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Diffstat (limited to 'pre_commit/store.py')
| -rw-r--r-- | pre_commit/store.py | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/pre_commit/store.py b/pre_commit/store.py new file mode 100644 index 0000000..760b37a --- /dev/null +++ b/pre_commit/store.py @@ -0,0 +1,250 @@ +import contextlib +import logging +import os.path +import sqlite3 +import tempfile +from typing import Callable +from typing import Generator +from typing import List +from typing import Optional +from typing import Sequence +from typing import Tuple + +import pre_commit.constants as C +from pre_commit import file_lock +from pre_commit import git +from pre_commit.util import CalledProcessError +from pre_commit.util import clean_path_on_failure +from pre_commit.util import cmd_output_b +from pre_commit.util import resource_text +from pre_commit.util import rmtree + + +logger = logging.getLogger('pre_commit') + + +def _get_default_directory() -> str: + """Returns the default directory for the Store. This is intentionally + underscored to indicate that `Store.get_default_directory` is the intended + way to get this information. This is also done so + `Store.get_default_directory` can be mocked in tests and + `_get_default_directory` can be tested. + """ + return os.environ.get('PRE_COMMIT_HOME') or os.path.join( + os.environ.get('XDG_CACHE_HOME') or os.path.expanduser('~/.cache'), + 'pre-commit', + ) + + +class Store: + get_default_directory = staticmethod(_get_default_directory) + + def __init__(self, directory: Optional[str] = None) -> None: + self.directory = directory or Store.get_default_directory() + self.db_path = os.path.join(self.directory, 'db.db') + + if not os.path.exists(self.directory): + os.makedirs(self.directory, exist_ok=True) + with open(os.path.join(self.directory, 'README'), 'w') as f: + f.write( + 'This directory is maintained by the pre-commit project.\n' + 'Learn more: https://github.com/pre-commit/pre-commit\n', + ) + + if os.path.exists(self.db_path): + return + with self.exclusive_lock(): + # Another process may have already completed this work + if os.path.exists(self.db_path): # pragma: no cover (race) + return + # To avoid a race where someone ^Cs between db creation and + # execution of the CREATE TABLE statement + fd, tmpfile = tempfile.mkstemp(dir=self.directory) + # We'll be managing this file ourselves + os.close(fd) + with self.connect(db_path=tmpfile) as db: + db.executescript( + 'CREATE TABLE repos (' + ' repo TEXT NOT NULL,' + ' ref TEXT NOT NULL,' + ' path TEXT NOT NULL,' + ' PRIMARY KEY (repo, ref)' + ');', + ) + self._create_config_table(db) + + # Atomic file move + os.rename(tmpfile, self.db_path) + + @contextlib.contextmanager + def exclusive_lock(self) -> Generator[None, None, None]: + def blocked_cb() -> None: # pragma: no cover (tests are in-process) + logger.info('Locking pre-commit directory') + + with file_lock.lock(os.path.join(self.directory, '.lock'), blocked_cb): + yield + + @contextlib.contextmanager + def connect( + self, + db_path: Optional[str] = None, + ) -> Generator[sqlite3.Connection, None, None]: + db_path = db_path or self.db_path + # sqlite doesn't close its fd with its contextmanager >.< + # contextlib.closing fixes this. + # See: https://stackoverflow.com/a/28032829/812183 + with contextlib.closing(sqlite3.connect(db_path)) as db: + # this creates a transaction + with db: + yield db + + @classmethod + def db_repo_name(cls, repo: str, deps: Sequence[str]) -> str: + if deps: + return f'{repo}:{",".join(sorted(deps))}' + else: + return repo + + def _new_repo( + self, + repo: str, + ref: str, + deps: Sequence[str], + make_strategy: Callable[[str], None], + ) -> str: + repo = self.db_repo_name(repo, deps) + + def _get_result() -> Optional[str]: + # Check if we already exist + with self.connect() as db: + result = db.execute( + 'SELECT path FROM repos WHERE repo = ? AND ref = ?', + (repo, ref), + ).fetchone() + return result[0] if result else None + + result = _get_result() + if result: + return result + with self.exclusive_lock(): + # Another process may have already completed this work + result = _get_result() + if result: # pragma: no cover (race) + return result + + logger.info(f'Initializing environment for {repo}.') + + directory = tempfile.mkdtemp(prefix='repo', dir=self.directory) + with clean_path_on_failure(directory): + make_strategy(directory) + + # Update our db with the created repo + with self.connect() as db: + db.execute( + 'INSERT INTO repos (repo, ref, path) VALUES (?, ?, ?)', + [repo, ref, directory], + ) + return directory + + def _complete_clone(self, ref: str, git_cmd: Callable[..., None]) -> None: + """Perform a complete clone of a repository and its submodules """ + + git_cmd('fetch', 'origin', '--tags') + git_cmd('checkout', ref) + git_cmd('submodule', 'update', '--init', '--recursive') + + def _shallow_clone(self, ref: str, git_cmd: Callable[..., None]) -> None: + """Perform a shallow clone of a repository and its submodules """ + + git_config = 'protocol.version=2' + git_cmd('-c', git_config, 'fetch', 'origin', ref, '--depth=1') + git_cmd('checkout', 'FETCH_HEAD') + git_cmd( + '-c', git_config, 'submodule', 'update', '--init', '--recursive', + '--depth=1', + ) + + def clone(self, repo: str, ref: str, deps: Sequence[str] = ()) -> str: + """Clone the given url and checkout the specific ref.""" + + def clone_strategy(directory: str) -> None: + git.init_repo(directory, repo) + env = git.no_git_env() + + def _git_cmd(*args: str) -> None: + cmd_output_b('git', *args, cwd=directory, env=env) + + try: + self._shallow_clone(ref, _git_cmd) + except CalledProcessError: + self._complete_clone(ref, _git_cmd) + + return self._new_repo(repo, ref, deps, clone_strategy) + + LOCAL_RESOURCES = ( + 'Cargo.toml', 'main.go', 'main.rs', '.npmignore', 'package.json', + 'pre_commit_dummy_package.gemspec', 'setup.py', 'environment.yml', + 'Makefile.PL', + ) + + def make_local(self, deps: Sequence[str]) -> str: + def make_local_strategy(directory: str) -> None: + for resource in self.LOCAL_RESOURCES: + contents = resource_text(f'empty_template_{resource}') + with open(os.path.join(directory, resource), 'w') as f: + f.write(contents) + + env = git.no_git_env() + + # initialize the git repository so it looks more like cloned repos + def _git_cmd(*args: str) -> None: + cmd_output_b('git', *args, cwd=directory, env=env) + + git.init_repo(directory, '<<unknown>>') + _git_cmd('add', '.') + git.commit(repo=directory) + + return self._new_repo( + 'local', C.LOCAL_REPO_VERSION, deps, make_local_strategy, + ) + + def _create_config_table(self, db: sqlite3.Connection) -> None: + db.executescript( + 'CREATE TABLE IF NOT EXISTS configs (' + ' path TEXT NOT NULL,' + ' PRIMARY KEY (path)' + ');', + ) + + def mark_config_used(self, path: str) -> None: + path = os.path.realpath(path) + # don't insert config files that do not exist + if not os.path.exists(path): + return + with self.connect() as db: + # TODO: eventually remove this and only create in _create + self._create_config_table(db) + db.execute('INSERT OR IGNORE INTO configs VALUES (?)', (path,)) + + def select_all_configs(self) -> List[str]: + with self.connect() as db: + self._create_config_table(db) + rows = db.execute('SELECT path FROM configs').fetchall() + return [path for path, in rows] + + def delete_configs(self, configs: List[str]) -> None: + with self.connect() as db: + rows = [(path,) for path in configs] + db.executemany('DELETE FROM configs WHERE path = ?', rows) + + def select_all_repos(self) -> List[Tuple[str, str, str]]: + with self.connect() as db: + return db.execute('SELECT repo, ref, path from repos').fetchall() + + def delete_repo(self, db_repo_name: str, ref: str, path: str) -> None: + with self.connect() as db: + db.execute( + 'DELETE FROM repos WHERE repo = ? and ref = ?', + (db_repo_name, ref), + ) + rmtree(path) |