deleted file mode 100644

@@ -1,463 +0,0 @@

-<?php

-

-namespace Telnyx\HttpClient;

-

-use Telnyx\Telnyx;

-use Telnyx\Error;

-use Telnyx\Util;

-

-// cURL constants are not defined in PHP < 5.5

-

-// @codingStandardsIgnoreStart

-// PSR2 requires all constants be upper case. Sadly, the CURL_SSLVERSION

-// constants do not abide by those rules.

-

-// Note the values 1 and 6 come from their position in the enum that

-// defines them in cURL's source code.

-if (!defined('CURL_SSLVERSION_TLSv1')) {

-    define('CURL_SSLVERSION_TLSv1', 1);

-}

-if (!defined('CURL_SSLVERSION_TLSv1_2')) {

-    define('CURL_SSLVERSION_TLSv1_2', 6);

-}

-// @codingStandardsIgnoreEnd

-

-if (!defined('CURL_HTTP_VERSION_2TLS')) {

-    define('CURL_HTTP_VERSION_2TLS', 4);

-}

-

-class CurlClient implements ClientInterface

-{

-    private static $instance;

-

-    public static function instance()

-    {

-        if (!self::$instance) {

-            self::$instance = new self();

-        }

-        return self::$instance;

-    }

-

-    protected $defaultOptions;

-

-    protected $userAgentInfo;

-

-    protected $enablePersistentConnections = null;

-

-    protected $enableHttp2 = null;

-

-    protected $curlHandle = null;

-

-    /**

-     * CurlClient constructor.

-     *

-     * Pass in a callable to $defaultOptions that returns an array of CURLOPT_* values to start

-     * off a request with, or an flat array with the same format used by curl_setopt_array() to

-     * provide a static set of options. Note that many options are overridden later in the request

-     * call, including timeouts, which can be set via setTimeout() and setConnectTimeout().

-     *

-     * Note that request() will silently ignore a non-callable, non-array $defaultOptions, and will

-     * throw an exception if $defaultOptions returns a non-array value.

-     *

-     * @param array|callable|null $defaultOptions

-     */

-    public function __construct($defaultOptions = null, $randomGenerator = null)

-    {

-        $this->defaultOptions = $defaultOptions;

-        $this->randomGenerator = $randomGenerator ?: new Util\RandomGenerator();

-        $this->initUserAgentInfo();

-

-        // TODO: curl_reset requires PHP >= 5.5.0. Once we drop support for PHP 5.4, we can simply

-        // initialize this to true.

-        $this->enablePersistentConnections = function_exists('curl_reset');

-

-        $this->enableHttp2 = $this->canSafelyUseHttp2();

-    }

-

-    public function __destruct()

-    {

-        $this->closeCurlHandle();

-    }

-

-    public function initUserAgentInfo()

-    {

-        $curlVersion = curl_version();

-        $this->userAgentInfo = [

-            'httplib' =>  'curl ' . $curlVersion['version'],

-            'ssllib' => $curlVersion['ssl_version'],

-        ];

-    }

-

-    public function getDefaultOptions()

-    {

-        return $this->defaultOptions;

-    }

-

-    public function getUserAgentInfo()

-    {

-        return $this->userAgentInfo;

-    }

-

-    /**

-     * @return boolean

-     */

-    public function getEnablePersistentConnections()

-    {

-        return $this->enablePersistentConnections;

-    }

-

-    /**

-     * @param boolean $enable

-     */

-    public function setEnablePersistentConnections($enable)

-    {

-        $this->enablePersistentConnections = $enable;

-    }

-

-    /**

-     * @return boolean

-     */

-    public function getEnableHttp2()

-    {

-        return $this->enableHttp2;

-    }

-

-    /**

-     * @param boolean $enable

-     */

-    public function setEnableHttp2($enable)

-    {

-        $this->enableHttp2 = $enable;

-    }

-

-    // USER DEFINED TIMEOUTS

-

-    const DEFAULT_TIMEOUT = 80;

-    const DEFAULT_CONNECT_TIMEOUT = 30;

-

-    private $timeout = self::DEFAULT_TIMEOUT;

-    private $connectTimeout = self::DEFAULT_CONNECT_TIMEOUT;

-

-    public function setTimeout($seconds)

