Connecting on Unix-like platforms using Lwt
This module contains functions for connecting to databases using the lwt.unix library, providing support for all drivers.
See also Caqti_lwt for basic Lwt support.
module Pool : Caqti_pool_sig.S with type 'a fiber := 'a Lwt.tinclude Caqti_connect_sig.S
with type 'a fiber := 'a Lwt.t
and type ('a, 'e) stream := ('a, 'e) Caqti_lwt.Stream.t
and type ('a, 'e) pool := ('a, 'e) Pool.t
and type connection := Caqti_lwt.connection
and type 'a with_switch := ?sw:Caqti_lwt.Switch.t -> 'a
and type 'a with_stdenv := 'aval connect :
?env:(Caqti_driver_info.t -> string -> Caqti_query.t) ->
?config:Caqti_connect_config.t ->
?tweaks_version:(int * int) ->
?sw:Caqti_lwt.Switch.t ->
Uri.t ->
(Caqti_lwt.connection, [> Caqti_error.load_or_connect ]) Stdlib.result Lwt.tconnect uri locates and loads a driver which can handle uri, passes uri to the driver, which establish a connection and returns a first-class module implementing Caqti_connection_sig.S.
connect uri connects to the database at uri and returns a first class module implementing Caqti_connection_sig.S for the given database system. In case of preemptive threading, the connection must only be used from the thread where it was created.
The correct driver for the database system is inferred from the schema of uri; see the respective drivers for the supported schemas and related URI syntax. A driver can either be linked in to the application or, if supported, dynamically linked using the caqti-dynload package.
val with_connection :
?env:(Caqti_driver_info.t -> string -> Caqti_query.t) ->
?config:Caqti_connect_config.t ->
?tweaks_version:(int * int) ->
Uri.t ->
(Caqti_lwt.connection ->
('a, [> Caqti_error.load_or_connect ] as 'e) Stdlib.result Lwt.t) ->
('a, 'e) Stdlib.result Lwt.tval connect_pool :
?pool_config:Caqti_pool_config.t ->
?post_connect:
(Caqti_lwt.connection -> (unit, 'connect_error) Stdlib.result Lwt.t) ->
?env:(Caqti_driver_info.t -> string -> Caqti_query.t) ->
?config:Caqti_connect_config.t ->
?tweaks_version:(int * int) ->
?sw:Caqti_lwt.Switch.t ->
Uri.t ->
((Caqti_lwt.connection, [> Caqti_error.connect ] as 'connect_error) Pool.t,
[> Caqti_error.load ])
Stdlib.resultconnect_pool uri is a pool of database connections constructed by connect uri.
Do not use pooling for connections to volatile resources like sqlite3::memory: and beware of temporary tables or other objects which may not be shared across connections to the same URI.
If you use preemptive threading, note that the connection pool must only be used from the thread where it was created. Use thread local storage to create a separate pool per thread if necessary.