wiki/zmq-sqlite

Server

def SQL():
    import sqlite3, hashlib, os; con = sqlite3.connect('.db', isolation_level=None)
    sql = lambda q, *p: list(con.execute(q, p))
    if not os.path.exists('.db-blob') and os.mkdir('.db-blob') is None:
        con.executescript('''PRAGMA journal_mode=WAL;
            CREATE TABLE kv(k, v, t DEFAULT CURRENT_TIMESTAMP);
            CREATE INDEX idx_kv_v ON kv(v); CREATE INDEX idx_kv_k_t ON kv(k,t DESC)''')
    def setitem(_, filename, blob):
        if not sql('SELECT 1 FROM kv WHERE v=?', sha1 := hashlib.sha1(blob).hexdigest()):
            with open(f'.db-blob/{sha1}', 'xb') as f: f.write(blob)
        sql('INSERT INTO kv(k,v) VALUES(?,?)', filename, sha1)
    def getitem(_, filename):
        if sha1 := sql('SELECT v FROM kv WHERE k=? ORDER BY t DESC', filename):
            return open(f'.db-blob/{sha1[0][0]}', 'rb').read()
    return type('', (), dict(__setitem__=setitem, __getitem__=getitem))()
sql = SQL()

import zmq; (socket := zmq.Context().socket(zmq.REP)).bind('tcp://*:5555')
while True:
    filename, blob = socket.recv_pyobj()
    sql[filename] = blob
    socket.send_string('OK')

Client

def put(filename, blob, addr='tcp://localhost:5555'):
    import zmq; (socket := zmq.Context().socket(zmq.REQ)).connect(addr)
    assert socket.send_pyobj((filename, blob)) or socket.recv_string() == 'OK'
put('hello', b'world')