[darwin] Update BLEScannerDelegate interface to have both a add and a…

… remove method

examples/chip-tool/commands/common/DeviceScanner.cpp

@@ -72,7 +72,7 @@ void DeviceScanner::OnNodeDiscovered(const DiscoveredNodeData & nodeData)
 }
 
 #if CHIP_TOOL_DEVICE_SCANNER_USE_BLE
-void DeviceScanner::OnBleScanResult(BLE_CONNECTION_OBJECT connObj, const ChipBLEDeviceIdentificationInfo & info)
+void DeviceScanner::OnBleScanAdd(BLE_CONNECTION_OBJECT connObj, const ChipBLEDeviceIdentificationInfo & info)
 {
     auto discriminator = info.GetDeviceDiscriminator();
     auto vendorId      = static_cast<VendorId>(info.GetVendorId());
@@ -85,6 +85,8 @@ void DeviceScanner::OnBleScanResult(BLE_CONNECTION_OBJECT connObj, const ChipBLE
     DeviceScannerResult result = { params, vendorId, productId, discriminator };
     mDiscoveredResults.push_back(result);
 }
+
+void DeviceScanner::OnBleScanRemove(BLE_CONNECTION_OBJECT connObj) {}
 #endif // CHIP_TOOL_DEVICE_SCANNER_USE_BLE
 
 CHIP_ERROR DeviceScanner::Get(uint16_t index, RendezvousParameters & params)

examples/chip-tool/commands/common/DeviceScanner.h

@@ -59,7 +59,8 @@ class DeviceScanner : public chip::Dnssd::CommissioningResolveDelegate
 
 #if CHIP_TOOL_DEVICE_SCANNER_USE_BLE
     /////////// BleScannerDelegate Interface /////////
-    void OnBleScanResult(BLE_CONNECTION_OBJECT connObj, const chip::Ble::ChipBLEDeviceIdentificationInfo & info) override;
+    void OnBleScanAdd(BLE_CONNECTION_OBJECT connObj, const chip::Ble::ChipBLEDeviceIdentificationInfo & info) override;
+    void OnBleScanRemove(BLE_CONNECTION_OBJECT connObj) override;
 #endif // CHIP_TOOL_DEVICE_SCANNER_USE_BLE
 
 private:

src/platform/Darwin/BleConnectionDelegateImpl.mm

@@ -42,6 +42,8 @@
 
 constexpr uint64_t kScanningWithDiscriminatorTimeoutInSeconds = 60;
 constexpr uint64_t kScanningWithoutDelegateTimeoutInSeconds = 120;
+constexpr uint64_t kCachePeripheralTimeoutInSeconds
+    = static_cast<uint64_t>(CHIP_DEVICE_CONFIG_BLE_SLOW_ADVERTISING_INTERVAL_MAX / 1000.0 * 8.0 * 0.625);
 constexpr const char * kBleWorkQueueName = "org.csa-iot.matter.framework.ble.workqueue";
 
 typedef NS_ENUM(uint8_t, BleConnectionMode) {
@@ -60,7 +62,7 @@ @interface BleConnection : NSObject <CBCentralManagerDelegate, CBPeripheralDeleg
 @property (strong, nonatomic) CBUUID * shortServiceUUID;
 @property (nonatomic, readonly, nullable) dispatch_source_t timer;
 @property (nonatomic, readonly) BleConnectionMode currentMode;
-@property (strong, nonatomic) NSMutableDictionary * cachedPeripherals;
+@property (strong, nonatomic) NSMutableDictionary<CBPeripheral *, NSDictionary *> * cachedPeripherals;
 @property (unsafe_unretained, nonatomic) bool found;
 @property (unsafe_unretained, nonatomic) chip::SetupDiscriminator deviceDiscriminator;
 @property (unsafe_unretained, nonatomic) void * appState;
@@ -81,6 +83,9 @@ - (void)updateWithPeripheral:(CBPeripheral *)peripheral;
 - (BOOL)isScanningWithoutDelegate;
 - (BOOL)isScanning;
 - (BOOL)isConnecting;
+- (void)addPeripheralToCache:(CBPeripheral *)peripheral data:(NSData *)data;
+- (void)removePeripheralFromCache:(CBPeripheral *)peripheral;
+- (void)removePeripheralsFromCache;
 
 @end
 
@@ -376,18 +381,7 @@ - (void)centralManager:(CBCentralManager *)central
     }
 
     if (![self isConnecting]) {
-        if ([_cachedPeripherals objectForKey:peripheral] == nil) {
-            ChipLogProgress(Ble, "Storing device %p with discriminator: %d", peripheral, discriminator);
-            if (_scannerDelegate) {
-                dispatch_async(_chipWorkQueue, ^{
-                    ChipBLEDeviceIdentificationInfo info;
-                    memcpy(&info, bytes, sizeof(info));
-                    _scannerDelegate->OnBleScanResult((__bridge void *) peripheral, info);
-                });
-            }
-        }
-
-        _cachedPeripherals[peripheral] = serviceData;
+        [self addPeripheralToCache:peripheral data:serviceData];
     }
 }
 
@@ -539,9 +533,9 @@ - (void)start
 - (void)stop
 {
     [self stopScanning];
-    _scannerDelegate = nil;
-    [_cachedPeripherals removeAllObjects];
+    [self removePeripheralsFromCache];
     _cachedPeripherals = nil;
+    _scannerDelegate = nil;
 
     if (!_centralManager || !_peripheral) {
         return;
@@ -594,17 +588,16 @@ - (void)connect:(CBPeripheral *)peripheral
 
