Current File : /home2/selectio/public_html/fms-worksuite/vendor/amphp/amp/lib/Loop/Driver.php
<?php
namespace Amp\Loop;
use Amp\Coroutine;
use Amp\Promise;
use React\Promise\PromiseInterface as ReactPromise;
use function Amp\Promise\rethrow;
/**
* Event loop driver which implements all basic operations to allow interoperability.
*
* Watchers (enabled or new watchers) MUST immediately be marked as enabled, but only be activated (i.e. callbacks can
* be called) right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* All registered callbacks MUST NOT be called from a file with strict types enabled (`declare(strict_types=1)`).
*/
abstract class Driver
{
// Don't use 1e3 / 1e6, they result in a float instead of int
const MILLISEC_PER_SEC = 1000;
const MICROSEC_PER_SEC = 1000000;
/** @var string */
private $nextId = "a";
/** @var Watcher[] */
private $watchers = [];
/** @var Watcher[] */
private $enableQueue = [];
/** @var Watcher[] */
private $deferQueue = [];
/** @var Watcher[] */
private $nextTickQueue = [];
/** @var callable(\Throwable):void|null */
private $errorHandler;
/** @var bool */
private $running = false;
/** @var array */
private $registry = [];
/**
* Run the event loop.
*
* One iteration of the loop is called one "tick". A tick covers the following steps:
*
* 1. Activate watchers created / enabled in the last tick / before `run()`.
* 2. Execute all enabled defer watchers.
* 3. Execute all due timer, pending signal and actionable stream callbacks, each only once per tick.
*
* The loop MUST continue to run until it is either stopped explicitly, no referenced watchers exist anymore, or an
* exception is thrown that cannot be handled. Exceptions that cannot be handled are exceptions thrown from an
* error handler or exceptions that would be passed to an error handler but none exists to handle them.
*
* @return void
*/
public function run()
{
$this->running = true;
try {
while ($this->running) {
if ($this->isEmpty()) {
return;
}
$this->tick();
}
} finally {
$this->stop();
}
}
/**
* @return bool True if no enabled and referenced watchers remain in the loop.
*/
private function isEmpty(): bool
{
foreach ($this->watchers as $watcher) {
if ($watcher->enabled && $watcher->referenced) {
return false;
}
}
return true;
}
/**
* Executes a single tick of the event loop.
*
* @return void
*/
private function tick()
{
if (empty($this->deferQueue)) {
$this->deferQueue = $this->nextTickQueue;
} else {
$this->deferQueue = \array_merge($this->deferQueue, $this->nextTickQueue);
}
$this->nextTickQueue = [];
$this->activate($this->enableQueue);
$this->enableQueue = [];
foreach ($this->deferQueue as $watcher) {
if (!isset($this->deferQueue[$watcher->id])) {
continue; // Watcher disabled by another defer watcher.
}
unset($this->watchers[$watcher->id], $this->deferQueue[$watcher->id]);
try {
/** @var mixed $result */
$result = ($watcher->callback)($watcher->id, $watcher->data);
if ($result === null) {
continue;
}
if ($result instanceof \Generator) {
$result = new Coroutine($result);
}
if ($result instanceof Promise || $result instanceof ReactPromise) {
rethrow($result);
}
} catch (\Throwable $exception) {
$this->error($exception);
}
}
/** @psalm-suppress RedundantCondition */
$this->dispatch(empty($this->nextTickQueue) && empty($this->enableQueue) && $this->running && !$this->isEmpty());
}
/**
* Activates (enables) all the given watchers.
*
* @param Watcher[] $watchers
*
* @return void
*/
abstract protected function activate(array $watchers);
/**
* Dispatches any pending read/write, timer, and signal events.
*
* @param bool $blocking
*
* @return void
*/
abstract protected function dispatch(bool $blocking);
/**
* Stop the event loop.
*
* When an event loop is stopped, it continues with its current tick and exits the loop afterwards. Multiple calls
* to stop MUST be ignored and MUST NOT raise an exception.
*
* @return void
*/
public function stop()
{
$this->running = false;
}
/**
* Defer the execution of a callback.
*
* The deferred callable MUST be executed before any other type of watcher in a tick. Order of enabling MUST be
* preserved when executing the callbacks.
*
* The created watcher MUST immediately be marked as enabled, but only be activated (i.e. callback can be called)
* right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param callable (string $watcherId, mixed $data) $callback The callback to defer. The `$watcherId` will be
* invalidated before the callback call.
* @param mixed $data Arbitrary data given to the callback function as the `$data` parameter.
*
* @return string An unique identifier that can be used to cancel, enable or disable the watcher.
*/
public function defer(callable $callback, $data = null): string
{
/** @psalm-var Watcher<null> $watcher */
$watcher = new Watcher;
$watcher->type = Watcher::DEFER;
$watcher->id = $this->nextId++;
$watcher->callback = $callback;
$watcher->data = $data;
$this->watchers[$watcher->id] = $watcher;
$this->nextTickQueue[$watcher->id] = $watcher;
return $watcher->id;
}
/**
* Delay the execution of a callback.
*
* The delay is a minimum and approximate, accuracy is not guaranteed. Order of calls MUST be determined by which
* timers expire first, but timers with the same expiration time MAY be executed in any order.
*
* The created watcher MUST immediately be marked as enabled, but only be activated (i.e. callback can be called)
* right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param int $delay The amount of time, in milliseconds, to delay the execution for.
* @param callable (string $watcherId, mixed $data) $callback The callback to delay. The `$watcherId` will be
* invalidated before the callback call.
* @param mixed $data Arbitrary data given to the callback function as the `$data` parameter.
*
* @return string An unique identifier that can be used to cancel, enable or disable the watcher.
*/
public function delay(int $delay, callable $callback, $data = null): string
{
if ($delay < 0) {
throw new \Error("Delay must be greater than or equal to zero");
}
/** @psalm-var Watcher<int> $watcher */
$watcher = new Watcher;
$watcher->type = Watcher::DELAY;
$watcher->id = $this->nextId++;
$watcher->callback = $callback;
$watcher->value = $delay;
$watcher->expiration = $this->now() + $delay;
$watcher->data = $data;
$this->watchers[$watcher->id] = $watcher;
$this->enableQueue[$watcher->id] = $watcher;
return $watcher->id;
}
/**
* Repeatedly execute a callback.
*
* The interval between executions is a minimum and approximate, accuracy is not guaranteed. Order of calls MUST be
* determined by which timers expire first, but timers with the same expiration time MAY be executed in any order.
* The first execution is scheduled after the first interval period.
*
* The created watcher MUST immediately be marked as enabled, but only be activated (i.e. callback can be called)
* right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param int $interval The time interval, in milliseconds, to wait between executions.
* @param callable (string $watcherId, mixed $data) $callback The callback to repeat.
* @param mixed $data Arbitrary data given to the callback function as the `$data` parameter.
*
* @return string An unique identifier that can be used to cancel, enable or disable the watcher.
*/
public function repeat(int $interval, callable $callback, $data = null): string
{
if ($interval < 0) {
throw new \Error("Interval must be greater than or equal to zero");
}
/** @psalm-var Watcher<int> $watcher */
$watcher = new Watcher;
$watcher->type = Watcher::REPEAT;
$watcher->id = $this->nextId++;
$watcher->callback = $callback;
$watcher->value = $interval;
$watcher->expiration = $this->now() + $interval;
$watcher->data = $data;
$this->watchers[$watcher->id] = $watcher;
$this->enableQueue[$watcher->id] = $watcher;
return $watcher->id;
}
/**
* Execute a callback when a stream resource becomes readable or is closed for reading.
*
* Warning: Closing resources locally, e.g. with `fclose`, might not invoke the callback. Be sure to `cancel` the
* watcher when closing the resource locally. Drivers MAY choose to notify the user if there are watchers on invalid
* resources, but are not required to, due to the high performance impact. Watchers on closed resources are
* therefore undefined behavior.
*
* Multiple watchers on the same stream MAY be executed in any order.
*
* The created watcher MUST immediately be marked as enabled, but only be activated (i.e. callback can be called)
* right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param resource $stream The stream to monitor.
* @param callable (string $watcherId, resource $stream, mixed $data) $callback The callback to execute.
* @param mixed $data Arbitrary data given to the callback function as the `$data` parameter.
*
* @return string An unique identifier that can be used to cancel, enable or disable the watcher.
*/
public function onReadable($stream, callable $callback, $data = null): string
{
/** @psalm-var Watcher<resource> $watcher */
$watcher = new Watcher;
$watcher->type = Watcher::READABLE;
$watcher->id = $this->nextId++;
$watcher->callback = $callback;
$watcher->value = $stream;
$watcher->data = $data;
$this->watchers[$watcher->id] = $watcher;
$this->enableQueue[$watcher->id] = $watcher;
return $watcher->id;
}
/**
* Execute a callback when a stream resource becomes writable or is closed for writing.
*
* Warning: Closing resources locally, e.g. with `fclose`, might not invoke the callback. Be sure to `cancel` the
* watcher when closing the resource locally. Drivers MAY choose to notify the user if there are watchers on invalid
* resources, but are not required to, due to the high performance impact. Watchers on closed resources are
* therefore undefined behavior.
*
* Multiple watchers on the same stream MAY be executed in any order.
*
* The created watcher MUST immediately be marked as enabled, but only be activated (i.e. callback can be called)
* right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param resource $stream The stream to monitor.
* @param callable (string $watcherId, resource $stream, mixed $data) $callback The callback to execute.
* @param mixed $data Arbitrary data given to the callback function as the `$data` parameter.
*
* @return string An unique identifier that can be used to cancel, enable or disable the watcher.
*/
public function onWritable($stream, callable $callback, $data = null): string
{
/** @psalm-var Watcher<resource> $watcher */
$watcher = new Watcher;
$watcher->type = Watcher::WRITABLE;
$watcher->id = $this->nextId++;
$watcher->callback = $callback;
$watcher->value = $stream;
$watcher->data = $data;
$this->watchers[$watcher->id] = $watcher;
$this->enableQueue[$watcher->id] = $watcher;
return $watcher->id;
}
/**
* Execute a callback when a signal is received.
*
* Warning: Installing the same signal on different instances of this interface is deemed undefined behavior.
* Implementations MAY try to detect this, if possible, but are not required to. This is due to technical
* limitations of the signals being registered globally per process.
*
* Multiple watchers on the same signal MAY be executed in any order.
*
* The created watcher MUST immediately be marked as enabled, but only be activated (i.e. callback can be called)
* right before the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param int $signo The signal number to monitor.
* @param callable (string $watcherId, int $signo, mixed $data) $callback The callback to execute.
* @param mixed $data Arbitrary data given to the callback function as the $data parameter.
*
* @return string An unique identifier that can be used to cancel, enable or disable the watcher.
*
* @throws UnsupportedFeatureException If signal handling is not supported.
*/
public function onSignal(int $signo, callable $callback, $data = null): string
{
/** @psalm-var Watcher<int> $watcher */
$watcher = new Watcher;
$watcher->type = Watcher::SIGNAL;
$watcher->id = $this->nextId++;
$watcher->callback = $callback;
$watcher->value = $signo;
$watcher->data = $data;
$this->watchers[$watcher->id] = $watcher;
$this->enableQueue[$watcher->id] = $watcher;
return $watcher->id;
}
/**
* Enable a watcher to be active starting in the next tick.
*
* Watchers MUST immediately be marked as enabled, but only be activated (i.e. callbacks can be called) right before
* the next tick. Callbacks of watchers MUST NOT be called in the tick they were enabled.
*
* @param string $watcherId The watcher identifier.
*
* @return void
*
* @throws InvalidWatcherError If the watcher identifier is invalid.
*/
public function enable(string $watcherId)
{
if (!isset($this->watchers[$watcherId])) {
throw new InvalidWatcherError($watcherId, "Cannot enable an invalid watcher identifier: '{$watcherId}'");
}
$watcher = $this->watchers[$watcherId];
if ($watcher->enabled) {
return; // Watcher already enabled.
}
$watcher->enabled = true;
switch ($watcher->type) {
case Watcher::DEFER:
$this->nextTickQueue[$watcher->id] = $watcher;
break;
case Watcher::REPEAT:
case Watcher::DELAY:
\assert(\is_int($watcher->value));
$watcher->expiration = $this->now() + $watcher->value;
$this->enableQueue[$watcher->id] = $watcher;
break;
default:
$this->enableQueue[$watcher->id] = $watcher;
break;
}
}
/**
* Cancel a watcher.
*
* This will detach the event loop from all resources that are associated to the watcher. After this operation the
* watcher is permanently invalid. Calling this function MUST NOT fail, even if passed an invalid watcher.
*
* @param string $watcherId The watcher identifier.
*
* @return void
*/
public function cancel(string $watcherId)
{
$this->disable($watcherId);
unset($this->watchers[$watcherId]);
}
/**
* Disable a watcher immediately.
*
* A watcher MUST be disabled immediately, e.g. if a defer watcher disables a later defer watcher, the second defer
* watcher isn't executed in this tick.
*
* Disabling a watcher MUST NOT invalidate the watcher. Calling this function MUST NOT fail, even if passed an
* invalid watcher.
*
* @param string $watcherId The watcher identifier.
*
* @return void
*/
public function disable(string $watcherId)
{
if (!isset($this->watchers[$watcherId])) {
return;
}
$watcher = $this->watchers[$watcherId];
if (!$watcher->enabled) {
return; // Watcher already disabled.
}
$watcher->enabled = false;
$id = $watcher->id;
switch ($watcher->type) {
case Watcher::DEFER:
if (isset($this->nextTickQueue[$id])) {
// Watcher was only queued to be enabled.
unset($this->nextTickQueue[$id]);
} else {
unset($this->deferQueue[$id]);
}
break;
default:
if (isset($this->enableQueue[$id])) {
// Watcher was only queued to be enabled.
unset($this->enableQueue[$id]);
} else {
$this->deactivate($watcher);
}
break;
}
}
/**
* Deactivates (disables) the given watcher.
*
* @param Watcher $watcher
*
* @return void
*/
abstract protected function deactivate(Watcher $watcher);
/**
* Reference a watcher.
*
* This will keep the event loop alive whilst the watcher is still being monitored. Watchers have this state by
* default.
*
* @param string $watcherId The watcher identifier.
*
* @return void
*
* @throws InvalidWatcherError If the watcher identifier is invalid.
*/
public function reference(string $watcherId)
{
if (!isset($this->watchers[$watcherId])) {
throw new InvalidWatcherError($watcherId, "Cannot reference an invalid watcher identifier: '{$watcherId}'");
}
$this->watchers[$watcherId]->referenced = true;
}
/**
* Unreference a watcher.
*
* The event loop should exit the run method when only unreferenced watchers are still being monitored. Watchers
* are all referenced by default.
*
* @param string $watcherId The watcher identifier.
*
* @return void
*/
public function unreference(string $watcherId)
{
if (!isset($this->watchers[$watcherId])) {
return;
}
$this->watchers[$watcherId]->referenced = false;
}
/**
* Stores information in the loop bound registry.
*
* Stored information is package private. Packages MUST NOT retrieve the stored state of other packages. Packages
* MUST use their namespace as prefix for keys. They may do so by using `SomeClass::class` as key.
*
* If packages want to expose loop bound state to consumers other than the package, they SHOULD provide a dedicated
* interface for that purpose instead of sharing the storage key.
*
* @param string $key The namespaced storage key.
* @param mixed $value The value to be stored.
*
* @return void
*/
final public function setState(string $key, $value)
{
if ($value === null) {
unset($this->registry[$key]);
} else {
$this->registry[$key] = $value;
}
}
/**
* Gets information stored bound to the loop.
*
* Stored information is package private. Packages MUST NOT retrieve the stored state of other packages. Packages
* MUST use their namespace as prefix for keys. They may do so by using `SomeClass::class` as key.
*
* If packages want to expose loop bound state to consumers other than the package, they SHOULD provide a dedicated
* interface for that purpose instead of sharing the storage key.
*
* @param string $key The namespaced storage key.
*
* @return mixed The previously stored value or `null` if it doesn't exist.
*/
final public function getState(string $key)
{
return isset($this->registry[$key]) ? $this->registry[$key] : null;
}
/**
* Set a callback to be executed when an error occurs.
*
* The callback receives the error as the first and only parameter. The return value of the callback gets ignored.
* If it can't handle the error, it MUST throw the error. Errors thrown by the callback or during its invocation
* MUST be thrown into the `run` loop and stop the driver.
*
* Subsequent calls to this method will overwrite the previous handler.
*
* @param callable(\Throwable $error):void|null $callback The callback to execute. `null` will clear the
* current handler.
*
* @return callable(\Throwable $error):void|null The previous handler, `null` if there was none.
*/
public function setErrorHandler(callable $callback = null)
{
$previous = $this->errorHandler;
$this->errorHandler = $callback;
return $previous;
}
/**
* Invokes the error handler with the given exception.
*
* @param \Throwable $exception The exception thrown from a watcher callback.
*
* @return void
* @throws \Throwable If no error handler has been set.
*/
protected function error(\Throwable $exception)
{
if ($this->errorHandler === null) {
throw $exception;
}
($this->errorHandler)($exception);
}
/**
* Returns the current loop time in millisecond increments. Note this value does not necessarily correlate to
* wall-clock time, rather the value returned is meant to be used in relative comparisons to prior values returned
* by this method (intervals, expiration calculations, etc.) and is only updated once per loop tick.
*
* Extending classes should override this function to return a value cached once per loop tick.
*
* @return int
*/
public function now(): int
{
return (int) (\microtime(true) * self::MILLISEC_PER_SEC);
}
/**
* Get the underlying loop handle.
*
* Example: the `uv_loop` resource for `libuv` or the `EvLoop` object for `libev` or `null` for a native driver.
*
* Note: This function is *not* exposed in the `Loop` class. Users shall access it directly on the respective loop
* instance.
*
* @return null|object|resource The loop handle the event loop operates on. `null` if there is none.
*/
abstract public function getHandle();
/**
* Returns the same array of data as getInfo().
*
* @return array
*/
public function __debugInfo()
{
// @codeCoverageIgnoreStart
return $this->getInfo();
// @codeCoverageIgnoreEnd
}
/**
* Retrieve an associative array of information about the event loop driver.
*
* The returned array MUST contain the following data describing the driver's currently registered watchers:
*
* [
* "defer" => ["enabled" => int, "disabled" => int],
* "delay" => ["enabled" => int, "disabled" => int],
* "repeat" => ["enabled" => int, "disabled" => int],
* "on_readable" => ["enabled" => int, "disabled" => int],
* "on_writable" => ["enabled" => int, "disabled" => int],
* "on_signal" => ["enabled" => int, "disabled" => int],
* "enabled_watchers" => ["referenced" => int, "unreferenced" => int],
* "running" => bool
* ];
*
* Implementations MAY optionally add more information in the array but at minimum the above `key => value` format
* MUST always be provided.
*
* @return array Statistics about the loop in the described format.
*/
public function getInfo(): array
{
$watchers = [
"referenced" => 0,
"unreferenced" => 0,
];
$defer = $delay = $repeat = $onReadable = $onWritable = $onSignal = [
"enabled" => 0,
"disabled" => 0,
];
foreach ($this->watchers as $watcher) {
switch ($watcher->type) {
case Watcher::READABLE:
$array = &$onReadable;
break;
case Watcher::WRITABLE:
$array = &$onWritable;
break;
case Watcher::SIGNAL:
$array = &$onSignal;
break;
case Watcher::DEFER:
$array = &$defer;
break;
case Watcher::DELAY:
$array = &$delay;
break;
case Watcher::REPEAT:
$array = &$repeat;
break;
default:
// @codeCoverageIgnoreStart
throw new \Error("Unknown watcher type");
// @codeCoverageIgnoreEnd
}
if ($watcher->enabled) {
++$array["enabled"];
if ($watcher->referenced) {
++$watchers["referenced"];
} else {
++$watchers["unreferenced"];
}
} else {
++$array["disabled"];
}
}
return [
"enabled_watchers" => $watchers,
"defer" => $defer,
"delay" => $delay,
"repeat" => $repeat,
"on_readable" => $onReadable,
"on_writable" => $onWritable,
"on_signal" => $onSignal,
"running" => (bool) $this->running,
];
}
}
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