Mercurial > hg-stable
changeset 45509:cc5f811b1f15
mergestate: extract a base class to be shared by future memmergestate
This extracts a new base class from `mergestate` and leaves all the
vfs-touching code in `mergestate`.
Differential Revision: https://phab.mercurial-scm.org/D9039
author | Martin von Zweigbergk <martinvonz@google.com> |
---|---|
date | Tue, 15 Sep 2020 11:17:24 -0700 |
parents | e833ff4dd0ea |
children | 19590b126764 |
files | mercurial/mergestate.py |
diffstat | 1 files changed, 237 insertions(+), 225 deletions(-) [+] |
line wrap: on
line diff
--- a/mercurial/mergestate.py Tue Sep 15 11:33:26 2020 -0700 +++ b/mercurial/mergestate.py Tue Sep 15 11:17:24 2020 -0700 @@ -127,7 +127,7 @@ ACTION_CREATED_MERGE = b'cm' -class mergestate(object): +class _mergestate_base(object): '''track 3-way merge state of individual files The merge state is stored on disk when needed. Two files are used: one with @@ -172,24 +172,6 @@ 'pu' and 'pr' for path conflicts. ''' - statepathv1 = b'merge/state' - statepathv2 = b'merge/state2' - - @staticmethod - def clean(repo): - """Initialize a brand new merge state, removing any existing state on - disk.""" - ms = mergestate(repo) - ms.reset() - return ms - - @staticmethod - def read(repo): - """Initialize the merge state, reading it from disk.""" - ms = mergestate(repo) - ms._read() - return ms - def __init__(self, repo): """Initialize the merge state. @@ -220,177 +202,6 @@ if self.mergedriver: self._mdstate = MERGE_DRIVER_STATE_SUCCESS - 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._mdstate = MERGE_DRIVER_STATE_SUCCESS - unsupported = set() - records = self._readrecords() - for rtype, record in records: - if rtype == RECORD_LOCAL: - self._local = bin(record) - elif rtype == RECORD_OTHER: - self._other = bin(record) - elif rtype == RECORD_MERGE_DRIVER_STATE: - bits = record.split(b'\0', 1) - mdstate = bits[1] - if len(mdstate) != 1 or mdstate not in ( - MERGE_DRIVER_STATE_UNMARKED, - MERGE_DRIVER_STATE_MARKED, - MERGE_DRIVER_STATE_SUCCESS, - ): - # the merge driver should be idempotent, so just rerun it - mdstate = MERGE_DRIVER_STATE_UNMARKED - - self._readmergedriver = bits[0] - self._mdstate = mdstate - elif rtype in ( - RECORD_MERGED, - RECORD_CHANGEDELETE_CONFLICT, - RECORD_PATH_CONFLICT, - RECORD_MERGE_DRIVER_MERGE, - LEGACY_RECORD_RESOLVED_OTHER, - ): - bits = record.split(b'\0') - # merge entry type MERGE_RECORD_MERGED_OTHER is deprecated - # and we now store related information in _stateextras, so - # lets write to _stateextras directly - if bits[1] == MERGE_RECORD_MERGED_OTHER: - self._stateextras[bits[0]][b'filenode-source'] = b'other' - else: - self._state[bits[0]] = bits[1:] - elif rtype == RECORD_FILE_VALUES: - filename, rawextras = record.split(b'\0', 1) - extraparts = rawextras.split(b'\0') - extras = {} - i = 0 - while i < len(extraparts): - extras[extraparts[i]] = extraparts[i + 1] - i += 2 - - self._stateextras[filename] = extras - elif rtype == RECORD_LABELS: - labels = record.split(b'\0', 2) - self._labels = [l for l in labels if len(l) > 0] - elif not rtype.islower(): - unsupported.add(rtype) - - if unsupported: - raise error.UnsupportedMergeRecords(unsupported) - - def _readrecords(self): - """Read merge state from disk and return a list of record (TYPE, data) - - We read data from both v1 and v2 files and decide which one to use. - - V1 has been used by version prior to 2.9.1 and contains less data than - v2. We read both versions and check if no data in v2 contradicts - 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 has overwritten the mergestate file and left an old v2 - file around. - - returns