Issue 4128, 5138 - Add Parser and Serializer implemented in C++

compiled/storage/Parser.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 "Parser.h"
+#include "../subscription/DownloadableSubscription.h"
+#include "../subscription/UserDefinedSubscription.h"
+#include "../filter/Filter.h"
+
+namespace
+{
+  bool IsSection(const String& value, const String& expectedSectionName)
+  {
+    auto valueLength = value.length();
+    // fast check whether it's a section and if its length is expected
+    if (!(valueLength == expectedSectionName.length() + 2 && value[0] == u'[' && value[valueLength - 1] == u']'))
+      return false;
+    OwnedString sectionName(DependentString(value, 1, valueLength - 2));
+    sectionName.toLower();
+    return sectionName == expectedSectionName;
+  }
+
+  bool IsSubscriptionSection(const String& value)
+  {
+    return IsSection(value, u"subscription"_str);
+  }
+
+  bool IsSubscriptionFiltersSection(const String& value)
+  {
+    return ::IsSection(value, u"subscription filters"_str);

[hub, 2018/03/09 14:32:16]

::IsSection() is inconsistent with above that doesn't use '::'

+  }
+
+  Subscription::KeyValue CreateKeyValue(const std::pair<DependentString, DependentString>& pair)
+  {
+    Subscription::KeyValue retValue;
+    retValue.first = TrimSpaces(pair.first);
+    retValue.second = TrimSpaces(pair.second);
+    return retValue;
+  }
+
+  void DecodeOpeningBracket(DependentString& value)
+  {
+    String::size_type skippedChars = 0;
+    for (String::size_type i = 1; i < value.length(); ++i)
+    {
+      if (value[i - 1] == u'\\' && value[i] == u'[')
+        ++skippedChars;
+      value[i - skippedChars] = value[i];
+    }
+    if (skippedChars > 0)
+      value.reset(value, 0, value.length() - skippedChars);
+  }
+}
+
+Parser::Parser()
+  : mCurrentState{State::Initial}
+{
+}
+
+void Parser::Process(const String& untrimmedLine)
+{
+  auto line = TrimSpaces(untrimmedLine);
+  // skip empty lines
+  if (line.length() == 0)
+    return;
+
+  if (IsSubscriptionSection(line))
+  {
+    Finalize();
+    mCurrentState = State::SubscriptionSection;
+    return;
+  }
+
+  switch (mCurrentState)
+  {
+  case State::Initial:
+    Initial_processLine(line);
+    break;
+  case State::SubscriptionSection:
+    SubscriptionSection_processLine(line);
+    break;
+  case State::SubscriptionFiltersSection:
+    SubscriptionFiltersSection_processLine(line);
+    break;
+  default:
+    ;
+  }
+}
+
+void Parser::Finalize()
+{
+  switch (mCurrentState)
+  {
+  case State::Initial:
+    // don't clear file properties because they are also the parser member
+    break;
+  case State::SubscriptionSection:
+    onSubscription(createSubscriptionFromProperties());
+    mSubscriptionProperties.clear();
+    break;
+  case State::SubscriptionFiltersSection:
+    onSubscription(std::move(mSubscription));
+    break;
+  default:
+    ;
+  }
+}
+
+Parser::Subscriptions::size_type Parser::GetSubscriptionCount() const
+{
+  return mSubscriptions.size();
+}
+
+Subscription* Parser::SubscriptionAt(Subscriptions::size_type index)
+{
+  if (index >= mSubscriptions.size())
+    return nullptr;
+  return SubscriptionPtr(mSubscriptions[index]).release();
+}
+
+SubscriptionPtr Parser::createSubscriptionFromProperties() const
+{
+  return Subscription::FromProperties(mSubscriptionProperties);
+}
+
+void Parser::Initial_processLine(const String& line)
+{
+  // skip # Adblock Plus preferences
+  if (line[0] == u'#')
+    return;
+
+  String::size_type assignSignPos = line.find(u'=');
+  if (assignSignPos != String::npos)
+  {
+    mFileProperties.emplace_back(CreateKeyValue(SplitString(line, assignSignPos)));
+    return;
+  }
+  onFail("Unexpected line value, it should be either a file property or the [Subscription] section");
+}
+
+void Parser::SubscriptionSection_processLine(const String& line)
+{
+  String::size_type assignSignPos = line.find(u'=');
+  if (assignSignPos != String::npos)
+  {
+    mSubscriptionProperties.emplace_back(CreateKeyValue(SplitString(line, assignSignPos)));
+    return;
+  }
+  if (IsSubscriptionFiltersSection(line))
+  {
+    mSubscription = createSubscriptionFromProperties();
+    mCurrentState = State::SubscriptionFiltersSection;
+    return;
+  }
+  onFail("Unexpected line value, it should be either a subscription property, the [Subscription filters] section or the [Subscription] section");
+}
+
+void Parser::SubscriptionFiltersSection_processLine(const String& line)
+{
+  OwnedString lineCopy{line};
+  DependentString lineForFilter{lineCopy};
+  DecodeOpeningBracket(lineForFilter);
+  mSubscription->AddFilter(*FilterPtr(Filter::FromText(lineForFilter)));
+  // any line is considered as a filter, there can be no error
+}
+
+void Parser::onSubscription(SubscriptionPtr subscription)
+{
+  mSubscriptions.emplace_back(std::move(subscription));
+}