-
Notifications
You must be signed in to change notification settings - Fork 3
/
Scope.scala
184 lines (155 loc) · 6.27 KB
/
Scope.scala
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
/*
* Copyright 2023 Valdemar Grange
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package gql.interpreter
import cats.effect._
import cats.implicits._
import cats.effect.implicits._
import cats.data._
trait Scope[F[_]] { self =>
def id: Unique.Token
def parent: Option[Scope[F]]
def isOpen: F[Boolean]
// Child order is reverse allocation order
def children: F[List[Scope[F]]]
def releaseChildren(children: NonEmptyList[Unique.Token]): F[Unit]
def openChild[A](r: Scope[F] => Resource[F, A]): F[Option[(Scope[F], A)]]
// None if already closed
def lease[A](r: Resource[F, A]): F[Option[A]]
// None if already closed
def child: F[Option[Scope[F]]]
// Closes all children in parallel
// Then closes all leases in parallel
def close: F[Unit]
def string(names: Map[Unique.Token, String] = Map.empty): F[String]
def root: Scope[F] = parent.fold(self)(_.root)
def path: NonEmptyChain[Unique.Token] =
NonEmptyChain.of(id) prependChain parent.map(_.path.toChain).getOrElse(Chain.empty)
}
object Scope {
sealed trait State[F[_]]
object State {
final case class Closed[F[_]]() extends State[F]
final case class Open[F[_]](
leases: List[Lease[F]],
children: List[Scope[F]]
) extends State[F]
}
def apply[F[_]](parent: Option[Scope[F]])(implicit F: Async[F]): Resource[F, Scope[F]] = {
val parent0 = parent
val stateF =
Resource.make(F.ref[State[F]](State.Open(Nil, Nil)))(_.getAndSet(State.Closed()).flatMap {
case State.Closed() => F.unit
case State.Open(leases, children) =>
children.parTraverse_(_.close) *> leases.parTraverse_(_.release)
})
stateF.evalMap { state =>
F.unique.map { tok =>
new Scope[F] { self =>
override def id: Unique.Token = tok
override def parent: Option[Scope[F]] = parent0
override def children: F[List[Scope[F]]] = state.get.map {
case State.Closed() => Nil
case State.Open(_, children) => children
}
override def releaseChildren(children: NonEmptyList[Unique.Token]): F[Unit] =
state.modify {
case State.Closed() => State.Closed() -> F.unit
case State.Open(leases, xs) =>
val asSet = children.toList.toSet
val (toRelease, toKeep) = xs.partition(c => asSet.contains(c.id))
State.Open(leases, toKeep) -> toRelease.parTraverse_(_.close)
}.flatten
override def openChild[A](r: Scope[F] => Resource[F, A]): F[Option[(Scope[F], A)]] =
F.uncancelable { _ =>
child.flatMap {
case None => F.pure(None)
case Some(s) => s.lease(r(s)).map(_ tupleLeft s)
}
}
// None if already closed
override def lease[A](r: Resource[F, A]): F[Option[A]] =
F.uncancelable { _ =>
state.get.flatMap {
case State.Closed() => F.pure(None)
case State.Open(_, _) =>
F.unique.flatMap { leaseToken =>
r.allocated.flatMap { case (a, release) =>
state
.modify[F[Option[A]]] {
case State.Closed() => State.Closed() -> release.as(None)
case State.Open(leases, children) =>
val release0 = release
val lease = new Lease[F] {
override def scope: Scope[F] = self
override def id: Unique.Token = leaseToken
override def release: F[Unit] = release0
}
State.Open(lease :: leases, children) -> F.pure(Some(a))
}
.flatten
}
}
}
}
// None if already closed
override def child: F[Option[Scope[F]]] =
Scope[F](Some(this)).allocated.flatMap { case (s, release) =>
state
.modify[F[Option[Scope[F]]]] {
case State.Closed() => State.Closed() -> release.as(None)
case State.Open(leases, children) => State.Open(leases, s :: children) -> F.pure(Some(s))
}
.flatten
}
override def close: F[Unit] =
state.modify {
case State.Closed() => State.Closed() -> F.unit
case State.Open(leases, children) =>
State.Closed() -> {
children.parTraverse_(_.close) *> leases.parTraverse_(_.release)
}
}.flatten
override def isOpen: F[Boolean] = state.get.map {
case State.Closed() => false
case State.Open(_, _) => true
}
def string(names: Map[Unique.Token, String] = Map.empty): F[String] = {
def loop(s: Scope[F], indent: Int): F[Chain[String]] = {
val pad = " " * indent + "|- "
val hd = pad + names.get(s.id).getOrElse(s"unknown-${s.id.toString()}")
s.isOpen.flatMap {
case false => F.pure(Chain(hd + " closed"))
case true =>
s.children.flatMap { cs =>
Chain
.fromSeq(cs)
.flatTraverse { c =>
loop(c, indent + 2)
}
.map { strs =>
if (strs.size === 0) Chain(hd)
else Chain(hd, " " * indent + "|-+") ++ strs
}
}
}
}
loop(self, 0).map(_.mkString_("\n"))
}
}
}
}
}
}