773 lines
20 KiB
JavaScript
773 lines
20 KiB
JavaScript
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import {
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readID,
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createID,
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writeID,
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GC,
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nextID,
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AbstractStructRef,
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AbstractStruct,
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replaceStruct,
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addStruct,
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addToDeleteSet,
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findRootTypeKey,
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compareIDs,
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getItem,
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getItemCleanEnd,
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getItemCleanStart,
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readContentDeleted,
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readContentBinary,
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readContentJSON,
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readContentAny,
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readContentString,
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readContentEmbed,
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readContentFormat,
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readContentType,
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addChangedTypeToTransaction,
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ContentType, ContentDeleted, StructStore, ID, AbstractType, Transaction // eslint-disable-line
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} from '../internals.js'
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import * as error from 'lib0/error.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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import * as maplib from 'lib0/map.js'
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import * as set from 'lib0/set.js'
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import * as binary from 'lib0/binary.js'
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/**
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* @todo This should return several items
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*
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* @param {StructStore} store
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* @param {ID} id
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* @return {{item:Item, diff:number}}
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*/
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export const followRedone = (store, id) => {
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/**
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* @type {ID|null}
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*/
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let nextID = id
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let diff = 0
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let item
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do {
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if (diff > 0) {
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nextID = createID(nextID.client, nextID.clock + diff)
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}
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item = getItem(store, nextID)
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diff = nextID.clock - item.id.clock
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nextID = item.redone
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} while (nextID !== null && item instanceof Item)
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return {
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item, diff
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}
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}
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/**
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* Make sure that neither item nor any of its parents is ever deleted.
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*
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* This property does not persist when storing it into a database or when
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* sending it to other peers
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*
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* @param {Item|null} item
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*/
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export const keepItem = item => {
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while (item !== null && !item.keep) {
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item.keep = true
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item = item.parent._item
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}
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}
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/**
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* Split leftItem into two items
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* @param {Transaction} transaction
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* @param {Item} leftItem
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* @param {number} diff
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* @return {Item}
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*
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* @function
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* @private
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*/
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export const splitItem = (transaction, leftItem, diff) => {
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const id = leftItem.id
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// create rightItem
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const rightItem = new Item(
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createID(id.client, id.clock + diff),
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leftItem,
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createID(id.client, id.clock + diff - 1),
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leftItem.right,
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leftItem.rightOrigin,
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leftItem.parent,
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leftItem.parentSub,
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leftItem.content.splice(diff)
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)
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if (leftItem.deleted) {
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rightItem.deleted = true
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}
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if (leftItem.keep) {
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rightItem.keep = true
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}
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if (leftItem.redone !== null) {
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rightItem.redone = createID(leftItem.redone.client, leftItem.redone.clock + diff)
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}
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// update left (do not set leftItem.rightOrigin as it will lead to problems when syncing)
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leftItem.right = rightItem
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// update right
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if (rightItem.right !== null) {
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rightItem.right.left = rightItem
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}
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// right is more specific.
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transaction._mergeStructs.add(rightItem.id)
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// update parent._map
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if (rightItem.parentSub !== null && rightItem.right === null) {
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rightItem.parent._map.set(rightItem.parentSub, rightItem)
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}
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leftItem.length = diff
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return rightItem
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}
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/**
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* Redoes the effect of this operation.
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*
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* @param {Transaction} transaction The Yjs instance.
