Functions::throttle() - Code Metrics - Inspection of "Add missing test for p()" - Im0rtality/Underscore - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( b24ad0...a8933b )

by Woody

created 2016-02-28 19:40 UTC

Functions::throttle() B

↳ Parent: Functions

Complexity

Conditions	3
Paths	2

Size

Total Lines	24
Code Lines	13

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	14
CRAP Score	3

Importance

Changes	2
Bugs	0	Features	0

Metric	Value
c	2
b	0
f	0
dl	0
loc	24
ccs	14
cts	14
cp	1
rs	8.9713
cc	3
eloc	13
nc	2
nop	3
crap	3

<?php

namespace Underscore;

class Functions
{
    /**
     * Creates a function that memoizes the result of the $payload
     *
     * @param callable $payload
     *
     * @return \Closure
     */
    public static function memoize($payload)
    {
        $function = function () use ($payload) {
            static $cache = [];
            $args = func_get_args();
            $hash = md5(serialize($args));

            if (!array_key_exists($hash, $cache)) {
                $cache[$hash] = call_user_func_array($payload, $args);
            }

            return $cache[$hash];
        };

        return $function;
    }

    /**
     * Creates function that simply returns given argument
     *
     * @return \Closure
     */
    public static function nop()
    {
        return function ($item) {
            return $item;
        };
    }

    /**
     * Creates a version of the function that can only be called one time.
     *
     * Repeated calls to the modified function will have no effect, returning
     * the value from the original call. Useful for initialization functions,
     * instead of having to set a boolean flag and then check it later.
     *
     * @param callable $function
     * @return \Closure
     */
    public static function once($function)
    {
        $called = false;
        $value = null;

        return function () use ($function, &$called, &$value) {
            if (!$called) {
                $args = func_get_args();
                $value = call_user_func_array($function, $args);
                $called = true;
            }

            return $value;
        };
    }

    /**
     * Provides a constant value that is only used for partial().
     *
     * @return \Closure
     */
    public static function p()
    {
        static $function;
        if (!$function) {
            $function = function () {
                return 'placeholder for partial';
            };
        }

        return $function;
    }

    /**
     * Partially apply a function by filling in any number of its arguments.
     *
     * You may pass p() in your list of arguments to specify an argument that
     * should not be pre-filled, but left open to supply at call-time.
     *
     * @param callable $function
     * @param mixed    $arg
     * @param          mixed ...
     * @return \Closure
     */
    public static function partial($function, $arg)

    {
        $bound = func_get_args();
        array_shift($bound); // remove $function

        $placeholder = static::p();

        return function () use ($function, $bound, $placeholder) {
            $inject = func_get_args();

            $args = [];
            foreach ($bound as $value) {
                if ($value === $placeholder) {
                    $args[] = array_shift($inject);
                } else {
                    $args[] = $value;
                }
            }

            // Append any remaining arguments
            $args = array_merge($args, $inject);

            return call_user_func_array($function, $args);
        };
    }

    /**
     * Returns the composition of a list of functions.
     *
     * Each function consumes the return value of the function that follows.
     * In math terms, composing the functions f(), g(), and h() produces f(g(h())).
     *
     * @param callable $function
     * @param          callable ...
     * @return \Closure
     */
    public static function compose($function)

    {
        $functions = array_reverse(func_get_args());

        return function ($value) use ($functions) {
            foreach ($functions as $function) {
                $value = $function($value);
            }

            return $value;
        };
    }

    /**
     * Wraps the first function inside of the wrapper function, passing it as the first argument.
     *
     * This allows the wrapper to execute code before and after the function runs,
     * adjust the arguments, and execute it conditionally.
     *
     * @param callable $function
     * @param callable $wrapper
     * @return \Closure
     */
    public static function wrap($function, $wrapper)
    {
        return function () use ($function, $wrapper) {
            $args = func_get_args();
            array_unshift($args, $function); // make $function the first argument
            return call_user_func_array($wrapper, $args);
        };
    }

    /**
     * Creates and returns a new, throttled version of the passed function.
     *
     * When invoked repeatedly, will only actually call the original function at
     * most once per every wait milliseconds. Useful for rate-limiting events that
     * occur faster than you can keep up with.
     *
     * By default, throttle will execute the function as soon as you call it
     * for the first time, and, if you call it again any number of times during
     * the wait period, as soon as that period is over. If you'd like to disable
     * the leading-edge call, pass `leading => false`.
     *
     * NOTE: Does not support the `trailing` option because there is no timeout
     * functionality in PHP (without using threads).
     *
     * NOTE: No arguments are passed to the function on the leading edge call!
     *
     * @param callable $function
     * @param integer  $wait
     * @param array    $options
     * @return \Closure
     */
    public static function throttle($function, $wait, array $options = [])
    {
        $options += [
            'leading' => true,
        ]; // @codeCoverageIgnore

