init.c

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/* init.c: bcmath library file. */
/*
    Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
    Copyright (C) 2000 Philip A. Nelson
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.  (LICENSE)
 
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to:
 
      The Free Software Foundation, Inc.
      59 Temple Place, Suite 330
      Boston, MA 02111-1307 USA.
 
    You may contact the author by:
       e-mail:  philnelson@acm.org
      us-mail:  Philip A. Nelson
                Computer Science Department, 9062
                Western Washington University
                Bellingham, WA 98226-9062
 
*************************************************************************/
 
#include "bcmath.h"
#include <stdbool.h>
#include <stddef.h>
#include <string.h>
#include "zend_alloc.h"
 
static bc_num _bc_new_num_nonzeroed_ex_internal(size_t length, size_t scale, bool persistent)
{
    size_t required_size = zend_safe_address_guarded(1, sizeof(bc_struct) + (ZEND_MM_ALIGNMENT - 1) + length, scale);
    required_size &= -ZEND_MM_ALIGNMENT;
    bc_num temp;
 
    if (!persistent && BCG(arena) && required_size <= BC_ARENA_SIZE - BCG(arena_offset)) {
        temp = (bc_num) (BCG(arena) + BCG(arena_offset));
        BCG(arena_offset) += required_size;
        temp->n_refs = 2; /* prevent freeing */
    } else {
        /* PHP Change: malloc() -> pemalloc(), removed free_list code, merged n_ptr and n_value */
        temp = pemalloc(required_size, persistent);
        temp->n_refs = 1;
    }
 
    temp->n_sign = PLUS;
    temp->n_len = length;
    temp->n_scale = scale;
    temp->n_value = (char *) temp + sizeof(bc_struct);
    return temp;
}
 
/* new_num allocates a number and sets fields to known values. */
bc_num _bc_new_num_ex(size_t length, size_t scale, bool persistent)
{
    bc_num temp = _bc_new_num_nonzeroed_ex_internal(length, scale, persistent);
    memset(temp->n_value, 0, length + scale);
    return temp;
}
 
bc_num _bc_new_num_nonzeroed_ex(size_t length, size_t scale, bool persistent)
{
    return _bc_new_num_nonzeroed_ex_internal(length, scale, persistent);
}
 
/* "Frees" a bc_num NUM.  Actually decreases reference count and only
   frees the storage if reference count is zero. */
void _bc_free_num_ex(bc_num *num, bool persistent)
{
    if (*num == NULL) {
        return;
    }
    (*num)->n_refs--;
    if ((*num)->n_refs == 0) {
        pefree(*num, persistent);
    }
    *num = NULL;
}
 
 
/* Initialize the number package! */
 
void bc_init_numbers(void)
{
    BCG(_zero_) = _bc_new_num_ex(1, 0, 1);
    BCG(_one_) = _bc_new_num_ex(1, 0, 1);
    BCG(_one_)->n_value[0] = 1;
    BCG(_two_) = _bc_new_num_ex(1, 0, 1);
    BCG(_two_)->n_value[0] = 2;
}
 
void bc_force_free_number(bc_num *num)
{
    pefree(*num, 1);
    *num = NULL;
}
 
 
/* Initialize a number NUM by making it a copy of zero. */
void bc_init_num(bc_num *num)
{
    *num = bc_copy_num(BCG(_zero_));
}