Lock::releaseLocks()   A
last analyzed

Complexity

Conditions 2
Paths 2

Size

Total Lines 6

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 0
CRAP Score 6

Importance

Changes 0
Metric Value
dl 0
loc 6
ccs 0
cts 6
cp 0
rs 10
c 0
b 0
f 0
cc 2
nc 2
nop 0
crap 6
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<?php
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namespace Basis;
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use Exception;
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use Predis\Client;
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class Lock
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{
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    private $redis;
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    private $locks = [];
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    public function __construct(Client $redis)
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    {
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        $this->redis = $redis;
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        register_shutdown_function([$this, 'releaseLocks']);
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    }
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    public function acquireOrQueue($name, $ttl = 1)
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    {
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        if (!$this->lock($name, $ttl)) {
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            if (!$this->lock("queue-$name")) {
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                // somebody else waiting for next
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                return false;
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            }
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            $this->waitUnlock($name);
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            $this->unlock("queue-$name");
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            if (!$this->lock($name, $ttl)) {
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                // somebody else take acquire locks
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                return false;
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            }
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        }
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        return true;
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    }
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    public function acquire($name, $ttl = 1)
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    {
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        while (!$this->lock($name, $ttl)) {
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            $this->waitUnlock($name);
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        }
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        return true;
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    }
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    public function exists($name)
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    {
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        return $this->redis->get("lock-$name") !== null;
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    }
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    public function lock($name, $ttl = 1)
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    {
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        if (in_array($name, $this->locks)) {
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            throw new Exception("Lock $name was already registered");
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        }
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        $result = $this->redis->set("lock-$name", 1, 'EX', $ttl, 'NX');
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        if ($result) {
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            $this->locks[] = $name;
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            return true;
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        }
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        return false;
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    }
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    public function releaseLocks()
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    {
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        foreach ($this->locks as $name) {
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            $this->unlock($name);
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        }
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    }
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    public function unlock($name)
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    {
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        if (!in_array($name, $this->locks)) {
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            throw new Exception("Lock $name was already registered");
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        }
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        foreach ($this->locks as $i => $candidate) {
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            if ($candidate == $name) {
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                unset($this->locks[$i]);
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                $this->redis->del("lock-$name");
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                break;
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            }
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        }
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        $this->locks = array_values($this->locks);
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    }
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    public function waitUnlock($name)
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    {
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        while ($this->exists($name)) {
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            // 100ms
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            usleep(100000);
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        }
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        return true;
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    }
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}
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