[PATCH 2 of 2] merge: adds documentation to the mergestate class
pierre-yves.david at ens-lyon.org
pierre-yves.david at ens-lyon.org
Wed Mar 5 13:05:08 CST 2014
# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1394045383 28800
# Wed Mar 05 10:49:43 2014 -0800
# Node ID 7760e02d58f2f00dd944ce585af63b8e05cfc69f
# Parent 37d4c6705c2470d788ad9ed4af3d1d6f27400032
merge: adds documentation to the mergestate class
Document most the new function involved in the new serialisation process (and a
few others).
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -60,10 +60,15 @@ class mergestate(object):
self._other = other
shutil.rmtree(self._repo.join("merge"), True)
self._dirty = False
def _read(self):
+ """Analyse each record content to restore a serialized state from disk
+
+ This function process "record" entry produced by the de-serialization
+ of on disk file.
+ """
self._state = {}
records = self._readrecords()
for rtype, record in records:
if rtype == 'L':
self._local = bin(record)
@@ -76,10 +81,23 @@ class mergestate(object):
raise util.Abort(_('unsupported merge state record:'
% rtype))
self._dirty = False
def _readrecords(self):
+ """Read merge state from disk and return a list of record (TYPE, data)
+
+ We read data from both V1 and Ve files decide which on to use.
+
+ V1 have been used by version prior to 2.9.1 and contains less data than
+ v2. We read both version and check if no data in v2 contradict one in
+ v1. If there is not contradiction we can safely assume that both v1
+ and v2 were written at the same time and use the extract data in v2. If
+ there is contradiction we ignore v2 content as we assume an old version
+ of Mercurial have over written the mergstate file and left an old v2
+ file around.
+
+ returns list of record [(TYPE, data), …]"""
v1records = self._readrecordsv1()
v2records = self._readrecordsv2()
oldv2 = set() # old format version of v2 record
for rec in v2records:
if rec[0] == 'L':
@@ -105,10 +123,17 @@ class mergestate(object):
return v1records
else:
return v2records
def _readrecordsv1(self):
+ """read on disk merge state for version 1 file
+
+ returns list of record [(TYPE, data), …]
+
+ Note: the "F" data from this file are one entry short
+ (no "other file node" entry)
+ """
records = []
try:
f = self._repo.opener(self.statepathv1)
for i, l in enumerate(f):
if i == 0:
@@ -120,10 +145,14 @@ class mergestate(object):
if err.errno != errno.ENOENT:
raise
return records
def _readrecordsv2(self):
+ """read on disk merge state for version 2 file
+
+ returns list of record [(TYPE, data), …]
+ """
records = []
try:
f = self._repo.opener(self.statepathv2)
data = f.read()
off = 0
@@ -141,24 +170,27 @@ class mergestate(object):
if err.errno != errno.ENOENT:
raise
return records
def commit(self):
+ """Write current state on disk (if necessary)"""
if self._dirty:
records = []
records.append(("L", hex(self._local)))
records.append(("O", hex(self._other)))
for d, v in self._state.iteritems():
records.append(("F", "\0".join([d] + v)))
self._writerecords(records)
self._dirty = False
def _writerecords(self, records):
+ """Write current state on disk (both v1 and v2)"""
self._writerecordsv1(records)
self._writerecordsv2(records)
def _writerecordsv1(self, records):
+ """Write current state on disk in a version 1 file"""
f = self._repo.opener(self.statepathv1, "w")
irecords = iter(records)
lrecords = irecords.next()
assert lrecords[0] == 'L'
f.write(hex(self._local) + "\n")
@@ -166,18 +198,27 @@ class mergestate(object):
if rtype == "F":
f.write("%s\n" % _droponode(data))
f.close()
def _writerecordsv2(self, records):
+ """Write current state on disk in a version 2 file"""
f = self._repo.opener(self.statepathv2, "w")
for key, data in records:
assert len(key) == 1
format = ">sI%is" % len(data)
f.write(_pack(format, key, len(data), data))
f.close()
def add(self, fcl, fco, fca, fd):
+ """add a new (potentially?) conflicting file the merge state
+ fcl: file context for local,
+ fco: file context for remote,
+ fca: file context for ancestors,
+ fd: file path of the resulting merge.
+
+ note: also write the local version to the `.hg/merge` directory.
+ """
hash = util.sha1(fcl.path()).hexdigest()
self._repo.opener.write("merge/" + hash, fcl.data())
self._state[fd] = ['u', hash, fcl.path(),
fca.path(), hex(fca.filenode()),
fco.path(), hex(fco.filenode()),
@@ -202,10 +243,11 @@ class mergestate(object):
def mark(self, dfile, state):
self._state[dfile][0] = state
self._dirty = True
def resolve(self, dfile, wctx):
+ """rerun merge process for file path `dfile`"""
if self[dfile] == 'r':
return 0
stateentry = self._state[dfile]
state, hash, lfile, afile, anode, ofile, onode, flags = stateentry
octx = self._repo[self._other]
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