def initialize_database(path: util.PathLike,
schema: SchemaLike,
files: bool = False) -> None:
"""
Initialize a bare database directory at *path*.
Initialization creates the directory at *path* if it does not
exist, writes the schema, an deletes any existing files defined by
the schema.
.. warning::
If *path* points to an existing directory, all relation files
defined by the schema will be overwritten or deleted.
Args:
path: the path to the destination database directory
schema: the destination database schema
files: if `True`, create an empty file for every relation in
*schema*
"""
path = Path(path).expanduser()
if isinstance(schema, (str, Path)):
schema = read_schema(schema)
path.mkdir(exist_ok=True)
write_schema(path, schema)
_cleanup_files(path, set(schema))
if files:
for name in schema:
path.joinpath(name).touch()
def __init__(self,
path: util.PathLike = None,
schema: tsdb.SchemaLike = None,
encoding: str = 'utf-8') -> None:
# Virtual test suites use a temporary directory
if path is None:
self._tempdir = tempfile.TemporaryDirectory()
path = Path(self._tempdir.name)
else:
path = Path(path).expanduser()
path.mkdir(exist_ok=True) # can fail if path is a file
# Ensure test suite directory has a relations file
if not path.joinpath(tsdb.SCHEMA_FILENAME).is_file():
if schema is None:
raise ITSDBError(
'*schema* argument is required for new test suites')
elif isinstance(schema, (str, Path)):
schema = tsdb.read_schema(schema)
tsdb.write_schema(path, schema)
super().__init__(path, autocast=False, encoding=encoding)
self._data: Dict[str, Table] = {}
def write_database(db: Database,
path: util.PathLike,
names: Iterable[str] = None,
schema: SchemaLike = None,
gzip: bool = False,
encoding: str = 'utf-8') -> None:
"""
Write TSDB database *db* to *path*.
If *path* is an existing file (not a directory), a
:class:`TSDBError` is raised. If *path* is an existing directory,
the files for all relations in the destination schema will be
cleared. Every relation name in *names* must exist in the
destination schema. If *schema* is given (even if it is the same
as for *db*), every record will be remade (using
:func:`make_record`) using the schema, and columns may be dropped
or `None` values inserted as necessary, but no more sophisticated
changes will be made.
.. warning::
If *path* points to an existing directory, all relation files
defined by the schema will be overwritten or deleted.
Args:
db: Database containing data to write
path: the path to the destination database directory
names: list of names of relations to write; if `None` use all
relations in the destination schema
schema: the destination database schema; if `None` use the
schema of *db*
gzip: if `True`, compress all non-empty files; if `False`, do
not compress
encoding: character encoding for the database files
"""
path = Path(path).expanduser()
if path.is_file():
raise TSDBError(f'not a directory: {path!s}')
remake_records = schema is not None
if schema is None:
schema = db.schema
elif isinstance(schema, (str, Path)):
schema = read_schema(schema)
if names is None:
names = list(schema)
# Prepare destination directory
path.mkdir(exist_ok=True)
write_schema(path, schema)
for name in names:
fields = schema[name]
relation: Iterable[Record] = []
if name in db.schema:
try:
relation = db[name]
except (TSDBError, KeyError):
pass
if remake_records:
relation = _remake_records(relation, db.schema[name], fields)
write(path,
name,
relation,
fields,
append=False,
gzip=gzip,
encoding=encoding)
# only delete other files at the end in case db.path == path
_cleanup_files(path, set(schema).difference(names))