yjs/protocols/history.js
2019-01-29 00:54:58 +01:00

47 lines
1.4 KiB
JavaScript

import * as encoding from '../lib/encoding.js'
import * as decoding from '../lib/decoding.js'
import { Y } from '../utils/Y.js' // eslint-disable-line
import { writeDeleteStore, readFreshDeleteStore, DeleteStore } from '../utils/DeleteStore.js' // eslint-disable-line
import { writeStateMap, readStateMap } from '../utils/StateStore.js'
/**
* @typedef {Object} HistorySnapshot
* @property {DeleteStore} HistorySnapshot.ds
* @property {Map<number,number>} HistorySnapshot.sm
* @property {Map<number,string>} HistorySnapshot.userMap
*/
/**
* @param {encoding.Encoder} encoder
* @param {Y} y
* @param {Map<number, string>} userMap
*/
export const writeHistorySnapshot = (encoder, y, userMap) => {
writeDeleteStore(encoder, y.ds)
writeStateMap(encoder, y.ss.state)
encoding.writeVarUint(encoder, userMap.size)
userMap.forEach((accountname, userid) => {
encoding.writeVarUint(encoder, userid)
encoding.writeVarString(encoder, accountname)
})
}
/**
*
* @param {decoding.Decoder} decoder
* @return {HistorySnapshot}
*/
export const readHistorySnapshot = decoder => {
const ds = readFreshDeleteStore(decoder)
const sm = readStateMap(decoder)
const size = decoding.readVarUint(decoder)
const userMap = new Map()
for (let i = 0; i < size; i++) {
const userid = decoding.readVarUint(decoder)
const accountname = decoding.readVarString(decoder)
userMap.set(userid, accountname)
}
return { ds, sm, userMap }
}