Serial bridge implementation

src/bridge/serial/PacketQueue.h

@@ -0,0 +1,113 @@
+/**
+ * MeshCore - A new lightweight, hybrid routing mesh protocol for packet radios
+ * Copyright (c) 2025 Scott Powell / rippleradios.com
+ *
+ * This project is maintained by the contributors listed in
+ * https://github.com/ripplebiz/MeshCore/graphs/contributors
+ *
+ * MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+#pragma once
+
+#include "MeshCore.h"
+
+#include <Packet.h>
+#include <string.h>
+
+#if MESH_PACKET_LOGGING
+#include <Arduino.h>
+#endif
+
+#ifndef MAX_QUEUE_SIZE
+#define MAX_QUEUE_SIZE 8
+#endif
+
+namespace bridge {
+
+class PacketQueue {
+private:
+  struct {
+    size_t len;
+    uint8_t bytes[MAX_TRANS_UNIT];
+  } buffer[MAX_QUEUE_SIZE];
+
+protected:
+  uint16_t head = 0, tail = 0;
+
+public:
+  size_t available() const { return (tail - head + MAX_QUEUE_SIZE) % MAX_QUEUE_SIZE; }
+
+  size_t enqueue(const uint8_t *bytes, const uint8_t len) {
+    if (len == 0 || len > MAX_TRANS_UNIT) {
+#if BRIDGE_DEBUG
+      Serial.printf("BRIDGE: enqueue() failed len=%d\n", len);
+#endif
+      return 0;
+    }
+
+    if ((tail + 1) % MAX_QUEUE_SIZE == head) { // Buffer full
+      head = (head + 1) % MAX_QUEUE_SIZE;      // Overwrite oldest packet
+    }
+
+    buffer[tail].len = len;
+    memcpy(buffer[tail].bytes, bytes, len);
+
+#if MESH_PACKET_LOGGING
+    Serial.printf("BRIDGE: enqueue() len=%d payload[5]=", len);
+    for (size_t i = 0; i < len && i < 5; ++i) {
+      Serial.printf("0x%02x ", buffer[tail].bytes[i]);
+    }
+    Serial.printf("\n");
+#endif
+
+    tail = (tail + 1) % MAX_QUEUE_SIZE;
+    return len;
+  }
+
+  size_t enqueue(const mesh::Packet *pkt) {
+    uint8_t bytes[MAX_TRANS_UNIT];
+    const size_t len = pkt->writeTo(bytes);
+    return enqueue(bytes, len);
+  }
+
+  size_t dequeue(uint8_t *bytes) {
+    if (head == tail) { // Buffer empty
+      return 0;
+    }
+
+    const size_t len = buffer[head].len;
+    memcpy(bytes, buffer[head].bytes, len);
+    head = (head + 1) % MAX_QUEUE_SIZE;
+
+#if MESH_PACKET_LOGGING
+    Serial.printf("BRIDGE: dequeue() payload[5]=");
+    for (size_t i = 0; i < len && i < 5; ++i) {
+      Serial.printf("0x%02x ", bytes[i]);
+    }
+    Serial.printf("\n");
+#endif
+
+    return len;
+  }
+};
+
+} // namespace bridge