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* @param {Item} item
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* @param {Set<Item>} redoitems
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*
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* @return {Item|null}
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*
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* @private
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*/
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export const redoItem = (transaction, item, redoitems) => {
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if (item.redone !== null) {
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return getItemCleanStart(transaction, item.redone)
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}
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let parentItem = item.parent._item
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/**
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* @type {Item|null}
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*/
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let left
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/**
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* @type {Item|null}
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*/
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let right
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if (item.parentSub === null) {
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// Is an array item. Insert at the old position
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left = item.left
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right = item
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} else {
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// Is a map item. Insert as current value
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left = item
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while (left.right !== null) {
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left = left.right
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if (left.id.client !== transaction.doc.clientID) {
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// It is not possible to redo this item because it conflicts with a
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// change from another client
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return null
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}
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}
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if (left.right !== null) {
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left = /** @type {Item} */ (item.parent._map.get(item.parentSub))
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}
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right = null
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}
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// make sure that parent is redone
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if (parentItem !== null && parentItem.deleted === true && parentItem.redone === null) {
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// try to undo parent if it will be undone anyway
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if (!redoitems.has(parentItem) || redoItem(transaction, parentItem, redoitems) === null) {
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return null
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}
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}
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if (parentItem !== null && parentItem.redone !== null) {
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while (parentItem.redone !== null) {
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parentItem = getItemCleanStart(transaction, parentItem.redone)
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}
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// find next cloned_redo items
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while (left !== null) {
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/**
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* @type {Item|null}
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*/
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let leftTrace = left
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// trace redone until parent matches
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while (leftTrace !== null && leftTrace.parent._item !== parentItem) {
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leftTrace = leftTrace.redone === null ? null : getItemCleanStart(transaction, leftTrace.redone)
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}
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if (leftTrace !== null && leftTrace.parent._item === parentItem) {
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left = leftTrace
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break
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}
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left = left.left
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}
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while (right !== null) {
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/**
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* @type {Item|null}
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*/
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let rightTrace = right
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// trace redone until parent matches
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while (rightTrace !== null && rightTrace.parent._item !== parentItem) {
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rightTrace = rightTrace.redone === null ? null : getItemCleanStart(transaction, rightTrace.redone)
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}
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if (rightTrace !== null && rightTrace.parent._item === parentItem) {
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right = rightTrace
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break
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}
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right = right.right
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}
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}
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const redoneItem = new Item(
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nextID(transaction),
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left, left === null ? null : left.lastId,
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right, right === null ? null : right.id,
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parentItem === null ? item.parent : /** @type {ContentType} */ (parentItem.content).type,
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item.parentSub,
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item.content.copy()
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)
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item.redone = redoneItem.id
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keepItem(redoneItem)
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redoneItem.integrate(transaction)
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return redoneItem
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}
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/**
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* Abstract class that represents any content.
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*/
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export class Item extends AbstractStruct {
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/**
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* @param {ID} id
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* @param {Item | null} left
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* @param {ID | null} origin
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* @param {Item | null} right
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* @param {ID | null} rightOrigin
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* @param {AbstractType<any>} parent
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* @param {string | null} parentSub
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* @param {AbstractContent} content
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*/
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constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
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super(id, content.getLength())
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/**
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* The item that was originally to the left of this item.
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* @type {ID | null}
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* @readonly
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*/
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this.origin = origin
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/**
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* The item that is currently to the left of this item.
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* @type {Item | null}
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*/
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this.left = left
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/**
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* The item that is currently to the right of this item.
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* @type {Item | null}
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*/
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this.right = right
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/**
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* The item that was originally to the right of this item.
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* @readonly
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* @type {ID | null}
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*/
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this.rightOrigin = rightOrigin
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/**
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* The parent type.
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* @type {AbstractType<any>}
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* @readonly
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*/
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this.parent = parent
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/**
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* If the parent refers to this item with some kind of key (e.g. YMap, the
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* key is specified here. The key is then used to refer to the list in which
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* to insert this item. If `parentSub = null` type._start is the list in
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* which to insert to. Otherwise it is `parent._map`.
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* @type {String | null}
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* @readonly
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*/
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this.parentSub = parentSub
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/**
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* Whether this item was deleted or not.
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* @type {Boolean}
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*/
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this.deleted = false
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/**
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* If this type's effect is reundone this type refers to the type that undid
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* this operation.
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* @type {ID | null}
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*/
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this.redone = null
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/**
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* @type {AbstractContent}
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*/
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this.content = content
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this.length = content.getLength()
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this.countable = content.isCountable()
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/**
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* If true, do not garbage collect this Item.
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*/
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this.keep = false
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}
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/**
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* @param {Transaction} transaction
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* @private
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*/
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integrate (transaction) {
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const store = transaction.doc.store
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const id = this.id
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const parent = this.parent
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const parentSub = this.parentSub
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const length = this.length
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/**
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* @type {Item|null}
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*/
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let o
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// set o to the first conflicting item
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if (this.left !== null) {
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o = this.left.right
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} else if (parentSub !== null) {
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o = parent._map.get(parentSub) || null
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while (o !== null && o.left !== null) {
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o = o.left
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}
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} else {
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o = parent._start
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}
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// TODO: use something like DeleteSet here (a tree implementation would be best)
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/**
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* @type {Set<Item>}
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*/
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const conflictingItems = new Set()
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/**
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* @type {Set<Item>}
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*/
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const itemsBeforeOrigin = new Set()
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// Let c in conflictingItems, b in itemsBeforeOrigin
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// ***{origin}bbbb{this}{c,b}{c,b}{o}***
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// Note that conflictingItems is a subset of itemsBeforeOrigin
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while (o !== null && o !== this.right) {
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itemsBeforeOrigin.add(o)
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conflictingItems.add(o)
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if (compareIDs(this.origin, o.origin)) {
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// case 1
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if (o.id.client < id.client) {
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this.left = o
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conflictingItems.clear()
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}
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} else if (o.origin !== null && itemsBeforeOrigin.has(getItem(store, o.origin))) {
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// case 2
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if (o.origin === null || !conflictingItems.has(getItem(store, o.origin))) {
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this.left = o
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conflictingItems.clear()
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}
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} else {
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break
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}
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o = o.right
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}
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// reconnect left/right + update parent map/start if necessary
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if (this.left !== null) {
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const right = this.left.right
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this.right = right
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this.left.right = this
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} else {
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let r
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if (parentSub !== null) {
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r = parent._map.get(parentSub) || null
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while (r !== null && r.left !== null) {
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r = r.left
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}
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} else {
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r = parent._start
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parent._start = this
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}
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this.right = r
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}
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if (this.right !== null) {
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this.right.left = this
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} else if (parentSub !== null) {
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// set as current parent value if right === null and this is parentSub
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parent._map.set(parentSub, this)
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if (this.left !== null) {
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// this is the current attribute value of parent. delete right
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this.left.delete(transaction)
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}
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}
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// adjust length of parent
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if (parentSub === null && this.countable && !this.deleted) {
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parent._length += length
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}
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addStruct(store, this)
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this.content.integrate(transaction, this)
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// add parent to transaction.changed
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addChangedTypeToTransaction(transaction, parent, parentSub)
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if ((parent._item !== null && parent._item.deleted) || (this.right !== null && parentSub !== null)) {
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// delete if parent is deleted or if this is not the current attribute value of parent
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this.delete(transaction)
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}
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}
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/**
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* Returns the next non-deleted item
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* @private
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*/
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get next () {
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let n = this.right
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while (n !== null && n.deleted) {
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n = n.right
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}
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return n
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}
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/**
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* Returns the previous non-deleted item
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* @private
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*/
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get prev () {
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let n = this.left
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while (n !== null && n.deleted) {
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n = n.left
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}
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return n
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}
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/**
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* Computes the last content address of this Item.
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*/
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get lastId () {
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return createID(this.id.client, this.id.clock + this.length - 1)
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}
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/**
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* Try to merge two items
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*
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* @param {Item} right
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* @return {boolean}
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*/
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mergeWith (right) {
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if (
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compareIDs(right.origin, this.lastId) &&
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this.right === right &&
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compareIDs(this.rightOrigin, right.rightOrigin) &&
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this.id.client === right.id.client &&
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this.id.clock + this.length === right.id.clock &&
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this.deleted === right.deleted &&
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this.redone === null &&
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right.redone === null &&
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this.content.constructor === right.content.constructor &&
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this.content.mergeWith(right.content)
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) {
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if (right.keep) {
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this.keep = true
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}
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this.right = right.right
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if (this.right !== null) {
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this.right.left = this
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}
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this.length += right.length
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return true
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}
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return false
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}
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/**
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* Mark this Item as deleted.
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*
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* @param {Transaction} transaction
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*/
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delete (transaction) {
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if (!this.deleted) {
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const parent = this.parent
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// adjust the length of parent
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if (this.countable && this.parentSub === null) {
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parent._length -= this.length
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}
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this.deleted = true
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addToDeleteSet(transaction.deleteSet, this.id, this.length)
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maplib.setIfUndefined(transaction.changed, parent, set.create).add(this.parentSub)
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this.content.delete(transaction)
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}
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}
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/**
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* @param {StructStore} store
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* @param {boolean} parentGCd
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*
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* @private
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*/
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gc (store, parentGCd) {
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if (!this.deleted) {
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throw error.unexpectedCase()
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}
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this.content.gc(store)
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if (parentGCd) {
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replaceStruct(store, this, new GC(this.id, this.length))
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} else {
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this.content = new ContentDeleted(this.length)
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}
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}
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/**
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* Transform the properties of this type to binary and write it to an
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* BinaryEncoder.
