141 lines
3.4 KiB
JavaScript
141 lines
3.4 KiB
JavaScript
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import {
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isDeleted,
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createDeleteSetFromStructStore,
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getStateVector,
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getItemCleanStart,
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createID,
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iterateDeletedStructs,
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writeDeleteSet,
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writeStateVector,
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readDeleteSet,
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readStateVector,
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createDeleteSet,
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getState,
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Transaction, Doc, DeleteSet, Item // eslint-disable-line
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} from '../internals.js'
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import * as map from 'lib0/map.js'
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import * as set from 'lib0/set.js'
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import * as encoding from 'lib0/encoding.js'
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import * as decoding from 'lib0/decoding.js'
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export class Snapshot {
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/**
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* @param {DeleteSet} ds
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* @param {Map<number,number>} sv state map
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*/
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constructor (ds, sv) {
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/**
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* @type {DeleteSet}
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* @private
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*/
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this.ds = ds
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/**
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* State Map
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* @type {Map<number,number>}
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* @private
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*/
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this.sv = sv
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}
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}
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/**
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* @param {Snapshot} snap1
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* @param {Snapshot} snap2
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* @return {boolean}
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*/
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export const equalSnapshots = (snap1, snap2) => {
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const ds1 = snap1.ds.clients
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const ds2 = snap2.ds.clients
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const sv1 = snap1.sv
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const sv2 = snap2.sv
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if (sv1.size !== sv2.size || ds1.size !== ds2.size) {
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return false
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}
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for (const [key, value] of sv1) {
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if (sv2.get(key) !== value) {
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return false
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}
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}
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for (const [client, dsitems1] of ds1) {
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const dsitems2 = ds2.get(client) || []
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if (dsitems1.length !== dsitems2.length) {
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return false
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}
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for (let i = 0; i < dsitems1.length; i++) {
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const dsitem1 = dsitems1[i]
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const dsitem2 = dsitems2[i]
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if (dsitem1.clock !== dsitem2.clock || dsitem1.len !== dsitem2.len) {
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return false
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}
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}
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}
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return true
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}
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/**
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* @param {Snapshot} snapshot
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* @return {Uint8Array}
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*/
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export const encodeSnapshot = snapshot => {
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const encoder = encoding.createEncoder()
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writeDeleteSet(encoder, snapshot.ds)
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writeStateVector(encoder, snapshot.sv)
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return encoding.toUint8Array(encoder)
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}
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/**
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* @param {Uint8Array} buf
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* @return {Snapshot}
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*/
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export const decodeSnapshot = buf => {
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const decoder = decoding.createDecoder(buf)
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return new Snapshot(readDeleteSet(decoder), readStateVector(decoder))
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}
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/**
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* @param {DeleteSet} ds
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* @param {Map<number,number>} sm
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* @return {Snapshot}
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*/
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export const createSnapshot = (ds, sm) => new Snapshot(ds, sm)
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export const emptySnapshot = createSnapshot(createDeleteSet(), new Map())
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/**
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* @param {Doc} doc
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* @return {Snapshot}
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*/
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export const snapshot = doc => createSnapshot(createDeleteSetFromStructStore(doc.store), getStateVector(doc.store))
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/**
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* @param {Item} item
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* @param {Snapshot|undefined} snapshot
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*
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* @protected
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* @function
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*/
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export const isVisible = (item, snapshot) => snapshot === undefined ? !item.deleted : (
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snapshot.sv.has(item.id.client) && (snapshot.sv.get(item.id.client) || 0) > item.id.clock && !isDeleted(snapshot.ds, item.id)
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)
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/**
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* @param {Transaction} transaction
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* @param {Snapshot} snapshot
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*/
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export const splitSnapshotAffectedStructs = (transaction, snapshot) => {
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const meta = map.setIfUndefined(transaction.meta, splitSnapshotAffectedStructs, set.create)
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const store = transaction.doc.store
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// check if we already split for this snapshot
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if (!meta.has(snapshot)) {
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snapshot.sv.forEach((clock, client) => {
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if (clock < getState(store, client)) {
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getItemCleanStart(transaction, store, createID(client, clock))
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}
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})
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iterateDeletedStructs(transaction, snapshot.ds, store, item => {})
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meta.add(snapshot)
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}
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}
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