unikernel/duniverse/ocaml-caqti/caqti-lwt/lib/caqti_lwt.ml

@@ -0,0 +1,78 @@
+(* Copyright (C) 2022--2025  Petter A. Urkedal <paurkedal@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version, with the LGPL-3.0 Linking Exception.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * and the LGPL-3.0 Linking Exception along with this library.  If not, see
+ * <http://www.gnu.org/licenses/> and <https://spdx.org>, respectively.
+ *)
+
+open Caqti_platform
+
+module Fiber = struct
+  type 'a t = 'a Lwt.t
+
+  module Infix = struct
+    let (>>=) = Lwt.Infix.(>>=)
+    let (>|=) = Lwt.Infix.(>|=)
+  end
+  open Infix
+
+  let return = Lwt.return
+  let catch = Lwt.catch
+  let finally = Lwt.finalize
+  let cleanup f g = Lwt.catch f (fun exn -> g () >>= fun () -> Lwt.fail exn)
+end
+
+module Stream = Caqti_platform.Stream.Make (Fiber)
+module Switch = Caqti_platform.Switch.Make (Fiber)
+
+module System_core = struct
+  module Fiber = Fiber
+  module Stream = Stream
+  module Switch = Switch
+
+  let async ~sw:_ = Lwt.async
+
+  module Mutex = Lwt_mutex
+
+  module Condition = struct
+    type t = unit Lwt_condition.t
+    let create = Lwt_condition.create
+    let wait c mutex = Lwt_condition.wait ~mutex c
+    let signal c = Lwt_condition.signal c ()
+  end
+
+  module Log = struct
+    type 'a log = 'a Logs_lwt.log
+    let err ?(src = Logging.default_log_src) = Logs_lwt.err ~src
+    let warn ?(src = Logging.default_log_src) = Logs_lwt.warn ~src
+    let info ?(src = Logging.default_log_src) = Logs_lwt.info ~src
+    let debug ?(src = Logging.default_log_src) = Logs_lwt.debug ~src
+  end
+
+  (* Cf. pgx_lwt. *)
+  module Sequencer = struct
+    type 'a t = 'a * Lwt_mutex.t
+    let create m = (m, Lwt_mutex.create ())
+    let enqueue (m, mutex) f = Lwt_mutex.with_lock mutex (fun () -> f m)
+  end
+end
+
+module type CONNECTION = Caqti_connection_sig.S
+  with type 'a fiber := 'a Lwt.t
+   and type ('a, 'e) stream := ('a, 'e) Stream.t
+
+type connection = (module CONNECTION)
+
+let or_fail = function
+ | Ok x -> Lwt.return x
+ | Error (#Caqti_error.t as err) -> Lwt.fail (Caqti_error.Exn err)

unikernel/duniverse/ocaml-caqti/caqti-lwt/lib/caqti_lwt.mli

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+(* Copyright (C) 2022--2023  Petter A. Urkedal <paurkedal@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version, with the LGPL-3.0 Linking Exception.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * and the LGPL-3.0 Linking Exception along with this library.  If not, see
+ * <http://www.gnu.org/licenses/> and <https://spdx.org>, respectively.
+ *)
+
+(** Prerequisities for connecting to databases using Lwt
+
+    This module contains most of the prerequisite types and modules.  Functions
+    to establish database connections are provided by the [caqti-lwt.unix] and
+    [caqti-mirage] libraries.  Pool instances are also found there due to
+    additional OS dependencies. *)
+
+(* A custom stream implementation instantiated for Lwt.  This is similar to
+ * {!Lwt_seq}, except with error handling. *)
+module Stream : Caqti_stream_sig.S with type 'a fiber := 'a Lwt.t
+
+(* This should ideally be {!Lwt_switch}, but we need a way to cancel cleanup
+ * jobs in order to avoid a memory leaks for long-lived pools. *)
+module Switch : Caqti_switch_sig.S with type 'a fiber := 'a Lwt.t
+
+(**/**)
+(* For private use by caqti-lwt.unix and caqti-mirage. *)
+module System_core : sig
+  include Caqti_platform.System_sig.CORE
+    with type 'a Fiber.t = 'a Lwt.t
+     and module Stream = Stream
+     and type Switch.t = Switch.t
+     and type stdenv := unit
+end
+(**/**)
+
+module type CONNECTION = Caqti_connection_sig.S
+  with type 'a fiber := 'a Lwt.t
+   and type ('a, 'e) stream := ('a, 'e) Stream.t
+
+type connection = (module CONNECTION)
+
+val or_fail : ('a, [< Caqti_error.t]) result -> 'a Lwt.t
+(** Converts an error to an Lwt future failed with a {!Caqti_error.Exn}
+    exception holding the error. *)

unikernel/duniverse/ocaml-caqti/caqti-lwt/lib/dune

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+(library
+ (name caqti_lwt)
+ (public_name caqti-lwt)
+ (libraries logs.lwt lwt caqti.platform))