rbc: fix invalid rbc-revs entries caused by missing cache growth
authorMads Kiilerich <madski@unity3d.com>
Mon, 18 Jul 2016 22:22:38 +0200
changeset 29604 db0095c83344
parent 29603 b181a650a886
child 29605 519bb4f9d3a4
child 29653 73ff159923c1
rbc: fix invalid rbc-revs entries caused by missing cache growth It was in some cases possible to end up writing to the cache file without growing it first. The range assignment in _setcachedata would append instead of writing at the requested position and thus write the new record in the wrong place. To fix this, we avoid looking up in too small caches, and when growing the cache, do it right before writing the new record to it so we know it has been done correctly.
mercurial/branchmap.py
tests/test-branches.t
--- a/mercurial/branchmap.py	Mon Jul 18 22:21:42 2016 +0200
+++ b/mercurial/branchmap.py	Mon Jul 18 22:22:38 2016 +0200
@@ -402,10 +402,9 @@
         if rev == nullrev:
             return changelog.branchinfo(rev)
 
-        # if requested rev is missing, add and populate all missing revs
+        # if requested rev isn't allocated, grow and cache the rev info
         if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
-            self._rbcrevs.extend('\0' * (len(changelog) * _rbcrecsize -
-                                         len(self._rbcrevs)))
+            return self._branchinfo(rev)
 
         # fast path: extract data from cache, use it if node is matching
         reponode = changelog.node(rev)[:_rbcnodelen]
@@ -452,6 +451,10 @@
         rbcrevidx = rev * _rbcrecsize
         rec = array('c')
         rec.fromstring(pack(_rbcrecfmt, node, branchidx))
+        if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
+            self._rbcrevs.extend('\0' *
+                                 (len(self._repo.changelog) * _rbcrecsize -
+                                  len(self._rbcrevs)))
         self._rbcrevs[rbcrevidx:rbcrevidx + _rbcrecsize] = rec
         self._rbcrevslen = min(self._rbcrevslen, rev)
 
--- a/tests/test-branches.t	Mon Jul 18 22:21:42 2016 +0200
+++ b/tests/test-branches.t	Mon Jul 18 22:22:38 2016 +0200
@@ -655,12 +655,16 @@
   $ rm .hg/cache/rbc*
   $ hg log -r "5 & branch(5)" -T "{rev}\n"
   5
-BUG: rbc-revs should have an entry as 5th record but has it misplaced as the
-first:
   $ f --size --hexdump .hg/cache/rbc-*
   .hg/cache/rbc-names-v1: size=1
   0000: 61                                              |a|
-  .hg/cache/rbc-revs-v1: size=8
-  0000: d8 cb c6 1d 00 00 00 00                         |........|
+  .hg/cache/rbc-revs-v1: size=112
+  0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+  0010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+  0020: 00 00 00 00 00 00 00 00 d8 cb c6 1d 00 00 00 00 |................|
+  0030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+  0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+  0050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+  0060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
 
   $ cd ..