chrome/browser/extensions/api/declarative/rules_registry_with_cache.cc

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/extensions/api/declarative/rules_registry_with_cache.h"

#include "base/bind.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "base/values.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/extensions/extension_info_map.h"
#include "chrome/browser/extensions/extension_prefs.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/extensions/extension_system.h"
#include "chrome/browser/extensions/extension_util.h"
#include "chrome/browser/extensions/state_store.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/common/extensions/extension.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/notification_details.h"
#include "content/public/browser/notification_source.h"

namespace {

const char kSuccess[] = "";
const char kDuplicateRuleId[] = "Duplicate rule ID: %s";

scoped_ptr<base::Value> RulesToValue(
    const std::vector<linked_ptr<extensions::RulesRegistry::Rule> >& rules) {
  scoped_ptr<base::ListValue> list(new base::ListValue());
  for (size_t i = 0; i < rules.size(); ++i)
    list->Append(rules[i]->ToValue().release());
  return list.PassAs<base::Value>();
}

std::vector<linked_ptr<extensions::RulesRegistry::Rule> > RulesFromValue(
    const base::Value* value) {
  std::vector<linked_ptr<extensions::RulesRegistry::Rule> > rules;

  const base::ListValue* list = NULL;
  if (!value || !value->GetAsList(&list))
    return rules;

  rules.reserve(list->GetSize());
  for (size_t i = 0; i < list->GetSize(); ++i) {
    const base::DictionaryValue* dict = NULL;
    if (!list->GetDictionary(i, &dict))
      continue;
    linked_ptr<extensions::RulesRegistry::Rule> rule(
        new extensions::RulesRegistry::Rule());
    if (extensions::RulesRegistry::Rule::Populate(*dict, rule.get()))
      rules.push_back(rule);
  }

  return rules;
}

// Returns the key to use for storing declarative rules in the state store.
std::string GetDeclarativeRuleStorageKey(const std::string& event_name,
                                         bool incognito) {
  if (incognito)
    return "declarative_rules.incognito." + event_name;
  else
    return "declarative_rules." + event_name;
}

}  // namespace


namespace extensions {

// RulesRegistryWithCache

RulesRegistryWithCache::RulesRegistryWithCache(
    Profile* profile,
    const std::string& event_name,
    content::BrowserThread::ID owner_thread,
    bool log_storage_init_delay,
    scoped_ptr<RuleStorageOnUI>* ui_part)
    : RulesRegistry(owner_thread, event_name),
      weak_ptr_factory_(profile ? this : NULL),
      storage_on_ui_(
          (profile ? (new RuleStorageOnUI(profile,
                                          event_name,
                                          owner_thread,
                                          weak_ptr_factory_.GetWeakPtr(),
                                          log_storage_init_delay))->GetWeakPtr()
                   : base::WeakPtr<RuleStorageOnUI>())),
      process_changed_rules_requested_(profile ? NOT_SCHEDULED_FOR_PROCESSING
                                               : NEVER_PROCESS) {
  if (!profile) {
    CHECK(!ui_part);
    return;
  }

  ui_part->reset(storage_on_ui_.get());

  storage_on_ui_->Init();
}

std::string RulesRegistryWithCache::AddRules(
    const std::string& extension_id,
    const std::vector<linked_ptr<Rule> >& rules) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  // Verify that all rule IDs are new.
  for (std::vector<linked_ptr<Rule> >::const_iterator i =
      rules.begin(); i != rules.end(); ++i) {
    const RuleId& rule_id = *((*i)->id);
    RulesDictionaryKey key(extension_id, rule_id);
    if (rules_.find(key) != rules_.end())
      return base::StringPrintf(kDuplicateRuleId, rule_id.c_str());
  }

  std::string error = AddRulesImpl(extension_id, rules);

  if (!error.empty())
    return error;

  // Commit all rules into |rules_| on success.
  for (std::vector<linked_ptr<Rule> >::const_iterator i =
      rules.begin(); i != rules.end(); ++i) {
    const RuleId& rule_id = *((*i)->id);
    RulesDictionaryKey key(extension_id, rule_id);
    rules_[key] = *i;
  }

  MaybeProcessChangedRules(extension_id);
  return kSuccess;
}

std::string RulesRegistryWithCache::RemoveRules(
    const std::string& extension_id,
    const std::vector<std::string>& rule_identifiers) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  std::string error = RemoveRulesImpl(extension_id, rule_identifiers);

  if (!error.empty())
    return error;

  // Commit removal of rules from |rules_| on success.
  for (std::vector<std::string>::const_iterator i =
      rule_identifiers.begin(); i != rule_identifiers.end(); ++i) {
    RulesDictionaryKey lookup_key(extension_id, *i);
    rules_.erase(lookup_key);
  }

  MaybeProcessChangedRules(extension_id);
  return kSuccess;
}

std::string RulesRegistryWithCache::RemoveAllRules(
    const std::string& extension_id) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  std::string error = RemoveAllRulesImpl(extension_id);

  if (!error.empty())
    return error;

  // Commit removal of rules from |rules_| on success.
  for (RulesDictionary::const_iterator i = rules_.begin();
      i != rules_.end();) {
    const RulesDictionaryKey& key = i->first;
    ++i;
    if (key.first == extension_id)
      rules_.erase(key);
  }

  MaybeProcessChangedRules(extension_id);
  return kSuccess;
}

std::string RulesRegistryWithCache::GetRules(
    const std::string& extension_id,
    const std::vector<std::string>& rule_identifiers,
    std::vector<linked_ptr<RulesRegistry::Rule> >* out) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  for (std::vector<std::string>::const_iterator i = rule_identifiers.begin();
      i != rule_identifiers.end(); ++i) {
    RulesDictionaryKey lookup_key(extension_id, *i);
    RulesDictionary::iterator entry = rules_.find(lookup_key);
    if (entry != rules_.end())
      out->push_back(entry->second);
  }
  return kSuccess;
}

std::string RulesRegistryWithCache::GetAllRules(
    const std::string& extension_id,
    std::vector<linked_ptr<RulesRegistry::Rule> >* out) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  for (RulesDictionary::const_iterator i = rules_.begin();
      i != rules_.end(); ++i) {
    const RulesDictionaryKey& key = i->first;
    if (key.first == extension_id)
      out->push_back(i->second);
  }
  return kSuccess;
}

void RulesRegistryWithCache::OnExtensionUnloaded(
    const std::string& extension_id) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));
  std::string error = RemoveAllRules(extension_id);
  if (!error.empty())
    LOG(ERROR) << error;
}

RulesRegistryWithCache::~RulesRegistryWithCache() {
}

void RulesRegistryWithCache::MarkReady(base::Time storage_init_time) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  if (!storage_init_time.is_null()) {
    UMA_HISTOGRAM_TIMES("Extensions.DeclarativeRulesStorageInitialization",
                        base::Time::Now() - storage_init_time);
  }

  ready_.Signal();
}

void RulesRegistryWithCache::DeserializeAndAddRules(
    const std::string& extension_id,
    scoped_ptr<base::Value> rules) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  AddRules(extension_id, RulesFromValue(rules.get()));
}

void RulesRegistryWithCache::ProcessChangedRules(
    const std::string& extension_id) {
  DCHECK(content::BrowserThread::CurrentlyOn(owner_thread()));

  process_changed_rules_requested_ = NOT_SCHEDULED_FOR_PROCESSING;

  std::vector<linked_ptr<RulesRegistry::Rule> > new_rules;
  std::string error = GetAllRules(extension_id, &new_rules);
  DCHECK_EQ(std::string(), error);
  content::BrowserThread::PostTask(
      content::BrowserThread::UI,
      FROM_HERE,
      base::Bind(&RuleStorageOnUI::WriteToStorage,
                 storage_on_ui_,
                 extension_id,
                 base::Passed(RulesToValue(new_rules))));
}

void RulesRegistryWithCache::MaybeProcessChangedRules(
    const std::string& extension_id) {
  if (process_changed_rules_requested_ != NOT_SCHEDULED_FOR_PROCESSING)
    return;

  process_changed_rules_requested_ = SCHEDULED_FOR_PROCESSING;
  ready_.Post(FROM_HERE,
              base::Bind(&RulesRegistryWithCache::ProcessChangedRules,
                         weak_ptr_factory_.GetWeakPtr(),
                         extension_id));
}

// RulesRegistryWithCache::RuleStorageOnUI

const char RulesRegistryWithCache::RuleStorageOnUI::kRulesStoredKey[] =
    "has_declarative_rules";

RulesRegistryWithCache::RuleStorageOnUI::RuleStorageOnUI(
    Profile* profile,
    const std::string& event_name,
    content::BrowserThread::ID rules_registry_thread,
    base::WeakPtr<RulesRegistryWithCache> registry,
    bool log_storage_init_delay)
    : profile_(profile),
      storage_key_(GetDeclarativeRuleStorageKey(event_name,
                                                profile->IsOffTheRecord())),
      rules_stored_key_(GetRulesStoredKey(event_name,
                                          profile->IsOffTheRecord())),
      log_storage_init_delay_(log_storage_init_delay),
      registry_(registry),
      rules_registry_thread_(rules_registry_thread),
      notified_registry_(false),
      weak_ptr_factory_(this) {}

RulesRegistryWithCache::RuleStorageOnUI::~RuleStorageOnUI() {}

// Returns the key to use for storing whether the rules have been stored.
// static
std::string RulesRegistryWithCache::RuleStorageOnUI::GetRulesStoredKey(
    const std::string& event_name,
    bool incognito) {
  std::string result(kRulesStoredKey);
  result += incognito ? ".incognito." : ".";
  return result + event_name;
}

// This is called from the constructor of RulesRegistryWithCache, so it is
// important that it both
// 1. calls no (in particular virtual) methods of the rules registry, and
// 2. does not create scoped_refptr holding the registry. (A short-lived
// scoped_refptr might delete the rules registry before it is constructed.)
void RulesRegistryWithCache::RuleStorageOnUI::Init() {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));

  ExtensionSystem& system = *ExtensionSystem::Get(profile_);
  extensions::StateStore* store = system.rules_store();
  if (store)
    store->RegisterKey(storage_key_);

  registrar_.Add(this,
                 chrome::NOTIFICATION_EXTENSION_LOADED,
                 content::Source<Profile>(profile_->GetOriginalProfile()));

  if (profile_->IsOffTheRecord())
    log_storage_init_delay_ = false;

  system.ready().Post(
      FROM_HERE,
      base::Bind(&RuleStorageOnUI::ReadRulesForInstalledExtensions,
                 GetWeakPtr()));
  system.ready().Post(FROM_HERE,
                      base::Bind(&RuleStorageOnUI::CheckIfReady, GetWeakPtr()));
}

void RulesRegistryWithCache::RuleStorageOnUI::WriteToStorage(
    const std::string& extension_id,
    scoped_ptr<base::Value> value) {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  if (!profile_)
    return;

  const base::ListValue* rules = NULL;
  CHECK(value->GetAsList(&rules));
  bool rules_stored_previously = GetDeclarativeRulesStored(extension_id);
  bool store_rules = !rules->empty();
  SetDeclarativeRulesStored(extension_id, store_rules);
  if (!rules_stored_previously && !store_rules)
    return;

  StateStore* store = ExtensionSystem::Get(profile_)->rules_store();
  if (store)
    store->SetExtensionValue(extension_id, storage_key_, value.Pass());
}

void RulesRegistryWithCache::RuleStorageOnUI::Observe(
    int type,
    const content::NotificationSource& source,
    const content::NotificationDetails& details) {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  DCHECK(type == chrome::NOTIFICATION_EXTENSION_LOADED);

  const extensions::Extension* extension =
      content::Details<const extensions::Extension>(details).ptr();
  // TODO(mpcomplete): This API check should generalize to any use of
  // declarative rules, not just webRequest.
  if (extension->HasAPIPermission(APIPermission::kDeclarativeContent) ||
      extension->HasAPIPermission(APIPermission::kDeclarativeWebRequest)) {
    ExtensionInfoMap* extension_info_map =
        ExtensionSystem::Get(profile_)->info_map();
    if (profile_->IsOffTheRecord() &&
        !extension_info_map->IsIncognitoEnabled(extension->id())) {
      // Ignore this extension.
    } else {
      ReadFromStorage(extension->id());
    }
  }
}

void RulesRegistryWithCache::RuleStorageOnUI::CheckIfReady() {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  if (notified_registry_ || !waiting_for_extensions_.empty())
    return;

  content::BrowserThread::PostTask(
      rules_registry_thread_,
      FROM_HERE,
      base::Bind(
          &RulesRegistryWithCache::MarkReady, registry_, storage_init_time_));
  notified_registry_ = true;
}

void
RulesRegistryWithCache::RuleStorageOnUI::ReadRulesForInstalledExtensions() {
  ExtensionSystem& system = *ExtensionSystem::Get(profile_);
  ExtensionService* extension_service = system.extension_service();
  DCHECK(extension_service);
  // In an OTR profile, we start on top of a normal profile already, so the
  // extension service should be ready.
  DCHECK(!profile_->IsOffTheRecord() || extension_service->is_ready());
  if (extension_service->is_ready()) {
    const ExtensionSet* extensions = extension_service->extensions();
    for (ExtensionSet::const_iterator i = extensions->begin();
         i != extensions->end();
         ++i) {
      bool needs_apis_storing_rules =
          (*i)->HasAPIPermission(APIPermission::kDeclarativeContent) ||
          (*i)->HasAPIPermission(APIPermission::kDeclarativeWebRequest);
      bool respects_off_the_record =
          !(profile_->IsOffTheRecord()) ||
          extension_util::IsIncognitoEnabled((*i)->id(), extension_service);
      if (needs_apis_storing_rules && respects_off_the_record)
        ReadFromStorage((*i)->id());
    }
  }
}

void RulesRegistryWithCache::RuleStorageOnUI::ReadFromStorage(
    const std::string& extension_id) {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  if (!profile_)
    return;

  if (log_storage_init_delay_ && storage_init_time_.is_null())
    storage_init_time_ = base::Time::Now();

  if (!GetDeclarativeRulesStored(extension_id)) {
    ExtensionSystem::Get(profile_)->ready().Post(
        FROM_HERE, base::Bind(&RuleStorageOnUI::CheckIfReady, GetWeakPtr()));
    return;
  }

  extensions::StateStore* store = ExtensionSystem::Get(profile_)->rules_store();
  if (!store)
    return;
  waiting_for_extensions_.insert(extension_id);
  store->GetExtensionValue(extension_id,
                           storage_key_,
                           base::Bind(&RuleStorageOnUI::ReadFromStorageCallback,
                                      weak_ptr_factory_.GetWeakPtr(),
                                      extension_id));
}

void RulesRegistryWithCache::RuleStorageOnUI::ReadFromStorageCallback(
    const std::string& extension_id,
    scoped_ptr<base::Value> value) {
  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  content::BrowserThread::PostTask(
      rules_registry_thread_,
      FROM_HERE,
      base::Bind(&RulesRegistryWithCache::DeserializeAndAddRules,
                 registry_,
                 extension_id,
                 base::Passed(&value)));

  waiting_for_extensions_.erase(extension_id);

  if (waiting_for_extensions_.empty())
    ExtensionSystem::Get(profile_)->ready().Post(
        FROM_HERE, base::Bind(&RuleStorageOnUI::CheckIfReady, GetWeakPtr()));
}

bool RulesRegistryWithCache::RuleStorageOnUI::GetDeclarativeRulesStored(
    const std::string& extension_id) const {
  CHECK(profile_);
  const ExtensionScopedPrefs* extension_prefs = ExtensionPrefs::Get(profile_);

  bool rules_stored = true;
  if (extension_prefs->ReadPrefAsBoolean(
          extension_id, rules_stored_key_, &rules_stored))
    return rules_stored;

  // Safe default -- if we don't know that the rules are not stored, we force
  // a read by returning true.
  return true;
}

void RulesRegistryWithCache::RuleStorageOnUI::SetDeclarativeRulesStored(
    const std::string& extension_id,
    bool rules_stored) {
  CHECK(profile_);
  ExtensionScopedPrefs* extension_prefs = ExtensionPrefs::Get(profile_);
  extension_prefs->UpdateExtensionPref(
      extension_id,
      rules_stored_key_,
      new base::FundamentalValue(rules_stored));
}

}  // namespace extensions