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 #include <string>
   8 #include <vector>
   9
  10 #include "base/bind.h"
  11 #include "base/logging.h"
  12 #include "dbus/bus.h"
  13 #include "dbus/message.h"
  14 #include "dbus/object_path.h"
  15 #include "dbus/object_proxy.h"
  16 #include "third_party/libxml/chromium/libxml_utils.h"
  17
  18 namespace {
  19
  20 // D-Bus specification constants.
  21 const char kIntrospectableInterface[] = "org.freedesktop.DBus.Introspectable";
  22 const char kIntrospect[] = "Introspect";
  23
  24 // String constants used for parsing D-Bus Introspection XML data.
  25 const char kInterfaceNode[] = "interface";
  26 const char kInterfaceNameAttribute[] = "name";
  27
  28 }  // namespace
  29
  30 namespace chromeos {
  31
  32 // The IntrospectableClient implementation used in production.
  33 class IntrospectableClientImpl : public IntrospectableClient {
  34  public:
  35   IntrospectableClientImpl() : bus_(NULL), weak_ptr_factory_(this) {}
  36
  37   virtual ~IntrospectableClientImpl() {
  38   }
  39
  40   // IntrospectableClient override.
  41   virtual void Introspect(const std::string& service_name,
  42                           const dbus::ObjectPath& object_path,
  43                           const IntrospectCallback& callback) OVERRIDE {
  44     dbus::MethodCall method_call(kIntrospectableInterface, kIntrospect);
  45
  46     dbus::ObjectProxy* object_proxy = bus_->GetObjectProxy(service_name,
  47                                                            object_path);
  48
  49     object_proxy->CallMethod(
  50         &method_call,
  51         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
  52         base::Bind(&IntrospectableClientImpl::OnIntrospect,
  53                    weak_ptr_factory_.GetWeakPtr(),
  54                    service_name, object_path, callback));
  55   }
  56
  57  protected:
  58   virtual void Init(dbus::Bus* bus) OVERRIDE { bus_ = bus; }
  59
  60  private:
  61   // Called by dbus:: when a response for Introspect() is recieved.
  62   void OnIntrospect(const std::string& service_name,
  63                     const dbus::ObjectPath& object_path,
  64                     const IntrospectCallback& callback,
  65                     dbus::Response* response) {
  66     // Parse response.
  67     bool success = false;
  68     std::string xml_data;
  69     if (response != NULL) {
  70       dbus::MessageReader reader(response);
  71       if (!reader.PopString(&xml_data)) {
  72         LOG(WARNING) << "Introspect response has incorrect paramters: "
  73                      << response->ToString();
  74       } else {
  75         success = true;
  76       }
  77     }
  78
  79     // Notify client.
  80     callback.Run(service_name, object_path, xml_data, success);
  81   }
  82
  83   dbus::Bus* bus_;
  84
  85   // Weak pointer factory for generating 'this' pointers that might live longer
  86   // than we do.
  87   // Note: This should remain the last member so it'll be destroyed and
  88   // invalidate its weak pointers before any other members are destroyed.
  89   base::WeakPtrFactory<IntrospectableClientImpl> weak_ptr_factory_;
  90
  91   DISALLOW_COPY_AND_ASSIGN(IntrospectableClientImpl);
  92 };
  93
  94 // The IntrospectableClient implementation used on Linux desktop, which does
  95 // nothing.
  96 class IntrospectableClientStubImpl : public IntrospectableClient {
  97  public:
  98   // IntrospectableClient override.
  99   virtual void Init(dbus::Bus* bus) OVERRIDE {}
 100   virtual void Introspect(const std::string& service_name,
 101                           const dbus::ObjectPath& object_path,
 102                           const IntrospectCallback& callback) OVERRIDE {
 103     VLOG(1) << "Introspect: " << service_name << " " << object_path.value();
 104     callback.Run(service_name, object_path, "", false);
 105   }
 106 };
 107
 108 IntrospectableClient::IntrospectableClient() {
 109 }
 110
 111 IntrospectableClient::~IntrospectableClient() {
 112 }
 113
 114 // static
 115 std::vector<std::string>
 116 IntrospectableClient::GetInterfacesFromIntrospectResult(
 117     const std::string& xml_data) {
 118   std::vector<std::string> interfaces;
 119
 120   XmlReader reader;
 121   if (!reader.Load(xml_data))
 122     return interfaces;
 123
 124   do {
 125     // Skip to the next open tag, exit when done.
 126     while (!reader.SkipToElement()) {
 127       if (!reader.Read()) {
 128         return interfaces;
 129       }
 130     }
 131
 132     // Only look at interface nodes.
 133     if (reader.NodeName() != kInterfaceNode)
 134       continue;
 135
 136     // Skip if missing the interface name.
 137     std::string interface_name;
 138     if (!reader.NodeAttribute(kInterfaceNameAttribute, &interface_name))
 139       continue;
 140
 141     interfaces.push_back(interface_name);
 142   } while (reader.Read());
 143
 144   return interfaces;
 145 }
 146
 147 // static
 148 IntrospectableClient* IntrospectableClient::Create(
 149     DBusClientImplementationType type) {
 150   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
 151     return new IntrospectableClientImpl();
 152   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
 153   return new IntrospectableClientStubImpl();
 154 }
 155
 156 }  // namespace chromeos