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 IntrospectableClient::IntrospectableClient() {
  95 }
  96
  97 IntrospectableClient::~IntrospectableClient() {
  98 }
  99
 100 // static
 101 std::vector<std::string>
 102 IntrospectableClient::GetInterfacesFromIntrospectResult(
 103     const std::string& xml_data) {
 104   std::vector<std::string> interfaces;
 105
 106   XmlReader reader;
 107   if (!reader.Load(xml_data))
 108     return interfaces;
 109
 110   do {
 111     // Skip to the next open tag, exit when done.
 112     while (!reader.SkipToElement()) {
 113       if (!reader.Read()) {
 114         return interfaces;
 115       }
 116     }
 117
 118     // Only look at interface nodes.
 119     if (reader.NodeName() != kInterfaceNode)
 120       continue;
 121
 122     // Skip if missing the interface name.
 123     std::string interface_name;
 124     if (!reader.NodeAttribute(kInterfaceNameAttribute, &interface_name))
 125       continue;
 126
 127     interfaces.push_back(interface_name);
 128   } while (reader.Read());
 129
 130   return interfaces;
 131 }
 132
 133 // static
 134 IntrospectableClient* IntrospectableClient::Create() {
 135   return new IntrospectableClientImpl();
 136 }
 137
 138 }  // namespace chromeos