package current
Pipeline language for keeping things up-to-date
Install
Dune Dependency
Authors
-
TThomas Leonard <talex5@gmail.com>
-
AAntonin Décimo <antonin@tarides.com>
-
TTim McGilchrist <timmcgil@gmail.com>
-
CCraig Ferguson <me@craigfe.io>
-
EEtienne MARAIS <etienne@maiste.fr>
-
AAnil Madhavapeddy <anil@recoil.org>
-
David Allsopp
-
EEwan Mellor <ewan@tarides.com>
-
KKate <kit.ty.kate@disroot.org>
-
MMark Elvers <mark.elvers@tunbury.org>
-
PPuneeth Chaganti <punchagan@muse-amuse.in>
-
LLucas Pluvinage <lucas@tarides.com>
-
NNavin Keswani <navin@novemberkilo.com>
-
TThomas Gazagnaire <thomas@gazagnaire.org>
-
Patrick Ferris
-
AArthur Wendling <art.wendling@gmail.com>
-
AAnurag Soni <anurag@sonianurag.com>
-
AAmbre Austen Suhamy <ambre@tarides.com>
-
BBen Andrew <benmandrew@gmail.com>
-
GGargi Sharma <gs051095@gmail.com>
-
JJonathan Coates <git@squiddev.cc>
-
JJules Aguillon <juloo.dsi@gmail.com>
-
MMagnus Skjegstad <magnus@skjegstad.com>
-
SShon Feder <shon.feder@gmail.com>
-
Ssmolck <46855713+smolck@users.noreply.github.com>
-
Ttatchi <corentin.leruth@gmail.com>
Maintainers
Sources
ocurrent-0.7.1.tbz
md5=8a60e0b0860f6353c0e001d8d74a88ca
sha512=fddde66e3390afa4d46e2d121f2b510358ef853b81b691dbf482b0cfc8f56b21f5a0c43618e1818e6378b8897eca5811af7a995b42e1cb955647727cad877e05
doc/src/current.cache/current_cache.ml.html
Source file current_cache.ml
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601
open Lwt.Infix module Job = Current.Job module Metrics = struct open Prometheus let namespace = "ocurrent" let subsystem = "cache" let memory_cache_items = let help = "Number of results cached in RAM" in Gauge.v_label ~label_name:"id" ~help ~namespace ~subsystem "memory_cache_items" let evaluations_total = let help = "Number of evaluations performed" in Counter.v ~help ~namespace ~subsystem "evaluations_total" end (* For each live job, the (op, key) of the database entry it will create. This is used to show build history for live jobs, which aren't yet in the database. *) let key_of_job_id = Hashtbl.create 10 let job_id_of_key = Hashtbl.create 10 module Schedule = struct type t = { valid_for : Duration.t option; } let v ?valid_for () = { valid_for } let default = v () end let durations = Duration.[ to_year, "years"; to_day, "days"; to_hour, "hours"; to_min, "minutes"; to_sec, "seconds" ] let pp_duration_rough f d = let rec aux = function | [] -> Fmt.pf f "%.3f s" (Duration.to_f d) | (to_int, units) :: xs -> let i = to_int d in if i < 5 then aux xs else Fmt.pf f "%d %s" i units in aux durations module Generic(Op : S.GENERIC) = struct module Value : sig (** Cache the value of the digest. *) type t val v : Op.Value.t -> t val value : t -> Op.Value.t val digest : t -> string val equal : t -> t -> bool end = struct type t = { value : Op.Value.t; digest : string; } let v value = { value; digest = Op.Value.digest value } let value t = t.value let digest t = t.digest let equal a b = a.digest = b.digest end module Instance = struct (** An Instance manages a single key. *) type op = { value : Value.t; (* The value currently being set. *) job : Job.t; mutable autocancelled : bool; (* This op is expected to fail *) } type latched = (Op.Outcome.t, [`Msg of string]) result option (** A previous outcome that can still be used while rebuilding. *) type t = { key : Op.Key.t; mutable build_number : int64; (* Number of recorded (incl failed) builds with this key. *) mutable ref_count : int; (* The number of watchers waiting for the result (for auto-cancel). *) mutable last_set : Current.Engine.Step.t; (* Last evaluation step setting this instance. *) mutable job_id : Current.job_id option; (* Current or last log *) mutable current : string option; (* The current digest value, if known. *) mutable desired : Value.t; (* The value we want. *) mutable ctx : Op.t; (* The context for [desired]. *) mutable op : [ | `Active of op * latched (* The currently-running