Certificate Transparency: Start tracking logs' state

net/cert/sth_observer.cc

Index: net/cert/sth_observer.cc
diff --git a/net/cert/sth_observer.cc b/net/cert/sth_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..abe462fe6ad7e0b8c1f610074fd5a024ea149822
--- /dev/null
+++ b/net/cert/sth_observer.cc
@@ -0,0 +1,54 @@
+// Copyright 2016 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 "net/cert/sth_observer.h"
+
+#include "base/logging.h"
+
+namespace net {
+
+namespace ct {
+
+STHReporterRegistrar::STHReporterRegistrar() : reporter_(nullptr) {}
+
+STHReporterRegistrar::~STHReporterRegistrar() {
+  DCHECK(reporter_ == nullptr || pending_observers_.empty());
+}
+
+void STHReporterRegistrar::SignUpForRegistration(STHObserver* observer) {
+  pending_observers_.insert(observer);
+  if (reporter_) {
+    reporter_->RegisterObserver(observer);
+  }
+}
+
+void STHReporterRegistrar::AssignReporter(STHReporter* reporter) {
+  DCHECK(reporter_ == nullptr);
+  reporter_ = reporter;
+
+  for (auto observer : pending_observers_) {
+    reporter_->RegisterObserver(observer);
+  }
+}
+
+void STHReporterRegistrar::UnregisterAll() {
+  if (reporter_) {
+    for (auto observer : pending_observers_) {
+      reporter_->UnregisterObserver(observer);
+    }
+  }
+
+  pending_observers_.clear();
+}
+
+void STHReporterRegistrar::UnregisterObserver(STHObserver* observer) {
+  DCHECK(pending_observers_.find(observer) != pending_observers_.end());
+
+  reporter_->UnregisterObserver(observer);
+  pending_observers_.erase(observer);
+}
+
+}  // namespace ct
+
+}  // namespace net