PackWriter._end: always try to release objcache and parentfd

[bup.git] / lib / bup / helpers.py

diff --git a/lib/bup/helpers.py b/lib/bup/helpers.py
index e2f543f6cf1af29054df8ac9b18dd72da0db930c..28d1c6d3595b612f17cfb14decadb0279ee4b8b9 100644 (file)
--- a/lib/bup/helpers.py
+++ b/lib/bup/helpers.py
@@ -12,7 +12,7 @@ import hashlib, heapq, math, operator, time, tempfile
 
 from bup import _helpers
 from bup import compat
-from bup.compat import argv_bytes, byte_int, pending_raise
+from bup.compat import argv_bytes, byte_int, nullcontext, pending_raise
 from bup.io import byte_stream, path_msg
 # This function should really be in helpers, not in bup.options.  But we
 # want options.py to be standalone so people can include it in other projects.
@@ -27,6 +27,21 @@ class Nonlocal:
     pass
 
 
+def nullcontext_if_not(manager):
+    return manager if manager is not None else nullcontext()
+
+
+@contextmanager
+def finalized(enter_result=None, finalize=None):
+    assert finalize
+    try:
+        yield enter_result
+    except BaseException as ex:
+        with pending_raise(ex):
+            finalize(enter_result)
+    finalize(enter_result)
+
+
 sc_page_size = os.sysconf('SC_PAGE_SIZE')
 assert(sc_page_size > 0)
 
@@ -273,6 +288,8 @@ def quote(x):
     if isinstance(x, compat.str_type):
         return squote(x)
     assert False
+    # some versions of pylint get confused
+    return None
 
 def shstr(cmd):
     """Return a shell quoted string for cmd if it's a sequence, else cmd.
@@ -437,10 +454,21 @@ class NotOk(Exception):
 
 class BaseConn:
     def __init__(self, outp):
+        self._base_closed = False
         self.outp = outp
 
     def close(self):
-        while self._read(65536): pass
+        self._base_closed = True
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, tb):
+        with pending_raise(exc_value, rethrow=False):
+            self.close()
+
+    def __del__(self):
+        assert self._base_closed
 
     def _read(self, size):
         raise NotImplementedError("Subclasses must implement _read")
@@ -742,7 +770,7 @@ def _mmap_do(f, sz, flags, prot, close):
         # string has all the same behaviour of a zero-length map, ie. it has
         # no elements :)
         return ''
-    map = mmap.mmap(f.fileno(), sz, flags, prot)
+    map = compat.mmap(f.fileno(), sz, flags, prot)
     if close:
         f.close()  # map will persist beyond file close
     return map
@@ -804,7 +832,7 @@ if _mincore:
             pos = _fmincore_chunk_size * ci;
             msize = min(_fmincore_chunk_size, st.st_size - pos)
             try:
-                m = mmap.mmap(fd, msize, mmap.MAP_PRIVATE, 0, 0, pos)
+                m = compat.mmap(fd, msize, mmap.MAP_PRIVATE, 0, 0, pos)
             except mmap.error as ex:
                 if ex.errno == errno.EINVAL or ex.errno == errno.ENODEV:
                     # Perhaps the file was a pipe, i.e. "... | bup split ..."
@@ -908,7 +936,7 @@ def handle_ctrl_c():
         if exctype == KeyboardInterrupt:
             log('\nInterrupted.\n')
         else:
-            return oldhook(exctype, value, traceback)
+            oldhook(exctype, value, traceback)
     sys.excepthook = newhook