Ez\DbLinker\Driver\Connection\MasterSlavesConnection

Complexity

Total Complexity

35

Size/Duplication

Total Lines	241
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	0

Importance

Changes	6
Bugs	1	Features	1

24 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	6	1
A	checkSlavesWeights()	0	8	3
A	connectToMaster()	0	5	1
A	connectToSlave()	0	5	1
A	isConnectedToMaster()	0	4	1
A	connection()	0	7	2
A	getCurrentConnection()	0	4	1
A	wrappedConnection()	0	7	2
A	wrappedDriver()	0	7	2
A	wrap()	0	10	3
A	chooseASlave()	0	14	4
A	totalSlavesWeight()	0	8	2
A	disableCurrentSlave()	0	6	1
A	slaves()	0	4	1
A	prepare()	0	5	1
A	query()	0	4	1
A	quote()	0	4	1
A	exec()	0	5	1
A	lastInsertId()	0	4	1
A	beginTransaction()	0	5	1
A	commit()	0	5	1
A	rollBack()	0	5	1
A	errorCode()	0	4	1
A	errorInfo()	0	4	1

<?php

namespace Ez\DbLinker\Driver\Connection;

use Doctrine\DBAL\Driver\Connection;
use SplObjectStorage;
use Exception;

class MasterSlavesConnection implements Connection, ConnectionWrapper
{
    private $master;
    private $slavesWeights;
    private $connection;
    private $driver;
    private $currentConnectionFactory;

    /**
     * @param Closure          $master
     * @param SplObjectStorage $slavesWeights
     */
    public function __construct($master, SplObjectStorage $slavesWeights)
    {
        $this->master = $master;
        $this->checkSlavesWeights($slavesWeights);
        $this->slavesWeights = $slavesWeights;
    }

    private function checkSlavesWeights(SplObjectStorage $slavesWeights)
    {
        foreach ($slavesWeights as $slave) {
            if ((int)$slavesWeights[$slave] < 0) {
                throw new Exception('Slave weight must be >= 0');
            }
        }
    }

    public function connectToMaster()
    {
        $this->currentConnectionFactory = $this->master;
        $this->connection = null;
    }

    public function connectToSlave()
    {
        $this->currentConnectionFactory = null;
        $this->connection = null;
    }

    public function isConnectedToMaster()
    {
        return $this->currentConnectionFactory === $this->master;
    }

    private function connection()
    {
        if ($this->connection === null) {
            $this->wrap();
        }
        return $this->connection;
    }

    /**
     * @inherit
     */
    public function getCurrentConnection()
    {
        return $this->wrappedConnection();
    }

    /**
     * @inherit
     */
    public function wrappedConnection()
    {
        if ($this->connection === null) {
            $this->wrap();
        }
        return $this->connection;
    }

    public function wrappedDriver()
    {
        if ($this->driver === null) {
            $this->wrap();
        }
        return $this->driver;
    }

    private function wrap()
    {
        if ($this->currentConnectionFactory === null) {
            $this->currentConnectionFactory = $this->chooseASlave() ?: $this->master;
        }
        $factory = $this->currentConnectionFactory;
        $connection = $factory();
        $this->connection = $connection->getWrappedConnection();
        $this->driver = $connection->getDriver();
    }

    private function chooseASlave()
    {
        $totalSlavesWeight = $this->totalSlavesWeight();
        if ($totalSlavesWeight < 1) {
            return null;
        }
        $weightTarget = mt_rand(1, $totalSlavesWeight);
        foreach ($this->slavesWeights as $slave) {
            $weightTarget -= $this->slavesWeights[$slave];
            if ($weightTarget <= 0) {
                return $slave;
            }
        }
    }

    private function totalSlavesWeight()
    {
        $weight = 0;
        foreach ($this->slavesWeights as $slave) {
            $weight += $this->slavesWeights[$slave];
        }
        return $weight;
    }

    public function disableCurrentSlave()
    {
        $this->slavesWeights->detach($this->currentConnectionFactory);
        $this->currentConnectionFactory = null;
        $this->connection = null;
    }

    public function slaves()
    {
        return clone $this->slavesWeights;
    }

    /**
     * Prepares a statement for execution and returns a Statement object.
     *
     * @param string $prepareString
     *
     * @return \Doctrine\DBAL\Driver\Statement
     */
    public function prepare($prepareString)
    {
        $this->connectToMaster();
        return $this->wrappedConnection()->prepare($prepareString);
    }

    /**
     * Executes an SQL statement, returning a result set as a Statement object.
     *
     * @return \Doctrine\DBAL\Driver\Statement
     */
    public function query()
    {
        return call_user_func_array([$this->wrappedConnection(), __FUNCTION__], func_get_args());
    }

    /**
     * Quotes a string for use in a query.
     *
     * @param string  $input
     * @param integer $type
     *
     * @return string
     */
    public function quote($input, $type = \PDO::PARAM_STR)
    {
        return $this->wrappedConnection()->quote($input, $type);
    }

    /**
     * Executes an SQL statement and return the number of affected rows.
     *
     * @param string $statement
     *
     * @return integer
     */
    public function exec($statement)
    {
        $this->connectToMaster();
        return $this->wrappedConnection()->exec($statement);
    }

    /**
     * Returns the ID of the last inserted row or sequence value.
     *
     * @param string|null $name
     *
     * @return string
     */
    public function lastInsertId($name = null)
    {
        return $this->wrappedConnection()->lastInsertId($name);
    }

    /**
     * Initiates a transaction.
     *
     * @return boolean TRUE on success or FALSE on failure.
     */
    public function beginTransaction()
    {
        $this->connectToMaster();
        return $this->wrappedConnection()->beginTransaction();
    }

    /**
     * Commits a transaction.
     *
     * @return boolean TRUE on success or FALSE on failure.
     */
    public function commit()
    {
        $this->connectToMaster();
        return $this->wrappedConnection()->commit();
    }

    /**
     * Rolls back the current transaction, as initiated by beginTransaction().
     *
     * @return boolean TRUE on success or FALSE on failure.
     */
    public function rollBack()
    {
        $this->connectToMaster();
        return $this->wrappedConnection()->rollBack();
    }

    /**
     * Returns the error code associated with the last operation on the database handle.
     *
     * @return string|null The error code, or null if no operation has been run on the database handle.
     */
    public function errorCode()
    {
        return $this->wrappedConnection()->errorCode();
    }

    /**
     * Returns extended error information associated with the last operation on the database handle.
     *
     * @return array
     */
    public function errorInfo()
    {
        return $this->wrappedConnection()->errorInfo();
    }
}