Module pool 

Connection pool for the capture proxy.

Sits in front of the DNS/TCP/TLS/handshake path. Before opening a fresh connection to an upstream, forward_request asks the pool whether we already have a working connection to (host, port, protocol). If yes, we reuse it and skip all handshake phases — DNS, TCP, TLS, and HTTP/2’s SETTINGS frame exchange — because the underlying transport is already established. If no, we fall through to the existing “fresh connection” path AND cache the resulting connection for the next request to the same upstream.

Currently pools two connection types:

• HTTP/2 SendRequest handles (cheap to clone; one handle per host can service unlimited concurrent streams via multiplexing).
• HTTP/1.1 keep-alive TcpStream / TlsStream — one stream per host for sequential reuse.

Entries auto-evict after IDLE_TIMEOUT of unused time.

Structs

ConnectionPool

Thread-safe connection pool shared across concurrent forward_request tasks. Cloneable — internal state lives behind an Arc<Mutex<...>> so cloning is cheap (bumps the ref-count).

Type Aliases

PooledH2Sender

The type stored per host in the HTTP/2 pool. SendRequest is Clone (it’s just a channel handle into the shared connection driver task), so we can hand out a fresh clone to every caller and multiplex requests over the same underlying TCP+TLS session for free.