git ssb

1
const Uint1Array = require('uint1array')
2
const EMPTY_STATE_ROOT = Buffer.from('4cf812be9be2c6008325050f43d06676a08612c7', 'hex')
3
4
function toTypedArray (array) {
5
  return new Uint1Array(new Uint8Array(array).buffer)
6
}
7
8
// helper functions for nodes
9
const EXTENSION = exports.EXTENSION = 0
10
const LBRANCH = exports.LBRANCH = 1
11
const RBRANCH = exports.RBRANCH = 2
12
const VALUE = exports.VALUE = 3
13
14
exports.setBranch = function (node, branch) {
15
  node['/'][LBRANCH] = branch[0]
16
  node['/'][RBRANCH] = branch[1]
17
}
18
19
exports.getBranch = function (node) {
20
  return node['/'].slice(LBRANCH, LBRANCH + 2)
21
}
22
23
exports.getValue = function (node) {
24
  return node['/'][VALUE]
25
}
26
27
exports.deleteValue = function (node) {
28
  delete node['/'][VALUE]
29
}
30
31
exports.getExtension = function (node) {
32
  if (node['/'][EXTENSION]) {
33
    const len = node['/'][EXTENSION][0]
34
    const extension = toTypedArray(node['/'][EXTENSION][1])
35
    return extension.subarray(0, len)
36
  } else {
37
    return toTypedArray([])
38
  }
39
}
40
41
exports.setExtension = function (node, ex) {
42
  if (ex && ex.length) {
43
    node['/'][EXTENSION] = [ex.length, Buffer.from(ex.buffer)]
44
  } else {
45
    delete node['/'][EXTENSION]
46
  }
47
}
48
49
exports.setValue = function (node, val) {
50
  node['/'][VALUE] = val
51
}
52
53
exports.isEmpty = function (node) {
54
  if (Buffer.isBuffer(node['/'])) {
55
    return !Buffer.compare(node['/'], EMPTY_STATE_ROOT)
56
  } else {
57
    return node['/'].every(el => !el)
58
  }
59
}
60