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*
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* This is called when this Item is sent to a remote peer.
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*
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* @param {encoding.Encoder} encoder The encoder to write data to.
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* @param {number} offset
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*
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* @private
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*/
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write (encoder, offset) {
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const origin = offset > 0 ? createID(this.id.client, this.id.clock + offset - 1) : this.origin
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const rightOrigin = this.rightOrigin
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const parentSub = this.parentSub
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const info = (this.content.getRef() & binary.BITS5) |
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(origin === null ? 0 : binary.BIT8) | // origin is defined
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(rightOrigin === null ? 0 : binary.BIT7) | // right origin is defined
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(parentSub === null ? 0 : binary.BIT6) // parentSub is non-null
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encoding.writeUint8(encoder, info)
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if (origin !== null) {
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writeID(encoder, origin)
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}
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if (rightOrigin !== null) {
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writeID(encoder, rightOrigin)
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}
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if (origin === null && rightOrigin === null) {
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const parent = this.parent
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if (parent._item === null) {
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// parent type on y._map
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// find the correct key
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const ykey = findRootTypeKey(parent)
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encoding.writeVarUint(encoder, 1) // write parentYKey
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encoding.writeVarString(encoder, ykey)
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} else {
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encoding.writeVarUint(encoder, 0) // write parent id
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writeID(encoder, parent._item.id)
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}
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if (parentSub !== null) {
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encoding.writeVarString(encoder, parentSub)
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}
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}
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this.content.write(encoder, offset)
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}
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}
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/**
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* @param {decoding.Decoder} decoder
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* @param {number} info
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*/
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const readItemContent = (decoder, info) => contentRefs[info & binary.BITS5](decoder)
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/**
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* A lookup map for reading Item content.
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*
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* @type {Array<function(decoding.Decoder):AbstractContent>}
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*/
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export const contentRefs = [
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() => { throw error.unexpectedCase() }, // GC is not ItemContent
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readContentDeleted,
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readContentJSON,
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readContentBinary,
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readContentString,
|
|
readContentEmbed,
|
|
readContentFormat,
|
|
readContentType,
|
|
readContentAny
|
|
]
|
|
|
|
/**
|
|
* Do not implement this class!
|
|
*/
|
|
export class AbstractContent {
|
|
/**
|
|
* @return {number}
|
|
*/
|
|
getLength () {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @return {Array<any>}
|
|
*/
|
|
getContent () {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* Should return false if this Item is some kind of meta information
|
|
* (e.g. format information).
|
|
*
|
|
* * Whether this Item should be addressable via `yarray.get(i)`
|
|
* * Whether this Item should be counted when computing yarray.length
|
|
*
|
|
* @return {boolean}
|
|
*/
|
|
isCountable () {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @return {AbstractContent}
|
|
*/
|
|
copy () {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @param {number} offset
|
|
* @return {AbstractContent}
|
|
*/
|
|
splice (offset) {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @param {AbstractContent} right
|
|
* @return {boolean}
|
|
*/
|
|
mergeWith (right) {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @param {Transaction} transaction
|
|
* @param {Item} item
|
|
*/
|
|
integrate (transaction, item) {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @param {Transaction} transaction
|
|
*/
|
|
delete (transaction) {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @param {StructStore} store
|
|
*/
|
|
gc (store) {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @param {encoding.Encoder} encoder
|
|
* @param {number} offset
|
|
*/
|
|
write (encoder, offset) {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
/**
|
|
* @return {number}
|
|
*/
|
|
getRef () {
|
|
throw error.methodUnimplemented()
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @private
|
|
*/
|
|
export class ItemRef extends AbstractStructRef {
|
|
/**
|
|
* @param {decoding.Decoder} decoder
|
|
* @param {ID} id
|
|
* @param {number} info
|
|
*/
|
|
constructor (decoder, id, info) {
|
|
super(id)
|
|
/**
|
|
* The item that was originally to the left of this item.
