Issue 5137 - [emscripten] Added basic filter storage implementation

compiled/storage/FilterStorage.cpp

+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-present eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <vector>
+
+#include "FilterStorage.h"
+#include "../filter/Filter.h"
+#include "../subscription/UserDefinedSubscription.h"
+#include "../FilterNotifier.h"
+
+FilterStorage* FilterStorage::mInstance = new FilterStorage();
+
+FilterStorage::Subscriptions::size_type FilterStorage::GetSubscriptionCount() const
+{
+  return mSubscriptions.size();
+}
+
+Subscription* FilterStorage::SubscriptionAt(FilterStorage::Subscriptions::size_type index) const
+{
+  if (index >= mSubscriptions.size())
+    return nullptr;
+
+  SubscriptionPtr result(mSubscriptions[index]);
+  return result.release();
+}
+
+int FilterStorage::IndexOfSubscription(const Subscription* subscription) const
+{
+  for (Subscriptions::size_type i = 0; i < mSubscriptions.size(); i++)
+    if (mSubscriptions[i] == subscription)
+      return i;
+  return -1;
+}
+
+Subscription* FilterStorage::GetSubscriptionForFilter(const Filter* filter) const
+{
+  SubscriptionPtr fallback;
+
+  for (Subscriptions::size_type i = 0; i < mSubscriptions.size(); i++)
+  {
+    SubscriptionPtr subscription(mSubscriptions[i]);
+    UserDefinedSubscription* userDefinedSubscription =
+        subscription->As<UserDefinedSubscription>();
+    if (userDefinedSubscription && !userDefinedSubscription->GetDisabled() &&
+        userDefinedSubscription->IsDefaultFor(filter))
+    {
+      SubscriptionPtr result(subscription);
+      return result.release();
+    }
+    else if (!fallback && userDefinedSubscription &&
+             userDefinedSubscription->IsGeneric())
+    {
+      fallback = subscription;
+    }
+  }
+
+  return fallback.release();
+}
+
+bool FilterStorage::AddSubscription(Subscription* subscription)
+{
+  assert(subscription, u"Attempt to add a null subscription"_str);
+
+  if (!subscription || subscription->GetListed())
+    return false;
+
+  mSubscriptions.emplace_back(subscription);
+  subscription->SetListed(true);
+
+  FilterNotifier::SubscriptionChange(
+    FilterNotifier::Topic::SUBSCRIPTION_ADDED,
+    subscription
+  );
+  return true;
+}
+
+bool FilterStorage::RemoveSubscription(Subscription* subscription)
+{
+  assert(subscription, u"Attempt to remove a null subscription"_str);
+
+  if (!subscription || !subscription->GetListed())
+    return false;
+
+  for (auto it = mSubscriptions.begin(); it != mSubscriptions.end(); ++it)
+  {
+    if (*it == subscription)
+    {
+      mSubscriptions.erase(it);
+      break;
+    }
+  }
+  subscription->SetListed(false);
+
+  FilterNotifier::SubscriptionChange(
+    FilterNotifier::Topic::SUBSCRIPTION_REMOVED,
+    subscription
+  );
+  return true;
+}
+
+bool FilterStorage::MoveSubscription(Subscription* subscription,
+                                     const Subscription* insertBefore)
+{
+  assert(subscription, u"Attempt to move a null subscription"_str);
+
+  int oldPos = IndexOfSubscription(subscription);
+  assert(oldPos >= 0, u"Attempt to move a subscription that is not in the list"_str);
+  if (oldPos == -1)
+    return false;
+
+  int newPos = -1;
+  if (insertBefore)
+    newPos = IndexOfSubscription(insertBefore);
+  if (newPos == -1)
+    newPos = mSubscriptions.size();
+
+  if (newPos > oldPos)
+    newPos--;
+
+  if (newPos == oldPos)
+    return false;
+
+  mSubscriptions.erase(mSubscriptions.begin() + oldPos);
+  mSubscriptions.emplace(mSubscriptions.begin() + newPos, subscription);
+
+  FilterNotifier::SubscriptionChange(
+    FilterNotifier::Topic::SUBSCRIPTION_MOVED,
+    subscription
+  );
+  return true;
+}