blob: fbe7c73c302883a67a2c9ba9b13e7cac49916c8a [file] [log] [blame]
# Copyright 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import atexit
import collections
import copy
import datetime
import hashlib
import os
import shutil
import subprocess
import sys
import tempfile
import unittest
def git_hash_data(data, typ='blob'):
"""Calculate the git-style SHA1 for some data.
Only supports 'blob' type data at the moment.
assert typ == 'blob', 'Only support blobs for now'
return hashlib.sha1('blob %s\0%s' % (len(data), data)).hexdigest()
class OrderedSet(collections.MutableSet):
# from
def __init__(self, iterable=None):
self.end = end = []
end += [None, end, end] # sentinel node for doubly linked list = {} # key --> [key, prev, next]
if iterable is not None:
self |= iterable
def __contains__(self, key):
return key in
def __eq__(self, other):
if isinstance(other, OrderedSet):
return len(self) == len(other) and list(self) == list(other)
return set(self) == set(other)
def __ne__(self, other):
if isinstance(other, OrderedSet):
return len(self) != len(other) or list(self) != list(other)
return set(self) != set(other)
def __len__(self):
return len(
def __iter__(self):
end = self.end
curr = end[2]
while curr is not end:
yield curr[0]
curr = curr[2]
def __repr__(self):
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, list(self))
def __reversed__(self):
end = self.end
curr = end[1]
while curr is not end:
yield curr[0]
curr = curr[1]
def add(self, key):
if key not in
end = self.end
curr = end[1]
curr[2] = end[1] =[key] = [key, curr, end]
def difference_update(self, *others):
for other in others:
for i in other:
def discard(self, key):
if key in
key, prev, nxt =
prev[2] = nxt
nxt[1] = prev
def pop(self, last=True): # pylint: disable=W0221
if not self:
raise KeyError('set is empty')
key = self.end[1][0] if last else self.end[2][0]
return key
class GitRepoSchema(object):
"""A declarative git testing repo.
Pass a schema to __init__ in the form of:
This is the repo
A - B - C - D
\ E /
Whitespace doesn't matter. Each line is a declaration of which commits come
before which other commits.
Every commit gets a tag 'tag_%(commit)s'
Every unique terminal commit gets a branch 'branch_%(commit)s'
Last commit in First line is the branch 'master'
Root commits get a ref 'root_%(commit)s'
Timestamps are in topo order, earlier commits (as indicated by their presence
in the schema) get earlier timestamps. Stamps start at the Unix Epoch, and
increment by 1 day each.
COMMIT = collections.namedtuple('COMMIT', 'name parents is_branch is_root')
def __init__(self, repo_schema='',
content_fn=lambda v: {v: {'data': v}}):
"""Builds a new GitRepoSchema.
repo_schema (str) - Initial schema for this repo. See class docstring for
info on the schema format.
content_fn ((commit_name) -> commit_data) - A function which will be
lazily called to obtain data for each commit. The results of this
function are cached (i.e. it will never be called twice for the same
commit_name). See the docstring on the GitRepo class for the format of
the data returned by this function.
self.master = None
self.par_map = {}
self.data_cache = {}
self.content_fn = content_fn
def walk(self):
"""(Generator) Walks the repo schema from roots to tips.
Generates GitRepoSchema.COMMIT objects for each commit.
Throws an AssertionError if it detects a cycle.
is_root = True
par_map = copy.deepcopy(self.par_map)
while par_map:
empty_keys = set(k for k, v in par_map.iteritems() if not v)
assert empty_keys, 'Cycle detected! %s' % par_map
for k in sorted(empty_keys):
yield self.COMMIT(k, self.par_map[k],
not any(k in v for v in self.par_map.itervalues()),
del par_map[k]
for v in par_map.itervalues():
is_root = False
def add_partial(self, commit, parent=None):
if commit not in self.par_map:
self.par_map[commit] = OrderedSet()
if parent is not None:
def add_commits(self, schema):
"""Adds more commits from a schema into the existing Schema.
schema (str) - See class docstring for info on schema format.
Throws an AssertionError if it detects a cycle.
for commits in (l.split() for l in schema.splitlines() if l.strip()):
parent = None
for commit in commits:
self.add_partial(commit, parent)
parent = commit
if parent and not self.master:
self.master = parent
for _ in self.walk(): # This will throw if there are any cycles.
def reify(self):
"""Returns a real GitRepo for this GitRepoSchema"""
return GitRepo(self)
def data_for(self, commit):
"""Obtains the data for |commit|.
See the docstring on the GitRepo class for the format of the returned data.
Caches the result on this GitRepoSchema instance.
if commit not in self.data_cache:
self.data_cache[commit] = self.content_fn(commit)
return self.data_cache[commit]
def simple_graph(self):
"""Returns a dictionary of {commit_subject: {parent commit_subjects}}
This allows you to get a very simple connection graph over the whole repo
for comparison purposes. Only commit subjects (not ids, not content/data)
are considered
ret = {}
for commit in self.walk():
ret.setdefault(, set()).update(commit.parents)
return ret
class GitRepo(object):
"""Creates a real git repo for a GitRepoSchema.
Obtains schema and content information from the GitRepoSchema.
The format for the commit data supplied by GitRepoSchema.data_for is:
SPECIAL_KEY: special_value,
"path/to/some/file": { 'data': "some data content for this file",
'mode': 0755 },
The SPECIAL_KEYs are the following attribues of the GitRepo class:
* AUTHOR_DATE - must be a datetime.datetime instance
* COMMITTER_DATE - must be a datetime.datetime instance
For file content, if 'data' is None, then this commit will `git rm` that file.
BASE_TEMP_DIR = tempfile.mkdtemp(suffix='base', prefix='git_repo')
atexit.register(shutil.rmtree, BASE_TEMP_DIR)
# Singleton objects to specify specific data in a commit dictionary.
AUTHOR_NAME = object()
AUTHOR_EMAIL = object()
AUTHOR_DATE = object()
DEFAULT_AUTHOR_NAME = 'Author McAuthorly'
DEFAULT_COMMITTER_NAME = 'Charles Committish'
COMMAND_OUTPUT = collections.namedtuple('COMMAND_OUTPUT', 'retcode stdout')
def __init__(self, schema):
"""Makes new GitRepo.
Automatically creates a temp folder under GitRepo.BASE_TEMP_DIR. It's
recommended that you clean this repo up by calling nuke() on it, but if not,
GitRepo will automatically clean up all allocated repos at the exit of the
program (assuming a normal exit like with sys.exit)
schema - An instance of GitRepoSchema
self.repo_path = tempfile.mkdtemp(dir=self.BASE_TEMP_DIR)
self.commit_map = {}
self._date = datetime.datetime(1970, 1, 1)
self.to_schema_refs = ['--branches']
self.git('config', '', 'testcase')
self.git('config', '', '')
for commit in schema.walk():
self._add_schema_commit(commit, schema.data_for(
self.last_commit = self[]
if schema.master:
self.git('update-ref', 'refs/heads/master', self[schema.master])
def __getitem__(self, commit_name):
"""Gets the hash of a commit by its schema name.
>>> r = GitRepo(GitRepoSchema('A B C'))
>>> r['B']
return self.commit_map[commit_name]
def _add_schema_commit(self, commit, commit_data):
commit_data = commit_data or {}
if commit.parents:
parents = list(commit.parents)
self.git('checkout', '--detach', '-q', self[parents[0]])
if len(parents) > 1:
self.git('merge', '--no-commit', '-q', *[self[x] for x in parents[1:]])
self.git('checkout', '--orphan', 'root_%s' %
self.git('rm', '-rf', '.')
env = self.get_git_commit_env(commit_data)
for fname, file_data in commit_data.iteritems():
deleted = False
if 'data' in file_data:
data = file_data.get('data')
if data is None:
deleted = True
self.git('rm', fname)
path = os.path.join(self.repo_path, fname)
pardir = os.path.dirname(path)
if not os.path.exists(pardir):
with open(path, 'wb') as f:
mode = file_data.get('mode')
if mode and not deleted:
os.chmod(path, mode)
self.git('add', fname)
rslt = self.git('commit', '--allow-empty', '-m',, env=env)
assert rslt.retcode == 0, 'Failed to commit %s' % str(commit)
self.commit_map[] = self.git('rev-parse', 'HEAD').stdout.strip()
self.git('tag', 'tag_%s' %, self[])
if commit.is_branch:
self.git('branch', '-f', 'branch_%s' %, self[])
def get_git_commit_env(self, commit_data=None):
commit_data = commit_data or {}
env = {}
for prefix in ('AUTHOR', 'COMMITTER'):
for suffix in ('NAME', 'EMAIL', 'DATE'):
singleton = '%s_%s' % (prefix, suffix)
key = getattr(self, singleton)
if key in commit_data:
val = commit_data[key]
if suffix == 'DATE':
val = self._date
self._date += datetime.timedelta(days=1)
val = getattr(self, 'DEFAULT_%s' % singleton)
env['GIT_%s' % singleton] = str(val)
return env
def git(self, *args, **kwargs):
"""Runs a git command specified by |args| in this repo."""
