103 lines
2.7 KiB
JavaScript
103 lines
2.7 KiB
JavaScript
/**
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* @module structs
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*/
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import { getStructReference } from '../utils/structReferences.js'
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import * as ID from '../utils/ID.js'
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import { writeStructToTransaction } from '../utils/Transaction.js'
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import * as decoding from '../lib/decoding.js'
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import * as encoding from '../lib/encoding.js'
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import { Y } from '../utils/Y.js' // eslint-disable-line
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// TODO should have the same base class as Item
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export class GC {
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constructor () {
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/**
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* @type {ID.ID}
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*/
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this._id = null
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this._length = 0
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}
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get _deleted () {
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return true
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}
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_integrate (y) {
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const id = this._id
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const userState = y.ss.getState(id.user)
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if (id.clock === userState) {
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y.ss.setState(id.user, id.clock + this._length)
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}
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y.ds.mark(this._id, this._length, true)
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let n = y.os.put(this)
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const prev = n.prev().val
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if (prev !== null && prev.constructor === GC && prev._id.user === n.val._id.user && prev._id.clock + prev._length === n.val._id.clock) {
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// TODO: do merging for all items!
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prev._length += n.val._length
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y.os.delete(n.val._id)
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n = prev
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}
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if (n.val) {
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n = n.val
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}
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const next = y.os.findNext(n._id)
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if (next !== null && next.constructor === GC && next._id.user === n._id.user && next._id.clock === n._id.clock + n._length) {
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n._length += next._length
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y.os.delete(next._id)
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}
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if (id.user !== ID.RootFakeUserID) {
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writeStructToTransaction(y._transaction, this)
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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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* @private
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*/
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_toBinary (encoder) {
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encoding.writeUint8(encoder, getStructReference(this.constructor))
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this._id.encode(encoder)
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encoding.writeVarUint(encoder, this._length)
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}
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/**
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* Read the next Item in a Decoder and fill this Item with the read data.
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*
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* This is called when data is received from a remote peer.
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*
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* @param {Y} y The Yjs instance that this Item belongs to.
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* @param {decoding.Decoder} decoder The decoder object to read data from.
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* @private
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*/
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_fromBinary (y, decoder) {
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/**
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* @type {any}
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*/
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const id = ID.decode(decoder)
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this._id = id
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this._length = decoding.readVarUint(decoder)
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const missing = []
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if (y.ss.getState(id.user) < id.clock) {
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missing.push(ID.createID(id.user, id.clock - 1))
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}
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return missing
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}
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_splitAt () {
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return this
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}
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_clonePartial (diff) {
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const gc = new GC()
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gc._id = ID.createID(this._id.user, this._id.clock + diff)
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gc._length = this._length - diff
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return gc
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}
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}
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