hexlib/hexlib/db.py
2019-12-29 17:13:35 -05:00

96 lines
3.1 KiB
Python

import base64
import sqlite3
class PersistentState:
"""Quick and dirty persistent dict-like SQLite wrapper"""
def __init__(self, dbfile="state.db", **dbargs):
self.dbfile = dbfile
if dbargs is None:
dbargs = {"timeout": 30000}
self.dbargs = dbargs
def __getitem__(self, table):
return Table(self, table)
class Table:
def __init__(self, state, table):
self._state = state
self._table = table
def __iter__(self):
with sqlite3.connect(self._state.dbfile, **self._state.dbargs) as conn:
conn.row_factory = sqlite3.Row
try:
cur = conn.execute("SELECT * FROM %s" % (self._table,))
for row in cur:
yield dict(row)
except:
return None
def __getitem__(self, item):
with sqlite3.connect(self._state.dbfile, **self._state.dbargs) as conn:
conn.row_factory = sqlite3.Row
try:
col_types = conn.execute("PRAGMA table_info(%s)" % self._table).fetchall()
cur = conn.execute("SELECT * FROM %s WHERE id=?" % (self._table,), (item,))
row = cur.fetchone()
if row:
return dict(
(col[0], _deserialize(row[col[0]], col_types[i]["type"]))
for i, col in enumerate(cur.description)
)
except:
return None
def __setitem__(self, key, value):
with sqlite3.connect(self._state.dbfile, **self._state.dbargs) as conn:
conn.row_factory = sqlite3.Row
sql = "INSERT INTO %s (id,%s) VALUES ('%s',%s)" % \
(self._table, ",".join(value.keys()), key, ",".join("?" for _ in value.values()))
try:
conn.execute(sql, list(_serialize(v) for v in value.values()))
except sqlite3.OperationalError:
conn.execute(
"create table if not exists %s (id text primary key,%s)" %
(self._table, ",".join("%s %s" % (k, _sqlite_type(v)) for k, v in value.items()))
)
conn.execute(sql, list(_serialize(v) for v in value.values()))
except sqlite3.IntegrityError:
sql = "UPDATE %s SET (%s) = (%s) WHERE id=?" \
% (self._table, ",".join(value.keys()), ",".join("?" for _ in value.values()))
args = [key]
args.extend(_serialize(v) for v in value.values())
conn.execute(
sql,
args
)
def _sqlite_type(value):
if isinstance(value, int):
return "integer"
if isinstance(value, float):
return "real"
if isinstance(value, bytes):
return "blob"
return "text"
def _serialize(value):
if isinstance(value, bytes):
return base64.b64encode(value)
return str(value)
def _deserialize(value, col_type):
if col_type == "blob":
return base64.b64decode(value)
return value