assert self.repo_path is not None
with open(os.devnull, 'wb') as devnull:
output = subprocess.check_output(
('git',) + args, cwd=self.repo_path, stderr=devnull, **kwargs)
return self.COMMAND_OUTPUT(0, output)
except subprocess.CalledProcessError as e:
return self.COMMAND_OUTPUT(e.returncode, e.output)
def git_commit(self, message):
return self.git('commit', '-am', message, env=self.get_git_commit_env())
def nuke(self):
"""Obliterates the git repo on disk.
Causes this GitRepo to be unusable.
self.repo_path = None
def run(self, fn, *args, **kwargs):
"""Run a python function with the given args and kwargs with the cwd set to
the git repo."""
assert self.repo_path is not None
curdir = os.getcwd()
return fn(*args, **kwargs)
def capture_stdio(self, fn, *args, **kwargs):
"""Run a python function with the given args and kwargs with the cwd set to
the git repo.
Returns the (stdout, stderr) of whatever ran, instead of the what |fn|
stdout = sys.stdout
stderr = sys.stderr
# "multiple statements on a line" pylint: disable=C0321
with tempfile.TemporaryFile() as out, tempfile.TemporaryFile() as err:
sys.stdout = out
sys.stderr = err
try:, *args, **kwargs)
except SystemExit:
sys.stdout = stdout
sys.stderr = stderr
def open(self, path, mode='rb'):
return open(os.path.join(self.repo_path, path), mode)
def to_schema(self):
lines = self.git('rev-list', '--parents', '--reverse', '--topo-order',
'--format=%s', *self.to_schema_refs).stdout.splitlines()
hash_to_msg = {}
ret = GitRepoSchema()
current = None
parents = []
for line in lines:
if line.startswith('commit'):
assert current is None
tokens = line.split()
current, parents = tokens[1], tokens[2:]
assert all(p in hash_to_msg for p in parents)
assert current is not None
hash_to_msg[current] = line
for parent in parents:
ret.add_partial(line, hash_to_msg[parent])
current = None
parents = []
assert current is None
return ret
class GitRepoSchemaTestBase(unittest.TestCase):
"""A TestCase with a built-in GitRepoSchema.
Expects a class variable REPO_SCHEMA to be a GitRepoSchema string in the form
described by that class.
You may also set class variables in the form COMMIT_%(commit_name)s, which
provide the content for the given commit_name commits.
You probably will end up using either GitRepoReadOnlyTestBase or
GitRepoReadWriteTestBase for real tests.
def getRepoContent(cls, commit):
return getattr(cls, 'COMMIT_%s' % commit, None)
def setUpClass(cls):
super(GitRepoSchemaTestBase, cls).setUpClass()
assert cls.REPO_SCHEMA is not None
cls.r_schema = GitRepoSchema(cls.REPO_SCHEMA, cls.getRepoContent)
class GitRepoReadOnlyTestBase(GitRepoSchemaTestBase):
"""Injects a GitRepo object given the schema and content from
GitRepoSchemaTestBase into TestCase classes which subclass this.
This GitRepo will appear as self.repo, and will be deleted and recreated once
for the duration of all the tests in the subclass.
def setUpClass(cls):
super(GitRepoReadOnlyTestBase, cls).setUpClass()
assert cls.REPO_SCHEMA is not None
cls.repo = cls.r_schema.reify()
def setUp(self):
self.repo.git('checkout', '-f', self.repo.last_commit)
def tearDownClass(cls):
super(GitRepoReadOnlyTestBase, cls).tearDownClass()
class GitRepoReadWriteTestBase(GitRepoSchemaTestBase):
"""Injects a GitRepo object given the schema and content from
GitRepoSchemaTestBase into TestCase classes which subclass this.
This GitRepo will appear as self.repo, and will be deleted and recreated for
each test function in the subclass.
def setUp(self):
super(GitRepoReadWriteTestBase, self).setUp()
self.repo = self.r_schema.reify()
def tearDown(self):
super(GitRepoReadWriteTestBase, self).tearDown()
def assertSchema(self, schema_string):