mojo/public/cpp/application/lib/service_connector.h

   1 // Copyright 2014 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 #ifndef MOJO_PUBLIC_CPP_APPLICATION_LIB_SERVICE_CONNECTOR_H_
   6 #define MOJO_PUBLIC_CPP_APPLICATION_LIB_SERVICE_CONNECTOR_H_
   7
   8 #include <assert.h>
   9
  10 #include <vector>
  11
  12 #include "mojo/public/interfaces/service_provider/service_provider.mojom.h"
  13
  14 namespace mojo {
  15 namespace internal {
  16
  17 template <class ServiceImpl, typename Context>
  18 class ServiceConnector;
  19
  20 // Specialization of ServiceConnection.
  21 // ServiceImpl: Subclass of InterfaceImpl<...>.
  22 // Context: Type of shared context.
  23 template <class ServiceImpl, typename Context>
  24 class ServiceConnection : public ServiceImpl {
  25  public:
  26   ServiceConnection() : ServiceImpl() {}
  27   ServiceConnection(Context* context) : ServiceImpl(context) {}
  28
  29   virtual void OnConnectionError() MOJO_OVERRIDE {
  30     service_connector_->RemoveConnection(static_cast<ServiceImpl*>(this));
  31     ServiceImpl::OnConnectionError();
  32   }
  33
  34 private:
  35   friend class ServiceConnector<ServiceImpl, Context>;
  36
  37   // Called shortly after this class is instantiated.
  38   void set_service_connector(
  39       ServiceConnector<ServiceImpl, Context>* connector) {
  40     service_connector_ = connector;
  41   }
  42
  43   ServiceConnector<ServiceImpl, Context>* service_connector_;
  44 };
  45
  46 template <typename ServiceImpl, typename Context>
  47 struct ServiceConstructor {
  48   static ServiceConnection<ServiceImpl, Context>* New(Context* context) {
  49     return new ServiceConnection<ServiceImpl, Context>(context);
  50   }
  51 };
  52
  53 template <typename ServiceImpl>
  54 struct ServiceConstructor<ServiceImpl, void> {
  55  public:
  56   static ServiceConnection<ServiceImpl, void>* New(void* context) {
  57     return new ServiceConnection<ServiceImpl, void>();
  58   }
  59 };
  60
  61 class ServiceConnectorBase {
  62  public:
  63   class Owner : public ServiceProvider {
  64    public:
  65     Owner();
  66     Owner(ScopedMessagePipeHandle service_provider_handle);
  67     virtual ~Owner();
  68     virtual void AddServiceConnector(
  69         internal::ServiceConnectorBase* service_connector) = 0;
  70     virtual void RemoveServiceConnector(
  71         internal::ServiceConnectorBase* service_connector) = 0;
  72
  73    protected:
  74     void set_service_connector_owner(ServiceConnectorBase* service_connector,
  75                                      Owner* owner) {
  76       service_connector->owner_ = owner;
  77     }
  78     ServiceProviderPtr service_provider_;
  79   };
  80   ServiceConnectorBase(const std::string& name) : name_(name), owner_(NULL) {}
  81   virtual ~ServiceConnectorBase();
  82   virtual void ConnectToService(const std::string& url,
  83                                 const std::string& name,
  84                                 ScopedMessagePipeHandle client_handle) = 0;
  85   std::string name() const { return name_; }
  86
  87  protected:
  88   std::string name_;
  89   Owner* owner_;
  90 };
  91
  92 template <class ServiceImpl, typename Context=void>
  93 class ServiceConnector : public internal::ServiceConnectorBase {
  94  public:
  95   ServiceConnector(const std::string& name, Context* context = NULL)
  96       : ServiceConnectorBase(name), context_(context) {}
  97
  98   virtual ~ServiceConnector() {
  99     ConnectionList doomed;
 100     doomed.swap(connections_);
 101     for (typename ConnectionList::iterator it = doomed.begin();
 102          it != doomed.end(); ++it) {
 103       delete *it;
 104     }
 105     assert(connections_.empty());  // No one should have added more!
 106   }
 107
 108   virtual void ConnectToService(const std::string& url,
 109                                 const std::string& name,
 110                                 ScopedMessagePipeHandle handle) MOJO_OVERRIDE {
 111     ServiceConnection<ServiceImpl, Context>* impl =
 112         ServiceConstructor<ServiceImpl, Context>::New(context_);
 113     impl->set_service_connector(this);
 114     BindToPipe(impl, handle.Pass());
 115
 116     connections_.push_back(impl);
 117   }
 118
 119   void RemoveConnection(ServiceImpl* impl) {
 120     // Called from ~ServiceImpl, in response to a connection error.
 121     for (typename ConnectionList::iterator it = connections_.begin();
 122          it != connections_.end(); ++it) {
 123       if (*it == impl) {
 124         delete impl;
 125         connections_.erase(it);
 126         if (connections_.empty())
 127           owner_->RemoveServiceConnector(this);
 128         return;
 129       }
 130     }
 131   }
 132
 133   Context* context() const { return context_; }
 134
 135  private:
 136   typedef std::vector<ServiceImpl*> ConnectionList;
 137   ConnectionList connections_;
 138   Context* context_;
 139 };
 140
 141 }  // namespace internal
 142 }  // namespace mojo
 143
 144 #endif  // MOJO_PUBLIC_CPP_APPLICATION_LIB_SERVICE_CONNECTOR_H_