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mixmix / ticktack



Tree: 3734f09bcf0c150f93dc4e556b99bab42b27be3a

Files: 3734f09bcf0c150f93dc4e556b99bab42b27be3a / state / obs.js

3720 bytesRaw
1var PullObv = require('pull-obv')
2var threadReduce = require('ssb-reduce-stream')
3var pull = require('pull-stream')
4var Next = require('pull-next')
5
6var nest = require('depnest')
7
8function isObject (o) {
9 return 'object' === typeof o
10}
11
12exports.gives = nest({
13 'state.obs.threads': true,
14 'state.obs.channel': true
15})
16
17exports.needs = nest({
18 'message.sync.unbox': 'first',
19 'sbot.pull.log': 'first',
20 'sbot.async.get': 'first',
21 'feed.pull.channel': 'first'
22})
23
24exports.create = function (api) {
25 var threadsObs
26
27 function createStateObs (reduce, createStream, opts, initial) {
28 var lastTimestamp = opts.last || Date.now()
29 var firstTimestamp = opts.first || Date.now()
30
31 function unbox () {
32 return pull(
33 pull.map(function (data) {
34 if(isObject(data.value.content)) return data
35 return api.message.sync.unbox(data)
36 }),
37 pull.filter(Boolean)
38 )
39 }
40
41 var obs = PullObv(
42 reduce,
43 pull(
44 Next(function () {
45 return createStream({reverse: true, limit: 500, lt: lastTimestamp})
46 }),
47 pull.through(function (data) {
48 lastTimestamp = data.timestamp
49 }),
50 unbox()
51 ),
52 //value recovered from localStorage
53 initial
54 )
55
56 var getting = {}
57 obs(function (state) {
58 var effect = state.effect
59 if(!effect) return
60
61 state.effect = null
62 if(getting[effect.key]) return
63
64 getting[effect.key] = true
65 api.sbot.async.get(effect.key, (err, msg) => {
66 if (!msg) return
67 obs.set(reduce(obs.value, {key: effect.key, value: msg}))
68 })
69 })
70
71 //stream live messages. this *should* work.
72 //there is no back pressure on new events
73 //only a show more on the top (currently)
74 pull(
75 Next(function () {
76 return createStream({limit: 500, gt: firstTimestamp, live: true})
77 }),
78 pull.drain(function (data) {
79 if(data.sync) return
80 firstTimestamp = data.timestamp
81 obs.set(reduce(obs.value, data))
82 })
83 )
84
85 return obs
86 }
87
88
89 return nest({
90 'state.obs.channel': function (channel) {
91
92 return createStateObs(
93 threadReduce,
94 function (opts) {
95 return opts.reverse ?
96 api.feed.pull.channel(channel)(opts):
97 pull(api.sbot.pull.log(opts), pull.filter(function (data) {
98 if(data.sync) return false
99 return data.value.content.channel === channel
100 }))
101 },
102 {}
103 )
104
105 // var channelObs = PullObv(
106 // threadReduce,
107 // createChannelStream({reverse: true, limit: 1000})
108 // )
109
110
111 },
112
113 'state.obs.threads': function buildThreadObs() {
114 if(threadsObs) return threadsObs
115
116 // DISABLE localStorage cache. mainly disabling this to make debugging the other stuff
117 // easier. maybe re-enable this later? also, should this be for every channel too? not sure.
118
119 // var initial
120 // try { initial = JSON.parse(localStorage.threadsState) }
121 // catch (_) { }
122
123 initial = {}
124
125 threadsObs = createStateObs(threadReduce, api.sbot.pull.log, initial, {})
126
127 threadsObs(function (threadsState) {
128 if(threadsState.ended && threadsState.ended !== true)
129 console.error('threadObs error:', threadsState.ended)
130 })
131
132 // var timer
133 // //keep localStorage up to date
134 // threadsObs(function (threadsState) {
135 // if(timer) return
136 // timer = setTimeout(function () {
137 // timer = null
138 // threadsState.last = lastTimestamp
139 // console.log('save state')
140 // localStorage.threadsState = JSON.stringify(threadsState)
141 // }, 1000)
142 // })
143
144 return threadsObs
145 }
146 })
147}
148
149
150

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