Documentation of descriptor discoverer class.

Simplify the process
This commit is contained in:
Vincent Coubard 2015-12-15 09:56:27 +00:00
parent 59ced0b4b1
commit c8d826ffd0
2 changed files with 177 additions and 100 deletions

View file

@ -13,42 +13,36 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "nRF5xCharacteristicDescriptorDiscoverer.h"
#include "ble_err.h"
#include "mbed-drivers/mbed_error.h"
#include "ble/DiscoveredCharacteristicDescriptor.h"
namespace {
void emptyDiscoveryCallback(const CharacteristicDescriptorDiscovery::DiscoveryCallbackParams_t*) { }
void emptyTerminationCallback(const CharacteristicDescriptorDiscovery::TerminationCallbackParams_t*) { }
nRF5xCharacteristicDescriptorDiscoverer::nRF5xCharacteristicDescriptorDiscoverer() :
discoveryRunning() {
// nothing to do
}
nRF5xCharacteristicDescriptorDiscoverer::nRF5xCharacteristicDescriptorDiscoverer(size_t concurrentConnectionsCount) :
maximumConcurrentConnectionsCount(concurrentConnectionsCount),
discoveryRunning(new Discovery[concurrentConnectionsCount]) {
}
nRF5xCharacteristicDescriptorDiscoverer::~nRF5xCharacteristicDescriptorDiscoverer() {
delete [] discoveryRunning;
nRF5xCharacteristicDescriptorDiscoverer::~nRF5xCharacteristicDescriptorDiscoverer() {
// nothing to do
}
ble_error_t nRF5xCharacteristicDescriptorDiscoverer::launch(
const DiscoveredCharacteristic& characteristic,
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
// 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 their is any descriptor to discover
if (descriptorEndHandle < descriptorStartHandle) {
CharacteristicDescriptorDiscovery::TerminationCallbackParams_t termParams = {
// check if there is any descriptor to discover
if (descriptorEndHandle < descriptorStartHandle) {
CharacteristicDescriptorDiscovery::TerminationCallbackParams_t termParams = {
characteristic,
BLE_ERROR_NONE
};
@ -57,19 +51,19 @@ ble_error_t nRF5xCharacteristicDescriptorDiscoverer::launch(
}
// check if we can run this discovery
if (isConnectionInUse(connHandle)) {
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;
return BLE_STACK_BUSY;
}
// try to launch the discovery
// try to launch the discovery
ble_error_t err = gattc_descriptors_discover(connHandle, descriptorStartHandle, descriptorEndHandle);
if(!err) {
if(!err) {
// commit the new discovery to its slot
*discovery = Discovery(characteristic, discoveryCallback, terminationCallback);
}
@ -78,23 +72,27 @@ ble_error_t nRF5xCharacteristicDescriptorDiscoverer::launch(
}
bool nRF5xCharacteristicDescriptorDiscoverer::isActive(const DiscoveredCharacteristic& characteristic) const {
return findRunningDiscovery(characteristic) != NULL;
for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
if(discoveryRunning[i].characteristic == characteristic) {
return true;
}
}
return false;
}
void nRF5xCharacteristicDescriptorDiscoverer::requestTerminate(const DiscoveredCharacteristic& characteristic) {
Discovery* discovery = findRunningDiscovery(characteristic);
if(discovery) {
discovery->onDiscovery = emptyDiscoveryCallback;
if(discovery) {
// call terminate anyway
discovery->terminate(BLE_ERROR_NONE);
discovery->onTerminate = emptyTerminationCallback;
terminate(discovery, BLE_ERROR_NONE);
}
}
void nRF5xCharacteristicDescriptorDiscoverer::process(uint16_t connectionHandle, const ble_gattc_evt_desc_disc_rsp_t& descriptors) {
Discovery* discovery = findRunningDiscovery(connectionHandle);
if(!discovery) {
error("logic error in nRF5xCharacteristicDescriptorDiscoverer::process !!!");
// the discovery has been removed
if(!discovery) {
return;
}
for (uint16_t i = 0; i < descriptors.count; ++i) {
@ -107,76 +105,67 @@ void nRF5xCharacteristicDescriptorDiscoverer::process(uint16_t connectionHandle,
uint16_t startHandle = descriptors.descs[descriptors.count - 1].handle + 1;
uint16_t endHandle = discovery->characteristic.getLastHandle();
if(startHandle > endHandle ||
(discovery->onDiscovery == emptyDiscoveryCallback && discovery->onTerminate == emptyTerminationCallback)) {
terminate(connectionHandle, BLE_ERROR_NONE);
if(startHandle > endHandle) {