|
|
* @type {ID | null}
|
|
*/
|
|
this.left = (info & binary.BIT8) === binary.BIT8 ? readID(decoder) : null
|
|
/**
|
|
* The item that was originally to the right of this item.
|
|
* @type {ID | null}
|
|
*/
|
|
this.right = (info & binary.BIT7) === binary.BIT7 ? readID(decoder) : null
|
|
const canCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
|
|
const hasParentYKey = canCopyParentInfo ? decoding.readVarUint(decoder) === 1 : false
|
|
/**
|
|
* If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
|
|
* and we read the next string as parentYKey.
|
|
* It indicates how we store/retrieve parent from `y.share`
|
|
* @type {string|null}
|
|
*/
|
|
this.parentYKey = canCopyParentInfo && hasParentYKey ? decoding.readVarString(decoder) : null
|
|
/**
|
|
* The parent type.
|
|
* @type {ID | null}
|
|
*/
|
|
this.parent = canCopyParentInfo && !hasParentYKey ? readID(decoder) : null
|
|
/**
|
|
* If the parent refers to this item with some kind of key (e.g. YMap, the
|
|
* key is specified here. The key is then used to refer to the list in which
|
|
* to insert this item. If `parentSub = null` type._start is the list in
|
|
* which to insert to. Otherwise it is `parent._map`.
|
|
* @type {String | null}
|
|
*/
|
|
this.parentSub = canCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoding.readVarString(decoder) : null
|
|
const missing = this._missing
|
|
if (this.left !== null) {
|
|
missing.push(this.left)
|
|
}
|
|
if (this.right !== null) {
|
|
missing.push(this.right)
|
|
}
|
|
if (this.parent !== null) {
|
|
missing.push(this.parent)
|
|
}
|
|
/**
|
|
* @type {AbstractContent}
|
|
*/
|
|
this.content = readItemContent(decoder, info)
|
|
this.length = this.content.getLength()
|
|
}
|
|
/**
|
|
* @param {Transaction} transaction
|
|
* @param {StructStore} store
|
|
* @param {number} offset
|
|
* @return {Item|GC}
|
|
*/
|
|
toStruct (transaction, store, offset) {
|
|
if (offset > 0) {
|
|
/**
|
|
* @type {ID}
|
|
*/
|
|
const id = this.id
|
|
this.id = createID(id.client, id.clock + offset)
|
|
this.left = createID(this.id.client, this.id.clock - 1)
|
|
this.content = this.content.splice(offset)
|
|
this.length -= offset
|
|
}
|
|
|
|
const left = this.left === null ? null : getItemCleanEnd(transaction, store, this.left)
|
|
const right = this.right === null ? null : getItemCleanStart(transaction, this.right)
|
|
let parent = null
|
|
let parentSub = this.parentSub
|
|
if (this.parent !== null) {
|
|
const parentItem = getItem(store, this.parent)
|
|
// Edge case: toStruct is called with an offset > 0. In this case left is defined.
|
|
// Depending in which order structs arrive, left may be GC'd and the parent not
|
|
// deleted. This is why we check if left is GC'd. Strictly we don't have
|
|
// to check if right is GC'd, but we will in case we run into future issues
|
|
if (!parentItem.deleted && (left === null || left.constructor !== GC) && (right === null || right.constructor !== GC)) {
|
|
parent = /** @type {ContentType} */ (parentItem.content).type
|
|
}
|
|
} else if (this.parentYKey !== null) {
|
|
parent = transaction.doc.get(this.parentYKey)
|
|
} else if (left !== null) {
|
|
if (left.constructor !== GC) {
|
|
parent = left.parent
|
|
parentSub = left.parentSub
|
|
}
|
|
} else if (right !== null) {
|
|
if (right.constructor !== GC) {
|
|
parent = right.parent
|
|
parentSub = right.parentSub
|
|
}
|
|
} else {
|
|
throw error.unexpectedCase()
|
|
}
|
|
|
|
return parent === null
|
|
? new GC(this.id, this.length)
|
|
: new Item(
|
|
this.id,
|
|
left,
|
|
this.left,
|
|
right,
|
|
this.right,
|
|
parent,
|
|
parentSub,
|
|
this.content
|
|
)
|
|
}
|
|
}
|