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a few changes to danog's changes

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This commit is contained in:
terrafrost 2016-09-07 23:26:22 -08:00
parent 7cf300984c
commit 72d1bdf60b
2 changed files with 90 additions and 116 deletions
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130
phpseclib/Math/BigInteger.php
View File

@ -3699,13 +3699,17 @@ class BigInteger
*/ */
function root($n = null) function root($n = null)
{ {
static $zero, $one, $two;
if (!isset($one)) {
$zero = new static(0);
$one = new static(1); $one = new static(1);
$two = new static(2); $two = new static(2);
}
if ($n === null) { if ($n === null) {
$n = $two; $n = $two;
} }
if ($n->compare($one) == -1) { if ($n->compare($one) == -1) {
return new static(0); return $zero;
} // we want positive exponents } // we want positive exponents
if ($this->compare($one) == -1) { if ($this->compare($one) == -1) {
return new static(0); return new static(0);
@ -3713,52 +3717,13 @@ class BigInteger
if ($this->compare($two) == -1) { if ($this->compare($two) == -1) {
return $one; return $one;
} // n-th root of 1 or 2 is 1 } // n-th root of 1 or 2 is 1
$root = new static(); $root = new static();
switch (MATH_BIGINTEGER_MODE) { if (MATH_BIGINTEGER_MODE == self::MODE_GMP && function_exists('gmp_root')) {
case self::MODE_BCMATH:
// g is our guess number
$g = 2;
// while (g^n < num) g=g*2
while (bccomp(bcpow($g, $n->value), $this->value) == -1) {
$g = bcmul($g, '2');
}
// if (g^n==num) num is a power of 2, we're lucky, end of job
if (bccomp(bcpow($g, $n->value), $this->value) == 0) {
$root->value = $g;
break;
}
// if we're here num wasn't a power of 2 :(
$og = $g; // og means original guess and here is our upper bound
$g = bcdiv($g, '2'); // g is set to be our lower bound
$step = bcdiv(bcsub($og, $g), '2'); // step is the half of upper bound - lower bound
$g = bcadd($g, $step); // we start at lower bound + step , basically in the middle of our interval
// while step!=1
while (bccomp($step, '1') == 1) {
$guess = bcpow($g, $n);
$step = bcdiv($step, '2');
$comp = bccomp($guess, $this->value); // compare our guess with real number
if ($comp == -1) { // if guess is lower we add the new step
$g = bcadd($g, $step);
} elseif ($comp == 1) { // if guess is higher we sub the new step
$g = bcsub($g, $step);
} else { // if guess is exactly the num we're done, we return the value
$root->value = $g;
break;
}
}
// whatever happened, g is the closest guess we can make so return it
$root->value = $g;
break;
case self::MODE_GMP:
if (function_exists('gmp_root')) {
$root->value = gmp_root($this->value, gmp_intval($n->value)); $root->value = gmp_root($this->value, gmp_intval($n->value));
break; return $this->_normalize($root);
} }
default:
// g is our guess number // g is our guess number
$g = $two; $g = $two;
// while (g^n < num) g=g*2 // while (g^n < num) g=g*2
@ -3769,7 +3734,7 @@ class BigInteger
// == 0 bccomp(bcpow($g,$n), $n->value)==0 // == 0 bccomp(bcpow($g,$n), $n->value)==0
if ($g->pow($n)->equals($this)) { if ($g->pow($n)->equals($this)) {
$root = $g; $root = $g;
break; return $this->_normalize($root);
} }
// if we're here num wasn't a power of 2 :( // if we're here num wasn't a power of 2 :(
@ -3778,26 +3743,31 @@ class BigInteger
$step = $og->subtract($g)->divide($two)[0]; // step is the half of upper bound - lower bound $step = $og->subtract($g)->divide($two)[0]; // step is the half of upper bound - lower bound
$g = $g->add($step); // we start at lower bound + step , basically in the middle of our interval $g = $g->add($step); // we start at lower bound + step , basically in the middle of our interval
// while step!=1 // while step>1
while ($step->compare($one) == 1) { while ($step->compare($one) == 1) {
$guess = $g->pow($n); $guess = $g->pow($n);
$step = $step->divide($two)[0]; $step = $step->divide($two)[0];
$comp = $guess->compare($this); // compare our guess with real number $comp = $guess->compare($this); // compare our guess with real number
if ($comp == -1) { // if guess is lower we add the new step switch ($comp) {
case -1: // if guess is lower we add the new step
$g = $g->add($step); $g = $g->add($step);
} elseif ($comp == 1) { // if guess is higher we sub the new step
$g = $g->subtract($step);
} else { // if guess is exactly the num we're done, we return the value
$root = $g;
break; break;
case 1: // if guess is higher we sub the new step
$g = $g->subtract($step);
break;
case 0: // if guess is exactly the num we're done, we return the value
$root = $g;
break 2;
} }
} }
if ($comp == 1) {
$g = $g->subtract($step);
}
// whatever happened, g is the closest guess we can make so return it // whatever happened, g is the closest guess we can make so return it
$root = $g; $root = $g;
break;
}
return $this->_normalize($root); return $this->_normalize($root);
} }
@ -3805,7 +3775,6 @@ class BigInteger
/** /**
* Performs exponentiation. * Performs exponentiation.
* *
*
* @param \phpseclib\Math\BigInteger $n * @param \phpseclib\Math\BigInteger $n
* @access public * @access public
* @return \phpseclib\Math\BigInteger * @return \phpseclib\Math\BigInteger
@ -3836,69 +3805,74 @@ class BigInteger
} }
return $res; return $res;
break;
} }
} }
/** /**
* Return the minimum BigInteger between two BigIntegers. * Return the minimum BigInteger between an arbitrary number of BigIntegers.
* *
* * @param \phpseclib\Math\BigInteger ...$param
* @param \phpseclib\Math\BigInteger $a
* @param \phpseclib\Math\BigInteger $b
* @access public * @access public
*
*
* @return \phpseclib\Math\BigInteger * @return \phpseclib\Math\BigInteger
*/ */
function min($b) static function min()
{ {
if ($this->compare($b) == '1') { $args = func_get_args();
return $b; if (count($args) == 1) {
return $args[0];
} }
$min = $args[0];
return $this; for ($i = 1; $i < count($args); $i++) {
$min = $min->compare($args[$i]) > 0 ? $args[$i] : $min;
}
return $min;
} }
/** /**
* Return the maximum BigInteger between two BigIntegers. * Return the maximum BigInteger between an arbitrary number of BigIntegers.
* *
* * @param \phpseclib\Math\BigInteger ...$param
* @param \phpseclib\Math\BigInteger $b
* @access public * @access public
*
* @return \phpseclib\Math\BigInteger * @return \phpseclib\Math\BigInteger
*/ */
function max($b) static function max()
{ {
if ($this->compare($b) == '1') { $args = func_get_args();
return $this; if (count($args) == 1) {
return $args[0];
} }
$max = $args[0];
return $b; for ($i = 1; $i < count($args); $i++) {
$max = $max->compare($args[$i]) < 0 ? $args[$i] : $max;
}
return $max;
} }
/** /**
* Execute a function n times, where n is the current BigInteger. * Execute a function n times, where n is the current BigInteger.
* The passed function must accept a paremeter that will be set to the the current number * The passed function must accept a parameter that will be set to the the current number
* (that number will range from zero to BigInteger - 1 if the BigInteger is positive, and from BigInteger - 1 to zero if the BigInteger is negative). * (that number will range from zero to BigInteger - 1 if the BigInteger is positive, and from BigInteger - 1 to zero if the BigInteger is negative).
* You can also set it to accept an optional parameter, that will be equal to the optional $userdata parameter. * You can also set it to accept an optional parameter, that will be equal to the optional $userdata parameter.
* *
* @access public * @access public
* @param callable $function * @param callable $function
* @param &$userdata * @param &$userdata
*
* @return \phpseclib\Math\BigInteger * @return \phpseclib\Math\BigInteger
*/ */
function loopforeach(callable $function, &$userdata = null) function loopforeach(callable $function, &$userdata = null)
{ {
if ($this->compare(new static(0)) < 0) { // negative static $zero;
if (!isset($zero)) {
$zero = new static(0);
}
if ($this->compare($zero) < 0) { // negative
$limit = new static(-PHP_INT_MAX - 1); $limit = new static(-PHP_INT_MAX - 1);
$one = new static(-1); $one = new static(-1);
} else { // positive } else { // positive
$limit = new static(PHP_INT_MAX); $limit = new static(PHP_INT_MAX);
$one = new static(1); $one = new static(1);
} }
if ($this->compare($limit) == -((int) $one->toString())) { if ($this->compare($limit) == -((int) $one->toString())) {
$oneint = (int) $one->toString(); $oneint = (int) $one->toString();
$thisint = (int) $this->toString(); $thisint = (int) $this->toString();

