Transport (neodriver_eio.Neodriver

type t

A TCP transport with bounded read and write timeouts, a TCP keep-alive flag and Bolt chunk framing.

val id : t -> int

The connection id of this transport (rendered as "#XXXX" in log lines; see Log.conn).

val keep_alive : t -> bool

Whether TCP keep-alive (SO_KEEPALIVE) is enabled on the connection's socket.

val set_read_timeout : t -> Eio.Time.Timeout.t -> unit

Replace the timeout bounding reads on the connection. The server advertises a receive timeout through the connection.recv_timeout_seconds HELLO hint, overriding the driver-configured default for that connection.

val set_write_timeout : t -> Eio.Time.Timeout.t -> unit

Replace the timeout bounding writes on the connection.

type tls_mode =

| Plain
| Secure of Tls_client.config
(*
How the connection is secured with TLS:
- Plain: no TLS.
- Secure config: wrap the connection in TLS with config's trust anchors and host (system trust store for bolt+s, trust-all for bolt+ssc, or explicit custom certificates).
*)

val connect : 
  [> `Network | `Platform of [> `Generic ] ] Eio.Resource.t ->
  Eio.Switch.t ->
  ?timeout:Eio.Time.Timeout.t ->
  ?write_timeout:Eio.Time.Timeout.t ->
  ?keep_alive:bool ->
  ?tls:tls_mode ->
  Neodriver_core.Addressing.t ->
  (t, Neodriver_core.Errors.t) Stdlib.result

Open a TCP connection to address (resolving host names as needed) and return a transport. Each resolved address (IPv4 and IPv6) is tried in turn until one connects. If tls is Secure _, the connection is wrapped in TLS before returning. keep_alive (default true) sets the SO_KEEPALIVE socket option on the TCP socket (before any TLS wrap); a failure to set it is treated like a connection failure for that address. The TCP connect and TLS handshake share a single timeout deadline; reads on the result are bounded by timeout and writes by write_timeout. The defaults (Eio.Time.Timeout.none) impose no deadline.

returns
Error _ if the address cannot be resolved, if every resolved address fails to connect or complete the TLS handshake (all failures are aggregated into the Service_unavailable message), or if the operation times out.

val read_exact : 
  t ->
  Stdlib.Bytes.t ->
  int ->
  int ->
  (unit, Neodriver_core.Errors.t) Stdlib.result

Read exactly len bytes into buf starting at offset off.

returns
Error _ on timeout or end-of-file.

val write : 
  t ->
  Stdlib.Bytes.t ->
  (unit, Neodriver_core.Errors.t) Stdlib.result

Write buf to the connection.

returns
Error _ on timeout or write failure.

val write_message : 
  t ->
  Stdlib.Bytes.t ->
  (unit, Neodriver_core.Errors.t) Stdlib.result

Write a Bolt message, splitting it into 16 KiB chunks prefixed by their size and terminated by a 0x0000 chunk.

val read_message : t -> (Stdlib.Bytes.t, Neodriver_core.Errors.t) Stdlib.result

Read one Bolt message, reassembling its chunks and skipping NOOP (empty) messages.

returns
Error _ on timeout or end-of-file.

val close : t -> unit

Close the connection.