index.Writer.__del__: replace with context management

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

diff --git a/lib/bup/index.py b/lib/bup/index.py
index a2abfa7a266bd84338b8b7365af61cd05a9e07f0..b9a4013be032bfd75d68e350250a43d4b9571d85 100644 (file)
--- a/lib/bup/index.py
+++ b/lib/bup/index.py
@@ -4,7 +4,7 @@ import errno, os, stat, struct, tempfile
 
 from bup import metadata, xstat
 from bup._helpers import UINT_MAX, bytescmp
-from bup.compat import range
+from bup.compat import pending_raise, range
 from bup.helpers import (add_error, log, merge_iter, mmap_readwrite,
                          progress, qprogress, resolve_parent, slashappend)
 
@@ -58,8 +58,12 @@ class MetaStoreReader:
             self._file.close()
             self._file = None
 
-    def __del__(self):
-        self.close()
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=True):
+            self.close()
 
     def metadata_at(self, ofs):
         self._file.seek(ofs)
@@ -101,9 +105,12 @@ class MetaStoreWriter:
             self._file.close()
             self._file = None
 
-    def __del__(self):
-        # Be optimistic.
-        self.close()
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=False):
+            self.close()
 
     def store(self, metadata):
         meta_encoded = metadata.encode(include_path=False)
@@ -127,7 +134,7 @@ class Level:
         (ofs,n) = (f.tell(), len(self.list))
         if self.list:
             count = len(self.list)
-            #log('popping %r with %d entries\n' 
+            #log('popping %r with %d entries\n'
             #    % (''.join(self.ename), count))
             for e in self.list:
                 e.write(f)
@@ -165,8 +172,8 @@ def _golevel(level, f, ename, newentry, metastore, tmax):
 
 class Entry:
     def __init__(self, basename, name, meta_ofs, tmax):
-        assert basename is None or type(basename) == bytes
-        assert name is None or type(name) == bytes
+        assert basename is None or isinstance(basename, bytes)
+        assert name is None or isinstance(name, bytes)
         self.basename = basename
         self.name = name
         self.meta_ofs = meta_ofs
@@ -402,7 +409,7 @@ class ExistingEntry(Entry):
 
     def __iter__(self):
         return self.iter()
-            
+
 
 class Reader:
     def __init__(self, filename):
@@ -432,8 +439,12 @@ class Reader:
                                                self.m[st.st_size - FOOTLEN
                                                       : st.st_size])[0]
 
-    def __del__(self):
-        self.close()
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=False):
+            self.close()
 
     def __len__(self):
         return int(self.count)
@@ -526,8 +537,12 @@ class Writer:
         self.f = os.fdopen(ffd, 'wb', 65536)
         self.f.write(INDEX_HDR)
 
-    def __del__(self):
-        self.abort()
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=False):
+            self.abort()
 
     def abort(self):
         f = self.f
@@ -557,7 +572,7 @@ class Writer:
 
     def _add(self, ename, entry):
         if self.lastfile and self.lastfile <= ename:
-            raise Error('%r must come before %r' 
+            raise Error('%r must come before %r'
                              % (''.join(ename), ''.join(self.lastfile)))
         self.lastfile = ename
         self.level = _golevel(self.level, self.f, ename, entry,
@@ -634,7 +649,7 @@ def reduce_paths(paths):
     paths = []
     prev = None
     for (rp, p) in xpaths:
-        if prev and (prev == rp 
+        if prev and (prev == rp
                      or (prev.endswith(b'/') and rp.startswith(prev))):
             continue # already superceded by previous path
         paths.append((rp, p))