transaction: add onclose/onabort hook for pre-close logic
Adds an optional onclose parameter to transactions that gets called just before
the transaction is committed. This allows things that build up data over the
course of the transaction (like the fncache) to commit their data.
Also adds onabort. It's not used, but will allow extensions to hook into onclose
and onabort to provide transaction support.
--- a/mercurial/transaction.py Mon Mar 24 15:38:20 2014 -0700
+++ b/mercurial/transaction.py Mon Mar 24 15:57:47 2014 -0700
@@ -42,12 +42,27 @@
opener.unlink(journal)
class transaction(object):
- def __init__(self, report, opener, journal, after=None, createmode=None):
+ def __init__(self, report, opener, journal, after=None, createmode=None,
+ onclose=None, onabort=None):
+ """Begin a new transaction
+
+ Begins a new transaction that allows rolling back writes in the event of
+ an exception.
+
+ * `after`: called after the transaction has been committed
+ * `createmode`: the mode of the journal file that will be created
+ * `onclose`: called as the transaction is closing, but before it is
+ closed
+ * `onabort`: called as the transaction is aborting, but before any files
+ have been truncated
+ """
self.count = 1
self.usages = 1
self.report = report
self.opener = opener
self.after = after
+ self.onclose = onclose
+ self.onabort = onabort
self.entries = []
self.map = {}
self.journal = journal
@@ -126,6 +141,9 @@
@active
def close(self):
'''commit the transaction'''
+ if self.count == 1 and self.onclose is not None:
+ self.onclose()
+
self.count -= 1
if self.count != 0:
return
@@ -149,6 +167,9 @@
self.usages = 0
self.file.close()
+ if self.onabort is not None:
+ self.onabort()
+
try:
if not self.entries:
if self.journal: