def _connect(self):
"""Get the SqliteDb object to use."""
if get_thread_id() not in self._dbs:
if os.path.exists(self._filename):
self._open_db()
else:
self._create_db()
return self._dbs[get_thread_id()]
def _read_db(self):
"""Read the metadata from a database so that we are ready to use it."""
with self._dbs[get_thread_id()] as db:
try:
schema_version, = db.execute_one("select version from coverage_schema")
except Exception as exc:
raise CoverageException(
"Data file {!r} doesn't seem to be a coverage data file: {}".format(
self._filename, exc
)
)
else:
if schema_version != SCHEMA_VERSION:
raise CoverageException(
"Couldn't use data file {!r}: wrong schema: {} instead of {}".format(
self._filename, schema_version, SCHEMA_VERSION
)
)
for row in db.execute("select value from meta where key = 'has_arcs'"):
self._has_arcs = bool(int(row[0]))
self._has_lines = not self._has_arcs
for path, file_id in db.execute("select path, id from file"):
self._file_map[path] = file_id
def __nonzero__(self):
if (get_thread_id() not in self._dbs and not os.path.exists(self._filename)):
return False
try:
with self._connect() as con:
rows = con.execute("select * from file limit 1")
return bool(list(rows))
except CoverageException:
return False
def _create_db(self):
"""Create a db file that doesn't exist yet.
Initializes the schema and certain metadata.
"""
if self._debug.should('dataio'):
self._debug.write("Creating data file {!r}".format(self._filename))
self._dbs[get_thread_id()] = db = SqliteDb(self._filename, self._debug)
with db:
db.executescript(SCHEMA)
db.execute("insert into coverage_schema (version) values (?)", (SCHEMA_VERSION,))
db.executemany(
"insert into meta (key, value) values (?, ?)",
[
('sys_argv', str(getattr(sys, 'argv', None))),
('version', __version__),
('when', datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')),
]
)
def loads(self, data):
"""Deserialize data from :meth:`dumps`
Use with a newly-created empty :class:`CoverageData` object. It's
undefined what happens if the object already has data in it.
Arguments:
data: A byte string of serialized data produced by :meth:`dumps`.
.. versionadded:: 5.0
"""
if self._debug.should('dataio'):
self._debug.write("Loading data into data file {!r}".format(self._filename))
if data[:1] != b'z':
raise CoverageException(
"Unrecognized serialization: {!r} (head of {} bytes)".format(data[:40], len(data))
)
script = to_string(zlib.decompress(data[1:]))
self._dbs[get_thread_id()] = db = SqliteDb(self._filename, self._debug)
with db:
db.executescript(script)
self._read_db()
self._have_used = True
def _open_db(self):
"""Open an existing db file, and read its metadata."""
if self._debug.should('dataio'):
self._debug.write("Opening data file {!r}".format(self._filename))
self._dbs[get_thread_id()] = SqliteDb(self._filename, self._debug)
self._read_db()