components/invalidation/impl/invalidator_registrar_with_memory.cc

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/invalidation/impl/invalidator_registrar_with_memory.h"

#include <cstddef>
#include <iterator>
#include <string>
#include <utility>
#include <vector>

#include "base/containers/flat_set.h"
#include "base/feature_list.h"
#include "base/logging.h"
#include "base/observer_list.h"
#include "base/stl_util.h"
#include "base/values.h"
#include "components/invalidation/public/topic_invalidation_map.h"
#include "components/prefs/pref_registry_simple.h"
#include "components/prefs/scoped_user_pref_update.h"
#include "third_party/abseil-cpp/absl/types/optional.h"

namespace invalidation {

namespace {

constexpr char kTopicsToHandlerDeprecated[] = "invalidation.topics_to_handler";

constexpr char kTopicsToHandler[] = "invalidation.per_sender_topics_to_handler";

constexpr char kHandler[] = "handler";
constexpr char kIsPublic[] = "is_public";

// Added in M76.
void MigratePrefs(PrefService* prefs, const std::string& sender_id) {
  const auto& old_prefs = prefs->GetDict(kTopicsToHandlerDeprecated);
  if (old_prefs.empty()) {
    return;
  }
  {
    ScopedDictPrefUpdate update(prefs, kTopicsToHandler);
    update->Set(sender_id, old_prefs.Clone());
  }
  prefs->ClearPref(kTopicsToHandlerDeprecated);
}

absl::optional<TopicData> FindAnyDuplicatedTopic(
    const std::set<TopicData>& lhs,
    const std::set<TopicData>& rhs) {
  auto intersection =
      base::STLSetIntersection<std::vector<TopicData>>(lhs, rhs);
  if (!intersection.empty()) {
    return intersection[0];
  }
  return absl::nullopt;
}

}  // namespace

BASE_FEATURE(kRestoreInterestingTopicsFeature,
             "InvalidatorRestoreInterestingTopics",
             base::FEATURE_ENABLED_BY_DEFAULT);

// static
void InvalidatorRegistrarWithMemory::RegisterProfilePrefs(
    PrefRegistrySimple* registry) {
  registry->RegisterDictionaryPref(kTopicsToHandlerDeprecated);
  registry->RegisterDictionaryPref(kTopicsToHandler);
}

// static
void InvalidatorRegistrarWithMemory::RegisterPrefs(
    PrefRegistrySimple* registry) {
  // For local state, we want to register exactly the same prefs as for profile
  // prefs; see comment in the header.
  RegisterProfilePrefs(registry);
}

// static
void InvalidatorRegistrarWithMemory::ClearTopicsWithObsoleteOwnerNames(
    PrefService* prefs) {
  // Go through all senders and their topics. Find topics with deprecated owner
  // name and mark them for cleanup.
  ScopedDictPrefUpdate update(prefs, kTopicsToHandler);
  for (auto sender_to_topics : update.Get()) {
    const std::string& sender_id = sender_to_topics.first;

    base::flat_set<std::string> topics_to_cleanup;
    for (auto topic_to_handler : sender_to_topics.second.DictItems()) {
      const std::string& topic_name = topic_to_handler.first;
      std::string handler_name;

      if (topic_to_handler.second.is_dict()) {
        const std::string* handler_name_ptr =
            topic_to_handler.second.FindStringKey(kHandler);
        if (handler_name_ptr)
          handler_name = *handler_name_ptr;
      } else if (topic_to_handler.second.is_string()) {
        handler_name = topic_to_handler.second.GetString();
      }

      // "Cloud" owner name used to be non unique and shared between all
      // instances of |CloudPolicyInvalidator|.
      // "RemoteCommand" owner name used to be non unique and shared between all
      // instances of |RemoteCommandsInvalidator|.
      if (handler_name == "Cloud" || handler_name == "RemoteCommand") {
        topics_to_cleanup.insert(topic_name);
      }
    }
    base::Value::Dict* topics_data = update->FindDict(sender_id);
    for (const std::string& topic_name : topics_to_cleanup) {
      topics_data->Remove(topic_name);
    }
  }
}

