harden USB telemetry transport

main/trikke_sensor_main.c

@@ -14,6 +14,8 @@
 #include "freertos/task.h"
 #include "l3g4200d.h"
 #include "trikke_protocol.h"
+#include "trikke_transport.h"
+#include "trikke_usb_transport.h"
 
 // Seeed Studio XIAO ESP32-C3: D4/SDA = GPIO6, D5/SCL = GPIO7.
 #define TRIKKE_I2C_PORT       I2C_NUM_0
@@ -54,6 +56,8 @@ typedef struct {
     QueueHandle_t sample_queue;
     atomic_uint_least32_t dropped_sample_count;
     atomic_uint_least32_t loop_overrun_count;
+    trikke_transport_t transport;
+    trikke_usb_transport_t usb_transport;
 } trikke_context_t;
 
 static trikke_context_t s_context;
@@ -157,22 +161,26 @@ static void acquisition_task(void *argument)
     }
 }
 
-static bool write_binary_packet(const uint8_t *packet, size_t packet_size)
-{
-    const size_t written = fwrite(packet, 1, packet_size, stdout);
-    const int flush_result = fflush(stdout);
-    const bool complete = written == packet_size && flush_result == 0;
-    if (!complete) {
-        clearerr(stdout);
-    }
-    return complete;
-}
-
 static void write_binary_packet_until_sent(
+    trikke_context_t *context,
+    trikke_transport_sender_t *sender,
     const uint8_t *packet,
     size_t packet_size)
 {
-    while (!write_binary_packet(packet, packet_size)) {
+    while (true) {
+        const trikke_transport_status_t status =
+            trikke_transport_sender_step(
+                sender, &context->transport, packet, packet_size);
+        if (status == TRIKKE_TRANSPORT_COMPLETE) {
+            return;
+        }
+        if (status == TRIKKE_TRANSPORT_FATAL) {
+            // Preserve the in-flight packet and stop consuming the queue. A
+            // fatal backend invariant is not safely recoverable or retryable.
+            while (true) {
+                vTaskDelay(portMAX_DELAY);
+            }
+        }
         vTaskDelay(pdMS_TO_TICKS(TRIKKE_TRANSPORT_RETRY_DELAY_MS));
     }
 }
@@ -185,12 +193,14 @@ static void output_task(void *argument)
     uint8_t packet[TRIKKE_WIRE_MAX_PACKET_SIZE] = {0};
     uint32_t packet_sequence = 0;
     uint32_t sample_packet_count = 0;
+    trikke_transport_sender_t sender;
+    trikke_transport_sender_init(&sender);
 
     size_t packet_size = trikke_encode_metadata_packet(
         packet, sizeof(packet), packet_sequence++, esp_timer_get_time(),
         atomic_load(&context->dropped_sample_count),
         atomic_load(&context->loop_overrun_count), &TRIKKE_METADATA);
-    write_binary_packet_until_sent(packet, packet_size);
+    write_binary_packet_until_sent(context, &sender, packet, packet_size);
 
     while (true) {
         trikke_wire_sample_t samples[TRIKKE_WIRE_MAX_RECORDS] = {0};
@@ -227,14 +237,15 @@ static void output_task(void *argument)
                 packet, sizeof(packet), packet_sequence++, esp_timer_get_time(),
                 atomic_load(&context->dropped_sample_count),
                 atomic_load(&context->loop_overrun_count), &TRIKKE_METADATA);
-            write_binary_packet_until_sent(packet, packet_size);
+            write_binary_packet_until_sent(
+                context, &sender, packet, packet_size);
         }
 
         packet_size = trikke_encode_sample_packet(
             packet, sizeof(packet), packet_sequence++,
             atomic_load(&context->dropped_sample_count),
             atomic_load(&context->loop_overrun_count), samples, sample_count);
-        write_binary_packet_until_sent(packet, packet_size);
+        write_binary_packet_until_sent(context, &sender, packet, packet_size);
         ++sample_packet_count;
     }
 }
@@ -324,6 +335,17 @@ void app_main(void)
     // binary frames whenever a payload byte equals LF.
     usb_serial_jtag_vfs_set_tx_line_endings(ESP_LINE_ENDINGS_LF);
 
+    err = trikke_usb_transport_init(
+        &s_context.usb_transport, &s_context.transport);
+    if (err != ESP_OK) {
+        ESP_LOGE(TAG, "USB transport initialization failed: %s",
+                 esp_err_to_name(err));
+        l3g4200d_deinit(&s_context.gyroscope);
+        adxl345_deinit(&s_context.accelerometer);
+        i2c_del_master_bus(bus);
+        return;
+    }
+
     s_context.sample_queue =
         xQueueCreate(TRIKKE_SAMPLE_QUEUE_DEPTH, sizeof(trikke_wire_sample_t));
     if (s_context.sample_queue == NULL) {
@@ -331,6 +353,7 @@ void app_main(void)
         l3g4200d_deinit(&s_context.gyroscope);
         adxl345_deinit(&s_context.accelerometer);
         i2c_del_master_bus(bus);
+        trikke_usb_transport_deinit(&s_context.usb_transport);
         return;
     }
 
@@ -351,6 +374,7 @@ void app_main(void)
         l3g4200d_deinit(&s_context.gyroscope);
         adxl345_deinit(&s_context.accelerometer);
         i2c_del_master_bus(bus);
+        trikke_usb_transport_deinit(&s_context.usb_transport);
         return;
     }