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Charles Lehner committed on 3/31/2016, 4:29:08 AM

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README.mdadded
index.jsadded
package.jsonadded
test.jsadded
README.mdView
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1 …+# pull-kvdiff
2 …+
3 …+diff key-value streams
4 …+
5 …+```js
6 …+var pull = require('pull-stream')
7 …+var kvdiff = require('pull-kvdiff')
8 …+
9 …+pull(
10 …+ kvdiff([
11 …+ pull.values([
12 …+ {key: 'a', value: 1},
13 …+ {key: 'b', value: 2},
14 …+ {key: 'c', value: 3},
15 …+ ]),
16 …+ pull.values([
17 …+ {key: 'a', value: 1},
18 …+ {key: 'b', value: 3},
19 …+ {key: 'd', value: 3},
20 …+ ])
21 …+ ], 'key'),
22 …+ pull.log()
23 …+)
24 …+```
25 …+output:
26 …+```json
27 …+{ key: 'b',
28 …+ values: [ { key: 'b', value: 2 }, { key: 'b', value: 3 } ],
29 …+ diff: { value: [ 2, 3 ] } }
30 …+{ key: 'c',
31 …+ values: [ { key: 'c', value: 3 }, ],
32 …+ diff: { key: [ 'c' ], value: [ 3 ] } }
33 …+{ key: 'd',
34 …+ values: [ , { key: 'd', value: 3 } ],
35 …+ diff: { key: [ , 'd' ], value: [ , 3 ] } }
36 …+```
37 …+
38 …+#### `kvdiff(sources, keyProp) → source`
39 …+
40 …+## License
41 …+
42 …+Copyright (c) 2016 Charles Lehner
43 …+
44 …+Usage of the works is permitted provided that this instrument is
45 …+retained with the works, so that any entity that uses the works is
46 …+notified of this instrument.
47 …+
48 …+DISCLAIMER: THE WORKS ARE WITHOUT WARRANTY.
index.jsView
@@ -1,0 +1,81 @@
1 …+var multicb = require('multicb')
2 …+
3 …+function diff(objs) {
4 …+ if (objs.length < 2) return {}
5 …+ var results
6 …+ var keys = {}
7 …+ for (var i = 0; i < objs.length; i++)
8 …+ for (var k in objs[i])
9 …+ keys[k] = true
10 …+
11 …+ var first = objs[0] || {}
12 …+ for (var i = 1; i < objs.length; i++) {
13 …+ var curr = objs[i] || {}
14 …+ for (var k in keys) {
15 …+ if (curr[k] !== first[k]) {
16 …+ changed = true
17 …+ var keyResults = (results || (results = {}))[k] || (results[k] = [])
18 …+ if (k in curr)
19 …+ keyResults[i] = curr[k]
20 …+ if (k in first)
21 …+ keyResults[0] = first[k]
22 …+ }
23 …+ }
24 …+ }
25 …+ return results
26 …+}
27 …+
28 …+module.exports = function (sources, keyProp) {
29 …+ var n = sources.length
30 …+ var results = {/* key: {values: [argI: value], waiting: n} */}
31 …+ var got = {/* key: bool */}
32 …+ var waiting = n
33 …+ return function read(end, cb) {
34 …+ if (end) {
35 …+ if (waiting == 0)
36 …+ return cb(end)
37 …+ var done = multicb({pluck: 1})
38 …+ for (var j = 0; j < sources.length; j++)
39 …+ if (sources[j])
40 …+ sources[j](end, done())
41 …+ return done(cb)
42 …+ }
43 …+ next(cb, -1)
44 …+ }
45 …+ function next(cb, i) {
46 …+ do {
47 …+ i++
48 …+ i %= n
49 …+ } while (!sources[i])
50 …+ sources[i](null, function (end, item) {
51 …+ if (end) {
52 …+ sources[i] = null
53 …+ if (0 == --waiting) doneReading(cb)
54 …+ else next(cb, i)
55 …+ return
56 …+ }
57 …+ var key = keyProp ? item[keyProp] : String(item)
58 …+ var keyResults = results[key] || (results[key] = {
59 …+ values: new Array(n),
60 …+ waiting: n
61 …+ })
62 …+ keyResults.values[i] = item
63 …+ if (--keyResults.waiting > 0) return next(cb, i)
