Two tweaks to BLE workflow

1. Use autoreload for restarting after a write. This gives time for
   a follow up command before restarting BLE.
2. Switch to recursive deletion of directories. This greatly
   simplifies deleting directories with contents.

Fixes adafruit/Adafruit_CircuitPython_BLE_File_Transfer#7

Author: tannewt

main.c

@@ -755,7 +755,7 @@ STATIC int run_repl(void) {
     usb_setup_with_vm();
     #endif
 
-    autoreload_suspend();
+    autoreload_suspend(AUTORELOAD_LOCK_REPL);
 
     // Set the status LED to the REPL color before running the REPL. For
     // NeoPixels and DotStars this will be sticky but for PWM or single LED it
@@ -785,7 +785,7 @@ STATIC int run_repl(void) {
     status_led_deinit();
     #endif
 
-    autoreload_resume();
+    autoreload_resume(AUTORELOAD_LOCK_REPL);
     return exit_code;
 }
 

supervisor/shared/autoreload.c

@@ -35,7 +35,7 @@ supervisor_allocation *next_code_allocation;
 
 static volatile uint32_t autoreload_delay_ms = 0;
 static bool autoreload_enabled = false;
-static bool autoreload_suspended = false;
+static size_t autoreload_suspended = 0;
 
 volatile bool reload_requested = false;
 
@@ -44,7 +44,7 @@ inline void autoreload_tick() {
         return;
     }
     if (autoreload_delay_ms == 1 && autoreload_enabled &&
-        !autoreload_suspended && !reload_requested) {
+        autoreload_suspended == 0 && !reload_requested) {
         mp_raise_reload_exception();
         reload_requested = true;
         supervisor_set_run_reason(RUN_REASON_AUTO_RELOAD);
@@ -62,12 +62,12 @@ void autoreload_disable() {
     autoreload_enabled = false;
 }
 
-void autoreload_suspend() {
-    autoreload_suspended = true;
+void autoreload_suspend(size_t lock_mask) {
+    autoreload_suspended |= lock_mask;
 }
 
-void autoreload_resume() {
-    autoreload_suspended = false;
+void autoreload_resume(size_t lock_mask) {
+    autoreload_suspended &= ~lock_mask;
 }
 
 inline bool autoreload_is_enabled() {

supervisor/shared/autoreload.h

@@ -40,6 +40,11 @@ enum {
     SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET = 0x20,
 };
 
+enum {
+    AUTORELOAD_LOCK_REPL = 0x1,
+    AUTORELOAD_LOCK_BLE = 0x2
+};
+
 typedef struct {
     uint8_t options;
     char filename[];
@@ -58,8 +63,8 @@ void autoreload_disable(void);
 bool autoreload_is_enabled(void);
 
 // Temporarily turn it off. Used during the REPL.
-void autoreload_suspend(void);
-void autoreload_resume(void);
+void autoreload_suspend(size_t lock_mask);
+void autoreload_resume(size_t lock_mask);
 
 void autoreload_now(void);
 

supervisor/shared/bluetooth/file_transfer.c

@@ -47,6 +47,7 @@
 #include "supervisor/usb.h"
 
 #include "py/mpstate.h"
+#include "py/stackctrl.h"
 
 STATIC bleio_service_obj_t supervisor_ble_service;
 STATIC bleio_uuid_obj_t supervisor_ble_service_uuid;
@@ -97,7 +98,7 @@ void supervisor_start_bluetooth_file_transfer(void) {
         NULL,                                       // no initial value
         NULL); // no description
 
-    uint32_t version = 1;
+    uint32_t version = 2;
     mp_buffer_info_t bufinfo;
     bufinfo.buf = &version;
     bufinfo.len = sizeof(version);
@@ -291,7 +292,7 @@ STATIC uint8_t _process_write(const uint8_t *raw_buf, size_t command_len) {
         // Don't reload until everything is written out of the packet buffer.
         common_hal_bleio_packet_buffer_flush(&_transfer_packet_buffer);
         // Trigger an autoreload
-        autoreload_now();
+        autoreload_start();
         return ANY_COMMAND;
     }
 
