+// ---------------------------------------------------------------------------
+// XMLHttpRequestStringReaderHelper
+
+XMLHttpRequestStringSnapshotReaderHelper::XMLHttpRequestStringSnapshotReaderHelper(XMLHttpRequestStringSnapshot& aSnapshot)
+  : mBuffer(aSnapshot.mBuffer)
+  , mLock(aSnapshot.mBuffer->mMutex)
+{
+}
+
+const char16_t*
+XMLHttpRequestStringSnapshotReaderHelper::Buffer() const
+{
+  return mBuffer->UnsafeData().BeginReading();
+}
+
+uint32_t
+XMLHttpRequestStringSnapshotReaderHelper::Length() const
+{
+  return mBuffer->UnsafeLength();
+}
+
+} // dom namespace
+} // mozilla namespace