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Twitterbatch.start
Begin collecting tasks before executing them.
queues.batch.start()
batch.start and batch.stop are used to enqueue many tasks without immediately
flushing them. Batching tasks can help improve performance. Read on below for more information.
batch.start increments an internal batchStartCounter. batch.stop decrements
it. Once the counter is 0, the notifyQueue and subsequent queues will be flushed.
queues.batch.start();
queues.batch.start();
queues.notifyQueue( console.log, console, [ "notify" ] );
queues.deriveQueue( console.log, console, [ "derive" ] );
queues.mutateQueue( console.log, console, [ "mutate" ] );
queues.batch.stop();
queues.batch.stop();
// Logs:
// notify
// derive
// mutate
Use
By enqueueing many tasks at once, it enables observables like can-observation and can-compute
to update their values a single time for multiple changes. For example, by wrapping the changes
to the list with batch.start and batch.stop the completeCount property of the list only updates
once:
class TodoList extends observe.Array {
get completeCount() {
return this.filter( ( todo ) => {
return todo.complete === true;
} ).length;
}
completeAll() {
queues.batch.start();
this.forEach( ( todo ) => {
todo.complete = true;
} );
queues.batch.stop();
}
}
const todos = new TodoList( [ { complete: false, complete: false } ] );
todos.on( "completeCount", function( completeCount ) {
console.log( "completeCount is ", completeCount );
} );
todos.completeCount; //-> 0
todos.completeAll();
// Logs:
// completeCount is 2