replace the misleadingly named VOID_CB function

Author: Changaco

libarchive/ffi.py

@@ -51,7 +51,9 @@
 )
 OPEN_CALLBACK = CFUNCTYPE(c_int, c_void_p, c_void_p)
 CLOSE_CALLBACK = CFUNCTYPE(c_int, c_void_p, c_void_p)
-VOID_CB = lambda *_: ARCHIVE_OK
+
+NO_OPEN_CB = ctypes.cast(None, OPEN_CALLBACK)
+NO_CLOSE_CB = ctypes.cast(None, CLOSE_CALLBACK)
 
 
 # Type aliases, for readability

libarchive/read.py

@@ -5,7 +5,7 @@
 from . import ffi
 from .ffi import (
     ARCHIVE_EOF, OPEN_CALLBACK, READ_CALLBACK, CLOSE_CALLBACK, SEEK_CALLBACK,
-    VOID_CB, page_size,
+    NO_OPEN_CB, NO_CLOSE_CB, page_size,
 )
 from .entry import ArchiveEntry, new_archive_entry
 
@@ -57,14 +57,14 @@ def new_archive_read(format_name='all', filter_name='all', passphrase=None):
 @contextmanager
 def custom_reader(
     read_func, format_name='all', filter_name='all',
-    open_func=VOID_CB, seek_func=None, close_func=VOID_CB,
+    open_func=None, seek_func=None, close_func=None,
     block_size=page_size, archive_read_class=ArchiveRead, passphrase=None,
 ):
     """Read an archive using a custom function.
     """
-    open_cb = OPEN_CALLBACK(open_func)
+    open_cb = OPEN_CALLBACK(open_func) if open_func else NO_OPEN_CB
     read_cb = READ_CALLBACK(read_func)
-    close_cb = CLOSE_CALLBACK(close_func)
+    close_cb = CLOSE_CALLBACK(close_func) if close_func else NO_CLOSE_CB
     with new_archive_read(format_name, filter_name, passphrase) as archive_p:
         if seek_func:
             ffi.read_set_seek_callback(archive_p, SEEK_CALLBACK(seek_func))
@@ -140,9 +140,9 @@ def seek_func(archive_p, context, offset, whence):
         # tell libarchive the current position
         return stream.tell()
 
-    open_cb = OPEN_CALLBACK(VOID_CB)
+    open_cb = NO_OPEN_CB
     read_cb = READ_CALLBACK(read_func)
-    close_cb = CLOSE_CALLBACK(VOID_CB)
+    close_cb = NO_CLOSE_CB
     with new_archive_read(format_name, filter_name, passphrase) as archive_p:
         if stream.seekable():
             ffi.read_set_seek_callback(archive_p, SEEK_CALLBACK(seek_func))

libarchive/write.py

@@ -5,8 +5,8 @@
 from . import ffi
 from .entry import ArchiveEntry, new_archive_entry
 from .ffi import (
-    OPEN_CALLBACK, WRITE_CALLBACK, CLOSE_CALLBACK, VOID_CB, REGULAR_FILE,
-    DEFAULT_UNIX_PERMISSION, ARCHIVE_EOF,
+    OPEN_CALLBACK, WRITE_CALLBACK, CLOSE_CALLBACK, NO_OPEN_CB, NO_CLOSE_CB,
+    REGULAR_FILE, DEFAULT_UNIX_PERMISSION, ARCHIVE_EOF,
     page_size, entry_sourcepath, entry_clear, read_disk_new, read_disk_open_w,
     read_next_header2, read_disk_descend, read_free, write_header, write_data,
     write_finish_entry, entry_set_size, entry_set_filetype, entry_set_perm,
@@ -187,17 +187,17 @@ def new_archive_write(format_name, filter_name=None, options='', passphrase=None
 @contextmanager
 def custom_writer(
     write_func, format_name, filter_name=None,
-    open_func=VOID_CB, close_func=VOID_CB, block_size=page_size,
+    open_func=None, close_func=None, block_size=page_size,
     archive_write_class=ArchiveWrite, options='', passphrase=None,
 ):
 
     def write_cb_internal(archive_p, context, buffer_, length):
         data = cast(buffer_, POINTER(c_char * length))[0]
         return write_func(data)
 
-    open_cb = OPEN_CALLBACK(open_func)
+    open_cb = OPEN_CALLBACK(open_func) if open_func else NO_OPEN_CB
     write_cb = WRITE_CALLBACK(write_cb_internal)
-    close_cb = CLOSE_CALLBACK(close_func)
+    close_cb = CLOSE_CALLBACK(close_func) if close_func else NO_CLOSE_CB
 
     with new_archive_write(format_name, filter_name, options,
                            passphrase) as archive_p: