Subversion Repositories qbpwcf-lib(archive)

<?php

namespace React\EventLoop;

interface LoopInterface

{

    /**

     * [Advanced] Register a listener to be notified when a stream is ready to read.

     *

     * Note that this low-level API is considered advanced usage.

     * Most use cases should probably use the higher-level

     * [readable Stream API](https://github.com/reactphp/stream#readablestreaminterface)

     * instead.

     *

     * The first parameter MUST be a valid stream resource that supports

     * checking whether it is ready to read by this loop implementation.

     * A single stream resource MUST NOT be added more than once.

     * Instead, either call [`removeReadStream()`](#removereadstream) first or

     * react to this event with a single listener and then dispatch from this

     * listener. This method MAY throw an `Exception` if the given resource type

     * is not supported by this loop implementation.

     *

     * The listener callback function MUST be able to accept a single parameter,

     * the stream resource added by this method or you MAY use a function which

     * has no parameters at all.

     *

     * The listener callback function MUST NOT throw an `Exception`.

     * The return value of the listener callback function will be ignored and has

     * no effect, so for performance reasons you're recommended to not return

     * any excessive data structures.

     *

     * If you want to access any variables within your callback function, you

     * can bind arbitrary data to a callback closure like this:

     *

     * ```php

     * $loop->addReadStream($stream, function ($stream) use ($name) {

     *     echo $name . ' said: ' . fread($stream);

     * });

     * ```

     *

     * See also [example #11](examples).

     *

     * You can invoke [`removeReadStream()`](#removereadstream) to remove the

     * read event listener for this stream.

     *

     * The execution order of listeners when multiple streams become ready at

     * the same time is not guaranteed.

     *

     * @param resource $stream   The PHP stream resource to check.

     * @param callable $listener Invoked when the stream is ready.

     * @throws \Exception if the given resource type is not supported by this loop implementation

     * @see self::removeReadStream()

     */

    public function addReadStream($stream, $listener);

    /**

     * [Advanced] Register a listener to be notified when a stream is ready to write.

     *

     * Note that this low-level API is considered advanced usage.

     * Most use cases should probably use the higher-level

     * [writable Stream API](https://github.com/reactphp/stream#writablestreaminterface)

     * instead.

     *

     * The first parameter MUST be a valid stream resource that supports

     * checking whether it is ready to write by this loop implementation.

     * A single stream resource MUST NOT be added more than once.

     * Instead, either call [`removeWriteStream()`](#removewritestream) first or

     * react to this event with a single listener and then dispatch from this

     * listener. This method MAY throw an `Exception` if the given resource type

     * is not supported by this loop implementation.

     *

     * The listener callback function MUST be able to accept a single parameter,

     * the stream resource added by this method or you MAY use a function which

     * has no parameters at all.

     *

     * The listener callback function MUST NOT throw an `Exception`.

     * The return value of the listener callback function will be ignored and has

     * no effect, so for performance reasons you're recommended to not return

     * any excessive data structures.

     *

     * If you want to access any variables within your callback function, you

     * can bind arbitrary data to a callback closure like this:

     *

     * ```php

     * $loop->addWriteStream($stream, function ($stream) use ($name) {

     *     fwrite($stream, 'Hello ' . $name);

     * });

     * ```

     *

     * See also [example #12](examples).

     *

     * You can invoke [`removeWriteStream()`](#removewritestream) to remove the

     * write event listener for this stream.

     *

     * The execution order of listeners when multiple streams become ready at

     * the same time is not guaranteed.

     *

     * Some event loop implementations are known to only trigger the listener if

     * the stream *becomes* readable (edge-triggered) and may not trigger if the

     * stream has already been readable from the beginning.

     * This also implies that a stream may not be recognized as readable when data

     * is still left in PHP's internal stream buffers.

     * As such, it's recommended to use `stream_set_read_buffer($stream, 0);`

     * to disable PHP's internal read buffer in this case.

     *

     * @param resource $stream   The PHP stream resource to check.

     * @param callable $listener Invoked when the stream is ready.

     * @throws \Exception if the given resource type is not supported by this loop implementation

     * @see self::removeWriteStream()

     */

    public function addWriteStream($stream, $listener);

    /**

     * Remove the read event listener for the given stream.

     *

     * Removing a stream from the loop that has already been removed or trying

     * to remove a stream that was never added or is invalid has no effect.

     *

     * @param resource $stream The PHP stream resource.

     */

    public function removeReadStream($stream);

    /**

     * Remove the write event listener for the given stream.

     *

     * Removing a stream from the loop that has already been removed or trying

     * to remove a stream that was never added or is invalid has no effect.

     *

     * @param resource $stream The PHP stream resource.

     */

    public function removeWriteStream($stream);

    /**

     * Enqueue a callback to be invoked once after the given interval.

     *

     * The timer callback function MUST be able to accept a single parameter,

     * the timer instance as also returned by this method or you MAY use a

     * function which has no parameters at all.

     *

     * The timer callback function MUST NOT throw an `Exception`.

     * The return value of the timer callback function will be ignored and has

     * no effect, so for performance reasons you're recommended to not return

     * any excessive data structures.

     *

     * Unlike [`addPeriodicTimer()`](#addperiodictimer), this method will ensure

     * the callback will be invoked only once after the given interval.

     * You can invoke [`cancelTimer`](#canceltimer) to cancel a pending timer.

     *

     * ```php

     * $loop->addTimer(0.8, function () {

     *     echo 'world!' . PHP_EOL;

     * });

     *

     * $loop->addTimer(0.3, function () {

     *     echo 'hello ';

     * });

     * ```

     *

     * See also [example #1](examples).

     *

     * If you want to access any variables within your callback function, you

     * can bind arbitrary data to a callback closure like this:

     *

     * ```php

     * function hello($name, LoopInterface $loop)

     * {

     *     $loop->addTimer(1.0, function () use ($name) {

     *         echo "hello $name\n";

     *     });

     * }

     *

     * hello('Tester', $loop);

     * ```

     *

     * This interface does not enforce any particular timer resolution, so

     * special care may have to be taken if you rely on very high precision with

     * millisecond accuracy or below. Event loop implementations SHOULD work on

     * a best effort basis and SHOULD provide at least millisecond accuracy

     * unless otherwise noted. Many existing event loop implementations are

     * known to provide microsecond accuracy, but it's generally not recommended

     * to rely on this high precision.

     *

     * Similarly, the execution order of timers scheduled to execute at the

     * same time (within its possible accuracy) is not guaranteed.

     *

     * This interface suggests that event loop implementations SHOULD use a

     * monotonic time source if available. Given that a monotonic time source is

     * only available as of PHP 7.3 by default, event loop implementations MAY

     * fall back to using wall-clock time.

     * While this does not affect many common use cases, this is an important

     * distinction for programs that rely on a high time precision or on systems

     * that are subject to discontinuous time adjustments (time jumps).

     * This means that if you schedule a timer to trigger in 30s and then adjust

     * your system time forward by 20s, the timer SHOULD still trigger in 30s.

     * See also [event loop implementations](#loop-implementations) for more details.

     *

     * @param int|float $interval The number of seconds to wait before execution.

     * @param callable  $callback The callback to invoke.

     *

     * @return TimerInterface

     */

    public function addTimer($interval, $callback);

    /**

     * Enqueue a callback to be invoked repeatedly after the given interval.

     *

     * The timer callback function MUST be able to accept a single parameter,

     * the timer instance as also returned by this method or you MAY use a

     * function which has no parameters at all.

     *

     * The timer callback function MUST NOT throw an `Exception`.

     * The return value of the timer callback function will be ignored and has

     * no effect, so for performance reasons you're recommended to not return

     * any excessive data structures.

     *

     * Unlike [`addTimer()`](#addtimer), this method will ensure the the

     * callback will be invoked infinitely after the given interval or until you

     * invoke [`cancelTimer`](#canceltimer).

     *

     * ```php

     * $timer = $loop->addPeriodicTimer(0.1, function () {

     *     echo 'tick!' . PHP_EOL;

     * });

     *

     * $loop->addTimer(1.0, function () use ($loop, $timer) {

     *     $loop->cancelTimer($timer);

     *     echo 'Done' . PHP_EOL;

     * });

     * ```

     *

     * See also [example #2](examples).

     *

     * If you want to limit the number of executions, you can bind

     * arbitrary data to a callback closure like this:

     *

     * ```php

     * function hello($name, LoopInterface $loop)

     * {

     *     $n = 3;

     *     $loop->addPeriodicTimer(1.0, function ($timer) use ($name, $loop, &$n) {

     *         if ($n > 0) {

     *             --$n;

     *             echo "hello $name\n";

     *         } else {

     *             $loop->cancelTimer($timer);

     *         }

     *     });

     * }

     *

     * hello('Tester', $loop);

     * ```

     *

     * This interface does not enforce any particular timer resolution, so

     * special care may have to be taken if you rely on very high precision with

     * millisecond accuracy or below. Event loop implementations SHOULD work on

     * a best effort basis and SHOULD provide at least millisecond accuracy

     * unless otherwise noted. Many existing event loop implementations are

     * known to provide microsecond accuracy, but it's generally not recommended

     * to rely on this high precision.

     *

     * Similarly, the execution order of timers scheduled to execute at the

     * same time (within its possible accuracy) is not guaranteed.

     *

     * This interface suggests that event loop implementations SHOULD use a

     * monotonic time source if available. Given that a monotonic time source is

     * only available as of PHP 7.3 by default, event loop implementations MAY

     * fall back to using wall-clock time.

     * While this does not affect many common use cases, this is an important

     * distinction for programs that rely on a high time precision or on systems

     * that are subject to discontinuous time adjustments (time jumps).

     * This means that if you schedule a timer to trigger in 30s and then adjust

     * your system time forward by 20s, the timer SHOULD still trigger in 30s.

     * See also [event loop implementations](#loop-implementations) for more details.

     *

     * Additionally, periodic timers may be subject to timer drift due to

     * re-scheduling after each invocation. As such, it's generally not

     * recommended to rely on this for high precision intervals with millisecond

     * accuracy or below.

     *

     * @param int|float $interval The number of seconds to wait before execution.

     * @param callable  $callback The callback to invoke.

     *

     * @return TimerInterface

     */

    public function addPeriodicTimer($interval, $callback);

    /**

     * Cancel a pending timer.

     *

     * See also [`addPeriodicTimer()`](#addperiodictimer) and [example #2](examples).

     *

     * Calling this method on a timer instance that has not been added to this

     * loop instance or on a timer that has already been cancelled has no effect.

     *

     * @param TimerInterface $timer The timer to cancel.

     *

     * @return void

     */

    public function cancelTimer(TimerInterface $timer);

    /**

     * Schedule a callback to be invoked on a future tick of the event loop.

     *

     * This works very much similar to timers with an interval of zero seconds,

     * but does not require the overhead of scheduling a timer queue.

     *

     * The tick callback function MUST be able to accept zero parameters.

     *

     * The tick callback function MUST NOT throw an `Exception`.

     * The return value of the tick callback function will be ignored and has

     * no effect, so for performance reasons you're recommended to not return

     * any excessive data structures.

     *

     * If you want to access any variables within your callback function, you

     * can bind arbitrary data to a callback closure like this:

     *

     * ```php

     * function hello($name, LoopInterface $loop)

     * {

     *     $loop->futureTick(function () use ($name) {

     *         echo "hello $name\n";

     *     });

     * }

     *

     * hello('Tester', $loop);

     * ```

     *

     * Unlike timers, tick callbacks are guaranteed to be executed in the order

     * they are enqueued.

