[utils] Create `DownloadCancelled` exception

as super-class of ExistingVideoReached, RejectedVideoReached, MaxDownloadsReached

Third parties can also sub-class this to cancel the download queue from a hook

yt_dlp/YoutubeDL.py

@@ -56,6 +56,7 @@ from .utils import (
     DEFAULT_OUTTMPL,
     determine_ext,
     determine_protocol,
+    DownloadCancelled,
     DownloadError,
     encode_compat_str,
     encodeFilename,
@@ -1320,7 +1321,7 @@ class YoutubeDL(object):
                 self.to_stderr('\r')
                 self.report_warning('The download speed is below throttle limit. Re-extracting data')
                 return wrapper(self, *args, **kwargs)
-            except (MaxDownloadsReached, ExistingVideoReached, RejectedVideoReached, LazyList.IndexError):
+            except (DownloadCancelled, LazyList.IndexError):
                 raise
             except Exception as e:
                 if self.params.get('ignoreerrors'):
@@ -2949,14 +2950,8 @@ class YoutubeDL(object):
                     url, force_generic_extractor=self.params.get('force_generic_extractor', False))
             except UnavailableVideoError:
                 self.report_error('unable to download video')
-            except MaxDownloadsReached:
-                self.to_screen('[info] Maximum number of downloads reached')
-                raise
-            except ExistingVideoReached:
-                self.to_screen('[info] Encountered a video that is already in the archive, stopping due to --break-on-existing')
-                raise
-            except RejectedVideoReached:
-                self.to_screen('[info] Encountered a video that did not match filter, stopping due to --break-on-reject')
+            except DownloadCancelled as e:
+                self.to_screen(f'[info] {e.msg}')
                 raise
             else:
                 if self.params.get('dump_single_json', False):

yt_dlp/utils.py

@@ -2542,14 +2542,29 @@ class PostProcessingError(YoutubeDLError):
         self.msg = msg
 
 
-class ExistingVideoReached(YoutubeDLError):
-    """ --max-downloads limit has been reached. """
-    pass
+class DownloadCancelled(YoutubeDLError):
+    """ Exception raised when the download queue should be interrupted """
+    msg = 'The download was cancelled'
+
+    def __init__(self, msg=None):
+        if msg is not None:
+            self.msg = msg
+        YoutubeDLError.__init__(self, self.msg)
 
 
-class RejectedVideoReached(YoutubeDLError):
+class ExistingVideoReached(DownloadCancelled):
+    """ --break-on-existing triggered """
+    msg = 'Encountered a video that is already in the archive, stopping due to --break-on-existing'
+
+
+class RejectedVideoReached(DownloadCancelled):
+    """ --break-on-reject triggered """
+    msg = 'Encountered a video that did not match filter, stopping due to --break-on-reject'
+
+
+class MaxDownloadsReached(DownloadCancelled):
     """ --max-downloads limit has been reached. """
-    pass
+    msg = 'Maximum number of downloads reached, stopping due to --max-downloads'
 
 
 class ThrottledDownload(YoutubeDLError):
@@ -2557,11 +2572,6 @@ class ThrottledDownload(YoutubeDLError):
     pass
 
 
-class MaxDownloadsReached(YoutubeDLError):
-    """ --max-downloads limit has been reached. """
-    pass
-
-
 class UnavailableVideoError(YoutubeDLError):
     """Unavailable Format exception.