git ssb

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