def checkout(self, commit_id):
if self.checkedout:
return
try:
commit_dict = self.repository.commits[commit_id]
except KeyError:
raise CommitNotFound("Could not find the commit %s" % commit_id)
self.commit_id = commit_id
self.msg = commit_dict['msg']
if 'parent' in commit_dict:
self.parent = Commit(self.repository)
self.parent.checkout(commit_dict['parent'])
self.schema = copy.deepcopy(self.parent.schema)
else:
self.parent = None
self.schema = Schema()
self.changelog = commit_dict['changelog']
for change in self.changelog:
self.schema.add(change)
self.checkedout = True
class Commit(object):
def __init__(self, repository):
self.repository = repository
self.parent = None
self.changelog = None
self.schema = None
self.commit_id = None
self.msg = None
self.checkedout = False
def checkout(self, commit_id):
if self.checkedout:
return
try:
commit_dict = self.repository.commits[commit_id]
except KeyError:
raise CommitNotFound("Could not find the commit %s" % commit_id)
self.commit_id = commit_id
self.msg = commit_dict['msg']
if 'parent' in commit_dict:
self.parent = Commit(self.repository)
self.parent.checkout(commit_dict['parent'])
self.schema = copy.deepcopy(self.parent.schema)
else:
self.parent = None
self.schema = Schema()
self.changelog = commit_dict['changelog']
for change in self.changelog:
self.schema.add(change)
self.checkedout = True
def toDict(self):
d = {
'changelog':self.changelog,
'msg':self.msg
}
if self.parent:
d['parent'] = self.parent.commit_id
return d
def getAncestors(self):
if self.parent:
parents = self.parent.getAncestors()
parents.append(self.commit_id)
return parents
else:
return [self.commit_id]
def rollback(self, to_commit=None):
"""Returns a changelog that will rollback the current commit to the given commit_id.
If to_commit is None than only this commit will be rolled back in the changelog."""
if to_commit is self.commit_id:
raise InvalidChange("Can't rollback to self")
if not to_commit:
to_commit = self.parent.commit_id
ancestors = self.getAncestors()
if to_commit not in ancestors:
raise CommitNotFound("Did not find %s in the list of ancestors of %s" % (to_commit, self.commit_id))
revlog = [self.reverse(change) for change in self.changelog]
revlog.reverse()
if self.parent.commit_id is not to_commit:
parentlog = self.parent.rollback(to_commit)
revlog.extend(parentlog)
return revlog
def rollforward(self, from_commit=None):
"""Return changelog from given commit to current commit"""
if from_commit is self.commit_id:
raise InvalidChange("Can't rollback to self")
if not from_commit:
from_commit = self.parent.commit_id
ancestors = self.getAncestors()
if from_commit not in ancestors:
raise CommitNotFound("Did not find %s in the list of ancestors of %s" % (from_commit, self.commit_id))
log = copy.deepcopy(self.changelog)
if self.parent.commit_id is not from_commit:
parentlog = self.parent.rollforward(from_commit)
parentlog.extend(log)
log = parentlog
return log
def reverse(self, change):
action = change['change']
table = change['schema']['id']
fields = change['schema']['properties']
new_change = copy.deepcopy(change)
if 'old_schema' in new_change:
del new_change['old_schema']
if action == 'create':
new_change['change'] = 'drop'
if action == 'drop':
new_change['change'] = 'create'
new_change['schema'] = change['old_schema']
if action == 'alter.add':
new_change['change'] = 'alter.drop'
if action == 'alter.modify':
for field in fields:
old = change['old_schema']['properties'][field]
new_change['schema']['properties'][field] = old
if action == 'alter.rename':
for field in fields:
newname = fields[field]
new_change['schema']['properties'][newname] = field
del new_change['schema']['properties'][field]
if action == 'alter.drop':
new_change['change'] = 'alter.add'
for field in fields:
old = change['old_schema']['properties'][field]
new_change['schema']['properties'][field] = old
return new_change
