-
Notifications
You must be signed in to change notification settings - Fork 211
/
timers.cljs
180 lines (163 loc) · 6.06 KB
/
timers.cljs
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
;; Copyright (c) Rich Hickey and contributors. All rights reserved.
;; The use and distribution terms for this software are covered by the
;; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
;; which can be found in the file epl-v10.html at the root of this distribution.
;; By using this software in any fashion, you are agreeing to be bound by
;; the terms of this license.
;; You must not remove this notice, or any other, from this software.
(ns cljs.core.async.impl.timers
(:require [cljs.core.async.impl.protocols :as impl]
[cljs.core.async.impl.channels :as channels]
[cljs.core.async.impl.dispatch :as dispatch]))
(def MAX_LEVEL 15) ;; 16 levels
(def P (/ 1 2))
(defn random-level
([] (random-level 0))
([level]
(if (and (< (.random js/Math) P)
(< level MAX_LEVEL))
(recur (inc level))
level)))
(deftype SkipListNode [key ^:mutable val forward]
ISeqable
(-seq [coll]
(list key val))
IPrintWithWriter
(-pr-writer [coll writer opts]
(pr-sequential-writer writer pr-writer "[" " " "]" opts coll)))
(defn skip-list-node
([level] (skip-list-node nil nil level))
([k v level]
(let [arr (make-array (inc level))]
(loop [i 0]
(when (< i (alength arr))
(aset arr i nil)
(recur (inc i))))
(SkipListNode. k v arr))))
(defn least-greater-node
([x k level] (least-greater-node x k level nil))
([x k level update]
(if-not (neg? level)
(let [x (loop [x x]
(if-let [x' (when (< level (alength (.-forward x)))
(aget (.-forward x) level))]
(if (< (.-key x') k)
(recur x')
x)
x))]
(when-not (nil? update)
(aset update level x))
(recur x k (dec level) update))
x)))
(deftype SkipList [header ^:mutable level]
Object
(put [coll k v]
(let [update (make-array MAX_LEVEL)
x (least-greater-node header k level update)
x (aget (.-forward x) 0)]
(if (and (not (nil? x)) (== (.-key x) k))
(set! (.-val x) v)
(let [new-level (random-level)]
(when (> new-level level)
(loop [i (inc level)]
(when (<= i (inc new-level))
(aset update i header)
(recur (inc i))))
(set! level new-level))
(let [x (skip-list-node k v (make-array new-level))]
(loop [i 0]
(when (<= i level)
(let [links (.-forward (aget update i))]
(if (< i (alength (.-forward x)))
(aset (.-forward x) i (aget links i))
(.push (.-forward x) (when (< i (alength links))
(aget links i))))
(if (< i (alength links))
(aset links i x)
(.push links x)))
(recur (inc i)))))))))
(remove [coll k]
(let [update (make-array MAX_LEVEL)
x (least-greater-node header k level update)
x (when-not (zero? (alength (.-forward x)))
(aget (.-forward x) 0))]
(when (and (not (nil? x)) (== (.-key x) k))
(loop [i 0]
(when (<= i level)
(let [links (.-forward (aget update i))]
(if (identical? x (when (< i (alength links))
(aget links i)))
(do
(aset links i (aget (.-forward x) i))
(recur (inc i)))
(recur (inc i))))))
(while (and (< 0 level (alength (.-forward header)))
(nil? (aget (.-forward header) level)))
(set! level (dec level))))))
(ceilingEntry [coll k]
(loop [x header level level]
(if-not (neg? level)
(let [nx (loop [x x]
(let [x' (when (< level (alength (.-forward x)))
(aget (.-forward x) level))]
(if-not (nil? x')
(if (> (.-key x') k)
x
(recur x'))
(when (zero? level)
x))))]
(if nx
(recur nx (dec level))
(recur x (dec level))))
(if (= (.-key x) k)
x
(aget (.-forward x) 0)))))
(floorEntry [coll k]
(loop [x header level level]
(if-not (neg? level)
(let [nx (loop [x x]
(let [x' (when (< level (alength (.-forward x)))
(aget (.-forward x) level))]
(if-not (nil? x')
(if (> (.-key x') k)
x
(recur x'))
(when (zero? level)
x))))]
(if nx
(recur nx (dec level))
(recur x (dec level))))
(when-not (identical? x header)
x))))
ISeqable
(-seq [coll]
(letfn [(iter [node]
(lazy-seq
(when-not (nil? node)
(cons [(.-key node) (.-val node)]
(iter (aget (.-forward node) 0))))))]
(iter (aget (.-forward header) 0))))
IPrintWithWriter
(-pr-writer [coll writer opts]
(let [pr-pair (fn [keyval]
(pr-sequential-writer writer pr-writer "" " " "" opts keyval))]
(pr-sequential-writer writer pr-pair "{" ", " "}" opts coll))))
(defn skip-list []
(SkipList. (skip-list-node 0) 0))
(def timeouts-map (skip-list))
(def TIMEOUT_RESOLUTION_MS 10)
(defn timeout
"returns a channel that will close after msecs"
[msecs]
(let [timeout (+ (.valueOf (js/Date.)) msecs)
me (.ceilingEntry timeouts-map timeout)]
(or (when (and me (< (.-key me) (+ timeout TIMEOUT_RESOLUTION_MS)))
(.-val me))
(let [timeout-channel (channels/chan nil)]
(.put timeouts-map timeout timeout-channel)
(dispatch/queue-delay
(fn []
(.remove timeouts-map timeout)
(impl/close! timeout-channel))
msecs)
timeout-channel))))