jkuchar/BigFileTools

<?php

namespace BigFileTools\Driver;

use Brick\Math\BigInteger;

/**
 * Aggregates results from more ISizeDrivers. First successful call to driver will return value.
 * Exceptions thrown during unsuccessful calls are saved into class state and are available over getter.
 *
 * @package BigFileTools\Driver
 */
class SizeDriverAggregator implements ISizeDriver
{
    /**
     * @var ISizeDriver[]
     */
    private $drivers = [];

    /**
     * @var ISizeDriver
     */
    private $lastUsedDriver = null;

    /**
     * @var Exception[]
     */
    private $lastExceptions = [];

    /**
     * @param ISizeDriver[] $drivers Ordered array of driver instances
     */
    public function __construct(array $drivers)
    {
        foreach($drivers as $driver) {
            $this->addDriver($driver);
        }
    }

    private function addDriver(ISizeDriver $driver)
    {
        $this->drivers[] = $driver;
    }

    /**
     * Returns first non-failing driver from last used of getFileSize()
     * @return ISizeDriver
     * @internal Should be used for debugging only
     */
    public function getLastUsedDriver()
    {
        return $this->lastUsedDriver;
    }

    /**
     * Returns file size
     * @param string $path Full path to file
     * @return BigInteger
     * @throws Exception
     */
    public function getFileSize($path)
    {
        $this->lastExceptions = [];
        foreach($this->drivers as $driver) {
            try{
                $result = $driver->getFileSize($path);
                $this->lastUsedDriver = $driver;
                return $result;
            } catch (Exception $exception) {
                $this->lastExceptions[] = $exception;
            }
        }

        throw new AggregateException(
            "Cannot get file size. All methods failed. Call getPreviousExceptions() to get more information.",
            null,
            $this->lastExceptions
        );
    }
}