Retry failed downloads, rather than crashing

.gitignore

@@ -0,0 +1,3 @@
+lib/__pycache__/
+ui/__pycache__/
+config.json

config.json

@@ -1,7 +1,8 @@
 {
     "workers_count": 4,
+    "max_retries": 0,
     "output_path": "output",
-    "major": 7,
-    "build": 288,
-    "minor": 38
+    "major": 8,
+    "build": 256,
+    "minor": 37
 }

lib/worker.py

@@ -1,4 +1,6 @@
 import os
+import time
+import sys
 
 from urllib.request import urlopen
 from PyQt5.QtCore import QThread, pyqtSignal
@@ -10,10 +12,12 @@
 class DownloadWorker(QThread):
 
     file_downloaded = pyqtSignal(bool)
+    max_retries_reached = pyqtSignal(bool)
 
     def __init__(self, download_queue,
                  masterhash, assets_url,
-                 decompress_data, output_dir):
+                 decompress_data, output_dir,
+                 max_retries = 0):
 
         self.stopped = False
         self.is_running = True
@@ -23,6 +27,7 @@ def __init__(self, download_queue,
         self.output_dir = output_dir
         self.download_queue = download_queue
         self.decompress_data = decompress_data
+        self.max_retries = max_retries
 
         QThread.__init__(self)
 
@@ -33,8 +38,21 @@ def run(self):
             if filename is not None:
                 file_url = join_path(self.assets_url, self.masterhash, filename)
 
-                file_data = urlopen(file_url)
-
+                self.retries = 0
+                while True:
+                    try:
+                        file_data = urlopen(file_url)
+                        break
+                    except Exception as e:
+                        print(f"An error occured while fetching {file_url}\n{e}")
+                        if self.retries < self.max_retries:
+                            self.retries += 1
+                            print("Retrying in 5 seconds...")
+                            time.sleep(5)
+                        else:
+                            self.max_retries_reached.emit(True)
+                            return self.stop()
+
                 os.makedirs(os.path.dirname(join_path(self.output_dir, filename)), exist_ok=True)
 
                 with open(join_path(self.output_dir, filename), 'wb') as f:

lib/worker_launcher.py

@@ -1,13 +1,13 @@
 from PyQt5.QtCore import QThread, pyqtSignal
 
-from lib.utils import join_path
+from lib.utils import join_path, build_alert_box
 from lib.worker import DownloadWorker
 
 
 class WorkerLauncher(QThread):
 
     file_downloaded = pyqtSignal(bool)
-    download_finished = pyqtSignal()
+    download_finished = pyqtSignal(bool)
 
     def __init__(self, download_widget):
         self.download_widget = download_widget
@@ -18,17 +18,20 @@ def run(self):
         self.thread_list = []
 
         self.download_widget.workers_count = self.download_widget.parent.settings_widget.workers_spinbox.value()
+        self.download_widget.max_retries = self.download_widget.parent.settings_widget.retries_spinbox.value()
 
         for _ in range(self.download_widget.workers_count):
             thread = DownloadWorker(self.download_widget.download_queue,
                                     self.download_widget.fingerprint['sha'], self.download_widget.assets_host,
                                     self.download_widget.enable_compression_checkbox.isChecked(),
                                     join_path(self.download_widget.parent.settings_widget.folder_path_input.text(),
-                                              self.download_widget.fingerprint['sha'])
+                                              self.download_widget.fingerprint['sha']),
+                                    self.download_widget.max_retries
                                     )
 
             self.thread_list.append(thread)
             thread.file_downloaded.connect(self.emit_file_downloaded)
+            thread.max_retries_reached.connect(self.max_retries_reached)
             thread.start()
 
         self.download_widget.download_queue.join()
@@ -39,6 +42,12 @@ def run(self):
     def emit_file_downloaded(self, update_status):
         self.file_downloaded.emit(update_status)
 
+    def max_retries_reached(self, boolean):
+        if boolean == True:
+            self.stop()
+            print("Max retries reached")
+            self.download_finished.emit(False)
+
     def stop(self):
         for thread in self.thread_list:
             thread.stop()

ui/download_widget.py

@@ -222,6 +222,11 @@ def on_info_fetched(self, login_failed):
 
         download_method = self.download_method_combo_box.currentText()
 
+        if login_failed == False:
+            self.parent.hide_loading()
+            self.parent.status_bar_label.setText('Connection error: couldn\'t connect to Supercell servers')
+            return build_alert_box('Connection error', 'An error occured when connecting to Supercell\'s servers. Please check the console and/or your internet connection!')
+
         login_failed_error_code = login_failed.read_vint()
 
         if login_failed_error_code == 7:
@@ -241,6 +246,8 @@ def on_info_fetched(self, login_failed):
                     self.assets_host = login_failed.read_string()
 
             else:
+                self.parent.hide_loading()
+                self.parent.status_bar_label.setText('Couldn\'t find any host to download assets !')
                 return build_alert_box('Download error', 'Couldn\'t find any host to download assets !')
 
             login_failed.read_string()
@@ -261,9 +268,13 @@ def on_info_fetched(self, login_failed):
             return
 
         elif login_failed_error_code == 10:
+            self.parent.hide_loading()
+            self.parent.status_bar_label.setText('Server is in maintenance, cannot fetch current info')
             return build_alert_box('Error', 'Server is in maintenance, cannot fetch current info')
 
         else:
+            self.parent.hide_loading()
+            self.parent.status_bar_label.setText('Wrong login failed code: {}'.format(login_failed_error_code))
             return build_alert_box('Error', 'Wrong login failed code: {}'.format(login_failed_error_code))
 
         if download_method == 'Latest Patch':
@@ -310,20 +321,24 @@ def request_login_failed(self):
 
         client_hello = (10100).to_bytes(2, 'big') + len(client_hello_writer.buffer).to_bytes(3, 'big') + bytes(2) + client_hello_writer.buffer
 
