Cashew: track cellular service state.

src/service_manager.cc

+// Copyright (c) 2010 The Chromium OS 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 "src/service_manager.h"
+
+#include <glog/logging.h>
+
+#include "src/service.h"
+
+namespace cashew {
+
+// Flimflam D-Bus indentifiers
+static const char* kFlimflamManagerName = "org.chromium.flimflam";
+static const char* kFlimflamManagerPath = "/";
+
+// Flimflam property names
+static const char* kServicesProperty = "Services";
+
+// Flimflam service types
+static const char* kTypeCellular = "cellular";
+
+ServiceManager::ServiceManager(DBus::Connection& connection)  // NOLINT
+    : DBus::ObjectProxy(connection, kFlimflamManagerPath,
+                        kFlimflamManagerName),
+      connection_(connection) {
+  // init our state with a GetProperties() call to Flimflam
+  // we'll update this state by monitoring PropertyChanged signals
+  GetFlimflamServices();
+}
+
+ServiceManager::~ServiceManager() {
+  DeleteServices(&services_);
+}
+
+const Service* ServiceManager::GetService(const std::string& service_path)
+    const {
+  ServiceMap::const_iterator it = services_.find(service_path);
+  if (it == services_.end()) {
+    return NULL;
+  }
+  DCHECK(it->second != NULL);
+  return static_cast<const Service *>(it->second);
+}
+
+// Flimflam Manager D-Bus Proxy methods
+
+void ServiceManager::PropertyChanged(const std::string& property_name,
+                                     const DBus::Variant& new_value) {
+  DLOG(INFO) << "PropertyChanged: property_name = " << property_name;
+
+  // we only care about Services changes
+  if (property_name.compare(kServicesProperty)) {
+      return;
+  }
+
+  // interpret new_value as a vector of service paths
+  ServicePathList paths;
+  DBus::MessageIter reader = new_value.reader();
+  reader >> paths;
+
+  OnServicesUpdate(paths);
+}
+
+void ServiceManager::StateChanged(const std::string& new_state) {
+  DLOG(INFO) << "StateChanged: new_state = " << new_state;
+  // TODO(vlaviano): switch on state and call private onFlimflamOffline(),
+  // onFlimflamOnline() hooks.  If we care.
+}
+
+// Private methods
+
+void ServiceManager::DeleteServices(ServiceMap *service_map) {
+  DCHECK(service_map != NULL);
+  while (!service_map->empty()) {
+    const std::string& path =
+        static_cast<std::string>(service_map->begin()->first);
+    DLOG(INFO) << "DeleteServices: deleting service: " << path;
+    Service *service = static_cast<Service *>(service_map->begin()->second);
+    delete service;
+    service_map->erase(service_map->begin());
+  }
+}
+
+void ServiceManager::GetFlimflamServices() {
+  DLOG(INFO) << "GetFlimflamServices";
+  PropertyMap properties;
+  // dbus-c++ throws exceptions
+  // invoke the "Existing Non-conformant Code" clause of the style guide and
+  // isolate the rest of the system from this
+  try {
+    // TODO(vlaviano): make this call asynchronous
+    properties = GetProperties();
+  } catch (DBus::Error& error) {  // NOLINT
+    LOG(WARNING) << "GetFlimflamServices: GetProperties() -> Exception: "
+        << error.name() << ": " << error.message();
+    // TODO(vlaviano): schedule another attempt later
+    return;
+  } catch (...) {  // NOLINT
+    LOG(WARNING) << "GetFlimflamServices: GetProperties() -> Exception";
+    // TODO(vlaviano): schedule another attempt later
+    return;
+  }
+
+  // grab Services property from result
+  PropertyMap::const_iterator it = properties.find(kServicesProperty);
+  if (it == properties.end()) {
+    DLOG(WARNING) << "GetFlimflamServices: no Services property";
+    return;
+  }
+  DBus::Variant value = static_cast<DBus::Variant>(it->second);
+
+  // interpret value as vector of service paths
+  ServicePathList paths;
+  DBus::MessageIter reader = value.reader();
+  reader >> paths;
+
+  OnServicesUpdate(paths);
+}
+
+void ServiceManager::OnServicesUpdate(const ServicePathList& paths) {
+  // Remember old set of services. This is the baseline from which we will
+  // determine what has changed.
+  ServiceMap old_services = services_;
+  services_.clear();
+
+  // Flimflam service types are embedded in their path names, so we can use
+  // the pattern "/cellular_" to decide which paths are cellular services.
+  static const std::string cellular_pattern = std::string("/") + kTypeCellular
+      + "_";
+
+  // Walk paths in this update and see if they're new to us
+  DLOG(INFO) << "OnServicesUpdate: " << paths.size() << " service paths";
+  ServicePathList::const_iterator it;
+  for (it = paths.begin(); it != paths.end(); ++it) {
+    const DBus::Path& path = *it;
+
+    // We only care about cellular services
+    if (path.find(cellular_pattern) == std::string::npos) {
+      continue;
+    }
+
+    ServiceMap::iterator old_it = old_services.find(path);
+    if (old_it != old_services.end()) {
+      // service is old: move it from old_services to services_
+      Service *service = static_cast<Service *>(old_it->second);
+      DCHECK(service != NULL);
+      old_services.erase(old_it);
+      services_[path] = service;
+    } else {
+      // service is new: create a Service obj for it and add it to services_
+      OnNewService(path);
+    }
+  }
+
+  // services left in old_services failed to appear in the update: delete them
+  DeleteServices(&old_services);
+}
+
+void ServiceManager::OnNewService(const DBus::Path& path) {
+  DLOG(INFO) << "OnNewService: " << path;
+  DCHECK(GetService(path) == NULL);
+  Service *service = new(std::nothrow) Service(connection_, path);
+  if (service == NULL) {
+    LOG(ERROR) << "OnNewService: couldn't create service for " << path;
+    return;
+  }
+  services_[path] = service;
+}
+
+}  // namespace cashew