Refactor the UpdateEngine and its actions in the component updater.

components/update_client/update_engine.cc

Index: components/update_client/update_engine.cc
diff --git a/components/update_client/update_engine.cc b/components/update_client/update_engine.cc
index b127befe91b3906c8b6277a1b9ad86ceb8886f34..afef9097097c21598b51bcd0e655cda99f66ee3e 100644
--- a/components/update_client/update_engine.cc
+++ b/components/update_client/update_engine.cc
@@ -4,19 +4,23 @@
 
 #include "components/update_client/update_engine.h"
 
+#include <utility>
+
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "base/threading/thread_task_runner_handle.h"
-#include "base/time/time.h"
 #include "components/prefs/pref_service.h"
-#include "components/update_client/action_update_check.h"
+#include "components/update_client/component.h"
 #include "components/update_client/configurator.h"
 #include "components/update_client/crx_update_item.h"
 #include "components/update_client/persisted_data.h"
 #include "components/update_client/update_checker.h"
 #include "components/update_client/update_client_errors.h"
+#include "components/update_client/utils.h"
 
 namespace update_client {
 
@@ -27,9 +31,7 @@ UpdateContext::UpdateContext(
     const UpdateClient::CrxDataCallback& crx_data_callback,
     const UpdateEngine::NotifyObserversCallback& notify_observers_callback,
     const UpdateEngine::Callback& callback,
-    UpdateChecker::Factory update_checker_factory,
-    CrxDownloader::Factory crx_downloader_factory,
-    PingManager* ping_manager)
+    CrxDownloader::Factory crx_downloader_factory)
     : config(config),
       is_foreground(is_foreground),
       enabled_component_updates(config->EnabledComponentUpdates()),
@@ -37,12 +39,12 @@ UpdateContext::UpdateContext(
       crx_data_callback(crx_data_callback),
       notify_observers_callback(notify_observers_callback),
       callback(callback),
-      main_task_runner(base::ThreadTaskRunnerHandle::Get()),
       blocking_task_runner(config->GetSequencedTaskRunner()),
-      update_checker_factory(update_checker_factory),
-      crx_downloader_factory(crx_downloader_factory),
-      ping_manager(ping_manager),
-      retry_after_sec(0) {}
+      crx_downloader_factory(crx_downloader_factory) {
+  for (const auto& id : ids)
+    components.insert(
+        std::make_pair(id, base::MakeUnique<Component>(*this, id)));
+}
 
 UpdateContext::~UpdateContext() {}
 
@@ -63,20 +65,6 @@ UpdateEngine::~UpdateEngine() {
   DCHECK(thread_checker_.CalledOnValidThread());
 }
 
-bool UpdateEngine::GetUpdateState(const std::string& id,
-                                  CrxUpdateItem* update_item) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  for (const auto* context : update_contexts_) {
-    const auto& update_items = context->update_items;
-    const auto it = update_items.find(id);
-    if (it != update_items.end()) {
-      *update_item = *it->second.get();
-      return true;
-    }
-  }
-  return false;
-}
-
 void UpdateEngine::Update(
     bool is_foreground,
     const std::vector<std::string>& ids,
@@ -90,29 +78,98 @@ void UpdateEngine::Update(
     return;
   }
 
-  std::unique_ptr<UpdateContext> update_context(new UpdateContext(
+  const auto result = update_contexts_.insert(base::MakeUnique<UpdateContext>(
       config_, is_foreground, ids, crx_data_callback,
-      notify_observers_callback_, callback, update_checker_factory_,
-      crx_downloader_factory_, ping_manager_));
+      notify_observers_callback_, callback, crx_downloader_factory_));
+
+  DCHECK(result.second);
 
-  std::unique_ptr<ActionUpdateCheck> update_check_action(new ActionUpdateCheck(
-      (*update_context->update_checker_factory)(config_, metadata_.get()),
-      config_->GetBrowserVersion(), config_->ExtraRequestParams()));
+  const auto& it = result.first;
+  const auto& update_context = *it;
+  DCHECK(update_context);
 
-  update_context->current_action = std::move(update_check_action);
-  update_contexts_.insert(update_context.get());
+  // Calls out to get the corresponding CrxComponent data for the CRXs in this
+  // update context.
+  DCHECK_EQ(ids.size(), update_context->ids.size());
+  DCHECK_EQ(update_context->ids.size(), update_context->components.size());
+  std::vector<CrxComponent> crx_components;
+  update_context->crx_data_callback.Run(update_context->ids, &crx_components);
+  DCHECK_EQ(update_context->ids.size(), crx_components.size());
 
