/* -*- 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 "gfxVars.h"

#include "gfxVarReceiver.h"

#include "mozilla/dom/ContentChild.h"

namespace mozilla {

namespace gfx {

StaticAutoPtr<gfxVars> gfxVars::sInstance;

StaticAutoPtr<nsTArray<gfxVars::VarBase*>> gfxVars::sVarList;

StaticAutoPtr<nsTArray<GfxVarUpdate>> gGfxVarInitUpdates;

void

gfxVars::SetValuesForInitialize(const nsTArray<GfxVarUpdate>& aInitUpdates)

{

  // This should only be called once

  MOZ_RELEASE_ASSERT(!gGfxVarInitUpdates);

  // We expect aInitUpdates to be provided before any other gfxVars operation,

  // and for sInstance to be null here, but handle the alternative.

  if (sInstance) {

    // Apply the updates, the object has been created already

    for (const auto& varUpdate : aInitUpdates) {

      ApplyUpdate(varUpdate);

    }

  } else {

      // Save the values for Initialize call

      gGfxVarInitUpdates = new nsTArray<GfxVarUpdate>(aInitUpdates);

  }

}

void

gfxVars::Initialize()

{

  if (sInstance) {

    MOZ_RELEASE_ASSERT(!gGfxVarInitUpdates, "Initial updates should not be present after any gfxVars operation");

    return;

  }

  // sVarList must be initialized first since it's used in the constructor for

  // sInstance.

  sVarList = new nsTArray<gfxVars::VarBase*>();

  sInstance = new gfxVars;

  // Note the GPU process is not handled here - it cannot send sync

  // messages, so instead the initial data is pushed down.

  if (XRE_IsContentProcess()) {

    MOZ_ASSERT(gGfxVarInitUpdates, "Initial updates should be provided in content process");

    if (!gGfxVarInitUpdates) {

      // No provided initial updates, sync-request them from parent.

      InfallibleTArray<GfxVarUpdate> initUpdates;

      dom::ContentChild::GetSingleton()->SendGetGfxVars(&initUpdates);

      gGfxVarInitUpdates = new nsTArray<GfxVarUpdate>(std::move(initUpdates));

    }

    for (const auto& varUpdate : *gGfxVarInitUpdates) {

      ApplyUpdate(varUpdate);

    }

    gGfxVarInitUpdates = nullptr;

  }

}

gfxVars::gfxVars()

{

}

void

gfxVars::Shutdown()

{

  sInstance = nullptr;

  sVarList = nullptr;

  gGfxVarInitUpdates = nullptr;

}

/* static */ void

gfxVars::ApplyUpdate(const GfxVarUpdate& aUpdate)

{

  // Only subprocesses receive updates and apply them locally.

  MOZ_ASSERT(!XRE_IsParentProcess());

  MOZ_DIAGNOSTIC_ASSERT(sVarList || gGfxVarInitUpdates);

  if (sVarList) {

    sVarList->ElementAt(aUpdate.index())->SetValue(aUpdate.value());

  } else if (gGfxVarInitUpdates) {

    // Too early, we haven't been initialized, so just add to

    // the array waiting for the initialization...

    gGfxVarInitUpdates->AppendElement(aUpdate);

  }

}

/* 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