m2mcallbackstorage.h

00001 /*
00002  * Copyright (c) 2017 ARM Limited. All rights reserved.
00003  * SPDX-License-Identifier: Apache-2.0
00004  * Licensed under the Apache License, Version 2.0 (the License); you may
00005  * not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  * http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00012  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef __M2M_CALLBACK_STORAGE_H__
00017 #define __M2M_CALLBACK_STORAGE_H__
00018 
00019 #include "mbed-client/m2mvector.h"
00020 
00021 class M2MBase;
00022 class M2MCallbackAssociation;
00023 class M2MCallbackStorage;
00024 
00025 typedef m2m::Vector<M2MCallbackAssociation> M2MCallbackAssociationList;
00026 
00027 // XXX: this should not be visible for client code
00028 class M2MCallbackAssociation
00029 {
00030 public:
00031 
00032     // Types of callbacks stored as "void*" in the _callback variable.
00033     // Note: the FPn<> -types are actually stored as pointers to object instances,
00034     // which needs to be handled externally when fetching and deleting the callbacks.
00035     enum M2MCallbackType {
00036         // typedef FP1<void, const char*> value_updated_callback;
00037         M2MBaseValueUpdatedCallback,
00038 
00039         // typedef void(*value_updated_callback2) (const char* object_name);
00040         M2MBaseValueUpdatedCallback2,
00041 
00042         // typedef FP1<void,void*> execute_callback;
00043         M2MResourceInstanceExecuteCallback,
00044 
00045         //typedef void(*execute_callback_2) (void *arguments);
00046         M2MResourceInstanceExecuteCallback2,
00047 
00048         // typedef FP1<void, M2MBlockMessage *> incoming_block_message_callback;
00049         M2MResourceInstanceIncomingBlockMessageCallback,
00050 
00051         // typedef FP3<void, const String &, uint8_t *&, uint32_t &> outgoing_block_message_callback;
00052         M2MResourceInstanceOutgoingBlockMessageCallback,
00053 
00054         // class M2MResourceCallback
00055         M2MResourceInstanceM2MResourceCallback,
00056 
00057         // typedef FP0<void> notification_sent_callback;
00058         M2MResourceInstanceNotificationSentCallback,
00059 
00060         // typedef void(*notification_sent_callback_2) (void);
00061         M2MResourceInstanceNotificationSentCallback2,
00062 
00063         // typedef FP2<void, const uint16_t, const M2MResourceBase::NotificationStatus> notification_status_callback;
00064         M2MResourceInstanceNotificationStatusCallback,
00065 
00066         // typedef void(*notification_status_callback_2) (const uint16_t msg_id, const M2MResourceBase::NotificationStatus status);
00067         M2MResourceInstanceNotificationStatusCallback2,
00068 
00069         // typedef void(*notification_delivery_status_cb) (const M2MBase& base,
00070         // const M2MBase::NotificationDeliveryStatus status, void *client_args);
00071         M2MBaseNotificationDeliveryStatusCallback,
00072 
00073         // typedef void(*value_set_callback) (const M2MResourceBase *resource,
00074         // uint8_t *value, const uint32_t value_length);
00075         M2MResourceBaseValueSetCallback,
00076 
00077         // typedef size_t(*read_resource_value_callback) (const M2MResourceBase& resource,
00078         // void *buffer, void *client_args);
00079         M2MResourceBaseValueReadCallback,
00080 
00081         // typedef bool(*write_resource_value_callback) (const M2MResourceBase& resource,
00082         // const uint8_t *buffer, const size_t buffer_size, void *client_args);
00083         M2MResourceBaseValueWriteCallback
00084     };
00085 
00086     /**
00087      * Dummy constructor which does not initialize any predictable value to members,
00088      * needed for array instantiation. Please use the parameterized constructor for real work.