-  update_context->current_action->Run(
-      update_context.get(),
-      base::Bind(&UpdateEngine::UpdateComplete, base::Unretained(this),
-                 update_context.get()));
+  for (size_t i = 0; i != update_context->ids.size(); ++i) {
+    const auto& id = update_context->ids[i];
+    const auto& crx_component = crx_components[i];
 
-  ignore_result(update_context.release());
+    DCHECK_EQ(id, GetCrxComponentID(crx_component));
+    DCHECK_EQ(1u, update_context->components.count(id));
+    DCHECK(update_context->components.at(id));
+
+    auto& component = *update_context->components.at(id);
+    component.set_on_demand(update_context->is_foreground);
+    component.set_crx_component(crx_component);
+    component.set_previous_version(crx_component.version);
+    component.set_previous_fp(crx_component.fingerprint);
+
+    // Handle |kNew| state. This will transition the components to |kChecking|.
+    component.Handle(base::Bind(&UpdateEngine::ComponentCheckingForUpdatesStart,
+                                base::Unretained(this), it,
+                                base::ConstRef(component)));
+  }
+}
+
+void UpdateEngine::ComponentCheckingForUpdatesStart(
+    const UpdateContextIterator& it,
+    const Component& component) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& update_context = *it;
+  DCHECK(update_context);
+
+  const auto id = component.id();
+  DCHECK_EQ(1u, update_context->components.count(id));
+  DCHECK(update_context->components.at(id));
+
+  // Handle |kChecking| state.
+  auto& mutable_component = *update_context->components.at(id);
+  mutable_component.Handle(base::Bind(
+      &UpdateEngine::ComponentCheckingForUpdatesComplete,
+      base::Unretained(this), it, base::ConstRef(mutable_component)));
+
+  ++update_context->num_components_ready_to_check;
+  if (update_context->num_components_ready_to_check <
+      update_context->ids.size()) {
+    return;
+  }
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(&UpdateEngine::DoUpdateCheck, base::Unretained(this), it));
 }
 
-void UpdateEngine::UpdateComplete(UpdateContext* update_context, Error error) {
+void UpdateEngine::DoUpdateCheck(const UpdateContextIterator& it) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(update_contexts_.find(update_context) != update_contexts_.end());
+
+  auto& update_context = *it;
+  DCHECK(update_context);
+
+  update_context->update_checker =
+      update_checker_factory_(config_, metadata_.get());
+
+  update_context->update_checker->CheckForUpdates(
+      update_context->ids, update_context->components,
+      config_->ExtraRequestParams(), update_context->enabled_component_updates,
+      base::Bind(&UpdateEngine::UpdateCheckDone, base::Unretained(this), it));
+}
+
+void UpdateEngine::UpdateCheckDone(const UpdateContextIterator& it,
+                                   int error,
+                                   int retry_after_sec) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& update_context = *it;
+  DCHECK(update_context);
+
+  update_context->retry_after_sec = retry_after_sec;
 
   const int throttle_sec(update_context->retry_after_sec);
   DCHECK_LE(throttle_sec, 24 * 60 * 60);
@@ -120,22 +177,161 @@ void UpdateEngine::UpdateComplete(UpdateContext* update_context, Error error) {
   // Only positive values for throttle_sec are effective. 0 means that no
   // throttling occurs and has the effect of resetting the member.
   // Negative values are not trusted and are ignored.
-  if (throttle_sec >= 0)
+  if (throttle_sec >= 0) {
     throttle_updates_until_ =
-        throttle_sec
-            ? base::TimeTicks::Now() +
-                  base::TimeDelta::FromSeconds(throttle_sec)
-            : base::TimeTicks();
+        throttle_sec ? base::TimeTicks::Now() +
+                           base::TimeDelta::FromSeconds(throttle_sec)
+                     : base::TimeTicks();
+  }
+
+  update_context->update_check_error = error;
 
-  auto callback = update_context->callback;
+  for (const auto& id : update_context->ids) {
+    DCHECK_EQ(1u, update_context->components.count(id));
+    DCHECK(update_context->components.at(id));
+
+    auto& component = *update_context->components.at(id);
+    component.UpdateCheckComplete();
+  }
+}
+
+void UpdateEngine::ComponentCheckingForUpdatesComplete(
+    const UpdateContextIterator& it,
+    const Component& component) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& update_context = *it;
+  DCHECK(update_context);
+
+  ++update_context->num_components_checked;
+  if (update_context->num_components_checked < update_context->ids.size()) {
+    return;
+  }
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(&UpdateEngine::UpdateCheckComplete,
+                            base::Unretained(this), it));
+}
+
+void UpdateEngine::UpdateCheckComplete(const UpdateContextIterator& it) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& update_context = *it;
+  DCHECK(update_context);
+
+  if (update_context->update_check_error) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(&UpdateEngine::UpdateComplete, base::Unretained(this), it,
+                   Error::UPDATE_CHECK_ERROR));
+    return;
+  }
 
