Skip to content

Commit

Permalink
feat(transaction): uncommited transactions can be rollbacked
Browse files Browse the repository at this point in the history
  • Loading branch information
cbourget authored and mbarbeau committed Mar 15, 2019
1 parent feeeb2a commit d93fe04
Showing 1 changed file with 53 additions and 12 deletions.
65 changes: 53 additions & 12 deletions packages/common/src/lib/entity/shared/transaction.ts
Original file line number Diff line number Diff line change
Expand Up @@ -145,11 +145,47 @@ export class EntityTransaction {
}

/**
* Abort this transaction
* @todo Raise event and synchronize stores?
* Rollback this transaction
*/
abort() {
this._inCommitPhase = false;
rollback() {
this.checkInCommitPhase();

const operationsFactory = () => new Map([
[EntityOperationType.Delete, []],
[EntityOperationType.Update, []],
[EntityOperationType.Insert, []]
]);
const storesOperations = new Map();

// Group operations by store and by operation type.
// Grouping operations allows us to revert them in bacth, thus, triggering
// observables only one per operation type.
for (const operation of this.operations.all()) {
const store = operation.store;
if (operation.store === undefined) { continue; }

let storeOperations = storesOperations.get(store);
if (storeOperations === undefined) {
storeOperations = operationsFactory();
storesOperations.set(store, storeOperations);
}
storeOperations.get(operation.type).push(operation);
}

Array.from(storesOperations.keys()).forEach((store: EntityStore<object>) => {
const operations = storesOperations.get(store);

const deletes = operations.get(EntityOperationType.Delete);
store.insertMany(deletes.map((_delete: EntityOperation) => _delete.previous));

const updates = operations.get(EntityOperationType.Update);
store.updateMany(updates.map((_update: EntityOperation) => _update.previous));

const inserts = operations.get(EntityOperationType.Insert);
store.deleteMany(inserts.map((_insert: EntityOperation) => _insert.current));
});

this.clear();
}

/**
Expand Down Expand Up @@ -178,7 +214,7 @@ export class EntityTransaction {
});

if (store !== undefined) {
store.update(current);
store.insert(current);
}
}

Expand Down Expand Up @@ -248,17 +284,15 @@ export class EntityTransaction {
* @param operations Commited operations
*/
private onCommitError(operations: EntityOperation[]) {
this.abort();
this._inCommitPhase = false;
}

/**
* Add an operation to the operations store
* @param operation Operation to add
*/
private addOperation(operation: EntityOperation) {
if (this.inCommitPhase === true) {
throw new Error('This transaction is in the commit phase. Abort or clear the transaction to proceed.');
}
this.checkInCommitPhase();

this.operations.insert(operation);
this.operations.state.update(operation, {added: true});
Expand All @@ -269,9 +303,7 @@ export class EntityTransaction {
* @param operation Operation to remove
*/
private removeOperation(operation: EntityOperation) {
if (this.inCommitPhase === true) {
throw new Error('This transaction is in the commit phase. Abort or clear the transaction to proceed.');
}
this.checkInCommitPhase();

this.operations.delete(operation);
this.operations.state.update(operation, {added: false});
Expand All @@ -297,4 +329,13 @@ export class EntityTransaction {
})
.map((value: {entity: EntityOperation, state: EntityOperationState}) => value.entity);
}

/**
* Check if the transaction is in the commit phase and throw an error if it is
*/
private checkInCommitPhase() {
if (this.inCommitPhase === true) {
throw new Error('This transaction is in the commit phase. Cannot complete this operation.');
}
}
}

0 comments on commit d93fe04

Please sign in to comment.