Runs a given batch operation as many times as possible in a given time span adjusting for execution rate dynamically

bulk-operation-loop.php

<?php
/**
 * This controller will run up to the alloted seconds fitting as many operations as possible
 * @param int $seconds
 * @return array
 */
public function bulk_operation($seconds = NULL, $identifier)
{
	$execution_time_limit = $seconds != NULL? $seconds : ini_get('max_execution_time');

	if( !empty($identifier) ){
		$ids = array($identifier);
		$this->_process_batch();
		return $ids;
	} else {
		$ids = array();
		// Run batches against the average execution time that day
		// The system sometimes tends to speed up after the initial batch
		// Timings as of script creation
		// Initial average response time: x
		// Hot average response time: y
		$execution_time_total = 0;
		$batch_size = 5;
		$estimated_execution_average = 1.5;
		while($batch_size > 0){
			$time_start = microtime(true);
			$batch = $this->_get_ids($batch_size);
			$ids = array_merge($ids, $batch);
			$this->_process_batch($batch);
			$time_end = microtime(true);

			// Determine the optimal size of the next batch
			$execution_time = $time_end - $time_start;
			$estimated_execution_average = $execution_time / $batch_size;
			$execution_time_total += $execution_time;
			// Calculate a new batch size
			// If we allow a batch to be too large, we might get inaccurate average execution times deviations
			// Don't race too close to our limit, the last thing we want is failed executions.
			$batch_size = min(20, floor( ($execution_time_limit - $execution_time_total ) / $estimated_execution_average * .8 ));
		}
	}

	return $ids;
}