/usr/lib/python3/dist-packages/wormhole/server/database.py is in magic-wormhole 0.10.3-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | from __future__ import unicode_literals
import os
import sqlite3
import tempfile
from pkg_resources import resource_string
from twisted.python import log
class DBError(Exception):
pass
def get_schema(version):
schema_bytes = resource_string("wormhole.server",
"db-schemas/v%d.sql" % version)
return schema_bytes.decode("utf-8")
def get_upgrader(new_version):
schema_bytes = resource_string("wormhole.server",
"db-schemas/upgrade-to-v%d.sql" % new_version)
return schema_bytes.decode("utf-8")
TARGET_VERSION = 3
def dict_factory(cursor, row):
d = {}
for idx, col in enumerate(cursor.description):
d[col[0]] = row[idx]
return d
def _initialize_db_schema(db, target_version):
"""Creates the application schema in the given database.
"""
log.msg("populating new database with schema v%s" % target_version)
schema = get_schema(target_version)
db.executescript(schema)
db.execute("INSERT INTO version (version) VALUES (?)",
(target_version,))
db.commit()
def _initialize_db_connection(db):
"""Sets up the db connection object with a row factory and with necessary
foreign key settings.
"""
db.row_factory = dict_factory
db.execute("PRAGMA foreign_keys = ON")
problems = db.execute("PRAGMA foreign_key_check").fetchall()
if problems:
raise DBError("failed foreign key check: %s" % (problems,))
def _open_db_connection(dbfile):
"""Open a new connection to the SQLite3 database at the given path.
"""
try:
db = sqlite3.connect(dbfile)
except (EnvironmentError, sqlite3.OperationalError) as e:
raise DBError("Unable to create/open db file %s: %s" % (dbfile, e))
_initialize_db_connection(db)
return db
def _get_temporary_dbfile(dbfile):
"""Get a temporary filename near the given path.
"""
fd, name = tempfile.mkstemp(
prefix=os.path.basename(dbfile) + ".",
dir=os.path.dirname(dbfile)
)
os.close(fd)
return name
def _atomic_create_and_initialize_db(dbfile, target_version):
"""Create and return a new database, initialized with the application
schema.
If anything goes wrong, nothing is left at the ``dbfile`` path.
"""
temp_dbfile = _get_temporary_dbfile(dbfile)
db = _open_db_connection(temp_dbfile)
_initialize_db_schema(db, target_version)
db.close()
os.rename(temp_dbfile, dbfile)
return _open_db_connection(dbfile)
def get_db(dbfile, target_version=TARGET_VERSION):
"""Open or create the given db file. The parent directory must exist.
Returns the db connection object, or raises DBError.
"""
if dbfile == ":memory:":
db = _open_db_connection(dbfile)
_initialize_db_schema(db, target_version)
elif os.path.exists(dbfile):
db = _open_db_connection(dbfile)
else:
db = _atomic_create_and_initialize_db(dbfile, target_version)
try:
version = db.execute("SELECT version FROM version").fetchone()["version"]
except sqlite3.DatabaseError as e:
# this indicates that the file is not a compatible database format.
# Perhaps it was created with an old version, or it might be junk.
raise DBError("db file is unusable: %s" % e)
while version < target_version:
log.msg(" need to upgrade from %s to %s" % (version, target_version))
try:
upgrader = get_upgrader(version+1)
except ValueError: # ResourceError??
log.msg(" unable to upgrade %s to %s" % (version, version+1))
raise DBError("Unable to upgrade %s to version %s, left at %s"
% (dbfile, version+1, version))
log.msg(" executing upgrader v%s->v%s" % (version, version+1))
db.executescript(upgrader)
db.commit()
version = version+1
if version != target_version:
raise DBError("Unable to handle db version %s" % version)
return db
def dump_db(db):
# to let _iterdump work, we need to restore the original row factory
orig = db.row_factory
try:
db.row_factory = sqlite3.Row
return "".join(db.iterdump())
finally:
db.row_factory = orig
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