terminate(discovery, BLE_ERROR_NONE);
return;
}
ble_error_t err = gattc_descriptors_discover(connectionHandle, startHandle, endHandle);
if(err) {
terminate(connectionHandle, err);
if(err) {
terminate(discovery, err);
return;
}
}
void nRF5xCharacteristicDescriptorDiscoverer::terminate(uint16_t handle, ble_error_t err) {
Discovery* discovery = findRunningDiscovery(handle);
if(!discovery) {
error("logic error in nRF5xCharacteristicDescriptorDiscoverer::process !!!");
// 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::Discovery*
nRF5xCharacteristicDescriptorDiscoverer::findRunningDiscovery(const DiscoveredCharacteristic& characteristic) {
for(size_t i = 0; i < maximumConcurrentConnectionsCount; ++i) {
if(discoveryRunning[i].characteristic == characteristic) {
for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
if(discoveryRunning[i].characteristic == characteristic && discoveryRunning[i].isEmpty() == false) {
return &discoveryRunning[i];
}
}
return NULL;
}
nRF5xCharacteristicDescriptorDiscoverer::Discovery*
nRF5xCharacteristicDescriptorDiscoverer::findRunningDiscovery(const DiscoveredCharacteristic& characteristic) const {
for(size_t i = 0; i < maximumConcurrentConnectionsCount; ++i) {
if(discoveryRunning[i].characteristic == characteristic) {
return &discoveryRunning[i];
}
}
return NULL;
}
nRF5xCharacteristicDescriptorDiscoverer::Discovery*
nRF5xCharacteristicDescriptorDiscoverer::Discovery*
nRF5xCharacteristicDescriptorDiscoverer::findRunningDiscovery(uint16_t handle) {
for(size_t i = 0; i < maximumConcurrentConnectionsCount; ++i) {
if(discoveryRunning[i].characteristic.getConnectionHandle() == handle &&
discoveryRunning[i] != Discovery()) {
for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
if(discoveryRunning[i].characteristic.getConnectionHandle() == handle &&
discoveryRunning[i].isEmpty() == false) {
return &discoveryRunning[i];
}
}
return NULL;
}
void nRF5xCharacteristicDescriptorDiscoverer::removeDiscovery(Discovery* discovery) {
for(size_t i = 0; i < maximumConcurrentConnectionsCount; ++i) {
if(&discoveryRunning[i] == discovery) {
discoveryRunning[i] = Discovery();
}
}
}
nRF5xCharacteristicDescriptorDiscoverer::Discovery*
nRF5xCharacteristicDescriptorDiscoverer::Discovery*
nRF5xCharacteristicDescriptorDiscoverer::getAvailableDiscoverySlot() {
for(size_t i = 0; i < maximumConcurrentConnectionsCount; ++i) {
if(discoveryRunning[i] == Discovery()) {
for(size_t i = 0; i < MAXIMUM_CONCURRENT_CONNECTIONS_COUNT; ++i) {
if(discoveryRunning[i].isEmpty()) {
return &discoveryRunning[i];
}
}
}
return NULL;
}
@ -185,7 +174,7 @@ bool nRF5xCharacteristicDescriptorDiscoverer::isConnectionInUse(uint16_t connHan
}
ble_error_t nRF5xCharacteristicDescriptorDiscoverer::gattc_descriptors_discover(
uint16_t connection_handle, uint16_t start_handle, uint16_t end_handle) {
uint16_t connection_handle, uint16_t start_handle, uint16_t end_handle) {
ble_gattc_handle_range_t discoveryRange = {
start_handle,
@ -193,9 +182,9 @@ ble_error_t nRF5xCharacteristicDescriptorDiscoverer::gattc_descriptors_discover(
};
uint32_t err = sd_ble_gattc_descriptors_discover(connection_handle, &discoveryRange);
switch(err) {
switch(err) {
case NRF_SUCCESS:
return BLE_ERROR_NONE;
return BLE_ERROR_NONE;
case BLE_ERROR_INVALID_CONN_HANDLE:
return BLE_ERROR_INVALID_PARAM;
case NRF_ERROR_INVALID_ADDR:

View file

@ -24,11 +24,11 @@
#include "ble_gattc.h"
/**
* @brief Manage the discovery of Characteristic descriptors
* @details is a bridge beetween BLE API and nordic stack regarding Characteristic
* Descriptor discovery. The BLE API can launch, monitorate and ask for termination
* of a discovery. The nordic stack will provide new descriptors and indicate when
* the discovery is done
* @brief Manage the discovery of Characteristic descriptors
* @details is a bridge between BLE API and Nordic stack regarding Characteristic
* Descriptor discovery. The BLE API can launch, monitor and ask for termination
* of a discovery. The Nordic stack will provide new descriptors and indicate when
* the discovery is done.