InvalidatorRegistrarWithMemory::InvalidatorRegistrarWithMemory(
    PrefService* prefs,
    const std::string& sender_id,
    bool migrate_old_prefs)
    : state_(DEFAULT_INVALIDATION_ERROR), prefs_(prefs), sender_id_(sender_id) {
  DCHECK(!sender_id_.empty());
  if (migrate_old_prefs) {
    MigratePrefs(prefs_, sender_id_);
  }
  const base::Value::Dict* pref_data =
      prefs_->GetDict(kTopicsToHandler).FindDict(sender_id_);
  if (!pref_data) {
    ScopedDictPrefUpdate update(prefs_, kTopicsToHandler);
    update->Set(sender_id_, base::Value::Dict());
    return;
  }
  // Restore |handler_name_to_subscribed_topics_map_| from prefs.
  if (!base::FeatureList::IsEnabled(kRestoreInterestingTopicsFeature))
    return;
  for (auto it : *pref_data) {
    const std::string& topic_name = it.first;
    if (it.second.is_dict()) {
      const std::string* handler = it.second.FindStringKey(kHandler);
      const absl::optional<bool> is_public = it.second.FindBoolKey(kIsPublic);
      if (!handler || !is_public) {
        continue;
      }
      handler_name_to_subscribed_topics_map_[*handler].insert(
          TopicData(topic_name, *is_public));
    } else if (it.second.is_string()) {
      handler_name_to_subscribed_topics_map_[it.second.GetString()].insert(
          TopicData(topic_name, false));
    }
  }
}

InvalidatorRegistrarWithMemory::~InvalidatorRegistrarWithMemory() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  CHECK(registered_handler_to_topics_map_.empty());
}

void InvalidatorRegistrarWithMemory::RegisterHandler(
    InvalidationHandler* handler) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  CHECK(handler);
  CHECK(!handlers_.HasObserver(handler));
  handlers_.AddObserver(handler);
}

void InvalidatorRegistrarWithMemory::UnregisterHandler(
    InvalidationHandler* handler) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  CHECK(handler);
  CHECK(handlers_.HasObserver(handler));
  handlers_.RemoveObserver(handler);
  registered_handler_to_topics_map_.erase(handler);
  // Note: Do *not* remove the entry from
  // |handler_name_to_subscribed_topics_map_| - we haven't actually unsubscribed
  // from any of the topics on the server, so GetAllSubscribedTopics() should
  // still return the topics.
}

bool InvalidatorRegistrarWithMemory::UpdateRegisteredTopics(
    InvalidationHandler* handler,
    const std::set<TopicData>& topics) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  CHECK(handler);
  CHECK(handlers_.HasObserver(handler));

  if (HasDuplicateTopicRegistration(handler, topics)) {
    return false;
  }

  std::set<TopicData> old_topics = registered_handler_to_topics_map_[handler];
  if (topics.empty()) {
    registered_handler_to_topics_map_.erase(handler);
  } else {
    registered_handler_to_topics_map_[handler] = topics;
  }

  // This does *not* remove subscribed topics which are not registered. This
  // behaviour is used by some handlers to keep topic subscriptions after
  // browser startup even if they are not included in the first call of this
  // method. It's useful to prevent unsubscribing from and subscribing to the
  // topics on each browser startup.
  //
  // TODO(crbug.com/1051893): make the unsubscription behaviour consistent
  // regardless of browser restart in between.
  auto topics_to_unregister =
      base::STLSetDifference<std::set<TopicData>>(old_topics, topics);
  RemoveSubscribedTopics(handler, topics_to_unregister);

  ScopedDictPrefUpdate update(prefs_, kTopicsToHandler);
  base::Value::Dict* pref_data = update->FindDict(sender_id_);
  for (const auto& topic : topics) {
    handler_name_to_subscribed_topics_map_[handler->GetOwnerName()].insert(
        topic);
    base::Value::Dict handler_pref;
    handler_pref.Set(kHandler, handler->GetOwnerName());
    handler_pref.Set(kIsPublic, topic.is_public);
    pref_data->Set(topic.name, std::move(handler_pref));
  }
  return true;
}

void InvalidatorRegistrarWithMemory::RemoveUnregisteredTopics(
    InvalidationHandler* handler) {
  auto topics_to_unregister =
      handler_name_to_subscribed_topics_map_[handler->GetOwnerName()];
  if (registered_handler_to_topics_map_.find(handler) !=
      registered_handler_to_topics_map_.end()) {
    topics_to_unregister = base::STLSetDifference<std::set<TopicData>>(
        topics_to_unregister, registered_handler_to_topics_map_[handler]);
  }

  RemoveSubscribedTopics(handler, std::move(topics_to_unregister));
}

Topics InvalidatorRegistrarWithMemory::GetRegisteredTopics(
    InvalidationHandler* handler) const {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  auto lookup = registered_handler_to_topics_map_.find(handler);
  return lookup != registered_handler_to_topics_map_.end()
             ? ConvertTopicSetToLegacyTopicMap(lookup->second)
             : Topics();
}

