Issue 5137 - [emscripten] Added basic filter storage implementation

compiled/subscription/Subscription.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
@@ skipping 21 matching lines @@
     : mID(id), mType(type), mDisabled(false)
 {
   annotate_address(this, "Subscription");
 }
 
 Subscription::~Subscription()
 {
   knownSubscriptions.erase(mID);
 }
 
-Filter* Subscription::FilterAt(unsigned index)
+Filter* Subscription::FilterAt(Subscription::Filters::size_type index)
 {
   if (index >= mFilters.size())
     return nullptr;
 
   FilterPtr result(mFilters[index]);
   return result.release();
 }
 
 int Subscription::IndexOfFilter(Filter* filter)
 {
-  for (unsigned i = 0; i < mFilters.size(); i++)
+  for (Filters::size_type i = 0; i < mFilters.size(); i++)
     if (mFilters[i] == filter)
       return i;
   return -1;
 }
 
 OwnedString Subscription::Serialize() const
 {
   OwnedString result(u"[Subscription]\nurl="_str);
   result.append(mID);
   result.append(u'\n');
@@ skipping 58 matching lines @@
 
   // This is a hack: we looked up the entry using id but create it using
   // subscription->mID. This works because both are equal at this point.
   // However, id refers to a temporary buffer which will go away.
   enter_context("Adding to known subscriptions");
   knownSubscription.assign(subscription->mID, subscription.get());
   exit_context();
 
   return subscription.release();
 }