Add override for flush()

Author: h2zero

src/NimBLEStream.cpp

@@ -701,6 +701,49 @@ size_t NimBLEStreamServer::write(const uint8_t* data, size_t len) {
     return NimBLEStream::write(data, len);
 }
 
+/**
+ * @brief Flush all pending TX data by attempting immediate sends.
+ * @details This blocks while trying to drain the TX buffer. If send cannot make
+ * progress (e.g. disconnected or persistent failure), queued TX/RX data is cleared.
+ */
+void NimBLEStreamServer::flush() {
+    if (!m_txBuf || m_txBuf->size() == 0) {
+        return;
+    }
+
+    const uint32_t timeoutMs  = static_cast<uint32_t>(std::min<unsigned long>(getTimeout(), 0xFFFFFFFFUL));
+    const uint32_t retryDelay = std::max<uint32_t>(1, ble_npl_time_ms_to_ticks32(5));
+    uint32_t       waitStart  = ble_npl_time_get();
+    while (m_txBuf->size() > 0) {
+        size_t before = m_txBuf->size();
+        bool   retry  = send();
+        size_t after  = m_txBuf->size();
+
+        if (after == 0) {
+            return;
+        }
+
+        if (after < before) {
+            waitStart = ble_npl_time_get();
+            continue;
+        }
+
+        if (retry && timeoutMs > 0) {
+            const uint32_t elapsed = ble_npl_time_get() - waitStart;
+            if (elapsed < ble_npl_time_ms_to_ticks32(timeoutMs)) {
+                ble_npl_time_delay(retryDelay);
+                continue;
+            }
+        }
+
+        m_txBuf->drop(m_txBuf->size());
+        if (m_rxBuf) {
+            m_rxBuf->drop(m_rxBuf->size());
+        }
+        return;
+    }
+}
+
 /**
  * @brief Attempt to send data from the TX buffer as BLE notifications.
  * @return true if a retry should be scheduled, false otherwise.
@@ -905,6 +948,49 @@ void NimBLEStreamClient::end() {
     NimBLEStream::end();
 }
 
+/**
+ * @brief Flush all pending TX data by attempting immediate writes.
+ * @details This blocks while trying to drain the TX buffer. If send cannot make
+ * progress (e.g. disconnected or persistent failure), queued TX/RX data is cleared.
+ */
+void NimBLEStreamClient::flush() {
+    if (!m_txBuf || m_txBuf->size() == 0) {
+        return;
+    }
+
+    const uint32_t timeoutMs  = static_cast<uint32_t>(std::min<unsigned long>(getTimeout(), 0xFFFFFFFFUL));
+    const uint32_t retryDelay = std::max<uint32_t>(1, ble_npl_time_ms_to_ticks32(5));
+    uint32_t       waitStart  = ble_npl_time_get();
+    while (m_txBuf->size() > 0) {
+        size_t before = m_txBuf->size();
+        bool   retry  = send();
+        size_t after  = m_txBuf->size();
+
+        if (after == 0) {
+            return;
+        }
+
+        if (after < before) {
+            waitStart = ble_npl_time_get();
+            continue;
+        }
+
+        if (retry && timeoutMs > 0) {
+            const uint32_t elapsed = ble_npl_time_get() - waitStart;
+            if (elapsed < ble_npl_time_ms_to_ticks32(timeoutMs)) {
+                ble_npl_time_delay(retryDelay);
+                continue;
+            }
+        }
+
+        m_txBuf->drop(m_txBuf->size());
+        if (m_rxBuf) {
+            m_rxBuf->drop(m_rxBuf->size());
+        }
+        return;
+    }
+}
+
 /**
  * @brief Write data to the stream, which will be sent as BLE writes to the remote characteristic.
  * @return True if a retry should be scheduled due to lack of BLE buffers, false otherwise.

src/NimBLEStream.h

@@ -82,8 +82,6 @@ class NimBLEStream : public Stream {
         return write(static_cast<uint8_t>(data));
     }
 
-    virtual void flush() override {}
-
     size_t availableForWrite() const;
 
     // Read up to len bytes into buffer (non-blocking)
@@ -159,6 +157,7 @@ class NimBLEStreamServer : public NimBLEStream {
     uint16_t getPeerHandle() const { return m_charCallbacks.m_peerHandle; }
     void     setCallbacks(NimBLECharacteristicCallbacks* pCallbacks) { m_charCallbacks.m_userCallbacks = pCallbacks; }
     bool     ready() const override;
+    virtual void flush() override;
 
     using NimBLEStream::write; // Inherit template write overloads
 
@@ -211,6 +210,7 @@ class NimBLEStreamClient : public NimBLEStream {
     void end() override;
     void setNotifyCallback(NimBLERemoteCharacteristic::notify_callback cb) { m_userNotifyCallback = cb; }
     bool ready() const override;
+    virtual void flush() override;
 
     using NimBLEStream::write; // Inherit template write overloads