138 lines
3.3 KiB
JavaScript
138 lines
3.3 KiB
JavaScript
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type State = {
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user: string,
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clock: number
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};
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function copyObject (o) {
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var c = {};
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for (var key in o) {
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c[key] = o[key];
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}
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return c;
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}
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type StateVector = Array<State>;
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type OperationSet = Object; // os[Id] = op
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type StateSet = Object;
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Y.Memory = (function(){ //eslint-disable-line no-unused-vars
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class Transaction extends AbstractTransaction { //eslint-disable-line
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ss: StateSet;
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os: OperationSet;
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store: OperationStore;
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constructor (store : OperationStore) {
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super(store);
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this.ss = store.ss;
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this.os = store.os;
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}
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*setOperation (op) {
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this.os[JSON.stringify(op.id)] = op;
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return op;
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}
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*getOperation (id) {
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return this.os[JSON.stringify(id)];
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}
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*removeOperation (id) {
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delete this.os[JSON.stringify(id)];
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}
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*setState (state : State) : State {
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this.ss[state.user] = state.clock;
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}
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*getState (user : string) : State {
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var clock = this.ss[user];
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if (clock == null){
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clock = 0;
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}
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return {
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user: user,
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clock: clock
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};
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}
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*getStateVector () : StateVector {
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var stateVector = [];
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for (var user in this.ss) {
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var clock = this.ss[user];
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stateVector.push({
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user: user,
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clock: clock
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});
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}
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return stateVector;
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}
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*getStateSet () : StateSet {
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return this.ss;
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}
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*getOperations (startSS : StateSet) {
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if (startSS == null){
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startSS = {};
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}
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var ops = [];
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var endSV : StateVector = yield* this.getStateVector();
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for (var endState of endSV) {
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var user = endState.user;
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if (user === "_") {
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continue;
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}
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var startPos = startSS[user] || 0;
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var endPos = endState.clock;
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for (var clock = startPos; clock <= endPos; clock++) {
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var op = yield* this.getOperation([user, clock]);
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if (op != null) {
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op = Struct[op.struct].encode(op);
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ops.push(yield* this.makeOperationReady.call(this, startSS, op));
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}
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}
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}
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return ops;
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}
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*makeOperationReady (ss, op) {
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// instead of ss, you could use currSS (a ss that increments when you add an operation)
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var clock;
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var o = op;
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while (true){
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// while unknown, go to the right
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o = yield* this.getOperation(o.right);
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if (o == null) {
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break;
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}
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clock = ss[o.id[0]];
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if (clock != null && o.id[1] < clock ) {
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break;
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}
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}
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op = copyObject(op);
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op.right = (o == null) ? null : o.id;
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return op;
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}
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}
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class OperationStore extends AbstractOperationStore { //eslint-disable-line no-undef
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constructor (y) {
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super(y);
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this.os = {};
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this.ss = {};
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}
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requestTransaction (makeGen : Function) {
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var t = new Transaction(this);
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var gen = makeGen.call(t, new Y.Map.Create(["_", 0]));
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var res = gen.next();
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while(!res.done){
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if (res.value === "transaction") {
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res = gen.next(t);
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} else {
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throw new Error("You may not yield this type. (Maybe you meant to use 'yield*'?)");
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}
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}
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}
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*removeDatabase () {
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delete this.os;
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}
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}
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return OperationStore;
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})();
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