*/
class nRF5xCharacteristicDescriptorDiscoverer
{
@ -36,64 +36,109 @@ class nRF5xCharacteristicDescriptorDiscoverer
typedef CharacteristicDescriptorDiscovery::TerminationCallback_t TerminationCallback_t;
public:
nRF5xCharacteristicDescriptorDiscoverer(size_t concurrentConnectionsCount = 3);
/**
* @brief Construct a new characteristic descriptor discoverer.
*/
nRF5xCharacteristicDescriptorDiscoverer();
/**
* @brief Destroy a characteristic descriptor discoverer.
*/
~nRF5xCharacteristicDescriptorDiscoverer();
/**
* Launch a new characteristic descriptor discovery for a given
* DiscoveredCharacteristic.
* @note: this will be called by BLE API side
* Launch a new characteristic descriptor discovery for a given DiscoveredCharacteristic.
* @param characteristic The characteristic owning the descriptors to discover.
* @param discoveryCallback The callback called when a descriptor is discovered.
* @param terminationCallback The callback called when the discovery process end.
* @return BLE_ERROR_NONE if characteristic descriptor discovery is launched successfully;
* else an appropriate error.
* @note: this will be called by BLE API side.
*/
ble_error_t launch(
const DiscoveredCharacteristic& characteristic,
const DiscoveryCallback_t& callback,
const DiscoveredCharacteristic& characteristic,
const DiscoveryCallback_t& discoveryCallback,
const TerminationCallback_t& terminationCallback
);
/**
* @brief indicate if a characteristic descriptor discovery is active for a
* given DiscoveredCharacteristic
* @note: this will be called by BLE API side
* @brief indicate if a characteristic descriptor discovery is active for a
* given DiscoveredCharacteristic.
* @param characteristic The characteristic for whom the descriptor might be
* currently discovered.
* @return true if descriptors of characteristic are discovered, false otherwise.
* @note: this will be called by BLE API side.
*/
bool isActive(const DiscoveredCharacteristic& characteristic) const;
/**
* @brief reauest the termination of characteristic descriptor discovery
* @brief request the termination of characteristic descriptor discovery
* for a give DiscoveredCharacteristic
* @note: this will be called by BLE API side
* @param characteristic The characteristic for whom the descriptor discovery
* should be stopped.
* @note: this will be called by BLE API side.
*/
void requestTerminate(const DiscoveredCharacteristic& characteristic);
/**
* @brief process descriptors discovered from the nordic stack
* @brief process descriptors discovered from the Nordic stack.
* @param connectionHandle The connection handle upon which descriptors has been
* discovered.
* @param descriptors Discovered descriptors.
* @note This will be called by the Nordic stack.
*/
void process(uint16_t handle, const ble_gattc_evt_desc_disc_rsp_t& descriptors);
void process(uint16_t connectionHandle, const ble_gattc_evt_desc_disc_rsp_t& descriptors);
/**
* @brief Called by the nordic stack when the discovery is over.
* @brief Called by the Nordic stack when the discovery is over.
* @param The connection handle upon which the discovery process is done.
* @param err An error if the termination is due to an error.
*/
void terminate(uint16_t handle, ble_error_t err);
void terminate(uint16_t connectionHandle, ble_error_t err);
private:
// protection against copy construction and assignment
nRF5xCharacteristicDescriptorDiscoverer(const nRF5xCharacteristicDescriptorDiscoverer&);
nRF5xCharacteristicDescriptorDiscoverer& operator=(const nRF5xCharacteristicDescriptorDiscoverer&);
/**
* @brief Discovery process, it store the DiscoveredCharacteristic, the
* discovery callback and the termination callback.
*/
struct Discovery {
/**
* @brief Construct an empty discovery, such can be considerate as a not running discovery.
