1 files changed, 125 insertions, 0 deletions
diff --git a/gfx/config/gfxVars.cpp b/gfx/config/gfxVars.cpp
new file mode 100644
index 000000000..6b41d29c9
--- /dev/null
+++ b/gfx/config/gfxVars.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set sts=2 ts=8 sw=2 tw=99 et: */
+/* 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 "gfxVars.h"
+#include "gfxVarReceiver.h"
+#include "mozilla/dom/ContentChild.h"
+
+namespace mozilla {
+namespace gfx {
+
+StaticAutoPtr<gfxVars> gfxVars::sInstance;
+StaticAutoPtr<nsTArray<gfxVars::VarBase*>> gfxVars::sVarList;
+
+void
+gfxVars::Initialize()
+{
+  if (sInstance) {
+    return;
+  }
+
+  // sVarList must be initialized first since it's used in the constructor for
+  // sInstance.
+  sVarList = new nsTArray<gfxVars::VarBase*>();
+  sInstance = new gfxVars;
+
+  // Like Preferences, we want content to synchronously get initial data on
+  // init. Note the GPU process is not handled here - it cannot send sync
+  // messages, so instead the initial data is pushed down.
+  if (XRE_IsContentProcess()) {
+    InfallibleTArray<GfxVarUpdate> vars;
+    dom::ContentChild::GetSingleton()->SendGetGfxVars(&vars);
+    for (const auto& var : vars) {
+      ApplyUpdate(var);
+    }
+  }
+}
+
+gfxVars::gfxVars()
+{
+}
+
+void
+gfxVars::Shutdown()
+{
+  sInstance = nullptr;
+  sVarList = nullptr;
+}
+
+/* static */ void
+gfxVars::ApplyUpdate(const GfxVarUpdate& aUpdate)
+{
+  // Only subprocesses receive updates and apply them locally.
+  MOZ_ASSERT(!XRE_IsParentProcess());
+  sVarList->ElementAt(aUpdate.index())->SetValue(aUpdate.value());
+}
+
+/* static */ void
+gfxVars::AddReceiver(gfxVarReceiver* aReceiver)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // Don't double-add receivers, in case a broken content process sends two
+  // init messages.
+  if (!sInstance->mReceivers.Contains(aReceiver)) {
+    sInstance->mReceivers.AppendElement(aReceiver);
+  }
+}
+
+/* static */ void
+gfxVars::RemoveReceiver(gfxVarReceiver* aReceiver)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (sInstance) {
+    sInstance->mReceivers.RemoveElement(aReceiver);
+  }
+}
+
+/* static */ nsTArray<GfxVarUpdate>
+gfxVars::FetchNonDefaultVars()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(sVarList);
+
+  nsTArray<GfxVarUpdate> updates;
+  for (size_t i = 0; i < sVarList->Length(); i++) {
+    VarBase* var = sVarList->ElementAt(i);
+    if (var->HasDefaultValue()) {
+      continue;
+    }
+
+    GfxVarValue value;
+    var->GetValue(&value);
+
+    updates.AppendElement(GfxVarUpdate(i, value));
+  }
+
+  return updates;
+}
+
+gfxVars::VarBase::VarBase()
+{
+  mIndex = gfxVars::sVarList->Length();
+  gfxVars::sVarList->AppendElement(this);
+}
+
+void
+gfxVars::NotifyReceivers(VarBase* aVar)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  GfxVarValue value;
+  aVar->GetValue(&value);
+
+  GfxVarUpdate update(aVar->Index(), value);
+  for (auto& receiver : mReceivers) {
+    receiver->OnVarChanged(update);
+  }
+}
+
+} // namespace gfx
+} // namespace mozilla