def loop

mylsm-lsm-store@0.6.0.1 · src/transfer/BackupIo.bend:174

import Base
import mylsm-lsm-store@0.6.0.1/src/transfer/Backup.bend as Backup
import mylsm-lsm-store@0.6.0.1/src/Fs.bend as Fs

174# Writes one bounded encoded chunk per state transition before publication.
175def loop(fuel: Nat, +destination: String, +temporary: String, state: State) -> IO(Result<&1, &1, Error, Unit>):
176  match fuel:
177    case 0n:
178      match state:
179        case Need{file, _}: close.failed(file, temporary, (7, "backup stream exceeded its transition budget"))
180        case Output{file, _}: close.failed(file, temporary, (7, "backup stream exceeded its transition budget"))
181        case Written{(file, _), _}:
182          do IO<Result<&1, &1, Error, Unit>>:
183            _closed : Unit <- File.close(file)
184            cleanup(temporary)
185            return Fail{Io{7, "backup stream exceeded its transition budget"}}
186    case 1n+rest:
187      match state:
188        case Need{file, stream}:
189          loop(rest, destination, temporary, Output{file, Backup.next(stream)})
190        case Output{file, result}:
191          match result:
192            case Fail{_}:
193              close.failed(file, temporary, (22, "backup encoder rejected its snapshot"))
194            case Done{Backup.End{}}:
195              publish.closed(destination, temporary, file, Done{Unit{}})
196            case Done{Backup.Chunk{stream, bytes}}:
197              do IO<Result<&1, &1, Error, Unit>>:
198                written : File & Result<&1, &1, U32 & String, Unit> <- Fs.write_bytes(file, bytes)
199                loop(rest, destination, temporary, Written{written, stream})
200        case Written{pair, stream}:
201          match pair:
202            case (file, Fail{error}): close.failed(file, temporary, error)
203            case (file, Done{Unit{}}): loop(rest, destination, temporary, Need{file, stream})