-    {

-        $this->timeout = (int) max($seconds, 0);

-        return $this;

-    }

-

-    public function setConnectTimeout($seconds)

-    {

-        $this->connectTimeout = (int) max($seconds, 0);

-        return $this;

-    }

-

-    public function getTimeout()

-    {

-        return $this->timeout;

-    }

-

-    public function getConnectTimeout()

-    {

-        return $this->connectTimeout;

-    }

-

-    // END OF USER DEFINED TIMEOUTS

-

-    public function request($method, $absUrl, $headers, $params, $hasFile)

-    {

-        $method = strtolower($method);

-

-        $opts = [];

-        if (is_callable($this->defaultOptions)) { // call defaultOptions callback, set options to return value

-            $opts = call_user_func_array($this->defaultOptions, func_get_args());

-            if (!is_array($opts)) {

-                throw new Error\Api("Non-array value returned by defaultOptions CurlClient callback");

-            }

-        } elseif (is_array($this->defaultOptions)) { // set default curlopts from array

-            $opts = $this->defaultOptions;

-        }

-

-        $params = Util\Util::objectsToIds($params);

-

-        if ($method == 'get') {

-            if ($hasFile) {

-                throw new Error\Api(

-                    "Issuing a GET request with a file parameter"

-                );

-            }

-            $opts[CURLOPT_HTTPGET] = 1;

-            if (count($params) > 0) {

-                $encoded = Util\Util::encodeParameters($params);

-                $absUrl = "$absUrl?$encoded";

-            }

-        } elseif ($method == 'post') {

-            $opts[CURLOPT_POST] = 1;

-            $opts[CURLOPT_POSTFIELDS] = $hasFile ? $params : json_encode($params);

-        } elseif ($method == 'patch') {

-            $opts[CURLOPT_CUSTOMREQUEST] = 'PATCH';

-            $opts[CURLOPT_POSTFIELDS] = $hasFile ? $params : json_encode($params);

-        } elseif ($method == 'delete') {

-            $opts[CURLOPT_CUSTOMREQUEST] = 'DELETE';

-            if (count($params) > 0) {

-                $encoded = Util\Util::encodeParameters($params);

-                $absUrl = "$absUrl?$encoded";

-            }

-        } else {

-            throw new Error\Api("Unrecognized method $method");

-        }

-

-        // It is only safe to retry network failures on POST requests if we

-        // add an Idempotency-Key header

-        if (($method == 'post') && (Telnyx::$maxNetworkRetries > 0)) {

-            if (!$this->hasHeader($headers, "Idempotency-Key")) {

-                array_push($headers, 'Idempotency-Key: ' . $this->randomGenerator->uuid());

-            }

-        }

-

-        // Create a callback to capture HTTP headers for the response

-        $rheaders = new Util\CaseInsensitiveArray();

-        $headerCallback = function ($curl, $header_line) use (&$rheaders) {

-            // Ignore the HTTP request line (HTTP/1.1 200 OK)

-            if (strpos($header_line, ":") === false) {

-                return strlen($header_line);

-            }

-            list($key, $value) = explode(":", trim($header_line), 2);

-            $rheaders[trim($key)] = trim($value);

-            return strlen($header_line);

-        };

-

-        // By default for large request body sizes (> 1024 bytes), cURL will

-        // send a request without a body and with a `Expect: 100-continue`

-        // header, which gives the server a chance to respond with an error

-        // status code in cases where one can be determined right away (say

-        // on an authentication problem for example), and saves the "large"

-        // request body from being ever sent.

-        //

-        // Unfortunately, the bindings don't currently correctly handle the

-        // success case (in which the server sends back a 100 CONTINUE), so

-        // we'll error under that condition. To compensate for that problem

-        // for the time being, override cURL's behavior by simply always

-        // sending an empty `Expect:` header.