64 …+ delete results[key]
65 …+ var result = diff(keyResults.values, keyProp)
66 …+ if (!result) return next(cb, i)
67 …+ cb(null, {key: key, values: keyResults.values, diff: result})
68 …+ })
69 …+ }
70 …+ function doneReading(cb) {
71 …+ next = doneReading
72 …+ for (var key in results) {
73 …+ var values = results[key].values
74 …+ var result = diff(values, keyProp)
75 …+ delete results[key]
76 …+ if (result)
77 …+ return cb(null, {key: key, values: values, diff: result})
78 …+ }
79 …+ cb(true)
80 …+ }
81 …+}
package.jsonView
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1 …+{
2 …+ "name": "pull-kvdiff",
3 …+ "version": "0.0.0",
4 …+ "description": "diff key-value streams",
5 …+ "homepage": "http://git-ssb.celehner.com/%25TZOXQlZsigfkBWfepmMVvm4jsvgyaXcXXD3GA8Wtmi0%3D.sha256",
6 …+ "bugs": "http://git-ssb.celehner.com/%25TZOXQlZsigfkBWfepmMVvm4jsvgyaXcXXD3GA8Wtmi0%3D.sha256/issues",
7 …+ "main": "index.js",
8 …+ "scripts": {
9 …+ "test": "node test"
10 …+ },
11 …+ "dependencies": {
12 …+ "multicb": "^1.2.1"
13 …+ },
14 …+ "devDependencies": {
15 …+ "tape": "^4.5.1",
16 …+ "pull-stream": "^3.2.0"
17 …+ },
18 …+ "author": "Charles Lehner (http://celehner.com/)",
19 …+ "license": "Fair"
20 …+}
test.jsView
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1 …+var test = require('tape')
2 …+var pull = require('pull-stream')
3 …+var kvdiff = require('.')
4 …+
5 …+test('kvdiff', function (t) {
6 …+ pull(
7 …+ kvdiff([
8 …+ pull.values([
9 …+ {key: 'a', value: 1},
10 …+ {key: 'b', value: 2},
11 …+ {key: 'c', value: 3},
12 …+ ]),
13 …+ pull.values([
14 …+ {key: 'a', value: 1},
15 …+ {key: 'b', value: 2},
16 …+ {key: 'c', value: 4},
17 …+ ]),
18 …+ pull.values([
19 …+ {key: 'a', value: 1},
20 …+ {key: 'b', value: 2},
21 …+ {key: 'd', value: 3},
22 …+ ])
23 …+ ],
24 …+ 'key'
25 …+ ),
26 …+ pull.collect(function (err, diff) {
27 …+ t.error(err, 'collect')
28 …+ t.deepEquals(diff, [
29 …+ {
30 …+ diff: {
31 …+ key: [ 'c', , ],
32 …+ value: [ 3, 4, ]
33 …+ },
34 …+ key: 'c',
35 …+ values: [ { key: 'c', value: 3 }, { key: 'c', value: 4 }, ] },
36 …+ {
37 …+ diff: {
38 …+ key: [ , , 'd' ],
39 …+ value: [ , , 3 ]
40 …+ },
41 …+ key: 'd',
42 …+ values: [ , , { key: 'd', value: 3 } ] }
43 …+
44 …+ ], 'values')
45 …+ t.end()
46 …+ }))
47 …+})
48 …+
49 …+test('kvdiff 2', function (t) {
50 …+ pull(
51 …+ kvdiff([
52 …+ pull.values([
53 …+ {key: 'a', value: 1},
54 …+ {key: 'b', value: 2},
55 …+ {key: 'c', value: 3},
56 …+ ]),
57 …+ pull.values([
58 …+ {key: 'a', value: 1},
59 …+ {key: 'b', value: 3},
60 …+ {key: 'd', value: 3},
61 …+ ])
62 …+ ], 'key'),
63 …+ pull.collect(function (err, diff) {
64 …+ t.error(err, 'collect')
65 …+ t.deepEquals(diff, [
66 …+ { key: 'b',
67 …+ values: [ { key: 'b', value: 2 }, { key: 'b', value: 3 } ],
68 …+ diff: { value: [ 2, 3 ] } },
69 …+ { key: 'c',
70 …+ values: [ { key: 'c', value: 3 }, ],
71 …+ diff: { key: [ 'c', ], value: [ 3, ] } },
72 …+ { key: 'd',
73 …+ values: [ , { key: 'd', value: 3 } ],
74 …+ diff: { key: [ , 'd' ], value: [ , 3 ] } }
75 …+ ])
76 …+ t.end()
77 …+ })
78 …+ )
79 …+})

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