        $previous = 0;

        $callback = function () use ($function, $wait, &$previous) {
            $now = floor(microtime(true) * 1000); // convert float to integer

            if (($wait - ($now - $previous)) <= 0) {
                $args = func_get_args();
                call_user_func_array($function, $args);
                $previous = $now;
            }
        };

        if ($options['leading'] !== false) {
            $callback();
        }

        return $callback;
    }

    /**
     * Creates a version of the function that will only be run after first being called count times.
     *
     * Useful for grouping asynchronous responses, where you want to be sure that
     * all the async calls have finished, before proceeding.
     *
     * @param integer  $count
     * @param callable $function
     * @return \Closure
     */
    public static function after($count, $function)
    {
        return function () use ($function, &$count) {
            if (--$count < 1) {
                $args = func_get_args();

                return call_user_func_array($function, $args);
            }
        };
    }

    /**
     * Creates a version of the function that can be called no more than count times.
     *
     * The result of the last function call is memoized and returned when count has been reached.
     *
     * @param integer  $count
     * @param callable $function
     * @return \Closure
     */
    public static function before($count, $function)
    {
        $memo = null;

        return function () use ($function, &$count, &$memo) {
            if (--$count > 0) {
                $args = func_get_args();
                $memo = call_user_func_array($function, $args);
            }