     * Also, once a callback is enqueued, there's no way to cancel this operation.

     *

     * This is often used to break down bigger tasks into smaller steps (a form

     * of cooperative multitasking).

     *

     * ```php

     * $loop->futureTick(function () {

     *     echo 'b';

     * });

     * $loop->futureTick(function () {

     *     echo 'c';

     * });

     * echo 'a';

     * ```

     *

     * See also [example #3](examples).

     *

     * @param callable $listener The callback to invoke.

     *

     * @return void

     */

    public function futureTick($listener);

    /**

     * Register a listener to be notified when a signal has been caught by this process.

     *

     * This is useful to catch user interrupt signals or shutdown signals from

     * tools like `supervisor` or `systemd`.

     *

     * The listener callback function MUST be able to accept a single parameter,

     * the signal added by this method or you MAY use a function which

     * has no parameters at all.

     *

     * The listener callback function MUST NOT throw an `Exception`.

     * The return value of the listener callback function will be ignored and has

     * no effect, so for performance reasons you're recommended to not return

     * any excessive data structures.

     *

     * ```php

     * $loop->addSignal(SIGINT, function (int $signal) {

     *     echo 'Caught user interrupt signal' . PHP_EOL;

     * });

     * ```

     *

     * See also [example #4](examples).

     *

     * Signaling is only available on Unix-like platform, Windows isn't

     * supported due to operating system limitations.

     * This method may throw a `BadMethodCallException` if signals aren't

     * supported on this platform, for example when required extensions are

     * missing.

     *

     * **Note: A listener can only be added once to the same signal, any

     * attempts to add it more then once will be ignored.**

     *

     * @param int $signal

     * @param callable $listener

     *

     * @throws \BadMethodCallException when signals aren't supported on this

     *     platform, for example when required extensions are missing.

     *

     * @return void

     */

    public function addSignal($signal, $listener);

    /**

     * Removes a previously added signal listener.

     *

     * ```php

     * $loop->removeSignal(SIGINT, $listener);

     * ```

     *

     * Any attempts to remove listeners that aren't registered will be ignored.

     *

     * @param int $signal

     * @param callable $listener

     *

     * @return void

     */

    public function removeSignal($signal, $listener);

    /**

     * Run the event loop until there are no more tasks to perform.

     *

     * For many applications, this method is the only directly visible

     * invocation on the event loop.

     * As a rule of thumb, it is usally recommended to attach everything to the

     * same loop instance and then run the loop once at the bottom end of the

     * application.

     *

     * ```php

     * $loop->run();

     * ```

     *

     * This method will keep the loop running until there are no more tasks

     * to perform. In other words: This method will block until the last

     * timer, stream and/or signal has been removed.

     *

     * Likewise, it is imperative to ensure the application actually invokes

     * this method once. Adding listeners to the loop and missing to actually

     * run it will result in the application exiting without actually waiting

     * for any of the attached listeners.

     *

     * This method MUST NOT be called while the loop is already running.

     * This method MAY be called more than once after it has explicity been

     * [`stop()`ped](#stop) or after it automatically stopped because it

     * previously did no longer have anything to do.

     *

     * @return void

     */

    public function run();

    /**

     * Instruct a running event loop to stop.

     *

     * This method is considered advanced usage and should be used with care.

     * As a rule of thumb, it is usually recommended to let the loop stop

     * only automatically when it no longer has anything to do.

     *

     * This method can be used to explicitly instruct the event loop to stop:

     *

     * ```php

     * $loop->addTimer(3.0, function () use ($loop) {

     *     $loop->stop();

     * });

     * ```

     *

     * Calling this method on a loop instance that is not currently running or

     * on a loop instance that has already been stopped has no effect.

     *

     * @return void

     */

    public function stop();

}