Diff: ble/GattServer.h

Revision:

710:b2e1a2660ec2

Child:

721:8f92a1a943d6

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ble/GattServer.h	Fri Jun 19 15:53:28 2015 +0100
@@ -0,0 +1,316 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __GATT_SERVER_H__
+#define __GATT_SERVER_H__
+
+#include "Gap.h"
+#include "GattService.h"
+#include "GattAttribute.h"
+#include "GattServerEvents.h"
+#include "GattCallbackParamTypes.h"
+#include "CallChainOfFunctionPointersWithContext.h"
+
+class GattServer {
+public:
+    /* Event callback handlers. */
+    typedef void (*EventCallback_t)(GattAttribute::Handle_t attributeHandle);
+    typedef void (*ServerEventCallback_t)(void);                    /**< independent of any particular attribute */
+
+protected:
+    GattServer() :
+        serviceCount(0),
+        characteristicCount(0),
+        dataSentCallChain(),
+        dataWrittenCallChain(),
+        dataReadCallChain(),
+        updatesEnabledCallback(NULL),
+        updatesDisabledCallback(NULL),
+        confirmationReceivedCallback(NULL) {
+        /* empty */
+    }
+
+    /*
+     * The following functions are meant to be overridden in the platform-specific sub-class.
+     */
+public:
+
+    /**
+     * Add a service declaration to the local server ATT table. Also add the
+     * characteristics contained within.
+     */
+    virtual ble_error_t addService(GattService &) {
+        return BLE_ERROR_NOT_IMPLEMENTED; /* default implementation; override this API if this capability is supported. */
+    }
+
+    /**
+     * Read the value of a characteristic from the local GattServer
+     * @param[in]     attributeHandle
+     *                  Attribute handle for the value attribute of the characteristic.
+     * @param[out]    buffer
+     *                  A buffer to hold the value being read.
+     * @param[in/out] lengthP
+     *                  Length of the buffer being supplied. If the attribute
+     *                  value is longer than the size of the supplied buffer,
+     *                  this variable will hold upon return the total attribute value length
+     *                  (excluding offset). The application may use this
+     *                  information to allocate a suitable buffer size.
+     *
+     * @return BLE_ERROR_NONE if a value was read successfully into the buffer.
+     */
+    virtual ble_error_t read(GattAttribute::Handle_t attributeHandle, uint8_t buffer[], uint16_t *lengthP) {
+        return BLE_ERROR_NOT_IMPLEMENTED; /* default implementation; override this API if this capability is supported. */
+    }
+
+    /**
+     * Read the value of a characteristic from the local GattServer
+     * @param[in]     connectionHandle
+     *                  Connection Handle.
+     * @param[in]     attributeHandle
+     *                  Attribute handle for the value attribute of the characteristic.
+     * @param[out]    buffer
+     *                  A buffer to hold the value being read.
+     * @param[in/out] lengthP
+     *                  Length of the buffer being supplied. If the attribute
+     *                  value is longer than the size of the supplied buffer,
+     *                  this variable will hold upon return the total attribute value length
+     *                  (excluding offset). The application may use this
+     *                  information to allocate a suitable buffer size.
+     *
+     * @return BLE_ERROR_NONE if a value was read successfully into the buffer.
+     *
+     * @note This API is a version of above with an additional connection handle
+     *     parameter to allow fetches for connection-specific multivalued
+     *     attribtues (such as the CCCDs).
+     */
+    virtual ble_error_t read(Gap::Handle_t connectionHandle, GattAttribute::Handle_t attributeHandle, uint8_t *buffer, uint16_t *lengthP) {
+        return BLE_ERROR_NOT_IMPLEMENTED; /* default implementation; override this API if this capability is supported. */
+    }
+
+    /**
+     * Update the value of a characteristic on the local GattServer.
+     *
+     * @param[in] attributeHandle
+     *              Handle for the value attribute of the Characteristic.
+     * @param[in] value
+     *              A pointer to a buffer holding the new value
+     * @param[in] size
+     *              Size of the new value (in bytes).
+     * @param[in] localOnly
+     *              Should this update be kept on the local
+     *              GattServer regardless of the state of the
+     *              notify/indicate flag in the CCCD for this
+     *              Characteristic? If set to true, no notification
+     *              or indication is generated.
+     *
+     * @return BLE_ERROR_NONE if we have successfully set the value of the attribute.
+     */
+    virtual ble_error_t write(GattAttribute::Handle_t, const uint8_t *, uint16_t, bool localOnly = false) {
+        return BLE_ERROR_NOT_IMPLEMENTED; /* default implementation; override this API if this capability is supported. */
+    }
+
+    /**
+     * Update the value of a characteristic on the local GattServer. A version
+     * of the same as above with connection handle parameter to allow updates
+     * for connection-specific multivalued attribtues (such as the CCCDs).
+     *
+     * @param[in] connectionHandle
+     *              Connection Handle.
+     * @param[in] attributeHandle
+     *              Handle for the value attribute of the Characteristic.
+     * @param[in] value
+     *              A pointer to a buffer holding the new value
+     * @param[in] size
+     *              Size of the new value (in bytes).
+     * @param[in] localOnly
+     *              Should this update be kept on the local
+     *              GattServer regardless of the state of the
+     *              notify/indicate flag in the CCCD for this
+     *              Characteristic? If set to true, no notification
+     *              or indication is generated.
+     *
+     * @return BLE_ERROR_NONE if we have successfully set the value of the attribute.
+     */
+    virtual ble_error_t write(Gap::Handle_t connectionHandle, GattAttribute::Handle_t, const uint8_t *, uint16_t, bool localOnly = false) {
+        return BLE_ERROR_NOT_IMPLEMENTED; /* default implementation; override this API if this capability is supported. */
+    }
+
+    /**
+     * A virtual function to allow underlying stacks to indicate if they support
+     * onDataRead(). It should be overridden to return true as applicable.
+     */
+    virtual bool isOnDataReadAvailable() const {
+        return false; /* default implementation; override this API if this capability is supported. */
+    }
+
+    /*
+     * APIs with non-virtual implementations.
+     */
+public:
+    /**
+     * Add a callback for the GATT event DATA_SENT (which is triggered when
+     * updates are sent out by GATT in the form of notifications).
+     *
+     * @Note: it is possible to chain together multiple onDataSent callbacks
+     * (potentially from different modules of an application) to receive updates
+     * to characteristics.
+     *
+     * @Note: it is also possible to setup a callback into a member function of
+     * some object.
+     */
+    void onDataSent(void (*callback)(unsigned count)) {dataSentCallChain.add(callback);}
+    template <typename T>
+    void onDataSent(T *objPtr, void (T::*memberPtr)(unsigned count)) {
+        dataSentCallChain.add(objPtr, memberPtr);
+    }
+
+    /**
+     * Setup a callback for when an attribute has its value updated by or at the
+     * connected peer. For a peripheral, this callback triggered when the local
+     * GATT server has an attribute updated by a write command from the peer.
+     * For a Central, this callback is triggered when a response is received for
+     * a write request.
+     *
+     * @Note: it is possible to chain together multiple onDataWritten callbacks
+     * (potentially from different modules of an application) to receive updates
+     * to characteristics. Many services, such as DFU and UART add their own
+     * onDataWritten callbacks behind the scenes to trap interesting events.
+     *
+     * @Note: it is also possible to setup a callback into a member function of
+     * some object.
+     */
+    void onDataWritten(void (*callback)(const GattWriteCallbackParams *eventDataP)) {dataWrittenCallChain.add(callback);}
+    template <typename T>
+    void onDataWritten(T *objPtr, void (T::*memberPtr)(const GattWriteCallbackParams *context)) {
+        dataWrittenCallChain.add(objPtr, memberPtr);
+    }
+
+    /**
+     * Setup a callback to be invoked on the peripheral when an attribute is
+     * being read by a remote client.
+     *
