import httplib from urlparse import urlparse from threading import Semaphore from logging import debug, info, warning, error from Config import Config from Exceptions import ParameterError __all__ = [ "ConnMan" ] class http_connection(object): def __init__(self, id, hostname, ssl, cfg): self.hostname = hostname self.ssl = ssl self.id = id self.counter = 0 if cfg.proxy_host != "": self.c = httplib.HTTPConnection(cfg.proxy_host, cfg.proxy_port) elif not ssl: self.c = httplib.HTTPConnection(hostname) else: self.c = httplib.HTTPSConnection(hostname) class ConnMan(object): conn_pool_sem = Semaphore() conn_pool = {} conn_max_counter = 800 ## AWS closes connection after some ~90 requests @staticmethod def get(hostname, ssl = None): cfg = Config() if ssl == None: ssl = cfg.use_https conn = None if cfg.proxy_host != "": if ssl: raise ParameterError("use_ssl=True can't be used with proxy") conn_id = "proxy://%s:%s" % (cfg.proxy_host, cfg.proxy_port) else: conn_id = "http%s://%s" % (ssl and "s" or "", hostname) ConnMan.conn_pool_sem.acquire() if not ConnMan.conn_pool.has_key(conn_id): ConnMan.conn_pool[conn_id] = [] if len(ConnMan.conn_pool[conn_id]): conn = ConnMan.conn_pool[conn_id].pop() debug("ConnMan.get(): re-using connection: %s#%d" % (conn.id, conn.counter)) ConnMan.conn_pool_sem.release() if not conn: debug("ConnMan.get(): creating new connection: %s" % conn_id) conn = http_connection(conn_id, hostname, ssl, cfg) conn.c.connect() conn.counter += 1 return conn @staticmethod def put(conn): if conn.id.startswith("proxy://"): conn.c.close() debug("ConnMan.put(): closing proxy connection (keep-alive not yet supported)") return if conn.counter >= ConnMan.conn_max_counter: conn.c.close() debug("ConnMan.put(): closing over-used connection") return ConnMan.conn_pool_sem.acquire() ConnMan.conn_pool[conn.id].append(conn) ConnMan.conn_pool_sem.release() debug("ConnMan.put(): connection put back to pool (%s#%d)" % (conn.id, conn.counter))