def exact.loop

mylsm-lsm-store@0.6.0.1 · src/coordinator/Io.bend:423

import Base
import bend-kit-bytes@0.3.2.0/bytes.bend as Bytes

423def exact.loop(
424  fuel: Nat,
425  state: ExactState
426) -> IO(
427  File & Result<&1, &1, U32 & String, ExactResult>
428):
429  match fuel:
430    case 0n:
431      match state:
432        case Need{file, remaining, _}:
433          match remaining:
434            case 0n: exact.complete(file, Nil{}, True{})
435            case 1n+_: IO.pure(File & Result<&1, &1, U32 & String, ExactResult>,
436              (file, Fail{(7, "socket frame read exhausted its bound")}))
437        case Read{pair, _, _}:
438          match pair:
439            case (file, Fail{error}):
440              IO.pure(File & Result<&1, &1, U32 & String, ExactResult>,
441                (file, Fail{error}))
442            case (file, Done{_}):
443              IO.pure(File & Result<&1, &1, U32 & String, ExactResult>,
444                (file, Fail{(7, "socket frame read exhausted its bound")}))
445    case 1n+rest:
446      match state:
447        case Need{file, remaining, chunks}:
448          match remaining:
449            case 0n: exact.complete(file, chunks, True{})
450            case 1n+rest_remaining:
451              +total = Nat.add(1n, rest_remaining)
452              do IO<File & Result<&1, &1, U32 & String, ExactResult>>:
453                pair : File & Result<&1, &1, U32 & String, Bytes.Bytes> <-
454                  read.bytes(file,
455                    U32.from_nat(Nat.min(65536n, total)))
456                exact.loop(rest, Read{pair, total, chunks})
457        case Read{pair, remaining, chunks}:
458          match pair:
459            case (file, Fail{error}):
460              IO.pure(File & Result<&1, &1, U32 & String, ExactResult>,
461                (file, Fail{error}))
462            case (file, Done{Bytes.Bytes{0, _}}):
463              exact.complete(file, chunks, False{})
464            case (file, Done{Bytes.Bytes{+length, words}}):
465              exact.loop(rest, Need{file,
466                Nat.sub(remaining, U32.to_nat(length)),
467                Con{Bytes.Bytes{length, words}, chunks}})