-        array_push($headers, 'Expect: ');

-

-        $absUrl = Util\Util::utf8($absUrl);

-        $opts[CURLOPT_URL] = $absUrl;

-        $opts[CURLOPT_RETURNTRANSFER] = true;

-        $opts[CURLOPT_CONNECTTIMEOUT] = $this->connectTimeout;

-        $opts[CURLOPT_TIMEOUT] = $this->timeout;

-        $opts[CURLOPT_HEADERFUNCTION] = $headerCallback;

-        $opts[CURLOPT_HTTPHEADER] = $headers;

-        $opts[CURLOPT_CAINFO] = Telnyx::getCABundlePath();

-        if (!Telnyx::getVerifySslCerts()) {

-            $opts[CURLOPT_SSL_VERIFYPEER] = false;

-        }

-

-        if (!isset($opts[CURLOPT_HTTP_VERSION]) && $this->getEnableHttp2()) {

-            // For HTTPS requests, enable HTTP/2, if supported

-            $opts[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_2TLS;

-        }

-

-        list($rbody, $rcode) = $this->executeRequestWithRetries($opts, $absUrl);

-

-        return [$rbody, $rcode, $rheaders];

-    }

-

-    /**

-     * @param array $opts cURL options

-     */

-    private function executeRequestWithRetries($opts, $absUrl)

-    {

-        $numRetries = 0;

-

-        while (true) {

-            $rcode = 0;

-            $errno = 0;

-

-            $this->resetCurlHandle();

-            curl_setopt_array($this->curlHandle, $opts);

-            $rbody = curl_exec($this->curlHandle);

-

-            if ($rbody === false) {

-                $errno = curl_errno($this->curlHandle);

-                $message = curl_error($this->curlHandle);

-            } else {

-                $rcode = curl_getinfo($this->curlHandle, CURLINFO_HTTP_CODE);

-            }

-            if (!$this->getEnablePersistentConnections()) {

-                $this->closeCurlHandle();

-            }

-

-            if ($this->shouldRetry($errno, $rcode, $numRetries)) {

-                $numRetries += 1;

-                $sleepSeconds = $this->sleepTime($numRetries);

-                usleep(intval($sleepSeconds * 1000000));

-            } else {

-                break;

-            }

-        }

-

-        if ($rbody === false) {

-            $this->handleCurlError($absUrl, $errno, $message, $numRetries);

-        }

-

-        return [$rbody, $rcode];

-    }

-

-    /**

-     * @param string $url

-     * @param int $errno

-     * @param string $message

-     * @param int $numRetries

-     * @throws Error\ApiConnection

-     */

-    private function handleCurlError($url, $errno, $message, $numRetries)

-    {

-        switch ($errno) {

-            case CURLE_COULDNT_CONNECT:

-            case CURLE_COULDNT_RESOLVE_HOST:

-            case CURLE_OPERATION_TIMEOUTED:

-                $msg = "Could not connect to Telnyx ($url).  Please check your "

-                 . "internet connection and try again.  If this problem persists, "

-                 . "you should check Telnyx's service status at "

-                 . "http://status.telnyx.com/, or";

-                break;

-            case CURLE_SSL_CACERT:

-            case CURLE_SSL_PEER_CERTIFICATE:

-                $msg = "Could not verify Telnyx's SSL certificate.  Please make sure "

-                 . "that your network is not intercepting certificates.  "

-                 . "(Try going to $url in your browser.)  "

-                 . "If this problem persists,";

-                break;

-            default:

-                $msg = "Unexpected error communicating with Telnyx.  "

-                 . "If this problem persists,";

-        }

-        $msg .= " let us know at support@telnyx.com.";

-

-        $msg .= "\n\n(Network error [errno $errno]: $message)";

-

-        if ($numRetries > 0) {

-            $msg .= "\n\nRequest was retried $numRetries times.";

-        }

-

-        throw new Error\ApiConnection($msg);

-    }

-

-    /**

-     * Checks if an error is a problem that we should retry on. This includes both

-     * socket errors that may represent an intermittent problem and some special

-     * HTTP statuses.

-     * @param int $errno

-     * @param int $rcode

-     * @param int $numRetries

-     * @return bool

-     */

-    private function shouldRetry($errno, $rcode, $numRetries)

-    {

-        if ($numRetries >= Telnyx::getMaxNetworkRetries()) {

-            return false;

-        }

-

-        // Retry on timeout-related problems (either on open or read).

-        if ($errno === CURLE_OPERATION_TIMEOUTED) {

-            return true;

-        }

-

-        // Destination refused the connection, the connection was reset, or a

-        // variety of other connection failures. This could occur from a single

-        // saturated server, so retry in case it's intermittent.