Topics InvalidatorRegistrarWithMemory::GetAllSubscribedTopics() const {
  std::set<TopicData> subscribed_topics;
  for (const auto& handler_to_topic : handler_name_to_subscribed_topics_map_) {
    subscribed_topics.insert(handler_to_topic.second.begin(),
                             handler_to_topic.second.end());
  }
  return ConvertTopicSetToLegacyTopicMap(subscribed_topics);
}

void InvalidatorRegistrarWithMemory::DispatchInvalidationsToHandlers(
    const TopicInvalidationMap& invalidation_map) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  // If we have no handlers, there's nothing to do.
  if (handlers_.empty()) {
    return;
  }

  for (const auto& handler_and_topics : registered_handler_to_topics_map_) {
    TopicInvalidationMap topics_to_emit = invalidation_map.GetSubsetWithTopics(
        ConvertTopicSetToLegacyTopicMap(handler_and_topics.second));
    if (topics_to_emit.Empty()) {
      continue;
    }
    handler_and_topics.first->OnIncomingInvalidation(topics_to_emit);
  }
}

void InvalidatorRegistrarWithMemory::UpdateInvalidatorState(
    InvalidatorState state) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  DVLOG(1) << "New invalidator state: " << InvalidatorStateToString(state_)
           << " -> " << InvalidatorStateToString(state);
  state_ = state;
  for (auto& observer : handlers_)
    observer.OnInvalidatorStateChange(state);
}

InvalidatorState InvalidatorRegistrarWithMemory::GetInvalidatorState() const {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  return state_;
}

void InvalidatorRegistrarWithMemory::UpdateInvalidatorInstanceId(
    const std::string& instance_id) {
  for (auto& observer : handlers_)
    observer.OnInvalidatorClientIdChange(instance_id);
}

std::map<std::string, Topics>
InvalidatorRegistrarWithMemory::GetHandlerNameToTopicsMap() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  std::map<std::string, Topics> names_to_topics;
  for (const auto& handler_and_topics : registered_handler_to_topics_map_) {
    names_to_topics[handler_and_topics.first->GetOwnerName()] =
        ConvertTopicSetToLegacyTopicMap(handler_and_topics.second);
  }
  return names_to_topics;
}

void InvalidatorRegistrarWithMemory::RequestDetailedStatus(
    base::RepeatingCallback<void(base::Value::Dict)> callback) const {
  callback.Run(CollectDebugData());
}

bool InvalidatorRegistrarWithMemory::HasDuplicateTopicRegistration(
    InvalidationHandler* handler,
    const std::set<TopicData>& topics) const {
  for (const auto& handler_and_topics : registered_handler_to_topics_map_) {
    if (handler_and_topics.first == handler) {
      continue;
    }

    if (absl::optional<TopicData> duplicate =
            FindAnyDuplicatedTopic(topics, handler_and_topics.second)) {
      DVLOG(1) << "Duplicate registration: trying to register "
               << duplicate->name << " for " << handler
               << " when it's already registered for "
               << handler_and_topics.first;
      return true;
    }
  }
  return false;
}

base::Value::Dict InvalidatorRegistrarWithMemory::CollectDebugData() const {
  base::Value::Dict return_value;
  return_value.SetByDottedPath(
      "InvalidatorRegistrarWithMemory.Handlers",
      static_cast<int>(handler_name_to_subscribed_topics_map_.size()));
  for (const auto& handler_to_topics : handler_name_to_subscribed_topics_map_) {
    const std::string& handler = handler_to_topics.first;
    for (const auto& topic : handler_to_topics.second) {
      return_value.SetByDottedPath(
          "InvalidatorRegistrarWithMemory." + topic.name, handler);
    }
  }
  return return_value;
}

void InvalidatorRegistrarWithMemory::RemoveSubscribedTopics(
    const InvalidationHandler* handler,
    const std::set<TopicData>& topics_to_unsubscribe) {
  ScopedDictPrefUpdate update(prefs_, kTopicsToHandler);
  base::Value::Dict* pref_data = update->FindDict(sender_id_);
  DCHECK(pref_data);
  for (const TopicData& topic : topics_to_unsubscribe) {
    pref_data->Remove(topic.name);
    handler_name_to_subscribed_topics_map_[handler->GetOwnerName()].erase(
        topic);
  }
}

}  // namespace invalidation