            return $memo;
        };
    }
}


1		<?php
2
3		namespace Underscore;
4
5		class Functions
6		{
7		/**
8		* Creates a function that memoizes the result of the $payload
9		*
10		* @param callable $payload
11		*
12		* @return \Closure
13		*/
14	1	public static function memoize($payload)
15		{
16		$function = function () use ($payload) {
17	1	static $cache = [];
18	1	$args = func_get_args();
19	1	$hash = md5(serialize($args));
20
21	1	if (!array_key_exists($hash, $cache)) {
22	1	$cache[$hash] = call_user_func_array($payload, $args);
23	1	}
24
25	1	return $cache[$hash];
26	1	};
27
28	1	return $function;
29		}
30
31		/**
32		* Creates function that simply returns given argument
33		*
34		* @return \Closure
35		*/
36	2	public static function nop()
37		{
38		return function ($item) {
39	2	return $item;
40	2	};
41		}
42
43		/**
44		* Creates a version of the function that can only be called one time.
45		*
46		* Repeated calls to the modified function will have no effect, returning
47		* the value from the original call. Useful for initialization functions,
48		* instead of having to set a boolean flag and then check it later.
49		*
50		* @param callable $function
51		* @return \Closure
52		*/
53	1	public static function once($function)
54		{
55	1	$called = false;
56	1	$value = null;
57
58		return function () use ($function, &$called, &$value) {
59	1	if (!$called) {
60	1	$args = func_get_args();
61	1	$value = call_user_func_array($function, $args);
62	1	$called = true;
63	1	}
64
65	1	return $value;
66	1	};
67		}
68
69		/**
70		* Provides a constant value that is only used for partial().
71		*
72		* @return \Closure
73		*/
74	1	public static function p()
75		{
76	1	static $function;
77	1	if (!$function) {
78		$function = function () {
79	1	return 'placeholder for partial';
80	1	};
81	1	}
82
83	1	return $function;
84		}
85
86		/**
87		* Partially apply a function by filling in any number of its arguments.
88		*
89		* You may pass p() in your list of arguments to specify an argument that
90		* should not be pre-filled, but left open to supply at call-time.
91		*
92		* @param callable $function
93		* @param mixed $arg
94		* @param mixed ...
95		* @return \Closure
96		*/
97	1	public static function partial($function, $arg)
		0 ignored issues – show Unused Code introduced 2016-02-28 14:04 UTC by Report Bug Copy Issue Report The parameter `$arg` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
98		{
99	1	$bound = func_get_args();
100	1	array_shift($bound); // remove $function
101
102	1	$placeholder = static::p();
103
104		return function () use ($function, $bound, $placeholder) {
105	1	$inject = func_get_args();
106
107	1	$args = [];
108	1	foreach ($bound as $value) {
109	1	if ($value === $placeholder) {
110	1	$args[] = array_shift($inject);
111	1	} else {
112	1	$args[] = $value;
113		}
114	1	}
115
116		// Append any remaining arguments
117	1	$args = array_merge($args, $inject);
118
119	1	return call_user_func_array($function, $args);
120	1	};
121		}
122
123		/**
124		* Returns the composition of a list of functions.
125		*
126		* Each function consumes the return value of the function that follows.
127		* In math terms, composing the functions f(), g(), and h() produces f(g(h())).
128		*
129		* @param callable $function
130		* @param callable ...
131		* @return \Closure
132		*/
133	1	public static function compose($function)
		0 ignored issues – show Unused Code introduced 2016-02-28 14:04 UTC by Report Bug Copy Issue Report The parameter `$function` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
134		{
135	1	$functions = array_reverse(func_get_args());
136
137		return function ($value) use ($functions) {
138	1	foreach ($functions as $function) {
139	1	$value = $function($value);
140	1	}
141
142	1	return $value;
143	1	};
144		}
145
146		/**
147		* Wraps the first function inside of the wrapper function, passing it as the first argument.
148		*
149		* This allows the wrapper to execute code before and after the function runs,
150		* adjust the arguments, and execute it conditionally.
151		*
152		* @param callable $function
153		* @param callable $wrapper
154		* @return \Closure
155		*/
156	1	public static function wrap($function, $wrapper)
157		{
158		return function () use ($function, $wrapper) {
159	1	$args = func_get_args();
160	1	array_unshift($args, $function); // make $function the first argument
161	1	return call_user_func_array($wrapper, $args);
162	1	};
163		}
164
165		/**
166		* Creates and returns a new, throttled version of the passed function.
167		*
168		* When invoked repeatedly, will only actually call the original function at
169		* most once per every wait milliseconds. Useful for rate-limiting events that
170		* occur faster than you can keep up with.
171		*
172		* By default, throttle will execute the function as soon as you call it
173		* for the first time, and, if you call it again any number of times during
174		* the wait period, as soon as that period is over. If you'd like to disable
175		* the leading-edge call, pass `leading => false`.
176		*
177		* NOTE: Does not support the `trailing` option because there is no timeout
178		* functionality in PHP (without using threads).
179		*
180		* NOTE: No arguments are passed to the function on the leading edge call!
181		*
182		* @param callable $function
183		* @param integer $wait
184		* @param array $options
185		* @return \Closure
186		*/
187	1	public static function throttle($function, $wait, array $options = [])
188		{
189		$options += [
190	1	'leading' => true,
191		]; // @codeCoverageIgnore
192
193	1	$previous = 0;
194
195		$callback = function () use ($function, $wait, &$previous) {
196	1	$now = floor(microtime(true) * 1000); // convert float to integer
197
198	1	if (($wait - ($now - $previous)) <= 0) {
199	1	$args = func_get_args();
200	1	call_user_func_array($function, $args);
201	1	$previous = $now;
202	1	}
203	1	};
204
205	1	if ($options['leading'] !== false) {
206	1	$callback();
207	1	}
208
209	1	return $callback;
210		}
211
212		/**
213		* Creates a version of the function that will only be run after first being called count times.
214		*
215		* Useful for grouping asynchronous responses, where you want to be sure that
216		* all the async calls have finished, before proceeding.
217		*
218		* @param integer $count
219		* @param callable $function
220		* @return \Closure
221		*/
222	1	public static function after($count, $function)
223		{
224		return function () use ($function, &$count) {
225	1	if (--$count < 1) {
226	1	$args = func_get_args();
227
228	1	return call_user_func_array($function, $args);
229		}
230	1	};
231		}
232
233		/**
234		* Creates a version of the function that can be called no more than count times.
235		*
236		* The result of the last function call is memoized and returned when count has been reached.
237		*
238		* @param integer $count
239		* @param callable $function
240		* @return \Closure
241		*/
242	1	public static function before($count, $function)
243		{
244	1	$memo = null;
245
246	1	return function () use ($function, &$count, &$memo) {
247	1	if (--$count > 0) {
248	1	$args = func_get_args();
249	1	$memo = call_user_func_array($function, $args);
250	1	}
251
252	1	return $memo;
253	1	};
254		}
255		}
256

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Functions::throttle() B

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