8
tests/Unit/Math/BigInteger/TestCase.php
View File

@ -405,16 +405,16 @@ abstract class Unit_Math_BigInteger_TestCase extends PhpseclibTestCase
{ {
$min = new \phpseclib\Math\BigInteger('20'); $min = new \phpseclib\Math\BigInteger('20');
$max = new \phpseclib\Math\BigInteger('20000'); $max = new \phpseclib\Math\BigInteger('20000');
$this->assertSame((string) $max, (string) $min->max($max)); $this->assertSame((string) $max, (string) \phpseclib\Math\BigInteger::max($min, $max));
$this->assertSame((string) $max, (string) $max->max($min)); $this->assertSame((string) $max, (string) \phpseclib\Math\BigInteger::max($max, $min));
} }
public function testMin() public function testMin()
{ {
$min = new \phpseclib\Math\BigInteger('20'); $min = new \phpseclib\Math\BigInteger('20');
$max = new \phpseclib\Math\BigInteger('20000'); $max = new \phpseclib\Math\BigInteger('20000');
$this->assertSame((string) $min, (string) $min->min($max)); $this->assertSame((string) $min, (string) \phpseclib\Math\BigInteger::min($min, $max));
$this->assertSame((string) $min, (string) $max->min($min)); $this->assertSame((string) $min, (string) \phpseclib\Math\BigInteger::min($max, $min));
} }
public function testLoopForeach() public function testLoopForeach()