Pony.fm/app/models/Entities/ResourceLogItem.php

<?php

	namespace Entities;
	use Illuminate\Support\Facades\Auth;
	use Illuminate\Support\Facades\DB;
	use Illuminate\Support\Facades\Request;
	use Traits\SlugTrait;

	class ResourceLogItem extends \Eloquent {
		protected $table = 'resource_log_items';
		public $timestamps = false;

		const VIEW = 1;
		const DOWNLOAD = 2;
		const PLAY = 3;

		public static function logItem($resourceType, $resourceId, $logType, $formatId = null) {
			$resourceIdColumn = $resourceType . '_id';

			$logItem = new ResourceLogItem();
			$logItem->{$resourceIdColumn} = $resourceId;
			$logItem->created_at = time();
			$logItem->log_type = $logType;
			$logItem->track_format_id = $formatId;
			$logItem->ip_address = Request::getClientIp();

			if (Auth::check()) {
				$logItem->user_id = Auth::user()->id;
			}

			$logItem->save();

			$resourceTable = $resourceType . 's';
			$countColumn = '';

			if ($logType == self::VIEW) $countColumn = 'view_count';
			else if ($logType == self::DOWNLOAD) $countColumn = 'download_count';
			else if ($logType == self::PLAY) $countColumn = 'play_count';

			// We do this to prevent a race condition. Sure I could simply increment the count columns and re-save back to the db
			// but that would require an additional SELECT and the operation would be non-atomic. If two log items are created
			// for the same resource at the same time, the cached values will still be correct with this method.

			DB::table($resourceTable)->whereId($resourceId)->update([$countColumn =>
				DB::raw('(SELECT
					COUNT(id)
				FROM
					resource_log_items
				WHERE ' .
					$resourceIdColumn . ' = ' . $resourceId . '
				AND
					log_type = ' . $logType . ')')]);

			if (Auth::check()) {
				$resourceUserId = ResourceUser::getId(Auth::user()->id, $resourceType, $resourceId);
				DB::table('resource_users')->whereId($resourceUserId)->update([$countColumn =>
					DB::raw('(SELECT
						COUNT(id)
					FROM
						resource_log_items
					WHERE
						user_id = ' . Auth::user()->id . '
					AND ' .
						$resourceIdColumn . ' = ' . $resourceId . '
					AND
						log_type = ' . $logType . ')')]);
			}
		}
	}