Asynchronous I/O that doesn’t get in your way, written in D
Class ConnectionPool
Generic connection pool class.
classConnectionPool(Connection)
;
The connection pool is creating connections using the supplied factory
function as needed whenever lockConnection is called. Connections are
associated to the calling fiber, as long as any copy of the returned
LockedConnection object still exists. Connections that are not associated
to any fiber will be kept in a pool of open connections for later reuse.
Note that, after retrieving a connection with lockConnection, the caller
has to make sure that the connection is actually physically open and to
reopen it if necessary. The ConnectionPool class has no knowledge of the
internals of the connection objects.
Removes an existing connection from the pool
It can be called with a locked connection, same connection
can be added back to the pool anytime. Any fibers that hold
a lock on this connection will keep behaving as expected.
Removes all currently unlocked connections from the pool.
Example
class Connection {
void write() {}
}
auto pool = new ConnectionPool!Connection({
return new Connection; // perform the connection here
});
// create and lock a first connection
auto c1 = pool.lockConnection();
c1.write();
// create and lock a second connection
auto c2 = pool.lockConnection();
c2.write();
// writing to c1 will still write to the first connection
c1.write();
// free up the reference to the first connection, so that it can be reused
destroy(c1);
// locking a new connection will reuse the first connection now instead of creating a new one
auto c3 = pool.lockConnection();
c3.write();