-        s = socket.create_connection(('game.clashroyaleapp.com', 9339))
-        s.send(client_hello)
+        try:
+            s = socket.create_connection(('game.clashroyaleapp.com', 9339))
+            s.send(client_hello)
 
-        header = s.recv(7)
-        message_length = int.from_bytes(header[2:5], 'big')
+            header = s.recv(7)
+            message_length = int.from_bytes(header[2:5], 'big')
 
-        login_failed = b''
+            login_failed = b''
 
-        while message_length:
-            data = s.recv(message_length)
-            message_length -= len(data)
-            login_failed += data
+            while message_length:
+                data = s.recv(message_length)
+                message_length -= len(data)
+                login_failed += data
 
-        return Reader(login_failed)
+            return Reader(login_failed)
+        except Exception as e:
+            print(e)
+            return False
 
     def update_client_hello_version(self):
         self.start_button.setEnabled(False)
@@ -354,7 +369,7 @@ def stop_download(self):
         self.worker_launcher.stop()
         self.worker_launcher.quit()
 
-        self.on_donwload_finish()
+        self.on_download_finish()
 
     def on_masterhash_changed(self, masterhash):
         if not is_masterhash_valid(masterhash):
@@ -369,6 +384,7 @@ def start_download(self, wanted_extensions):
         self.downloaded_files = 0
         self.download_start_time = datetime.utcnow()
         self.download_queue = Queue()
+        self.downloading = True
 
         overwrite_existing_file = False
 
@@ -396,7 +412,7 @@ def start_download(self, wanted_extensions):
         self.worker_launcher = WorkerLauncher(self)
 
         self.worker_launcher.file_downloaded.connect(self.update_download_count)
-        self.worker_launcher.download_finished.connect(self.on_donwload_finish)
+        self.worker_launcher.download_finished.connect(self.on_download_finish)
 
         self.worker_launcher.start()
 
@@ -409,26 +425,33 @@ def update_download_count(self, update_status):
                                                                                                                      self.downloaded_files,
                                                                                                                      self.total_files))
 
-    def on_donwload_finish(self):
+    def on_download_finish(self, success = True):
         self.parent.hide_loading()
         self.download_method_combo_box.setEnabled(True)
 
         if self.downloaded_files:
             elapsed_time = (datetime.utcnow() - self.download_start_time).seconds
-
-            self.parent.status_bar_label.setText('''Download finished ! {} files downloaded in {}min {}s'''.format(self.downloaded_files,
-                                                                                                                   *divmod(elapsed_time, 60)))
-
+
+            if success == True:
+                self.parent.status_bar_label.setText('''Download finished ! {} files downloaded in {}min {}s'''.format(self.downloaded_files,
+                                                                                                                    *divmod(elapsed_time, 60)))
+            else:
+                self.parent.status_bar_label.setText('''Download failed ! {} files downloaded in {}min {}s'''.format(self.downloaded_files,
+                                                                                                                    *divmod(elapsed_time, 60)))
+                if self.downloading == True:
+                    build_alert_box("Max retries reached", "Check your internet connection, and/or increase the max retries in the Settings.")
+
         else:
             self.parent.status_bar_label.setText('No files were downloaded !')
 
+        self.downloading = False
         self.progress_bar.reset()
         self.stop_button.setEnabled(False)
         self.start_button.setEnabled(True)
 
     def display_bruteforce_info(self):
         self.parent.status_bar_label.setText('Bruteforce started ! Trying with major {}, build {}, minor {}'.format(self.major, self.build, self.minor))
-
+    
 
 class InfoFetcherThread(QThread):
     info_fetched = pyqtSignal(object)

ui/settings_widget.py

@@ -46,6 +46,11 @@ def init_ui(self):
         self.workers_spinbox.setRange(1, 10)
         self.workers_spinbox.setValue(max(min(self.config['workers_count'], 10), 1))
 
+        self.retries_spinbox = QSpinBox()
+
+        self.retries_spinbox.setRange(1, 10)
+        self.retries_spinbox.setValue(max(self.config['max_retries'], 0))
+
         self.save_settings_button = QPushButton('Save settings', self)
         self.save_settings_button.setIcon(QIcon('ui/assets/save.png'))
         self.save_settings_button.setIconSize(QSize(17, 17))
@@ -55,6 +60,8 @@ def init_ui(self):
         self.main_layout.addWidget(self.browse_folder_widget)
         self.main_layout.addWidget(QLabel('Workers count (up to 10):'))
         self.main_layout.addWidget(self.workers_spinbox)
+        self.main_layout.addWidget(QLabel('Max retries:'))
+        self.main_layout.addWidget(self.retries_spinbox)
         self.main_layout.addWidget(self.save_settings_button)
 
         self.setLayout(self.main_layout)
@@ -66,5 +73,6 @@ def browse_folder(self):
 
     def save_settings(self):
         self.config['workers_count'] = self.workers_spinbox.value()
+        self.config['max_retries'] = self.retries_spinbox.value()
 
         self.parent.save_config()