operation. *) | `Finished of (Op.Outcome.t, [`Msg of string]) result | `Retry of latched (* Need to try again. *) ]; mutable mtime : float; (* Time last operation completed (if finished or error). *) mutable expires : (float * (unit -> unit)) option; (* Time and cancel function. *) notify : unit Current_incr.var; (* Async thread sets this to update results. *) release : unit -> unit; (* Remove [t] from cache (call when inactive and ref-count = 0). *) } (* State model: The first time a key is used, a new instance is created in the Retry state. Whenever an instance is wanted and we are in Retry, we transition to Active and start the Lwt builder process. The only way to leave Active is by the Lwt process finishing. While Active, we may flag that the value we are setting is out-of-date, that the user wants to cancel, or that we should cancel because the build is no longer needed. But we still wait for the process to finish, possibly encouraging it using [Job.cancel]. When an Active job finishes: - If it was auto-cancelled then we discard the result and return to Retry. - Otherwise we store the result on disk. - If we need to rebuild (because the user asked for another value during the build) then we return to Retry. - Otherwise, we move to Finished or Error, depending on whether the operation succeeded. In Finished or Error, the user can trigger a rebuild, moving us back to Retry. Also, if the user sets a different value then we move to Retry. The user can only ask to cancel while we are Active. They can only ask to Rebuild when Finished or Error. If we reach the scheduled time for a rebuild while in Finished or Error then we also move to Retry, but we also continue reporting the previous result while rebuilding. *) let pp_op f (k, v) = Op.pp f (k, Value.value v) let pp_desired f t = pp_op f (t.key, t.desired) let pp f t = match t.op with | `Finished (Error (`Msg msg)) -> Fmt.pf f "%a: %s" pp_desired t msg | `Finished (Ok _) -> Fmt.pf f "%a (completed)" pp_desired t | `Retry _ -> Fmt.pf f "%a (retry scheduled)" pp_desired t | `Active (op, _) -> if Value.equal op.value t.desired then Fmt.pf f "%a (in-progress)" pp_op (t.key, op.value) else Fmt.pf f "%a (stale), then %a" pp_op (t.key, op.value) pp_desired t (* Caller needs to notify about the change, if needed. *) let invalidate t = match t.op with | `Retry _ -> t.current <- None; Db.invalidate ~op:Op.id (Op.Key.digest t.key) | _ -> assert false let notify t = Current_incr.change t.notify () ~eq:(fun _ _ -> false); Current.Engine.update () (* If [t] isn't in (or moving to) the desired state, start a thread to do that, unless we already tried that and failed. Only call this if the instance is currently wanted. If called from an async thread, you must call [notify] afterwards too. *) let rec maybe_start ~config t = assert (t.ref_count > 0); match t.op with | `Finished (Error _) -> () (* Wait for error to be cleared. *) | `Active _ when not Op.auto_cancel -> (* Already running something and we don't auto-cancel. When the stale job completes, we'll get called again. *) () | `Active (op, _) when Value.equal t.desired op.value -> (* We're already working to set the desired value. Just keep going. *) () | `Active (op, _) -> assert Op.auto_cancel; Log.info (fun f -> f "Auto-cancelling %a" pp_op (t.key, op.value)); op.autocancelled <- true; (* Cancel existing job. When that finishes, we'll get called again. *) Job.cancel op.job "Auto-cancelling job because it is no longer needed" | `Retry latched -> publish ~latched ~config t | `Finished outcome -> match t.current with | Some current when current = Value.digest t.desired -> () (* Already the desired value. *) | _ -> (* Either we don't know the current state, or we know we want something different. We're not already running, and we haven't already failed. Time to publish! *) let latched = if Op.latched then Some outcome else None in publish ~latched ~config t and maybe_restart ~config t = maybe_start ~config t; notify t and publish ~latched ~config t = (* Once we start publishing, we don't know the state (it might be better to wait until the job starts before doing this): *) t.current <- None; let ctx = t.ctx in let switch = Current.Switch.create ~label:Op.id () in let priority = if latched = None then `High else `Low in let job = Job.create ~priority ~switch ~label:Op.id ~config () in let job_id = Job.id job in t.job_id <- Some job_id; let op = { value = t.desired; job; autocancelled = false } in let ready = !Job.timestamp () |> Unix.gmtime in t.op <- `Active (op, latched); let pp_op f = pp_op f (t.key, op.value) in Job.log job "New job: %t" pp_op; Lwt.async (fun () -> Job.start_time job >>= fun _ -> Lwt.pause () >|= fun () -> (* Ensure we're outside any propagate *) notify t ); let key_digest = Op.Key.digest t.key in Hashtbl.add key_of_job_id job_id (Op.id, key_digest); Hashtbl.add job_id_of_key (Op.id, key_digest) job_id; Lwt.async (fun () -> Lwt.finalize (fun () -> Lwt.catch (fun () -> Op.run ctx job t.key (Value.value op.value)) (fun ex -> Lwt.return (Error (`Msg (Printexc.to_string ex)))) >>= fun outcome -> Lwt.pause () >|= fun () -> (* Ensure we're outside any propagate *) let end_time = Unix.gmtime @@ !Job.timestamp () in if op.autocancelled then ( t.op <- `Retry latched; invalidate t ) else ( (* Record the result *) let running = match Lwt.state (Job.start_time job) with | Lwt.Return x -> Some (Unix.gmtime x) | Lwt.Sleep when Stdlib.Result.is_ok outcome -> Fmt.failwith "Job.start not called!"; | _ -> None in let outcome = match Current.Job.cancelled_state op.job, outcome with | Error (`Msg msg), _ -> Job.log job "%s" msg; Error (`Msg "Cancelled") | Ok (), Ok _ -> Job.log job "Job succeeded"; outcome | Ok (), Error (`Msg m) -> Job.log job "Job failed: %s" m; match Current.Log_matcher.analyse_job job with | None -> outcome | Some e -> Error (`Msg e) in t.mtime <- !Job.timestamp (); let job_id = Job.id job in Db.record ~op:Op.id ~job_id ~key:key_digest ~value:(Value.digest op.value) ~ready ~running ~finished:end_time ~build:t.build_number (Stdlib.Result.map Op.Outcome.marshal outcome); t.build_number <- Int64.succ t.build_number; match outcome with | Ok outcome -> t.current <- Some (Value.digest op.value); t.op <- `Finished (Ok outcome); | Error e -> if Value.equal op.value t.desired then ( t.op <- `Finished (Error e) ) else ( (* It failed, but we have a new value to set: ignore the stale error. *) t.op <- `Retry None; invalidate t ) ) ) (fun () -> Hashtbl.remove key_of_job_id (Job.id job); Hashtbl.remove job_id_of_key (Op.id, key_digest); Current.Switch.turn_off switch >|= fun () -> (* While we were working, we might have decided we wanted something else. If so, start that now. *) if t.ref_count > 0 then maybe_restart ~config t else t.release () ) ) let limit_expires t time = let set () = let remaining_time = time -. !Job.timestamp () in let sleep_thread = if remaining_time > 0.0 then !Job.sleep remaining_time else Lwt.return_unit in let cancelled = ref false in Lwt.async (fun () -> Lwt.try_bind (fun () -> sleep_thread) (fun () -> Lwt.pause () >|= fun () -> (* Ensure we're outside any propagate *) if not !cancelled then ( t.expires <- None; Log.info (fun f -> f "Result for %a has expired" pp_desired t); let latched = match t.op with | `Finished x -> Some x | `Retry x -> x | _ -> None in t.op <- `Retry latched; t.current <- None; match Current_incr.observe Current.Config.now with | Some config -> maybe_restart ~config t | None -> Log.warn (fun f -> f "Can't trigger restart as config is now None (shutting down?)") ) ) (function | Lwt.Canceled -> Lwt.return_unit | ex -> Log.err (fun f -> f "Expiry thread failed: %a" Fmt.exn ex); Lwt.return_unit ); ); let cancel () = Lwt.cancel sleep_thread; cancelled := true in t.expires <- Some (time, cancel) in match t.expires with | Some (prev, _) when prev <= time -> () (* Already expiring by [time] *) | Some (_, cancel) -> cancel (); set () | None -> set () let cancel_expires t = match t.expires with | Some (_, cancel) -> cancel (); t.expires <- None | None -> () (* Create a new in-memory instance, initialising it from the database. *) let load ~release ctx key desired = let step_id = Current.Engine.Step.now () in let current, job_id, op, mtime, build_number = match Db.lookup ~op:Op.id (Op.Key.digest key) with | Some { Db.value; job_id; outcome; finished; build; rebuild; _ } -> let current, op = match outcome with | _ when rebuild -> None, `Retry None | Error e when value <> Value.digest desired -> (* The saved state was an error, but the desired value has changed, so clear it. *) let latched = if Op.latched then Some (Error e) else None in Some value, `Retry latched | outcome -> try Some value, `Finished (Result.map Op.Outcome.unmarshal outcome) with ex -> Log.warn (fun f -> f "Failed to restore %S cached outcome: %a (will rebuild)" Op.id Fmt.exn ex); Db.invalidate ~op:Op.id (Op.Key.digest key); None, `Retry None in current, Some job_id, op, finished, Int64.succ build | None -> None, None, `Retry None, Unix.gettimeofday (), 0L in let notify = Current_incr.var () in { key; current; desired; ctx; op; job_id; last_set = step_id; ref_count = 0; release; mtime; build_number; notify; expires = None } (* Register the actions for a resolved (non-active) instance. Report it as changed when a rebuild is requested (manually or via the schedule). *) let register_resolved t ~schedule ~config = let key = t.key in match t.job_id with | None -> assert false | Some job_id -> let rebuild () = match t.op with | `Finished _ | `Retry _ -> t.op <- `Retry None; invalidate t; maybe_restart ~config t; Option.get t.job_id | `Active _ -> Log.info (fun f -> f "Rebuild(%a): already rebuilding" pp_op (key, t.desired)); Option.get t.job_id in match schedule.Schedule.valid_for with | None -> Current.Job.register_actions job_id @@ object method pp f = pp f t method rebuild = Some rebuild end | Some duration -> let expires = Duration.to_f duration +. t.mtime in limit_expires t expires; Current.Job.register_actions job_id @@ object method pp f = let remaining_time = expires -. !Job.timestamp () in if remaining_time <= 0.0 then Fmt.pf f "%a (expired)" pp_op (key, t.desired) else Fmt.pf f "%a will be invalid after %a" pp_op (key, t.desired) pp_duration_rough (Duration.of_f remaining_time) method rebuild = Some rebuild end let register_actions ~schedule ~config t = match t.op with | `Finished _ | `Retry _ -> register_resolved ~schedule ~config t | `Active _ -> cancel_expires t; Current.Job.register_actions (Option.get t.job_id) @@ object method pp f = pp f t method rebuild = None end let update ~value ~ctx t = let step_id = Current.Engine.Step.now () in let changed = not (Value.equal value t.desired) in if t.last_set = step_id then ( if changed then Fmt.failwith "Error: instance %a set to different values in the same step!" pp_op (t.key, value); ) else ( t.last_set <- step_id; t.ctx <- ctx; if changed then ( t.desired <- value; (* Clear any error when the desired value changes: *) match Op.latched, t.op with | _, (`Active _ | `Finished (Ok _)) -> () | true, `Retry _ -> () | true, `Finished (Error x) -> t.op <- `Retry (Some (Error x)); | false, (`Finished (Error _) | `Retry _ )-> t.op <- `Retry None ); ) let run ~config ~schedule t = t.ref_count <- t.ref_count + 1; Current.Engine.on_disable (fun () -> (* This is called at the end of a propagation if we're no longer needed. *) t.ref_count <- t.ref_count - 1; if t.ref_count = 0 then ( match t.op with | `Finished _ | `Retry _ -> cancel_expires t; t.release () | `Active (op, _) -> if Op.auto_cancel then ( op.autocancelled <- true; Job.cancel op.job "Auto-cancelling job because it is no longer needed" ) (* Will release later when job finishes, if still