def get.sst.loop

mylsm-lsm-store@0.6.0.1 · src/ByteDurableDb.bend:1124

import Base
import mylsm-lsm-store@0.6.0.1/src/ByteMemTable.bend as ByteMemTable
import mylsm-lsm-store@0.6.0.1/src/DbLock.bend as DbLock
import mylsm-lsm-store@0.6.0.1/src/scan/SstCursor.bend as SstCursor
import mylsm-lsm-store@0.6.0.1/src/scan/VisibleStats.bend as VisibleStats
import bend-kit-bytes@0.3.2.0/bytes.bend as Bytes

1124def get.sst.loop(
1125  fuel: Nat,
1126  +path: String,
1127  lock: DbLock.Lock,
1128  table: ByteMemTable.Table,
1129  state: PointRead
1130) -> IO(Handle & Result<&1, &1, Error, Maybe<&1, Bytes.Bytes>>):
1131  match fuel:
1132    case 0n:
1133      get.sst.exhausted(path, lock, table, state)
1134    case 1n+rest:
1135      match state:
1136        case Need{cursor, query}:
1137          do IO<Handle & Result<&1, &1, Error, Maybe<&1, Bytes.Bytes>>>:
1138            step : SstCursor.Step <- SstCursor.next(cursor)
1139            get.sst.loop(rest, path, lock, table, Read{step, query})
1140        case Read{step, query}:
1141          match step:
1142            case SstCursor.Item{entry, cursor}:
1143              match entry:
1144                case ByteMemTable.Entry{key, val}:
1145                  match val:
1146                    case None{}:
1147                      get.sst.loop(rest, path, lock, table, Need{cursor, query})
1148                    case Some{value}:
1149                      get.sst.loop(rest, path, lock, table,
1150                        get.sst.compare.order(value, cursor, key,
1151                          ByteMemTable.bytes.clone(query)))
1152            case SstCursor.Skip{cursor}:
1153              get.sst.loop(rest, path, lock, table, Need{cursor, query})
1154            case SstCursor.End{}:
1155              IO.pure(Handle & Result<&1, &1, Error, Maybe<&1, Bytes.Bytes>>,
1156                (Handle{path, lock, table, Open{}, VisibleStats.Stats{0n, 0n}}, Done{None{}}))
1157            case SstCursor.Error{(code, message)}:
1158              IO.pure(Handle & Result<&1, &1, Error, Maybe<&1, Bytes.Bytes>>,
1159                (Handle{path, lock, table, Open{}, VisibleStats.Stats{0n, 0n}}, Fail{recovery.error(code, message)}))
1160        case Compare{value, cursor, query, order}:
1161          match order:
1162            case EQ{}:
1163              get.sst.closed(path, lock, table, Some{value}, cursor)
1164            case GT{}:
1165              get.sst.closed(path, lock, table, None{}, cursor)
1166            case LT{}:
1167              get.sst.loop(rest, path, lock, table, Need{cursor, query})