package caqti

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Unified interface to relational database libraries

Install 

dune-project
 Dependency

github.com Readme Changelog Edit opam file Versions (24)

Authors

  1. P
    Petter A. Urkedal <paurkedal@gmail.com>
  2. N
    Nathan Rebours <nathan@cryptosense.com>

Maintainers

  1. P
    Petter A. Urkedal <paurkedal@gmail.com>

Sources

caqti-v1.6.0.tbz
sha256=1bf0c0d60547033c10d6148cf5297b25ab66c9a2832b680329df2f3816bc674d
sha512=0b03bd1788d99bbac59679338768a5633ec473346eed333fca4c104bc88f04c24e138af2228fc20dcf295b7106778328d228643ae8235a3f722f54cc69919295

doc/caqti/Caqti_connect_sig/module-type-S/index.html

Module type Caqti_connect_sig.S

type +'a future

The type of a deferred value of type 'a.

module Pool : Caqti_pool_sig.S with type 'a future := 'a future

A pool implementation for the current concurrency library.

module Stream : Caqti_stream.S with type 'a future := 'a future
module type CONNECTION = Caqti_connection_sig.S with type 'a future := 'a future and type ('a, 'err) stream := ('a, 'err) Stream.t

The connection API specialized for the current concurrency library.

type connection = (module CONNECTION)

Shortcut for the connection API passed as a value.

connect 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.

If you use preemptive threading, note that the connection must only be used from the thread where it was created.

val with_connection : Uri.t -> (connection -> ('a, [> Caqti_error.load_or_connect ] as 'e) result future) -> ('a, 'e) result future

with_connection uri f calls connect on uri. If connect evaluates to Ok connection, with_connection passes the connection to f. Once f either evaluates to a result, or raises an exception, with_connection closes the database connection.

val connect_pool : ?max_size:int -> ?max_idle_size:int -> ?post_connect:(connection -> (unit, 'connect_error) result future) -> Uri.t -> ((connection, [> Caqti_error.connect ] as 'connect_error) Pool.t, [> Caqti_error.load ]) result

connect_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.

  • parameter max_size

    The maximum number of open connections. Must be at least 1. For drivers which does not support concurrent connections, this will be ignored and the value 1 used instead.

  • parameter max_idle_size

    The maximum number of idle connections to put into the pool for reuse. Defaults to max_size. Must be between 0 and max_size. If you set this, you must also set max_size. For drivers which does not support pooling, this will be ignored and the value 0 used instead. For drivers which does not support concurrent connections, but supports pooling, the value will clipped to a maximum of 1.