chromeos/dbus/introspectable_client.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chromeos/dbus/introspectable_client.h"
   6
   7
   8 #include "base/bind.h"
   9 #include "base/logging.h"
  10 #include "dbus/bus.h"
  11 #include "dbus/message.h"
  12 #include "dbus/object_proxy.h"
  13 #include "third_party/libxml/chromium/libxml_utils.h"
  14
  15 namespace {
  16
  17 // D-Bus specification constants.
  18 const char kIntrospectableInterface[] = "org.freedesktop.DBus.Introspectable";
  19 const char kIntrospect[] = "Introspect";
  20
  21 // String constants used for parsing D-Bus Introspection XML data.
  22 const char kInterfaceNode[] = "interface";
  23 const char kInterfaceNameAttribute[] = "name";
  24
  25 }  // namespace
  26
  27 namespace chromeos {
  28
  29 // The IntrospectableClient implementation used in production.
  30 class IntrospectableClientImpl : public IntrospectableClient {
  31  public:
  32   IntrospectableClientImpl() : bus_(NULL), weak_ptr_factory_(this) {}
  33
  34   ~IntrospectableClientImpl() override {}
  35
  36   // IntrospectableClient override.
  37   void Introspect(const std::string& service_name,
  38                   const dbus::ObjectPath& object_path,
  39                   const IntrospectCallback& callback) override {
  40     dbus::MethodCall method_call(kIntrospectableInterface, kIntrospect);
  41
  42     dbus::ObjectProxy* object_proxy = bus_->GetObjectProxy(service_name,
  43                                                            object_path);
  44
  45     object_proxy->CallMethod(
  46         &method_call,
  47         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
  48         base::Bind(&IntrospectableClientImpl::OnIntrospect,
  49                    weak_ptr_factory_.GetWeakPtr(),
  50                    service_name, object_path, callback));
  51   }
  52
  53  protected:
  54   void Init(dbus::Bus* bus) override { bus_ = bus; }
  55
  56  private:
  57   // Called by dbus:: when a response for Introspect() is recieved.
  58   void OnIntrospect(const std::string& service_name,
  59                     const dbus::ObjectPath& object_path,
  60                     const IntrospectCallback& callback,
  61                     dbus::Response* response) {
  62     // Parse response.
  63     bool success = false;
  64     std::string xml_data;
  65     if (response != NULL) {
  66       dbus::MessageReader reader(response);
  67       if (!reader.PopString(&xml_data)) {
  68         LOG(WARNING) << "Introspect response has incorrect paramters: "
  69                      << response->ToString();
  70       } else {
  71         success = true;
  72       }
  73     }
  74
  75     // Notify client.
  76     callback.Run(service_name, object_path, xml_data, success);
  77   }
  78
  79   dbus::Bus* bus_;
  80
  81   // Weak pointer factory for generating 'this' pointers that might live longer
  82   // than we do.
  83   // Note: This should remain the last member so it'll be destroyed and
  84   // invalidate its weak pointers before any other members are destroyed.
  85   base::WeakPtrFactory<IntrospectableClientImpl> weak_ptr_factory_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(IntrospectableClientImpl);
  88 };
  89
  90 IntrospectableClient::IntrospectableClient() {
  91 }
  92
  93 IntrospectableClient::~IntrospectableClient() {
  94 }
  95
  96 // static
  97 std::vector<std::string>
  98 IntrospectableClient::GetInterfacesFromIntrospectResult(
  99     const std::string& xml_data) {
 100   std::vector<std::string> interfaces;
 101
 102   XmlReader reader;
 103   if (!reader.Load(xml_data))
 104     return interfaces;
 105
 106   do {
 107     // Skip to the next open tag, exit when done.
 108     while (!reader.SkipToElement()) {
 109       if (!reader.Read()) {
 110         return interfaces;
 111       }
 112     }
 113
 114     // Only look at interface nodes.
 115     if (reader.NodeName() != kInterfaceNode)
 116       continue;
 117
 118     // Skip if missing the interface name.
 119     std::string interface_name;
 120     if (!reader.NodeAttribute(kInterfaceNameAttribute, &interface_name))
 121       continue;
 122
 123     interfaces.push_back(interface_name);
 124   } while (reader.Read());
 125
 126   return interfaces;
 127 }
 128
 129 // static
 130 IntrospectableClient* IntrospectableClient::Create() {
 131   return new IntrospectableClientImpl();
 132 }
 133
 134 }  // namespace chromeos