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   ~IntrospectableClientImpl() override {}
  38
  39   // IntrospectableClient override.
  40   void Introspect(const std::string& service_name,
  41                   const dbus::ObjectPath& object_path,
  42                   const IntrospectCallback& callback) override {
  43     dbus::MethodCall method_call(kIntrospectableInterface, kIntrospect);
  44
  45     dbus::ObjectProxy* object_proxy = bus_->GetObjectProxy(service_name,
  46                                                            object_path);
  47
  48     object_proxy->CallMethod(
  49         &method_call,
  50         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
  51         base::Bind(&IntrospectableClientImpl::OnIntrospect,
  52                    weak_ptr_factory_.GetWeakPtr(),
  53                    service_name, object_path, callback));
  54   }
  55
  56  protected:
  57   void Init(dbus::Bus* bus) override { bus_ = bus; }
  58
  59  private:
  60   // Called by dbus:: when a response for Introspect() is recieved.
  61   void OnIntrospect(const std::string& service_name,
  62                     const dbus::ObjectPath& object_path,
  63                     const IntrospectCallback& callback,
  64                     dbus::Response* response) {
  65     // Parse response.
  66     bool success = false;
  67     std::string xml_data;
  68     if (response != NULL) {
  69       dbus::MessageReader reader(response);
  70       if (!reader.PopString(&xml_data)) {
  71         LOG(WARNING) << "Introspect response has incorrect paramters: "
  72                      << response->ToString();
  73       } else {
  74         success = true;
  75       }
  76     }
  77
  78     // Notify client.
  79     callback.Run(service_name, object_path, xml_data, success);
  80   }
  81
  82   dbus::Bus* bus_;
  83
  84   // Weak pointer factory for generating 'this' pointers that might live longer
  85   // than we do.
  86   // Note: This should remain the last member so it'll be destroyed and
  87   // invalidate its weak pointers before any other members are destroyed.
  88   base::WeakPtrFactory<IntrospectableClientImpl> weak_ptr_factory_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(IntrospectableClientImpl);
  91 };
  92
  93 IntrospectableClient::IntrospectableClient() {
  94 }
  95
  96 IntrospectableClient::~IntrospectableClient() {
  97 }
  98
  99 // static
 100 std::vector<std::string>
 101 IntrospectableClient::GetInterfacesFromIntrospectResult(
 102     const std::string& xml_data) {
 103   std::vector<std::string> interfaces;
 104
 105   XmlReader reader;
 106   if (!reader.Load(xml_data))
 107     return interfaces;
 108
 109   do {
 110     // Skip to the next open tag, exit when done.
 111     while (!reader.SkipToElement()) {
 112       if (!reader.Read()) {
 113         return interfaces;
 114       }
 115     }
 116
 117     // Only look at interface nodes.
 118     if (reader.NodeName() != kInterfaceNode)
 119       continue;
 120
 121     // Skip if missing the interface name.
 122     std::string interface_name;
 123     if (!reader.NodeAttribute(kInterfaceNameAttribute, &interface_name))
 124       continue;
 125
 126     interfaces.push_back(interface_name);
 127   } while (reader.Read());
 128
 129   return interfaces;
 130 }
 131
 132 // static
 133 IntrospectableClient* IntrospectableClient::Create() {
 134   return new IntrospectableClientImpl();
 135 }
 136
 137 }  // namespace chromeos