00089      */
00090     M2MCallbackAssociation();
00091 
00092     M2MCallbackAssociation(const M2MBase *object, void *callback, M2MCallbackType type, void *client_args);
00093 
00094 public:
00095     /** Object, where the callback is associated to. This is used as key on searches, must not be null. */
00096     const M2MBase *_object;
00097 
00098     /**
00099      * Callback pointer, actual data type of the is dependent of _type.
00100      *
00101      * We could also use eg. a union with specific pointer types to avoid ugly casts, but that would
00102      * then require a type-specific get_callback_<type>() to avoid casts on caller side too - unless
00103      * the get_callback() would return this object and the caller would access the union._callback_<type>
00104      * variable according to the _type.
00105      */
00106     void *_callback;
00107 
00108     /** Type of the data _callback points to and needed for interpreting the data in it. */
00109     M2MCallbackType _type;
00110 
00111     void *_client_args;
00112 };
00113 
00114 
00115 class M2MCallbackStorage
00116 {
00117 public:
00118 
00119     ~M2MCallbackStorage();
00120 
00121     // get the shared instance of the storage.
00122     // TODO: tie this' instance to the nsdlinterface or similar class instead, as it would help
00123     // to manage the lifecycle of the object. This would also remove the need for these static methods.
00124     static M2MCallbackStorage *get_instance();
00125 
00126     // utility for deleting the singleton instance, used on unit test and on application exit
00127     static void delete_instance();
00128 
00129     static bool add_callback(const M2MBase &object,
00130                              void *callback,
00131                              M2MCallbackAssociation::M2MCallbackType type,
00132                              void *client_args = 0);
00133 
00134     // remove all callbacks attached for given object
00135     static void remove_callbacks(const M2MBase &object);
00136 
00137     // remove callback if one exists, return old value of it
00138     static void* remove_callback(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type);
00139 
00140     // XXX: needed for protecting the vector during iteration, but that would add a dependency on PAL here
00141     // void lock();
00142     // void release();
00143 
00144     // XXX: const_iterator would be nicer
00145     //int get_callback(const M2MBase &object, void &*callback, M2MCallbackType type);
00146 
00147     static bool does_callback_exist(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type);
00148 
00149     static void* get_callback(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type);
00150 
00151     static M2MCallbackAssociation* get_association_item(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type);
00152     // XXX: this is actually not needed unless the client has multiple callbacks per object and type.
00153     inline const M2MCallbackAssociationList& get_callbacks() const;
00154 
00155 private:
00156     bool does_callback_exist(const M2MBase &object, void *callback, M2MCallbackAssociation::M2MCallbackType type) const;
00157     void do_remove_callbacks(const M2MBase &object);
00158     void* do_remove_callback(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type);
00159     bool do_add_callback(const M2MBase &object, void *callback, M2MCallbackAssociation::M2MCallbackType type, void *client_args);
00160     void* do_get_callback(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type) const;
00161 
00162     M2MCallbackAssociation* do_get_association_item(const M2MBase &object, M2MCallbackAssociation::M2MCallbackType type) const;
00163 
00164 private:
00165 
00166     /**
00167      * Currently there is only one storage object, which is shared between all the interfaces and
00168      * M2M objects.
00169      */
00170     static M2MCallbackStorage *_static_instance;
00171 
00172     /**
00173      * Callback objects stored. There combination of <object>+<type> is used on searches and
00174      * the code does not fully support for adding multiple callbacks for <object>+<type> -pair.
00175      * But that should not be too hard if the feature was added to M2M object API too, it just
00176      * requires the M2M objects to iterate through the callbacks associated to it, not just call
00177      * the get_callback(<object>,<type>) and call the first one.
00178      */
00179     M2MCallbackAssociationList _callbacks;
00180 };
00181 
00182 inline const M2MCallbackAssociationList& M2MCallbackStorage::get_callbacks() const
00183 {
00184     return _callbacks;
00185 }
00186 
00187 #endif // !__M2M_CALLBACK_STORAGE_H__