Runner.php
294 lines
| 1 | <?php |
| 2 | /* |
| 3 | * Copyright 2014 Google Inc. |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | namespace Google\Task; |
| 19 | |
| 20 | use Google\Service\Exception as GoogleServiceException; |
| 21 | use Google\Task\Exception as GoogleTaskException; |
| 22 | |
| 23 | /** |
| 24 | * A task runner with exponential backoff support. |
| 25 | * |
| 26 | * @see https://developers.google.com/drive/web/handle-errors#implementing_exponential_backoff |
| 27 | */ |
| 28 | class Runner |
| 29 | { |
| 30 | const TASK_RETRY_NEVER = 0; |
| 31 | const TASK_RETRY_ONCE = 1; |
| 32 | const TASK_RETRY_ALWAYS = -1; |
| 33 | |
| 34 | /** |
| 35 | * @var integer $maxDelay The max time (in seconds) to wait before a retry. |
| 36 | */ |
| 37 | private $maxDelay = 60; |
| 38 | |
| 39 | /** |
| 40 | * @var integer $delay The previous delay from which the next is calculated. |
| 41 | */ |
| 42 | private $delay = 1; |
| 43 | |
| 44 | /** |
| 45 | * @var integer $factor The base number for the exponential back off. |
| 46 | */ |
| 47 | private $factor = 2; |
| 48 | |
| 49 | /** |
| 50 | * @var float $jitter A random number between -$jitter and $jitter will be |
| 51 | * added to $factor on each iteration to allow for a better distribution of |
| 52 | * retries. |
| 53 | */ |
| 54 | private $jitter = 0.5; |
| 55 | |
| 56 | /** |
| 57 | * @var integer $attempts The number of attempts that have been tried so far. |
| 58 | */ |
| 59 | private $attempts = 0; |
| 60 | |
| 61 | /** |
| 62 | * @var integer $maxAttempts The max number of attempts allowed. |
| 63 | */ |
| 64 | private $maxAttempts = 1; |
| 65 | |
| 66 | /** |
| 67 | * @var callable $action The task to run and possibly retry. |
| 68 | */ |
| 69 | private $action; |
| 70 | |
| 71 | /** |
| 72 | * @var array $arguments The task arguments. |
| 73 | */ |
| 74 | private $arguments; |
| 75 | |
| 76 | /** |
| 77 | * @var array $retryMap Map of errors with retry counts. |
| 78 | */ |
| 79 | protected $retryMap = [ |
| 80 | '500' => self::TASK_RETRY_ALWAYS, |
| 81 | '503' => self::TASK_RETRY_ALWAYS, |
| 82 | 'rateLimitExceeded' => self::TASK_RETRY_ALWAYS, |
| 83 | 'userRateLimitExceeded' => self::TASK_RETRY_ALWAYS, |
| 84 | 6 => self::TASK_RETRY_ALWAYS, // CURLE_COULDNT_RESOLVE_HOST |
| 85 | 7 => self::TASK_RETRY_ALWAYS, // CURLE_COULDNT_CONNECT |
| 86 | 28 => self::TASK_RETRY_ALWAYS, // CURLE_OPERATION_TIMEOUTED |
| 87 | 35 => self::TASK_RETRY_ALWAYS, // CURLE_SSL_CONNECT_ERROR |
| 88 | 52 => self::TASK_RETRY_ALWAYS, // CURLE_GOT_NOTHING |
| 89 | 'lighthouseError' => self::TASK_RETRY_NEVER |
| 90 | ]; |
| 91 | |
| 92 | /** |
| 93 | * Creates a new task runner with exponential backoff support. |
| 94 | * |
| 95 | * @param array $config The task runner config |
| 96 | * @param string $name The name of the current task (used for logging) |
| 97 | * @param callable $action The task to run and possibly retry |
| 98 | * @param array $arguments The task arguments |
| 99 | * @throws \Google\Task\Exception when misconfigured |
| 100 | */ |
| 101 | // @phpstan-ignore-next-line |
| 102 | public function __construct( |
| 103 | $config, |
| 104 | $name, |
| 105 | $action, |
| 106 | array $arguments = [] |
| 107 | ) { |
| 108 | if (isset($config['initial_delay'])) { |
| 109 | if ($config['initial_delay'] < 0) { |
| 110 | throw new GoogleTaskException( |
| 111 | 'Task configuration `initial_delay` must not be negative.' |
| 112 | ); |
| 113 | } |
| 114 | |
| 115 | $this->delay = $config['initial_delay']; |
| 116 | } |
| 117 | |
| 118 | if (isset($config['max_delay'])) { |
| 119 | if ($config['max_delay'] <= 0) { |
| 120 | throw new GoogleTaskException( |
| 121 | 'Task configuration `max_delay` must be greater than 0.' |
| 122 | ); |
| 123 | } |
| 124 | |
| 125 | $this->maxDelay = $config['max_delay']; |
| 126 | } |
| 127 | |
| 128 | if (isset($config['factor'])) { |
| 129 | if ($config['factor'] <= 0) { |
| 130 | throw new GoogleTaskException( |
| 131 | 'Task configuration `factor` must be greater than 0.' |
| 132 | ); |
| 133 | } |
| 134 | |
| 135 | $this->factor = $config['factor']; |
| 136 | } |
| 137 | |
| 138 | if (isset($config['jitter'])) { |
| 139 | if ($config['jitter'] <= 0) { |
| 140 | throw new GoogleTaskException( |
| 141 | 'Task configuration `jitter` must be greater than 0.' |
| 142 | ); |
| 143 | } |
| 144 | |
| 145 | $this->jitter = $config['jitter']; |
| 146 | } |
| 147 | |
| 148 | if (isset($config['retries'])) { |
| 149 | if ($config['retries'] < 0) { |
| 150 | throw new GoogleTaskException( |
| 151 | 'Task configuration `retries` must not be negative.' |
| 152 | ); |
| 153 | } |
| 154 | $this->maxAttempts += $config['retries']; |
| 155 | } |
| 156 | |
| 157 | if (!is_callable($action)) { |
| 158 | throw new GoogleTaskException( |
| 159 | 'Task argument `$action` must be a valid callable.' |
| 160 | ); |
| 161 | } |
| 162 | |
| 163 | $this->action = $action; |
| 164 | $this->arguments = $arguments; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Checks if a retry can be attempted. |
| 169 | * |
| 170 | * @return boolean |
| 171 | */ |
| 172 | public function canAttempt() |
| 173 | { |
| 174 | return $this->attempts < $this->maxAttempts; |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Runs the task and (if applicable) automatically retries when errors occur. |
| 179 | * |
| 180 | * @return mixed |
| 181 | * @throws \Google\Service\Exception on failure when no retries are available. |
| 182 | */ |
| 183 | public function run() |
| 184 | { |
| 185 | while ($this->attempt()) { |
| 186 | try { |
| 187 | return call_user_func_array($this->action, $this->arguments); |
| 188 | } catch (GoogleServiceException $exception) { |
| 189 | $allowedRetries = $this->allowedRetries( |
| 190 | $exception->getCode(), |
| 191 | $exception->getErrors() |
| 192 | ); |
| 193 | |
| 194 | if (!$this->canAttempt() || !$allowedRetries) { |
| 195 | throw $exception; |
| 196 | } |
| 197 | |
| 198 | if ($allowedRetries > 0) { |
| 199 | $this->maxAttempts = min( |
| 200 | $this->maxAttempts, |
| 201 | $this->attempts + $allowedRetries |
| 202 | ); |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Runs a task once, if possible. This is useful for bypassing the `run()` |
| 210 | * loop. |
| 211 | * |
| 212 | * NOTE: If this is not the first attempt, this function will sleep in |
| 213 | * accordance to the backoff configurations before running the task. |
| 214 | * |
| 215 | * @return boolean |
| 216 | */ |
| 217 | public function attempt() |
| 218 | { |
| 219 | if (!$this->canAttempt()) { |
| 220 | return false; |
| 221 | } |
| 222 | |
| 223 | if ($this->attempts > 0) { |
| 224 | $this->backOff(); |
| 225 | } |
| 226 | |
| 227 | $this->attempts++; |
| 228 | |
| 229 | return true; |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * Sleeps in accordance to the backoff configurations. |
| 234 | */ |
| 235 | private function backOff() |
| 236 | { |
| 237 | $delay = $this->getDelay(); |
| 238 | |
| 239 | usleep((int) ($delay * 1000000)); |
| 240 | } |
| 241 | |
| 242 | /** |
| 243 | * Gets the delay (in seconds) for the current backoff period. |
| 244 | * |
| 245 | * @return int |
| 246 | */ |
| 247 | private function getDelay() |
| 248 | { |
| 249 | $jitter = $this->getJitter(); |
| 250 | $factor = $this->attempts > 1 ? $this->factor + $jitter : 1 + abs($jitter); |
| 251 | |
| 252 | return $this->delay = min($this->maxDelay, $this->delay * $factor); |
| 253 | } |
| 254 | |
| 255 | /** |
| 256 | * Gets the current jitter (random number between -$this->jitter and |
| 257 | * $this->jitter). |
| 258 | * |
| 259 | * @return float |
| 260 | */ |
| 261 | private function getJitter() |
| 262 | { |
| 263 | return $this->jitter * 2 * mt_rand() / mt_getrandmax() - $this->jitter; |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * Gets the number of times the associated task can be retried. |
| 268 | * |
| 269 | * NOTE: -1 is returned if the task can be retried indefinitely |
| 270 | * |
| 271 | * @return integer |
| 272 | */ |
| 273 | public function allowedRetries($code, $errors = []) |
| 274 | { |
| 275 | if (isset($this->retryMap[$code])) { |
| 276 | return $this->retryMap[$code]; |
| 277 | } |
| 278 | |
| 279 | if ( |
| 280 | !empty($errors) && |
| 281 | isset($errors[0]['reason'], $this->retryMap[$errors[0]['reason']]) |
| 282 | ) { |
| 283 | return $this->retryMap[$errors[0]['reason']]; |
| 284 | } |
| 285 | |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | public function setRetryMap($retryMap) |
| 290 | { |
| 291 | $this->retryMap = $retryMap; |
| 292 | } |
| 293 | } |
| 294 |