-        if ($errno === CURLE_COULDNT_CONNECT) {

-            return true;

-        }

-

-        // 409 conflict

-        if ($rcode === 409) {

-            return true;

-        }

-

-        return false;

-    }

-

-    private function sleepTime($numRetries)

-    {

-        // Apply exponential backoff with $initialNetworkRetryDelay on the

-        // number of $numRetries so far as inputs. Do not allow the number to exceed

-        // $maxNetworkRetryDelay.

-        $sleepSeconds = min(

-            Telnyx::getInitialNetworkRetryDelay() * 1.0 * pow(2, $numRetries - 1),

-            Telnyx::getMaxNetworkRetryDelay()

-        );

-

-        // Apply some jitter by randomizing the value in the range of

-        // ($sleepSeconds / 2) to ($sleepSeconds).

-        $sleepSeconds *= 0.5 * (1 + $this->randomGenerator->randFloat());

-

-        // But never sleep less than the base sleep seconds.

-        $sleepSeconds = max(Telnyx::getInitialNetworkRetryDelay(), $sleepSeconds);

-

-        return $sleepSeconds;

-    }

-

-    /**

-     * Initializes the curl handle. If already initialized, the handle is closed first.

-     */

-    private function initCurlHandle()

-    {

-        $this->closeCurlHandle();

-        $this->curlHandle = curl_init();

-    }

-

-    /**

-     * Closes the curl handle if initialized. Do nothing if already closed.

-     */

-    private function closeCurlHandle()

-    {

-        if (!is_null($this->curlHandle)) {

-            curl_close($this->curlHandle);

-            $this->curlHandle = null;

-        }

-    }

-

-    /**

-     * Resets the curl handle. If the handle is not already initialized, or if persistent

-     * connections are disabled, the handle is reinitialized instead.

-     */

-    private function resetCurlHandle()

-    {

-        if (!is_null($this->curlHandle) && $this->getEnablePersistentConnections()) {

-            curl_reset($this->curlHandle);

-        } else {

-            $this->initCurlHandle();

-        }

-    }

-

-    /**

-     * Indicates whether it is safe to use HTTP/2 or not.

-     *

-     * @return boolean

-     */

-    private function canSafelyUseHttp2()

-    {

-        // Versions of curl older than 7.60.0 don't respect GOAWAY frames

-        // (cf. https://github.com/curl/curl/issues/2416), which Telnyx use.

-        $curlVersion = curl_version()['version'];

-        return (version_compare($curlVersion, '7.60.0') >= 0);

-    }

-

-    /**

-     * Checks if a list of headers contains a specific header name.

-     *

-     * @param string[] $headers

-     * @param string $name

-     * @return boolean

-     */

-    private function hasHeader($headers, $name)

-    {

-        foreach ($headers as $header) {

-            if (strncasecmp($header, "{$name}: ", strlen($name) + 2) === 0) {

-                return true;

-            }

-        }

-

-        return false;

-    }

-}

new file mode 100644

@@ -0,0 +1,463 @@

+<?php

+

+namespace Telnyx\HttpClient;

+

+use Telnyx\Telnyx;

+use Telnyx\Error;

+use Telnyx\Util;

+

+// cURL constants are not defined in PHP < 5.5

+

+// @codingStandardsIgnoreStart

+// PSR2 requires all constants be upper case. Sadly, the CURL_SSLVERSION

+// constants do not abide by those rules.

+

+// Note the values 1 and 6 come from their position in the enum that

+// defines them in cURL's source code.

+if (!defined('CURL_SSLVERSION_TLSv1')) {

+    define('CURL_SSLVERSION_TLSv1', 1);

+}

+if (!defined('CURL_SSLVERSION_TLSv1_2')) {

+    define('CURL_SSLVERSION_TLSv1_2', 6);

+}

+// @codingStandardsIgnoreEnd

+

+if (!defined('CURL_HTTP_VERSION_2TLS')) {

+    define('CURL_HTTP_VERSION_2TLS', 4);

+}

+

+class CurlClient implements ClientInterface

+{

+    private static $instance;

+

+    public static function instance()

+    {

+        if (!self::$instance) {

+            self::$instance = new self();

+        }

+        return self::$instance;

+    }

+

+    protected $defaultOptions;

+

+    protected $userAgentInfo;

+

+    protected $enablePersistentConnections = null;

+

+    protected $enableHttp2 = null;

+

+    protected $curlHandle = null;

+

+    /**

+     * CurlClient constructor.