list of record [(TYPE, data), ...]""" - v1records = self._readrecordsv1() - v2records = self._readrecordsv2() - if self._v1v2match(v1records, v2records): - return v2records - else: - # v1 file is newer than v2 file, use it - # we have to infer the "other" changeset of the merge - # we cannot do better than that with v1 of the format - mctx = self._repo[None].parents()[-1] - v1records.append((RECORD_OTHER, mctx.hex())) - # add place holder "other" file node information - # nobody is using it yet so we do no need to fetch the data - # if mctx was wrong `mctx[bits[-2]]` may fails. - for idx, r in enumerate(v1records): - if r[0] == RECORD_MERGED: - bits = r[1].split(b'\0') - bits.insert(-2, b'') - v1records[idx] = (r[0], b'\0'.join(bits)) - return v1records - - def _v1v2match(self, v1records, v2records): - oldv2 = set() # old format version of v2 record - for rec in v2records: - if rec[0] == RECORD_LOCAL: - oldv2.add(rec) - elif rec[0] == RECORD_MERGED: - # drop the onode data (not contained in v1) - oldv2.add((RECORD_MERGED, _droponode(rec[1]))) - for rec in v1records: - if rec not in oldv2: - return False - else: - return True - - 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.vfs(self.statepathv1) - for i, l in enumerate(f): - if i == 0: - records.append((RECORD_LOCAL, l[:-1])) - else: - records.append((RECORD_MERGED, l[:-1])) - f.close() - except IOError as err: - if err.errno != errno.ENOENT: - raise - return records - - def _readrecordsv2(self): - """read on disk merge state for version 2 file - - This format is a list of arbitrary records of the form: - - [type][length][content] - - `type` is a single character, `length` is a 4 byte integer, and - `content` is an arbitrary byte sequence of length `length`. - - Mercurial versions prior to 3.7 have a bug where if there are - unsupported mandatory merge records, attempting to clear out the merge - state with hg update --clean or similar aborts. The 't' record type - works around that by writing out what those versions treat as an - advisory record, but later versions interpret as special: the first - character is the 'real' record type and everything onwards is the data. - - Returns list of records [(TYPE, data), ...].""" - records = [] - try: - f = self._repo.vfs(self.statepathv2) - data = f.read() - off = 0 - end = len(data) - while off < end: - rtype = data[off : off + 1] - off += 1 - length = _unpack(b'>I', data[off : (off + 4)])[0] - off += 4 - record = data[off : (off + length)] - off += length - if rtype == RECORD_OVERRIDE: - rtype, record = record[0:1], record[1:] - records.append((rtype, record)) - f.close() - except IOError as err: - if err.errno != errno.ENOENT: - raise - return records - @util.propertycache def mergedriver(self): # protect against the following: @@ -506,38 +317,6 @@ records.append((RECORD_LABELS, labels)) return records - 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.vfs(self.statepathv1, b'wb') - irecords = iter(records) - lrecords = next(irecords) - assert lrecords[0] == RECORD_LOCAL - f.write(hex(self._local) + b'\n') - for rtype, data in irecords: - if rtype == RECORD_MERGED: - f.write(b'%s\n' % _droponode(data)) - f.close() - - def _writerecordsv2(self, records): - """Write current state on disk in a version 2 file - - See the docstring for _readrecordsv2 for why we use 't'.""" - # these are the records that all version 2 clients can read - allowlist = (RECORD_LOCAL, RECORD_OTHER, RECORD_MERGED) - f = self._repo.vfs(self.statepathv2, b'wb') - for key, data in records: - assert len(key) == 1 - if key not in allowlist: - key, data = RECORD_OVERRIDE, b'%s%s' % (key, data) - format = b'>sI%is' % len(data) - f.write(_pack(format, key, len(data), data)) - f.close() - @staticmethod def getlocalkey(path): """hash the path of a local file context for storage in the .hg/merge @@ -546,11 +325,10 @@ return hex(hashutil.sha1(path).digest()) def _make_backup(self, fctx, localkey): - self._repo.vfs.write(b'merge/' + localkey, fctx.data()) + raise NotImplementedError() def _restore_backup(self, fctx, localkey, flags): - with self._repo.vfs(b'merge/' + localkey) as f: - fctx.write(f.read(), flags) + raise NotImplementedError() def add(self, fcl, fco, fca, fd): """add a new (potentially?) conflicting file the merge state @@ -789,6 +567,240 @@ self._results[f] = 0, ACTION_GET +class mergestate(_mergestate_base): + + statepathv1 = b'merge/state' + statepathv2 = b'merge/state2' + + @staticmethod + def clean(repo): + """Initialize a brand new merge state, removing any existing state on + disk.""" + ms = mergestate(repo) + ms.reset() + return ms + + @staticmethod + def read(repo): + """Initialize the merge state, reading it from disk.""" + ms = mergestate(repo) + ms._read() + return ms + + 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._mdstate = MERGE_DRIVER_STATE_SUCCESS + unsupported = set() + records = self._readrecords() + for rtype, record in records: + if rtype == RECORD_LOCAL: + self._local = bin(record) + elif rtype == RECORD_OTHER: + self._other = bin(record) + elif rtype == RECORD_MERGE_DRIVER_STATE: + bits = record.split(b'\0', 1) + mdstate = bits[1] + if len(mdstate) != 1 or mdstate not in ( + MERGE_DRIVER_STATE_UNMARKED, + MERGE_DRIVER_STATE_MARKED, + MERGE_DRIVER_STATE_SUCCESS, + ): + # the merge driver should be idempotent, so just rerun it + mdstate = MERGE_DRIVER_STATE_UNMARKED + + self._readmergedriver = bits[0] + self._mdstate = mdstate + elif rtype in ( + RECORD_MERGED, + RECORD_CHANGEDELETE_CONFLICT, + RECORD_PATH_CONFLICT, + RECORD_MERGE_DRIVER_MERGE, + LEGACY_RECORD_RESOLVED_OTHER, + ): + bits = record.split(b'\0') + # merge entry type MERGE_RECORD_MERGED_OTHER is deprecated + # and we now store related information in _stateextras, so + # lets write to _stateextras directly + if bits[1] == MERGE_RECORD_MERGED_OTHER: + self._stateextras[bits[0]][b'filenode-source'] = b'other' + else: + self._state[bits[0]] = bits[1:] + elif rtype == RECORD_FILE_VALUES: + filename, rawextras = record.split(b'\0', 1) + extraparts = rawextras.split(b'\0') + extras = {} + i = 0 + while i < len(extraparts): + extras[extraparts[i]] = extraparts[i + 1] + i += 2 + + self._stateextras[filename] = extras + elif rtype == RECORD_LABELS: + labels = record.split(b'\0', 2) + self._labels = [l for l in labels if len(l) > 0] + elif not rtype.islower(): + unsupported.add(rtype) + + if unsupported: + raise error.UnsupportedMergeRecords(unsupported) + + def _readrecords(self): + """Read merge state from disk and return a list of record (TYPE, data) + + We read data from both v1 and v2 files and decide which one to use. + + V1 has been used by version prior to 2.9.1 and contains less data than + v2. We read both versions and check if no data in v2 contradicts + 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 has overwritten the mergestate file and left an old v2 + file around. + + returns list of record [(TYPE, data), ...]""" + v1records = self._readrecordsv1() + v2records = self._readrecordsv2() + if self._v1v2match(v1records, v2records): + return v2records + else: + # v1 file is newer than v2 file, use it + # we have to infer the "other" changeset of the merge + # we cannot do better than that with v1 of the format + mctx = self._repo[None].parents()[-1] + v1records.append((RECORD_OTHER, mctx.hex())) + # add place holder "other" file node information + # nobody is using it yet so we do no need to fetch the data + # if mctx was wrong `mctx[bits[-2]]` may fails. + for idx, r in enumerate(v1records): + if r[0] == RECORD_MERGED: + bits = r[1].split(b'\0') + bits.insert(-2, b'') + v1records[idx] = (r[0], b'\0'.join(bits)) + return v1records + + def _v1v2match(self, v1records, v2records): + oldv2 = set() # old format version of v2 record + for rec in v2records: + if rec[0] == RECORD_LOCAL: + oldv2.add(rec) + elif rec[0] == RECORD_MERGED: + # drop the onode data (not contained in v1) + oldv2.add((RECORD_MERGED, _droponode(rec[1]))) + for rec in v1records: + if rec not in oldv2: + return False + else: + return True + + 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.vfs(self.statepathv1) + for i, l in enumerate(f): + if i == 0: + records.append((RECORD_LOCAL, l[:-1])) + else: + records.append((RECORD_MERGED, l[:-1])) + f.close() + except IOError as err: + if err.errno != errno.ENOENT: + raise + return records + + def _readrecordsv2(self): + """read on disk merge state for version 2 file + + This format is a list of arbitrary records of the form: + + [type][length][content] + + `type` is a single character, `length` is a 4 byte integer, and + `content` is an arbitrary byte sequence of length `length`. + + Mercurial versions prior to 3.7 have a bug where if there are + unsupported mandatory merge records, attempting to clear out the merge + state with hg update --clean or similar aborts. The 't' record type + works around that by writing out what those versions treat as an + advisory record, but later versions interpret as special: the first + character is the 'real' record type and everything onwards is the data. + + Returns list of records [(TYPE, data), ...].""" + records = [] + try: + f = self._repo.vfs(self.statepathv2) + data = f.read() + off = 0 + end = len(data) + while off < end: + rtype = data[off : off + 1] + off += 1 + length = _unpack(b'>I', data[off : (off + 4)])[0] + off += 4 + record = data[off : (off + length)] + off += length + if rtype == RECORD_OVERRIDE: + rtype, record = record[0:1], record[1:] + records.append((rtype, record)) + f.close() + except IOError as err: + if err.errno != errno.ENOENT: + raise + return records + + 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.vfs(self.statepathv1, b'wb') + irecords = iter(records) + lrecords = next(irecords) + assert lrecords[0] == RECORD_LOCAL + f.write(hex(self._local) + b'\n') + for rtype, data in irecords: + if rtype == RECORD_MERGED: + f.write(b'%s\n' % _droponode(data)) + f.close() + + def _writerecordsv2(self, records): + """Write current state on disk in a version 2 file + + See the docstring for _readrecordsv2 for why we use 't'.""" + # these are the records that all version 2 clients can read + allowlist = (RECORD_LOCAL, RECORD_OTHER, RECORD_MERGED) + f = self._repo.vfs(self.statepathv2, b'wb') + for key, data in records: + assert len(key) == 1 + if key not in allowlist: + key, data = RECORD_OVERRIDE, b'%s%s' % (key, data) + format = b'>sI%is' % len(data) + f.write(_pack(format, key, len(data), data)) + f.close() + + def _make_backup(self, fctx, localkey): + self._repo.vfs.write(b'merge/' + localkey, fctx.data()) + + def _restore_backup(self, fctx, localkey, flags): + with self._repo.vfs(b'merge/' + localkey) as f: + fctx.write(f.read(), flags) + + def reset(self): + shutil.rmtree(self._repo.vfs.join(b'merge'), True) + + def recordupdates(repo, actions, branchmerge, getfiledata): """record merge actions to the dirstate""" # remove (must come first)