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module Http_client_conncache

: sig

Connection cache

This module allows one to create special connection caches, e.g. by deriving from the official ones

#
type channel_binding_id = int

Same as in Http_client.channel_binding_id

#
type private_data = exn option
#
type conn_state = [
| `Inactive of channel_binding_id * private_data
| `Active of < >
]

A TCP connection may be either `Inactive, i.e. it is not used by any pipeline, or `Active obj, i.e. it is in use by the pipeline obj (this is the Http_client.pipeline coerced to < >).

Since Ocamlnet-3.3, `Inactive connections carry the channel binding ID as argument. Since 3.8, there is the option of storing an exception value private_data. This may be used by implementations to store private data together with the file descriptor.

#
type peer = [
| `Direct of string * int
| `Http_proxy of string * int
| `Http_proxy_connect of (string * int) * (string * int)
| `Socks5 of (string * int) * (string * int)
]
#
class type connection_cache =
#
method get_connection_state : Unix.file_descr -> conn_state

Returns the state of the file descriptor, or raises Not_found

#
method set_connection_state : Unix.file_descr -> peer -> conn_state -> unit

Sets the state of the file descriptor. It is allowed that inactive descriptors are simply closed and forgotten. It is also possible that this method raises Not_found, leaving it to the caller to close the connection.

#
method find_inactive_connection : peer -> channel_binding_id -> Unix.file_descr * private_data

Returns an inactive connection to the passed peer, or raise Not_found. Since Ocamlnet-3.3, the required channel binding ID is also an argument of this method.

#
method find_my_connections : < > -> Unix.file_descr list

Returns all active connections owned by the object

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method close_connection : Unix.file_descr -> unit

Deletes the connection from the cache, and closes it

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method close_all : unit -> unit

Closes all descriptors known to the cache

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class restrictive_cache : unit -> connection_cache

A restrictive cache closes connections as soon as there are no pending requests.

#
class aggressive_cache : unit -> connection_cache

This type of cache tries to keep connections as long open as possible. The consequence is that users are responsible for closing the descriptors (by calling close_connection_cache) when the cache is no longer in use. It is also possible to derive a special version of the cache from this class, e.g. for closing descriptors when they are idle for some time.

end