+     *

+     * Pass in a callable to $defaultOptions that returns an array of CURLOPT_* values to start

+     * off a request with, or an flat array with the same format used by curl_setopt_array() to

+     * provide a static set of options. Note that many options are overridden later in the request

+     * call, including timeouts, which can be set via setTimeout() and setConnectTimeout().

+     *

+     * Note that request() will silently ignore a non-callable, non-array $defaultOptions, and will

+     * throw an exception if $defaultOptions returns a non-array value.

+     *

+     * @param array|callable|null $defaultOptions

+     */

+    public function __construct($defaultOptions = null, $randomGenerator = null)

+    {

+        $this->defaultOptions = $defaultOptions;

+        $this->randomGenerator = $randomGenerator ?: new Util\RandomGenerator();

+        $this->initUserAgentInfo();

+

+        // TODO: curl_reset requires PHP >= 5.5.0. Once we drop support for PHP 5.4, we can simply

+        // initialize this to true.

+        $this->enablePersistentConnections = function_exists('curl_reset');

+

+        $this->enableHttp2 = $this->canSafelyUseHttp2();

+    }

+

+    public function __destruct()

+    {

+        $this->closeCurlHandle();

+    }

+

+    public function initUserAgentInfo()

+    {

+        $curlVersion = curl_version();

+        $this->userAgentInfo = [

+            'httplib' =>  'curl ' . $curlVersion['version'],

+            'ssllib' => $curlVersion['ssl_version'],

+        ];

+    }

+

+    public function getDefaultOptions()

+    {

+        return $this->defaultOptions;

+    }

+

+    public function getUserAgentInfo()

+    {

+        return $this->userAgentInfo;

+    }

+

+    /**

+     * @return boolean

+     */

+    public function getEnablePersistentConnections()

+    {

+        return $this->enablePersistentConnections;

+    }

+

+    /**

+     * @param boolean $enable

+     */

+    public function setEnablePersistentConnections($enable)

+    {

+        $this->enablePersistentConnections = $enable;

+    }

+

+    /**

+     * @return boolean

+     */

+    public function getEnableHttp2()

+    {

+        return $this->enableHttp2;

+    }

+

+    /**

+     * @param boolean $enable

+     */

+    public function setEnableHttp2($enable)

+    {

+        $this->enableHttp2 = $enable;

+    }

+

+    // USER DEFINED TIMEOUTS

+

+    const DEFAULT_TIMEOUT = 80;

+    const DEFAULT_CONNECT_TIMEOUT = 30;

+

+    private $timeout = self::DEFAULT_TIMEOUT;

+    private $connectTimeout = self::DEFAULT_CONNECT_TIMEOUT;

+

+    public function setTimeout($seconds)

+    {

+        $this->timeout = (int) max($seconds, 0);

+        return $this;

+    }

+

+    public function setConnectTimeout($seconds)

+    {

+        $this->connectTimeout = (int) max($seconds, 0);

+        return $this;

+    }

+

+    public function getTimeout()

+    {

+        return $this->timeout;

+    }

+

+    public function getConnectTimeout()

+    {

+        return $this->connectTimeout;

+    }

+

+    // END OF USER DEFINED TIMEOUTS

+

+    public function request($method, $absUrl, $headers, $params, $hasFile)

+    {

+        $method = strtolower($method);

+

+        $opts = [];

+        if (is_callable($this->defaultOptions)) { // call defaultOptions callback, set options to return value

+            $opts = call_user_func_array($this->defaultOptions, func_get_args());

+            if (!is_array($opts)) {

+                throw new Error\Api("Non-array value returned by defaultOptions CurlClient callback");

+            }

+        } elseif (is_array($this->defaultOptions)) { // set default curlopts from array

+            $opts = $this->defaultOptions;

+        }

+

+        $params = Util\Util::objectsToIds($params);

+

+        if ($method == 'get') {

+            if ($hasFile) {

+                throw new Error\Api(

+                    "Issuing a GET request with a file parameter"

+                );

+            }

+            $opts[CURLOPT_HTTPGET] = 1;

+            if (count($params) > 0) {

+                $encoded = Util\Util::encodeParameters($params);

