Refactor net::NetLog to provide implementation of observer pattern, not just the interface.

net/base/net_log.cc

Index: net/base/net_log.cc
diff --git a/net/base/net_log.cc b/net/base/net_log.cc
index 4d9e55a15e412c9552d964c9b094840b56e36cd1..aff3e62e04b1a5b5a43244057e2297447b6e1a67 100644
--- a/net/base/net_log.cc
+++ b/net/base/net_log.cc
@@ -187,6 +187,15 @@ NetLog* NetLog::ThreadSafeObserver::net_log() const {
   return net_log_;
 }
 
+NetLog::NetLog(LogLevel base_log_level)
+    : last_id_(0),
+      base_log_level_(base_log_level),
+      effective_log_level_(LOG_NONE) {

[mmenke, 2013/05/30 18:18:59]

effective_log_level_ isn't being set correctly here, though if you follow my
suggestion on a set_base_log_level function, that issue will go away anyways.

[kouhei (in TOK), 2013/05/31 06:30:03]

Done.

+}
+
+NetLog::~NetLog() {
+}
+
 void NetLog::AddGlobalEntry(EventType type) {
   AddEntry(type,
            Source(net::NetLog::SOURCE_NONE, NextID()),
@@ -203,6 +212,62 @@ void NetLog::AddGlobalEntry(
            &parameters_callback);
 }
 
+uint32 NetLog::NextID() {
+  return base::subtle::NoBarrier_AtomicIncrement(&last_id_, 1);
+}
+
+NetLog::LogLevel NetLog::GetLogLevel() const {
+  base::subtle::Atomic32 log_level =
+      base::subtle::NoBarrier_Load(&effective_log_level_);
+  return static_cast<net::NetLog::LogLevel>(log_level);
+}
+
+void NetLog::AddThreadSafeObserver(
+    net::NetLog::ThreadSafeObserver* observer,
+    LogLevel log_level) {
+  base::AutoLock lock(lock_);
+
+  observers_.AddObserver(observer);
+  OnAddObserver(observer, log_level);
+  UpdateLogLevel();
+}
+
+void NetLog::SetObserverLogLevel(
+    net::NetLog::ThreadSafeObserver* observer,
+    LogLevel log_level) {
+  base::AutoLock lock(lock_);
+
+  DCHECK(observers_.HasObserver(observer));
+  OnSetObserverLogLevel(observer, log_level);
+  UpdateLogLevel();
+}
+
+void NetLog::RemoveThreadSafeObserver(
+    net::NetLog::ThreadSafeObserver* observer) {
+  base::AutoLock lock(lock_);
+
+  DCHECK(observers_.HasObserver(observer));
+  observers_.RemoveObserver(observer);
+  OnRemoveObserver(observer);
+  UpdateLogLevel();
+}
+
+void NetLog::UpdateLogLevel() {
+  lock_.AssertAcquired();
+
+  // Look through all the observers and find the finest granularity
+  // log level (higher values of the enum imply *lower* log levels).
+  LogLevel new_effective_log_level = base_log_level_;
+  ObserverListBase<ThreadSafeObserver>::Iterator it(observers_);
+  ThreadSafeObserver* observer;
+  while ((observer = it.GetNext()) != NULL) {
+    new_effective_log_level =
+        std::min(new_effective_log_level, observer->log_level());
+  }
+  base::subtle::NoBarrier_Store(&effective_log_level_,
+                                new_effective_log_level);
+}
+
 // static
 std::string NetLog::TickCountToString(const base::TimeTicks& time) {
   int64 delta_time = (time - base::TimeTicks()).InMilliseconds();
@@ -330,6 +395,13 @@ void NetLog::AddEntry(EventType type,
   OnAddEntry(entry);
 }
 
+void NetLog::OnAddEntry(const Entry& entry) {

[mmenke, 2013/05/30 18:18:59]

Can just get rid of this function and inline its body.

[kouhei (in TOK), 2013/05/31 06:30:03]

Done.

+  base::AutoLock lock(lock_);
+
+  // Notify all of the log observers.
+  FOR_EACH_OBSERVER(ThreadSafeObserver, observers_, OnAddEntry(entry));
+}
+
 void BoundNetLog::AddEntry(NetLog::EventType type,
                            NetLog::EventPhase phase) const {
   if (!net_log_)