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@stevekuznetsov
Last active Mar 11, 2017
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Rebase Script for OSE
#!/usr/bin/env python
from __future__ import print_function
import sys
_DROP_PREFIX = '[DROP]'
_SQUASH_PREFIX = '[SQUASH]'
_CARRY_PREFIX = '[CARRY]'
_SPEC_SUBJECT = _CARRY_PREFIX + '[BUILD] Specfile updates'
_TITO_PREFIX = 'Automatic commit of package'
class Action(object):
pick = 'pick' # use the commit as-is
reword = 'reword' # edit the subject
edit = 'edit' # edit the content
squash = 'squash' # meld into previous
fixup = 'fixup' # meld but drop the subject
execute = 'exec' # run a shell command
drop = 'drop' # remove the commit
class Commit(object):
"""
An entry in an interactive git rebase
file, containing the action, hash and
subject.
"""
def __init__(self, action, hash, subject):
self.action = action
self.hash = hash
self.subject = subject
def __str__(self):
return '{} {} {}'.format(self.action, self.hash, self.subject)
def load_commits(rebase_path):
"""
Load the list of commits we need to deal
with from a file generated from an inter-
active `git rebase`.
:param rebase_path: path to the rebase file
:return: list of commits
"""
commits = []
with open(rebase_path) as rebase_file:
for line in rebase_file:
line = line.strip('\n')
# when we first load a rebase file, all
# the commits are in the 'pick' state
if line.startswith(Action.pick):
commits.append(Commit(
action=Action.pick,
hash=line[5:12],
subject=line[13:]
))
return commits
def dump_commits(rebase_path, commits):
"""
Write the list of commits to the rebase
file for `git rebase` to operate on.
:param rebase_path: path to the rebase file
:param commits: commits to write
"""
with open(rebase_path, 'w') as rebase_file:
for commit in commits:
rebase_file.write(str(commit))
rebase_file.write('\n')
def validate_commits(commits):
"""
Validate that the list of commits we are
about to operate on meets our assumptions.
:param commits: commits to check
"""
tito_index = -1
spec_index = -1
for index, commit in enumerate(commits):
drop_commit = commit.subject.startswith(_DROP_PREFIX)
carry_commit = commit.subject.startswith(_CARRY_PREFIX)
squash_commit = commit.subject.startswith(_SQUASH_PREFIX)
tito_commit = commit.subject.startswith(_TITO_PREFIX)
if not drop_commit and not carry_commit and not squash_commit and not tito_commit:
print('Commit `{}` ({}) invalid!'.format(commit.subject, commit.hash))
exit(1)
if tito_commit:
tito_index = index
if commit.subject == _SPEC_SUBJECT:
spec_index = index
if tito_index < 0:
print('No commit from `tito tag` found!')
exit(1)
if spec_index < 0:
print('No carry commit for `.spec` file found!')
exit(1)
if tito_index < spec_index:
print('Found the `tito tag` commit before the `.spec` file commit!')
exit(1)
def remove_drop_commits(commits):
"""
Remove commits labelled for removal with
the '[DROP]' prefix in their commit subject.
:param commits: commits to prune
:return: pruned commits
"""
for commit in commits:
if commit.subject.startswith(_DROP_PREFIX):
commit.action = Action.drop
return commits
def commit_index(commits, filter):
"""
Find the index of a commit you know exists
in the list of commits by passing a filter
function that matches it. The first match
is returned.
:param commits: commits to search
:param filter: filter function taking commit
:return: first match
"""
for index, commit in enumerate(commits):
if filter(commit):
return index
def squash_tito_commits(commits):
"""
Squash the auto-generated commit from the
last `tito tag` with the carry commit for
the `.spec` file.
:param commits: commits to consider
:return: updated commits
"""
tito_index = commit_index(commits, lambda c: c.subject.startswith(_TITO_PREFIX))
spec_index = commit_index(commits, lambda c: c.subject == _SPEC_SUBJECT)
tito_commit = commits.pop(tito_index)
tito_commit.action = Action.fixup
commits.insert(spec_index + 1, tito_commit)
return commits
def squash_named_commits(commits):
"""
Search through the list of commits and re-order
any commits marked for squash. We need to make
sure we squash the commits in the same order
that they were originally committed in so that
we can ensure they apply cleanly on top of each
other.
:param commits: commits to search through
:return: updated commits
"""
carry_commits = []
for commit in commits:
if commit.subject.startswith(_CARRY_PREFIX):
carry_commits.append(commit)
for carry_commit in carry_commits:
squash_subject = _SQUASH_PREFIX + carry_commit.subject
carry_commit_index = commits.index(carry_commit)
squash_commit_indicies = []
for index, commit in enumerate(commits):
if commit.subject == squash_subject:
squash_commit_indicies.append(index)
for index, squash_commit_index in enumerate(squash_commit_indicies):
squash_commit = commits.pop(squash_commit_index)
squash_commit.action = Action.fixup
commits.insert(carry_commit_index + index + 1, squash_commit)
return commits
rebase_path = sys.argv[1]
commits = load_commits(rebase_path)
validate_commits(commits)
commits = remove_drop_commits(commits)
commits = squash_tito_commits(commits)
commits = squash_named_commits(commits)
dump_commits(rebase_path, commits)
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