+                $absUrl = "$absUrl?$encoded";

+            }

+        } elseif ($method == 'post') {

+            $opts[CURLOPT_POST] = 1;

+            $opts[CURLOPT_POSTFIELDS] = $hasFile ? $params : json_encode($params);

+        } elseif ($method == 'patch') {

+            $opts[CURLOPT_CUSTOMREQUEST] = 'PATCH';

+            $opts[CURLOPT_POSTFIELDS] = $hasFile ? $params : json_encode($params);

+        } elseif ($method == 'delete') {

+            $opts[CURLOPT_CUSTOMREQUEST] = 'DELETE';

+            if (count($params) > 0) {

+                $encoded = Util\Util::encodeParameters($params);

+                $absUrl = "$absUrl?$encoded";

+            }

+        } else {

+            throw new Error\Api("Unrecognized method $method");

+        }

+

+        // It is only safe to retry network failures on POST requests if we

+        // add an Idempotency-Key header

+        if (($method == 'post') && (Telnyx::$maxNetworkRetries > 0)) {

+            if (!$this->hasHeader($headers, "Idempotency-Key")) {

+                array_push($headers, 'Idempotency-Key: ' . $this->randomGenerator->uuid());

+            }

+        }

+

+        // Create a callback to capture HTTP headers for the response

+        $rheaders = new Util\CaseInsensitiveArray();

+        $headerCallback = function ($curl, $header_line) use (&$rheaders) {

+            // Ignore the HTTP request line (HTTP/1.1 200 OK)

+            if (strpos($header_line, ":") === false) {

+                return strlen($header_line);

+            }

+            list($key, $value) = explode(":", trim($header_line), 2);

+            $rheaders[trim($key)] = trim($value);

+            return strlen($header_line);

+        };

+

+        // By default for large request body sizes (> 1024 bytes), cURL will

+        // send a request without a body and with a `Expect: 100-continue`

+        // header, which gives the server a chance to respond with an error

+        // status code in cases where one can be determined right away (say

+        // on an authentication problem for example), and saves the "large"

+        // request body from being ever sent.

+        //

+        // Unfortunately, the bindings don't currently correctly handle the

+        // success case (in which the server sends back a 100 CONTINUE), so

+        // we'll error under that condition. To compensate for that problem

+        // for the time being, override cURL's behavior by simply always

+        // sending an empty `Expect:` header.

+        array_push($headers, 'Expect: ');

+

+        $absUrl = Util\Util::utf8($absUrl);

+        $opts[CURLOPT_URL] = $absUrl;

+        $opts[CURLOPT_RETURNTRANSFER] = true;

+        $opts[CURLOPT_CONNECTTIMEOUT] = $this->connectTimeout;

+        $opts[CURLOPT_TIMEOUT] = $this->timeout;

+        $opts[CURLOPT_HEADERFUNCTION] = $headerCallback;

+        $opts[CURLOPT_HTTPHEADER] = $headers;

+        $opts[CURLOPT_CAINFO] = Telnyx::getCABundlePath();

+        if (!Telnyx::getVerifySslCerts()) {

+            $opts[CURLOPT_SSL_VERIFYPEER] = false;

+        }

+

+        if (!isset($opts[CURLOPT_HTTP_VERSION]) && $this->getEnableHttp2()) {

+            // For HTTPS requests, enable HTTP/2, if supported

+            $opts[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_2TLS;

+        }

+

+        list($rbody, $rcode) = $this->executeRequestWithRetries($opts, $absUrl);

+

+        return [$rbody, $rcode, $rheaders];

+    }

+

+    /**

+     * @param array $opts cURL options

+     */

+    private function executeRequestWithRetries($opts, $absUrl)

+    {

+        $numRetries = 0;

+

+        while (true) {

+            $rcode = 0;

+            $errno = 0;

+

+            $this->resetCurlHandle();

+            curl_setopt_array($this->curlHandle, $opts);

+            $rbody = curl_exec($this->curlHandle);

+

+            if ($rbody === false) {

+                $errno = curl_errno($this->curlHandle);

+                $message = curl_error($this->curlHandle);

+            } else {

+                $rcode = curl_getinfo($this->curlHandle, CURLINFO_HTTP_CODE);

+            }

+            if (!$this->getEnablePersistentConnections()) {

+                $this->closeCurlHandle();

