public function open()

in thrift/lib/hack/src/transport/TSocketPool.php [189:327]

• 102 lines of code
• 25 McCabe index (conditional complexity)

  public function open(): void {
    // Check if we want order randomization
    if ($this->randomize_) {
      // warning: don't use shuffle here because it leads to uneven
      // load distribution
      $n = count($this->servers_);
      $s = $this->servers_;
      for ($i = 1; $i < $n; $i++) {
        $j = mt_rand(0, $i);
        $tmp = $s[$i];
        $s[$i] = $s[$j];
        $s[$j] = $tmp;
      }
      $this->servers_ = $s;
    }

    // Count servers to identify the "last" one
    $numServers = count($this->servers_);
    $has_conn_errors = false;

    $fail_reason = array(); // reasons of conn failures
    for ($i = 0; $i < $numServers; ++$i) {

      // host port is stored as an array
      list($host, $port) = $this->servers_[$i];

      $failtimeKey = TSocketPool::getAPCFailtimeKey($host, $port);
      // Cache miss? Assume it's OK
      $lastFailtime = (int) $this->apcFetch($failtimeKey);
      $this->apcLog(
        "TSocketPool: host $host:$port last fail time: ".$lastFailtime,
      );

      $retryIntervalPassed = false;

      // Cache hit...make sure enough the retry interval has elapsed
      if ($lastFailtime > 0) {
        $elapsed = time() - $lastFailtime;
        if ($elapsed > $this->retryInterval_) {
          $retryIntervalPassed = true;
          if ($this->debug_ && $this->debugHandler_ !== null) {
            $dh = $this->debugHandler_;
            $dh(
              'TSocketPool: retryInterval '.
              '('.
              $this->retryInterval_.
              ') '.
              'has passed for host '.
              $host.
              ':'.
              $port,
            );
          }
        }
      }

      // Only connect if not in the middle of a fail interval, OR if this
      // is the LAST server we are trying, just hammer away on it
      $isLastServer = false;
      if ($this->alwaysTryLast_) {
        $isLastServer = ($i == ($numServers - 1));
      }

      if (($lastFailtime === 0) ||
          ($isLastServer) ||
          ($lastFailtime > 0 && $retryIntervalPassed)) {

        // Set underlying TSocket params to this one
          $this->host_ = $host;
        $this->port_ = $port;

        // Try up to numRetries_ connections per server
        for ($attempt = 0; $attempt < $this->numRetries_; $attempt++) {
          try {
            // Use the underlying TSocket open function
            parent::open();

            // Only clear the failure counts if required to do so
            if ($lastFailtime > 0) {
              $this->apcStore($failtimeKey, 0);
            }

            // Successful connection, return now
            return;

          } catch (TException $tx) {
            // Connection failed
            // keep the reason for the last try
            $errstr = $this->getErrStr();
            $errno = $this->getErrNo();
            if ($errstr !== null || $errno !== null) {
              $fail_reason[$i] = '('.$errstr.'['.$errno.'])';
            } else {
              $fail_reason[$i] = '(?)';
            }
          }
        }

        // For transient errors (like Resource temporarily unavailable),
        // we might want not to cache the failure.
        if ($this->alwaysRetryForTransientFailure_ &&
            $this->isTransientConnectFailure($this->getErrNo())) {
          continue;
        }

        $dh = ($this->debug_ ? $this->debugHandler_ : null);

        $has_conn_errors = $this->recordFailure(
          $host,
          $port,
          $this->maxConsecutiveFailures_,
          $this->retryInterval_,
          $dh,
        );
      } else {
        $fail_reason[$i] = '(cached-down)';
      }
    }

    // Holy shit we failed them all. The system is totally ill!
    $error = 'TSocketPool: All hosts in pool are down. ';
    $hosts = array();
    foreach ($this->servers_ as $i => $server) {
      // array(host, port) (reasons, if exist)
      list($host, $port) = $server;
      $h = $host.':'.$port;
      if (array_key_exists($i, $fail_reason)) {
        $h .= (string) $fail_reason[$i];
      }
      $hosts[] = $h;
    }
    $hostlist = implode(',', $hosts);
    $error .= '('.$hostlist.')';
    if ($this->debug_ && $this->debugHandler_ !== null) {
      $dh = $this->debugHandler_;
      $dh($error);
    }
    throw new TTransportException($error);
  }