/*

   +----------------------------------------------------------------------+

   | Copyright (c) The PHP Group                                          |

   +----------------------------------------------------------------------+

   | This source file is subject to version 3.01 of the PHP license,      |

   | that is bundled with this package in the file LICENSE, and is        |

   | available through the world-wide-web at the following url:           |

   | https://www.php.net/license/3_01.txt                                 |

   | If you did not receive a copy of the PHP license and are unable to   |

   | obtain it through the world-wide-web, please send a note to          |

   | license@php.net so we can mail you a copy immediately.               |

   +----------------------------------------------------------------------+

   | Author: Stig Sæther Bakken <ssb@php.net>                             |

   +----------------------------------------------------------------------+

 */

#include "php.h"

#include <stdlib.h>

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include <string.h>

#include <errno.h>

#include <stdio.h>

#ifdef PHP_WIN32

#include "win32/time.h"

#else

#include <sys/time.h>

#endif

#include "ext/random/php_random.h"

#include "ext/random/php_random_csprng.h"

#ifdef HAVE_GETTIMEOFDAY

ZEND_TLS struct timeval prev_tv = { 0, 0 };

/* {{{ Generates a unique ID */

PHP_FUNCTION(uniqid)

{

  char *prefix = "";

  bool more_entropy = 0;

  zend_string *uniqid;

  int sec, usec;

  size_t prefix_len = 0;

  struct timeval tv;

  ZEND_PARSE_PARAMETERS_START(0, 2)

    Z_PARAM_OPTIONAL

    Z_PARAM_STRING(prefix, prefix_len)

    Z_PARAM_BOOL(more_entropy)

  ZEND_PARSE_PARAMETERS_END();

  /* This implementation needs current microsecond to change,

   * hence we poll time until it does. This is much faster than

   * calling usleep(1) which may cause the kernel to schedule

   * another process, causing a pause of around 10ms.

   */

  do {

    (void)gettimeofday((struct timeval *) &tv, (struct timezone *) NULL);

  } while (tv.tv_sec == prev_tv.tv_sec && tv.tv_usec == prev_tv.tv_usec);

  prev_tv.tv_sec = tv.tv_sec;

  prev_tv.tv_usec = tv.tv_usec;

  sec = (int) tv.tv_sec;

  usec = (int) (tv.tv_usec % 0x100000);

  /* The max value usec can have is 0xF423F, so we use only five hex

   * digits for usecs.

   */

  if (more_entropy) {

    uint32_t bytes;

    double seed;

    if (php_random_bytes_silent(&bytes, sizeof(uint32_t)) == FAILURE) {

      bytes = php_random_generate_fallback_seed();

    }

    seed = ((double) bytes / UINT32_MAX) * 10.0;

    uniqid = strpprintf(0, "%s%08x%05x%.8F", prefix, sec, usec, seed);

  } else {

    uniqid = strpprintf(0, "%s%08x%05x", prefix, sec, usec);

  }

  RETURN_STR(uniqid);

}

#endif

/* }}} */