* @note #isEmpty function will return true
*/
Discovery() : characteristic(), onDiscovery(), onTerminate() { }
Discovery(const DiscoveredCharacteristic& c, const DiscoveryCallback_t& dCb, const TerminationCallback_t& tCb) :
characteristic(c),
onDiscovery(dCb),
onTerminate(tCb) {
/**
* @brief Construct a valid discovery process.
*
* @param c the characteristic from whom descriptors will be discovered.
* @param dCb The discovery callback called each time a descriptor is discovered.
* @param tCb The termination callback called when the discovery terminate.
*
* @note #isEmpty function will return false
*/
Discovery(const DiscoveredCharacteristic& c, const DiscoveryCallback_t& dCb, const TerminationCallback_t& tCb) :
characteristic(c),
onDiscovery(dCb),
onTerminate(tCb) {
}
DiscoveredCharacteristic characteristic;
DiscoveryCallback_t onDiscovery;
TerminationCallback_t onTerminate;
void process(GattAttribute::Handle_t handle, const UUID& uuid) {
CharacteristicDescriptorDiscovery::DiscoveryCallbackParams_t params = {
/**
* @brief Process the discovery of a descriptor.
*
* @param handle The attribute handle of the descriptor found
* @param uuid The UUID of the descriptor found.
*/
void process(GattAttribute::Handle_t handle, const UUID& uuid) {
CharacteristicDescriptorDiscovery::DiscoveryCallbackParams_t params = {
characteristic,
DiscoveredCharacteristicDescriptor(
characteristic.getGattClient(),
@ -105,36 +150,79 @@ private:
onDiscovery.call(&params);
}
void terminate(ble_error_t err) {
/**
* @brief Terminate the discovery process.
*
* @param err Error associate with the termination
*
* @note after this call #isEmpty function will return true.
*/
void terminate(ble_error_t err) {
CharacteristicDescriptorDiscovery::TerminationCallbackParams_t params = {
characteristic,
err
};
onTerminate.call(&params);
}
/**
* @brief check if the discovery process is empty or not. Empty discovery are
* not running.
* @detail Discovery are empty after:
* - a default construction
* - a copy construction form a default constructed
* - an assignment from a default constructed Discovery
* @return true if the Discovery is empty and false otherwise.
*/
bool isEmpty() const {
return *this == Discovery();
}
/**
* @brief equal to operator, test if two discovery process are equal
* @param lhs left hand side of the expression
* @param rhs right hand side of the expression
* @return true if lhs == rhs
*/
friend bool operator==(const Discovery& lhs, const Discovery& rhs) {
return lhs.characteristic == rhs.characteristic &&
lhs.onDiscovery == rhs.onDiscovery &&
lhs.onTerminate == rhs.onTerminate;
}
/**
* @brief not equal to operator, test if two discovery process are not equal
* @param lhs left hand side of the expression
* @param rhs right hand side of the expression
* @return true if lhs != rhs
*/
friend bool operator!=(const Discovery& lhs, const Discovery& rhs) {
return !(lhs == rhs);
}
};
// find a running discovery process
Discovery* findRunningDiscovery(const DiscoveredCharacteristic& characteristic);
Discovery* findRunningDiscovery(const DiscoveredCharacteristic& characteristic) const;
Discovery* findRunningDiscovery(uint16_t handle);
void removeDiscovery(Discovery* discovery);
Discovery* getAvailableDiscoverySlot();
// Called to terminate a discovery is over.
void terminate(Discovery* discovery, ble_error_t err);
// get one slot for a discovery process
Discovery* getAvailableDiscoverySlot();
// indicate if a connection is already running a discovery
bool isConnectionInUse(uint16_t connHandle);
static ble_error_t gattc_descriptors_discover(uint16_t connection_handle, uint16_t start_handle, uint16_t end_handle);
// low level start of a discovery
static ble_error_t gattc_descriptors_discover(uint16_t connection_handle, uint16_t start_handle, uint16_t end_handle);
size_t maximumConcurrentConnectionsCount;
Discovery *discoveryRunning;
// count of concurrent connections which can run a descriptor discovery process
static const size_t MAXIMUM_CONCURRENT_CONNECTIONS_COUNT = 3;
// array of running discoveries
Discovery discoveryRunning[MAXIMUM_CONCURRENT_CONNECTIONS_COUNT];
};
#endif /*__NRF_CHARACTERISTIC_DESCRIPTOR_DISCOVERY_H__*/