@@ -345,12 +346,45 @@ STATIC uint8_t _process_write_data(const uint8_t *raw_buf, size_t command_len) {
         // Don't reload until everything is written out of the packet buffer.
         common_hal_bleio_packet_buffer_flush(&_transfer_packet_buffer);
         // Trigger an autoreload
-        autoreload_now();
+        autoreload_start();
         return ANY_COMMAND;
     }
     return WRITE_DATA;
 }
 
+STATIC FRESULT _delete_directory_contents(FATFS *fs, const TCHAR *path) {
+    FF_DIR dir;
+    FRESULT res = f_opendir(fs, &dir, path);
+    FILINFO file_info;
+    // Check the stack since we're putting paths on it.
+    if (mp_stack_usage() >= MP_STATE_THREAD(stack_limit)) {
+        return FR_INT_ERR;
+    }
+    while (res == FR_OK) {
+        res = f_readdir(&dir, &file_info);
+        if (res != FR_OK || file_info.fname[0] == '\0') {
+            break;
+        }
+        size_t pathlen = strlen(path);
+        size_t fnlen = strlen(file_info.fname);
+        TCHAR full_path[pathlen + 1 + fnlen];
+        memcpy(full_path, path, pathlen);
+        full_path[pathlen] = '/';
+        size_t full_pathlen = pathlen + 1 + fnlen;
+        memcpy(full_path + pathlen + 1, file_info.fname, fnlen);
+        full_path[full_pathlen] = '\0';
+        if ((file_info.fattrib & AM_DIR) != 0) {
+            res = _delete_directory_contents(fs, full_path);
+        }
+        if (res != FR_OK) {
+            break;
+        }
+        res = f_unlink(fs, full_path);
+    }
+    f_closedir(&dir);
+    return res;
+}
+
 STATIC uint8_t _process_delete(const uint8_t *raw_buf, size_t command_len) {
     const struct delete_command *command = (struct delete_command *)raw_buf;
     size_t header_size = 4;
@@ -370,7 +404,16 @@ STATIC uint8_t _process_delete(const uint8_t *raw_buf, size_t command_len) {
     FATFS *fs = &((fs_user_mount_t *)MP_STATE_VM(vfs_mount_table)->obj)->fatfs;
     char *path = (char *)((uint8_t *)command) + header_size;
     path[command->path_length] = '\0';
-    FRESULT result = f_unlink(fs, path);
+    FRESULT result;
+    FILINFO file;
+    if (f_stat(fs, path, &file) == FR_OK) {
+        if ((file.fattrib & AM_DIR) != 0) {
+            result = _delete_directory_contents(fs, path);
+        }
+        if (result == FR_OK) {
+            result = f_unlink(fs, path);
+        }
+    }
     if (result != FR_OK) {
         response.status = STATUS_ERROR;
     }
@@ -504,6 +547,7 @@ void supervisor_bluetooth_file_transfer_background(void) {
         if (size == 0) {
             break;
         }
+        autoreload_suspend(AUTORELOAD_LOCK_BLE);
         // TODO: If size < 0 return an error.
         current_offset += size;
         #if CIRCUITPY_VERBOSE_BLE
@@ -521,6 +565,7 @@ void supervisor_bluetooth_file_transfer_background(void) {
             response[0] = next_command;
             response[1] = STATUS_ERROR_PROTOCOL;
             common_hal_bleio_packet_buffer_write(&_transfer_packet_buffer, response, 2, NULL, 0);
+            autoreload_resume(AUTORELOAD_LOCK_BLE);
             break;
         }
         switch (current_state) {
@@ -550,6 +595,9 @@ void supervisor_bluetooth_file_transfer_background(void) {
         if (next_command != THIS_COMMAND) {
             current_offset = 0;
         }
+        if (next_command == ANY_COMMAND) {
+            autoreload_resume(AUTORELOAD_LOCK_BLE);
+        }
     }
     running = false;
 }
@@ -558,4 +606,5 @@ void supervisor_bluetooth_file_transfer_disconnected(void) {
     next_command = ANY_COMMAND;
     current_offset = 0;
     f_close(&active_file);
+    autoreload_resume(AUTORELOAD_LOCK_BLE);
 }