-  update_contexts_.erase(update_context);
-  delete update_context;
+  for (const auto& id : update_context->ids)
+    update_context->component_queue.push(id);
 
-  callback.Run(error);
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(&UpdateEngine::HandleComponent, base::Unretained(this), it));
+}
+
+void UpdateEngine::HandleComponent(const UpdateContextIterator& it) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& update_context = *it;
+  DCHECK(update_context);
+
+  auto& queue = update_context->component_queue;
+
+  if (queue.empty()) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&UpdateEngine::UpdateComplete,
+                              base::Unretained(this), it, Error::NONE));
+    return;
+  }
+
+  const auto& id = queue.front();
+  DCHECK_EQ(1u, update_context->components.count(id));
+  const auto& component = update_context->components.at(id);
+  DCHECK(component);
+
+  auto& next_update_delay = (*it)->next_update_delay;
+  if (!next_update_delay.is_zero() && component->IsUpdateAvailable()) {
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&UpdateEngine::HandleComponent, base::Unretained(this), it),
+        next_update_delay);
+
+    next_update_delay = base::TimeDelta();
+
+    notify_observers_callback_.Run(
+        UpdateClient::Observer::Events::COMPONENT_WAIT, id);
+    return;
+  }
+
+  component->Handle(base::Bind(&UpdateEngine::HandleComponentComplete,
+                               base::Unretained(this), it));
+}
+
+void UpdateEngine::HandleComponentComplete(const UpdateContextIterator& it) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& update_context = *it;
+  DCHECK(update_context);
+
+  auto& queue = update_context->component_queue;
+  DCHECK(!queue.empty());
+
+  const auto& id = queue.front();
+  DCHECK_EQ(1u, update_context->components.count(id));
+  const auto& component = update_context->components.at(id);
+  DCHECK(component);
+
+  if (component->IsHandled()) {
+    (*it)->next_update_delay = component->GetUpdateDuration();
+
+    // Only ping when the server response included an update for this component.
+    if (component->CanPing()) {
+      ping_manager_->SendPing(*component);
+    }
+
+    queue.pop();
+  }
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(&UpdateEngine::HandleComponent, base::Unretained(this), it));
+}
+
+void UpdateEngine::UpdateComplete(const UpdateContextIterator& it,
+                                  Error error) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& update_context = *it;
+  DCHECK(update_context);
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(update_context->callback, error));
+
+  update_contexts_.erase(it);
+}
+
+bool UpdateEngine::GetUpdateState(const std::string& id,
+                                  CrxUpdateItem* update_item) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  for (const auto& context : update_contexts_) {
+    const auto it = context->components.find(id);
+    if (it != context->components.end()) {
+      *update_item = it->second->GetCrxUpdateItem();
+      return true;
+    }
+  }
+  return false;
 }
 
 bool UpdateEngine::IsThrottled(bool is_foreground) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
   if (is_foreground || throttle_updates_until_.is_null())
     return false;
 
@@ -147,4 +343,33 @@ bool UpdateEngine::IsThrottled(bool is_foreground) const {
          now < throttle_updates_until_;
 }
 
+void UpdateEngine::SendUninstallPing(const std::string& id,
+                                     const base::Version& version,
+                                     int reason,
+                                     const Callback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto result = update_contexts_.insert(base::MakeUnique<UpdateContext>(
+      config_, false, std::vector<std::string>{id},
+      UpdateClient::CrxDataCallback(), UpdateEngine::NotifyObserversCallback(),
+      callback, nullptr));
+
+  DCHECK(result.second);
+
+  const auto& it = result.first;
+  const auto& update_context = *it;
+  DCHECK(update_context);
+  DCHECK_EQ(1u, update_context->ids.size());
+  DCHECK_EQ(1u, update_context->components.count(id));
+  const auto& component = update_context->components.at(id);
+
+  component->Uninstall(version, reason);
+
+  update_context->component_queue.push(id);
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(&UpdateEngine::HandleComponent, base::Unretained(this), it));
+}
+
 }  // namespace update_client