Our Perforce server experienced some kind of database corruption a few years ago.
While the file data and revision history are mostly intact,
some metadata for several changesets got lost.
For example, inspecting certain changelists produces errors.
"""
$ p4 describe -s 12345
Date 2019/02/26 16:46:17:
Operation: user-describe
Operation 'user-describe' failed.
Change 12345 description missing!
"""
While some metadata (like changeset descriptions) is obviously lost,
most of it can be reconstructed via other commands:
* `p4 changes -l -t //...@12345,12345` --
to obtain date+time, author, beginning of changeset description;
* `p4 files -a //...@12345,12345` --
to obtain file revisions, file types, file actions;
* `p4 diff2 -u //...@12344 //...@12345` --
to get a unified diff of text files in a changeset;
* `p4 print -o binary.blob@12345 //depot/binary.blob@12345` --
to get a revision of a binary file.
It might be possible to teach git-p4 to fallback to other methods if `p4 describe` fails,
but it's probably too special-cased (really depends on kind and scale of DB corruption),
so some manual intervention is perhaps acceptable.
So, with some manual work, it's possible to reconstruct `p4 -G describe ...` output manually.
In our case, once git-p4 passes `p4 describe` stage,
it can proceed further just fine.
Thus, it's tempting to feed resurrected metadata to git-p4 when a normal `p4 describe` would fail.
This functionality may be useful to cache changelist information,
or to make some changes to changelist info before feeding it to git-p4.
A new config parameter is introduced to tell git-p4
to load certain changelist descriptions from files instead of from a server.
For simplicity, it's one pickled file per changelist.
```
git config --add git-p4.damagedChangelists 12345.pickled
git config --add git-p4.damagedChangelists 12346.pickled
```
The following trivial script may be used to produce pickled `p4 -G describe`-compatible output.
"""
#!/usr/bin/python2
import pickle
import time
# recovered commits of interest
changes = [
{
'change': '12345',
'status': 'submitted',
'code': 'stat',
'user': 'username1',
'time': str(int(time.mktime(time.strptime('2019/02/28 16:00:30', '%Y/%m/%d %H:%M:%S')))),
'client': 'username1_hostname1',
'desc': 'A bug is fixed.\nDetails are below:<lost>\n',
'depotFile0': '//depot/branch1/foo.sh',
'action0': 'edit',
'rev0': '28',
'type0': 'xtext',
'depotFile1': '//depot/branch1/bar.py',
'action1': 'edit',
'rev1': '43',
'type1': 'text',
'depotFile2': '//depot/branch1/baz.doc',
'action2': 'edit',
'rev2': '8',
'type2': 'binary',
'depotFile3': '//depot/branch1/qqq.c',
'action3': 'edit',
'rev3': '6',
'type3': 'ktext',
},
]
for change in changes:
pickle.dump(change, open('{0}.pickled'.format(change['change']), 'wb'))
"""
Signed-off-by: Andrey Mazo <amazo@xxxxxxxxxxxxxx>
---
Notes:
Documentation changes and tests are obviously missing,
but I hoped to get some feedback on the idea overall
before working on those.
git-p4.py | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/git-p4.py b/git-p4.py
index 40bc84573b..3133419280 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -24,10 +24,11 @@
import stat
import zipfile
import zlib
import ctypes
import errno
+import pickle
# support basestring in python3
try:
unicode = unicode
except NameError:
@@ -2615,10 +2616,12 @@ def __init__(self):
self.knownAlienLabelBranches = {}
self.tz = "%+03d%02d" % (- time.timezone / 3600, ((- time.timezone % 3600) / 60))
self.labels = {}
+ self.damagedChangelists = {}
+
# Force a checkpoint in fast-import and wait for it to finish
def checkpoint(self):
self.gitStream.write("checkpoint\n\n")
self.gitStream.write("progress checkpoint\n\n")
out = self.gitOutput.readline()
@@ -3312,10 +3315,25 @@ def getAlienLabelBranchMapping(self):
for mapping in alienLabelBranches:
if mapping:
(alien, ours) = mapping.split(":")
self.knownAlienLabelBranches[alien] = ours
+ def loadDamagedChangelists(self):
+ damagedChangelists = gitConfigList("git-p4.damagedChangelists")
+ for clPickled in damagedChangelists:
+ if not clPickled:
+ continue
+
+ try:
+ clDesc = pickle.load(open(clPickled, 'rb'))
+ if not ("status" in clDesc and "user" in clDesc and "time" in clDesc and "change" in clDesc):
+ die("Changelist description read from {0} doesn't have required fields".format(clPickled))
+ except (IOError, TypeError) as e:
+ die("Can't read changelist description dict from {0}: {1}".format(clPickled, str(e)))
+
+ self.damagedChangelists[int(clDesc["change"])] = clDesc
+
def updateOptionDict(self, d):
option_keys = {}
if self.keepRepoPath:
option_keys['keepRepoPath'] = 1
@@ -3413,11 +3431,14 @@ def searchParent(self, parent, branch, target):
return None
def importChanges(self, changes, origin_revision=0):
cnt = 1
for change in changes:
- description = p4_describe(change)
+ if change in self.damagedChangelists:
+ description = self.damagedChangelists[change]
+ else:
+ description = p4_describe(change)
self.updateOptionDict(description)
if not self.silent:
sys.stdout.write("\rImporting revision %s (%s%%)" % (change, cnt * 100 / len(changes)))
sys.stdout.flush()
@@ -3704,10 +3725,12 @@ def run(self, args):
bad_changesfile = True
break
if bad_changesfile:
die("Option --changesfile is incompatible with revision specifiers")
+ self.loadDamagedChangelists()
+
newPaths = []
for p in self.depotPaths:
if p.find("@") != -1:
atIdx = p.index("@")
self.changeRange = p[atIdx:]
--
2.19.2