+     * @Note: this functionality may not be available on all underlying stacks.
+     * You could use GattCharacteristic::setReadAuthorizationCallback() as an
+     * alternative.
+     *
+     * @Note: it is possible to chain together multiple onDataRead callbacks
+     * (potentially from different modules of an application) to receive updates
+     * to characteristics. Services may add their own onDataRead callbacks
+     * behind the scenes to trap interesting events.
+     *
+     * @Note: it is also possible to setup a callback into a member function of
+     * some object.
+     *
+     * @return BLE_ERROR_NOT_IMPLEMENTED if this functionality isn't available;
+     *         else BLE_ERROR_NONE.
+     */
+    ble_error_t onDataRead(void (*callback)(const GattReadCallbackParams *eventDataP)) {
+        if (!isOnDataReadAvailable()) {
+            return BLE_ERROR_NOT_IMPLEMENTED;
+        }
+
+        dataReadCallChain.add(callback);
+        return BLE_ERROR_NONE;
+    }
+    template <typename T>
+    ble_error_t onDataRead(T *objPtr, void (T::*memberPtr)(const GattReadCallbackParams *context)) {
+        if (!isOnDataReadAvailable()) {
+            return BLE_ERROR_NOT_IMPLEMENTED;
+        }
+
+        dataReadCallChain.add(objPtr, memberPtr);
+        return BLE_ERROR_NONE;
+    }
+
+    /**
+     * Setup a callback for when notifications/indications are enabled for a
+     * characteristic on the local GattServer.
+     */
+    void onUpdatesEnabled(EventCallback_t callback) {updatesEnabledCallback = callback;}
+
+    /**
+     * Setup a callback for when notifications/indications are disabled for a
+     * characteristic on the local GattServer.
+     */
+    void onUpdatesDisabled(EventCallback_t callback) {updatesDisabledCallback = callback;}
+
+    /**
+     * Setup a callback for when the GATT server receives a response for an
+     * indication event sent previously.
+     */
+    void onConfirmationReceived(EventCallback_t callback) {confirmationReceivedCallback = callback;}
+
+    /* Entry points for the underlying stack to report events back to the user. */
+protected:
+    void handleDataWrittenEvent(const GattWriteCallbackParams *params) {
+        if (dataWrittenCallChain.hasCallbacksAttached()) {
+            dataWrittenCallChain.call(params);
+        }
+    }
+
+    void handleDataReadEvent(const GattReadCallbackParams *params) {
+        if (dataReadCallChain.hasCallbacksAttached()) {
+            dataReadCallChain.call(params);
+        }
+    }
+
+    void handleEvent(GattServerEvents::gattEvent_e type, GattAttribute::Handle_t charHandle) {
+        switch (type) {
+            case GattServerEvents::GATT_EVENT_UPDATES_ENABLED:
+                if (updatesEnabledCallback) {
+                    updatesEnabledCallback(charHandle);
+                }
+                break;
+            case GattServerEvents::GATT_EVENT_UPDATES_DISABLED:
+                if (updatesDisabledCallback) {
+                    updatesDisabledCallback(charHandle);
+                }
+                break;
+            case GattServerEvents::GATT_EVENT_CONFIRMATION_RECEIVED:
+                if (confirmationReceivedCallback) {
+                    confirmationReceivedCallback(charHandle);
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    void handleDataSentEvent(unsigned count) {
+        if (dataSentCallChain.hasCallbacksAttached()) {
+            dataSentCallChain.call(count);
+        }
+    }
+
+protected:
+    uint8_t serviceCount;
+    uint8_t characteristicCount;
+
+private:
+    CallChainOfFunctionPointersWithContext<unsigned>                        dataSentCallChain;
+    CallChainOfFunctionPointersWithContext<const GattWriteCallbackParams *> dataWrittenCallChain;
+    CallChainOfFunctionPointersWithContext<const GattReadCallbackParams *>  dataReadCallChain;
+    EventCallback_t                                                         updatesEnabledCallback;
+    EventCallback_t                                                         updatesDisabledCallback;
+    EventCallback_t                                                         confirmationReceivedCallback;
+
+private:
+    /* disallow copy and assignment */
+    GattServer(const GattServer &);
+    GattServer& operator=(const GattServer &);
+};
+
+#endif // ifndef __GATT_SERVER_H__
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