+            }

+

+            if ($this->shouldRetry($errno, $rcode, $numRetries)) {

+                $numRetries += 1;

+                $sleepSeconds = $this->sleepTime($numRetries);

+                usleep(intval($sleepSeconds * 1000000));

+            } else {

+                break;

+            }

+        }

+

+        if ($rbody === false) {

+            $this->handleCurlError($absUrl, $errno, $message, $numRetries);

+        }

+

+        return [$rbody, $rcode];

+    }

+

+    /**

+     * @param string $url

+     * @param int $errno

+     * @param string $message

+     * @param int $numRetries

+     * @throws Error\ApiConnection

+     */

+    private function handleCurlError($url, $errno, $message, $numRetries)

+    {

+        switch ($errno) {

+            case CURLE_COULDNT_CONNECT:

+            case CURLE_COULDNT_RESOLVE_HOST:

+            case CURLE_OPERATION_TIMEOUTED:

+                $msg = "Could not connect to Telnyx ($url).  Please check your "

+                 . "internet connection and try again.  If this problem persists, "

+                 . "you should check Telnyx's service status at "

+                 . "http://status.telnyx.com/, or";

+                break;

+            case CURLE_SSL_CACERT:

+            case CURLE_SSL_PEER_CERTIFICATE:

+                $msg = "Could not verify Telnyx's SSL certificate.  Please make sure "

+                 . "that your network is not intercepting certificates.  "

+                 . "(Try going to $url in your browser.)  "

+                 . "If this problem persists,";

+                break;

+            default:

+                $msg = "Unexpected error communicating with Telnyx.  "

+                 . "If this problem persists,";

+        }

+        $msg .= " let us know at support@telnyx.com.";

+

+        $msg .= "\n\n(Network error [errno $errno]: $message)";

+

+        if ($numRetries > 0) {

+            $msg .= "\n\nRequest was retried $numRetries times.";

+        }

+

+        throw new Error\ApiConnection($msg);

+    }

+

+    /**

+     * Checks if an error is a problem that we should retry on. This includes both

+     * socket errors that may represent an intermittent problem and some special

+     * HTTP statuses.

+     * @param int $errno

+     * @param int $rcode

+     * @param int $numRetries

+     * @return bool

+     */

+    private function shouldRetry($errno, $rcode, $numRetries)

+    {

+        if ($numRetries >= Telnyx::getMaxNetworkRetries()) {

+            return false;

+        }

+

+        // Retry on timeout-related problems (either on open or read).

+        if ($errno === CURLE_OPERATION_TIMEOUTED) {

+            return true;

+        }

+

+        // Destination refused the connection, the connection was reset, or a

+        // variety of other connection failures. This could occur from a single

+        // saturated server, so retry in case it's intermittent.

+        if ($errno === CURLE_COULDNT_CONNECT) {

+            return true;

+        }

+

+        // 409 conflict

+        if ($rcode === 409) {

+            return true;

+        }

+

+        return false;

+    }

+

+    private function sleepTime($numRetries)

+    {

+        // Apply exponential backoff with $initialNetworkRetryDelay on the

+        // number of $numRetries so far as inputs. Do not allow the number to exceed

+        // $maxNetworkRetryDelay.

+        $sleepSeconds = min(

+            Telnyx::getInitialNetworkRetryDelay() * 1.0 * pow(2, $numRetries - 1),

+            Telnyx::getMaxNetworkRetryDelay()

+        );

+

+        // Apply some jitter by randomizing the value in the range of

+        // ($sleepSeconds / 2) to ($sleepSeconds).

+        $sleepSeconds *= 0.5 * (1 + $this->randomGenerator->randFloat());

+

+        // But never sleep less than the base sleep seconds.

+        $sleepSeconds = max(Telnyx::getInitialNetworkRetryDelay(), $sleepSeconds);

+

+        return $sleepSeconds;

+    }

+

+    /**

+     * Initializes the curl handle. If already initialized, the handle is closed first.

+     */

+    private function initCurlHandle()

+    {

+        $this->closeCurlHandle();

+        $this->curlHandle = curl_init();

+    }

+

+    /**

+     * Closes the curl handle if initialized. Do nothing if already closed.

+     */

+    private function closeCurlHandle()