 - (void)updateWithDelegate:(chip::DeviceLayer::BleScannerDelegate *)delegate
 {
-    [_cachedPeripherals removeAllObjects];
     _scannerDelegate = delegate;
     _currentMode = (delegate == nullptr) ? kScanningWithoutDelegate : kScanning;
 
     if (_currentMode == kScanning) {
         for (CBPeripheral * cachedPeripheral in _cachedPeripherals) {
-            NSData * serviceData = _cachedPeripherals[cachedPeripheral];
+            NSData * serviceData = _cachedPeripherals[cachedPeripheral][@"data"];
             dispatch_async(_chipWorkQueue, ^{
                 ChipBLEDeviceIdentificationInfo info;
                 memcpy(&info, [serviceData bytes], sizeof(info));
-                _scannerDelegate->OnBleScanResult((__bridge void *) cachedPeripheral, info);
+                _scannerDelegate->OnBleScanAdd((__bridge void *) cachedPeripheral, info);
             });
         }
     }
@@ -620,7 +613,7 @@ - (void)updateWithDiscriminator:(const chip::SetupDiscriminator &)deviceDiscrimi
 
     CBPeripheral * peripheral = nil;
     for (CBPeripheral * cachedPeripheral in _cachedPeripherals) {
-        NSData * serviceData = _cachedPeripherals[cachedPeripheral];
+        NSData * serviceData = _cachedPeripherals[cachedPeripheral][@"data"];
         ChipBLEDeviceIdentificationInfo info;
         memcpy(&info, [serviceData bytes], sizeof(info));
 
@@ -630,6 +623,8 @@ - (void)updateWithDiscriminator:(const chip::SetupDiscriminator &)deviceDiscrimi
         }
     }
 
+    [self removePeripheralsFromCache];
+
     if (peripheral) {
         ChipLogProgress(Ble, "Connecting to cached device: %p", peripheral);
         [self connect:peripheral];
@@ -649,6 +644,62 @@ - (void)updateWithPeripheral:(CBPeripheral *)peripheral
     [self stopScanning];
 }
 
+- (void)addPeripheralToCache:(CBPeripheral *)peripheral data:(NSData *)data
+{
+    dispatch_source_t timeoutTimer;
+
+    if ([_cachedPeripherals objectForKey:peripheral]) {
+        timeoutTimer = _cachedPeripherals[peripheral][@"timer"];
+    } else {
+        auto delegate = _scannerDelegate;
+        if (delegate) {
+            dispatch_async(_chipWorkQueue, ^{
+                ChipBLEDeviceIdentificationInfo info;
+                auto bytes = (const uint8_t *) [data bytes];
+                memcpy(&info, bytes, sizeof(info));
+                delegate->OnBleScanAdd((__bridge void *) peripheral, info);
+            });
+        }
+
+        timeoutTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, _workQueue);
+        dispatch_source_set_event_handler(timeoutTimer, ^{
+            [self removePeripheralFromCache:peripheral];
+        });
+        dispatch_resume(timeoutTimer);
+    }
+
+    auto timeout = static_cast<int64_t>(kCachePeripheralTimeoutInSeconds * NSEC_PER_SEC);
+    dispatch_source_set_timer(timeoutTimer, dispatch_walltime(nullptr, timeout), DISPATCH_TIME_FOREVER, 5 * NSEC_PER_SEC);
+
+    _cachedPeripherals[peripheral] = @{
+        @"data" : data,
+        @"timer" : timeoutTimer,
+    };
+}
+
+- (void)removePeripheralFromCache:(CBPeripheral *)peripheral
+{
+    auto entry = [_cachedPeripherals objectForKey:peripheral];
+    if (entry) {
+        dispatch_source_cancel(entry[@"timer"]);
+        [_cachedPeripherals removeObjectForKey:peripheral];
+
+        auto delegate = _scannerDelegate;
+        if (delegate) {
+            dispatch_async(_chipWorkQueue, ^{
+                delegate->OnBleScanRemove((__bridge void *) peripheral);
+            });
+        }
+    }
+}
+
+- (void)removePeripheralsFromCache
+{
+    for (CBPeripheral * peripheral in _cachedPeripherals) {
+        [self removePeripheralFromCache:peripheral];
+    }
+}
+
 /**
  * private static method to copy service and characteristic UUIDs from CBCharacteristic to a pair of ChipBleUUID objects.
  * this is used in calls into Chip layer to decouple it from CoreBluetooth

src/platform/Darwin/BleScannerDelegate.h

@@ -30,7 +30,10 @@ class DLL_EXPORT BleScannerDelegate
     virtual ~BleScannerDelegate() {}
 
     // Called when a scan result is available.
-    virtual void OnBleScanResult(BLE_CONNECTION_OBJECT connObj, const Ble::ChipBLEDeviceIdentificationInfo & info) = 0;
+    virtual void OnBleScanAdd(BLE_CONNECTION_OBJECT connObj, const Ble::ChipBLEDeviceIdentificationInfo & info) = 0;
+
+    // Called when a scan result is not available anymore.
+    virtual void OnBleScanRemove(BLE_CONNECTION_OBJECT connObj) = 0;
 };
 
 } // namespace DeviceLayer