unneeded. *) ) ); (* Ensure a build is in progress if we need one: *) maybe_start ~config t; (* Read from [t.notify] so that we re-evaluate the following when something changes. *) Current_incr.read (Current_incr.of_var t.notify) @@ fun () -> Prometheus.Counter.inc_one Metrics.evaluations_total; register_actions ~config ~schedule t; (* Return the current state: *) let v, update = match t.op with | `Finished x -> (x :> Op.Outcome.t Current_term.Output.t), None | `Retry None -> Error (`Active `Ready), None | `Retry (Some latched) -> (latched :> Op.Outcome.t Current_term.Output.t), Some `Ready | `Active (op, latched) -> let a = let started = Job.start_time op.job in if Lwt.state started = Lwt.Sleep then if Job.is_waiting_for_confirmation op.job then `Waiting_for_confirmation else `Ready else `Running in match latched with | None -> Error (`Active a), None | Some latched -> (latched :> Op.Outcome.t Current_term.Output.t), Some a in let metadata = { Current.Metadata.job_id = t.job_id; update } in Current_incr.write (v, Some metadata) end module Instances = Map.Make(String) (* The in-memory cache. *) let instances : Instance.t Instances.t ref = ref Instances.empty (* Caller needs to notify about the change, if needed. *) let invalidate key = let key = Op.Key.digest key in match Instances.find_opt key !instances with | Some i -> i.op <- `Retry None; Instance.invalidate i (* (also invalidates the database) *) | None -> Db.invalidate ~op:Op.id key let run ?(schedule=Schedule.default) ctx key value = Current_incr.of_cc begin Current_incr.read Current.Config.now @@ function | None -> Current_incr.write (Error (`Active `Ready), None) | Some config -> Log.debug (fun f -> f "set: %a" Op.pp (key, value)); let key_digest = Op.Key.digest key in let value = Value.v value in (* Ensure the instance exists and has [i.desired = value]: *) let i = match Instances.find_opt key_digest !instances with | Some i -> (* Instance already exists in the memory cache. Update it if needed. *) Instance.update ~ctx i ~value; i | None -> (* Not in memory cache. Restore from disk if available, or create a new instance if not. Either way, [i.desired] is set to [value]. *) let release () = assert (Instances.mem key_digest !instances); instances := Instances.remove key_digest !instances; Prometheus.Gauge.dec_one (Metrics.memory_cache_items Op.id) in let i = Instance.load ~release ctx key value in instances := Instances.add key_digest i !instances; Prometheus.Gauge.inc_one (Metrics.memory_cache_items Op.id); i in Instance.run ~config ~schedule i end let reset ~db = !instances |> Instances.iter (fun _ i -> i.Instance.ref_count <- -1); instances := Instances.empty; Prometheus.Gauge.set (Metrics.memory_cache_items Op.id) 0.0; if db then Db.drop_all Op.id end module Make(B : S.BUILDER) = struct module Adaptor = struct type t = B.t let id = B.id module Key = B.Key module Value = Current.Unit module Outcome = B.Value let run op job key () = B.build op job key let pp f (key, ()) = B.pp f key let auto_cancel = B.auto_cancel let latched = false end include Generic(Adaptor) let get ?schedule ctx key = run ?schedule ctx key () end module Output(P : S.PUBLISHER) = struct module Adaptor = struct include P let run = P.publish let latched = false end include Generic(Adaptor) let set ?schedule ctx key value = run ?schedule ctx key value end module S = S module Db = struct include Db let key ~job_id = lookup_job_id job_id |> Option.map snd let history ~limit ~job_id = let key = match Hashtbl.find_opt key_of_job_id job_id with | None -> Db.lookup_job_id job_id | Some _ as k -> k in match key with | None -> None, [] | Some (op, key) -> let complete = Db.history ~limit ~op key in let active = Hashtbl.find_opt job_id_of_key (op, key) in active, complete end
sectionYPositions = computeSectionYPositions($el), 10)"
x-init="setTimeout(() => sectionYPositions = computeSectionYPositions($el), 10)"
>