Diff: microbit/microbit-dal/nRF51822/source/nRF5xCharacteristicDescriptorDiscoverer.cpp

Revision:

0:b9164b348919

diff -r 000000000000 -r b9164b348919 microbit/microbit-dal/nRF51822/source/nRF5xCharacteristicDescriptorDiscoverer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/microbit/microbit-dal/nRF51822/source/nRF5xCharacteristicDescriptorDiscoverer.cpp	Mon Oct 17 12:41:20 2016 +0000
@@ -0,0 +1,235 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2015 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.
+ */
+#include "nRF5xCharacteristicDescriptorDiscoverer.h"
+#include "ble_err.h"
+#include "ble/DiscoveredCharacteristicDescriptor.h"
+
+nRF5xCharacteristicDescriptorDiscoverer::nRF5xCharacteristicDescriptorDiscoverer() :
+    discoveryRunning() {
+    // nothing to do
+}
+
+nRF5xCharacteristicDescriptorDiscoverer::~nRF5xCharacteristicDescriptorDiscoverer() {
+    // nothing to do
+}
+
+ble_error_t nRF5xCharacteristicDescriptorDiscoverer::launch(
+    const DiscoveredCharacteristic& characteristic,
+    const CharacteristicDescriptorDiscovery::DiscoveryCallback_t& discoveryCallback,
+    const CharacteristicDescriptorDiscovery::TerminationCallback_t& terminationCallback
+) {
+    Gap::Handle_t connHandle = characteristic.getConnectionHandle();
+    // it is ok to deduce that the start handle for descriptors is after
+    // the characteristic declaration and the characteristic value declaration
+    // see BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part G] (3.3)
+    Gap::Handle_t descriptorStartHandle = characteristic.getDeclHandle() + 2;
+    Gap::Handle_t descriptorEndHandle = characteristic.getLastHandle();
+
+    // check if there is any descriptor to discover
+    if (descriptorEndHandle < descriptorStartHandle) {
+        CharacteristicDescriptorDiscovery::TerminationCallbackParams_t termParams = {
+            characteristic,
+            BLE_ERROR_NONE
+        };
+        terminationCallback.call(&termParams);
+        return BLE_ERROR_NONE;
+    }
+
+    // check if we can run this discovery
+    if (isConnectionInUse(connHandle)) {
+        return BLE_STACK_BUSY;
+    }
+
+    // get a new discovery slot, if none are available, just return
+    Discovery* discovery = getAvailableDiscoverySlot();
+    if(discovery == NULL) {
+        return BLE_STACK_BUSY;
+    }
+
+    // try to launch the discovery
+    ble_error_t err = gattc_descriptors_discover(connHandle, descriptorStartHandle, descriptorEndHandle);
+    if(!err) {
+        // commit the new discovery to its slot
+        *discovery = Discovery(characteristic, discoveryCallback, terminationCallback);
+    }
+
+    return err;
+}
+
+bool nRF5xCharacteristicDescriptorDiscoverer::isActive(const DiscoveredCharacteristic& characteristic) const {
+    for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
+        if(discoveryRunning[i].getCharacteristic() == characteristic) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void nRF5xCharacteristicDescriptorDiscoverer::requestTerminate(const DiscoveredCharacteristic& characteristic) {
+    Discovery* discovery = findRunningDiscovery(characteristic);
+    if(discovery) {
+        // call terminate anyway
+        terminate(discovery, BLE_ERROR_NONE);
+    }
+}
+
+void nRF5xCharacteristicDescriptorDiscoverer::process(uint16_t connectionHandle, const ble_gattc_evt_desc_disc_rsp_t& descriptors) {
+    Discovery* discovery = findRunningDiscovery(connectionHandle);
+    // the discovery has been removed
+    if(!discovery) {
+        return;
+    }
+
+    for (uint16_t i = 0; i < descriptors.count; ++i) {
+        discovery->process(
+            descriptors.descs[i].handle, UUID(descriptors.descs[i].uuid.uuid)
+        );
+    }
+
+    // prepare the next discovery request (if needed)
+    uint16_t startHandle = descriptors.descs[descriptors.count - 1].handle + 1;
+    uint16_t endHandle = discovery->getCharacteristic().getLastHandle();
+
+    if(startHandle > endHandle) {
+        terminate(discovery, BLE_ERROR_NONE);
+        return;
+    }
+
+    ble_error_t err = gattc_descriptors_discover(connectionHandle, startHandle, endHandle);
+    if(err) {
+        terminate(discovery, err);
+        return;
+    }
+}
+
+void nRF5xCharacteristicDescriptorDiscoverer::terminate(uint16_t handle, ble_error_t err) {
+    Discovery* discovery = findRunningDiscovery(handle);
+    // the discovery has already been terminated
+    if(!discovery) {
+        return;
+    }
+
+    terminate(discovery, err);
+}
+
+void nRF5xCharacteristicDescriptorDiscoverer::terminate(Discovery* discovery, ble_error_t err) {
+    // temporary copy, user code can try to launch a new discovery in the onTerminate
+    // callback. So, this discovery should not appear in such case.
+    Discovery tmp = *discovery;
+    *discovery = Discovery();
+    tmp.terminate(err);
+}
+
+nRF5xCharacteristicDescriptorDiscoverer::Discovery*
+nRF5xCharacteristicDescriptorDiscoverer::findRunningDiscovery(const DiscoveredCharacteristic& characteristic) {
+    for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
+        if((discoveryRunning[i].getCharacteristic() == characteristic) &&
+           (discoveryRunning[i].isEmpty() == false)) {
+            return &discoveryRunning[i];
+        }
+    }
+    return NULL;
+}
+
+nRF5xCharacteristicDescriptorDiscoverer::Discovery*
+nRF5xCharacteristicDescriptorDiscoverer::findRunningDiscovery(uint16_t handle) {
+    for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
+        if((discoveryRunning[i].getCharacteristic().getConnectionHandle() == handle) &&
+           (discoveryRunning[i].isEmpty() == false)) {
+            return &discoveryRunning[i];
+        }
+    }
+    return NULL;
+}
+
+nRF5xCharacteristicDescriptorDiscoverer::Discovery*
+nRF5xCharacteristicDescriptorDiscoverer::getAvailableDiscoverySlot() {
+    for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
+        if(discoveryRunning[i].isEmpty()) {
+            return &discoveryRunning[i];
+        }
+    }
+    return NULL;
+}
+
+bool nRF5xCharacteristicDescriptorDiscoverer::isConnectionInUse(uint16_t connHandle) {
+     return findRunningDiscovery(connHandle) != NULL;
+}
+
+ble_error_t nRF5xCharacteristicDescriptorDiscoverer::gattc_descriptors_discover(
+    uint16_t connection_handle, uint16_t start_handle, uint16_t end_handle) {
+
+    ble_gattc_handle_range_t discoveryRange = {
+        start_handle,
+        end_handle
+    };
+    uint32_t err = sd_ble_gattc_descriptors_discover(connection_handle, &discoveryRange);
+
+    switch(err) {
+        case NRF_SUCCESS:
+            return BLE_ERROR_NONE;
+        case BLE_ERROR_INVALID_CONN_HANDLE:
+            return BLE_ERROR_INVALID_PARAM;
+        case NRF_ERROR_INVALID_ADDR:
+            return BLE_ERROR_PARAM_OUT_OF_RANGE;
+        case NRF_ERROR_BUSY:
+            return BLE_STACK_BUSY;
+        default:
+            return BLE_ERROR_UNSPECIFIED;
+    }
+}
+
+// implementation of nRF5xCharacteristicDescriptorDiscoverer::Discovery
+
+nRF5xCharacteristicDescriptorDiscoverer::Discovery::Discovery() :
+    characteristic(), onDiscovery(), onTerminate() {
+}
+
+nRF5xCharacteristicDescriptorDiscoverer::Discovery::Discovery(
+    const DiscoveredCharacteristic& c, const DiscoveryCallback_t& dCb, const TerminationCallback_t& tCb) :
+    characteristic(c), onDiscovery(dCb), onTerminate(tCb) {
+}
+
+void nRF5xCharacteristicDescriptorDiscoverer::Discovery::process(
+    GattAttribute::Handle_t handle, const UUID& uuid) {
+    CharacteristicDescriptorDiscovery::DiscoveryCallbackParams_t params = {
+        characteristic,
+        DiscoveredCharacteristicDescriptor(
+            characteristic.getGattClient(),
+            characteristic.getConnectionHandle(),
+            handle,
+            uuid
+        )
+    };
+    onDiscovery.call(&params);
+}
+
+void nRF5xCharacteristicDescriptorDiscoverer::Discovery::terminate(ble_error_t err) {
+    CharacteristicDescriptorDiscovery::TerminationCallbackParams_t params = {
+        characteristic,
+        err
+    };
+
+    onTerminate.call(&params);
+}
+
+bool nRF5xCharacteristicDescriptorDiscoverer::Discovery::isEmpty() const {
+    return *this == Discovery();
+}
+
+const DiscoveredCharacteristic& nRF5xCharacteristicDescriptorDiscoverer::Discovery::getCharacteristic() const {
+    return characteristic;
+}
\ No newline at end of file