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In-depth PHP kernel in_array, php kernel in_array_PHP tutorial

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Release： 2016-07-12 09:05:21
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Deep into PHP kernel in_array, php kernel in_array

I accidentally saw a piece of code

1. a.php

<?php
$y="12";
$x = array();
for($j=0;$j<50000;$j++){
    $x[]= "{$j}";
}

for($i=0;$i<30000;$i++){
    if(in_array($y,$x,true)){
        continue;
    }
}
?>
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Test

[root@dev tmp]# time php a.php

real    0m0.101s
user    0m0.080s
sys     0m0.013s
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2.b.php

<?php                                                                                                                                                                                        
$y="1800";
$x = array();
for($j=0;$j<50000;$j++){
    $x[]= "{$j}";
}
 
for($i=0;$i<30000;$i++){
    if(in_array($y,$x)){
        continue;
    }   
}
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Test

[root@dev tmp]# time php b.php 

real    0m9.517s
user    0m4.486s
sys     0m0.015s
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Requires 9s

There are serious efficiency issues with b.php, please follow up and test it

[root@dev tmp]# ltrace -c  php b.php     
% time     seconds  usecs/call     calls      function
------ ----------- ----------- --------- --------------------
 52.92  175.486683         224    780155 strtol
 33.34  110.550182    55275091         2 __libc_start_main
  6.33   20.999979         177    118479 memcpy
  3.56   11.819558         234     50394 __ctype_b_loc
  1.66    5.510564         285     19294 free
  1.42    4.704605      156820        30 dlopen
  0.43    1.416750          76     18430 malloc
  0.13    0.422050          76      5510 strlen
  0.08    0.258620          76      3375 __ctype_tolower_loc
  0.04    0.137245          77      1770 strrchr
  0.02    0.067158          76       880 strcasecmp
  0.02    0.059222          76       776 calloc
  0.01    0.034591       17295         2 getprotobyname
  0.01    0.031099          76       407 realloc
  0.01    0.021277          77       276 memset
  0.00    0.011502         383        30 dlclose
  0.00    0.010671          85       125 
  0.00    0.006806          73        93 fileno
  0.00    0.006095          76        80 strncasecmp
  0.00    0.005397          77        70 strchr
  0.00    0.005139         160        32 ftell
  0.00    0.004405         137        32 fclose
  0.00    0.003644         104        35 __fxstat
  0.00    0.003432         107        32 fopen
  0.00    0.003103         107        29 munmap
  0.00    0.003062          78        39 getenv
  0.00    0.003031         104        29 mmap
  0.00    0.003027         104        29 isatty
  0.00    0.002825         104        27 __xstat
  0.00    0.002468          82        30 dlsym
  0.00    0.002167          74        29 sysconf
  0.00    0.001956          75        26 _setjmp
  0.00    0.001419         109        13 __lxstat
  0.00    0.001294          76        17 memchr
  0.00    0.001125        1125         1 SYS_clone
  0.00    0.001099        1099         1 tzset
  0.00    0.001098        1098         1 exit
  0.00    0.001075        1075         1 ERR_load_crypto_strings
  0.00    0.000986         986         1 using_history
  0.00    0.000837         837         1 SYS_exit_group
  0.00    0.000606          75         8 __strdup
  0.00    0.000596          74         8 strcmp
  0.00    0.000591          73         8 __memcpy_chk
  0.00    0.000457          76         6 fflush
  0.00    0.000326         108         3 getcwd
  0.00    0.000309          77         4 __errno_location
  0.00    0.000271         271         1 setlocale
  0.00    0.000271         271         1 scandir
  0.00    0.000238          79         3 __sprintf_chk
  0.00    0.000222         111         2 signal
  0.00    0.000206         206         1 SSL_library_init
  0.00    0.000186         186         1 fgetc
  0.00    0.000155         155         1 ERR_load_ERR_strings
  0.00    0.000154          77         2 xmlSetGenericErrorFunc
  0.00    0.000151          75         2 __strtok_r
  0.00    0.000151          75         2 xmlParserInputBufferCreateFilenameDefault
  0.00    0.000148         148         1 xmlInitParser
  0.00    0.000147          73         2 xmlOutputBufferCreateFilenameDefault
  0.00    0.000130         130         1 OpenSSL_add_all_ciphers
  0.00    0.000122         122         1 EVP_cleanup
  0.00    0.000112         112         1 access
  0.00    0.000109         109         1 rewind
  0.00    0.000106         106         1 OPENSSL_add_all_algorithms_noconf
  0.00    0.000105         105         1 sigprocmask
  0.00    0.000093          93         1 gnu_get_libc_version
  0.00    0.000090          90         1 OpenSSL_add_all_digests
  0.00    0.000084          84         1 xmlCleanupParser
  0.00    0.000081          81         1 xmlRelaxNGCleanupTypes
  0.00    0.000079          79         1 xmlSetStructuredErrorFunc
  0.00    0.000078          78         1 SSL_get_ex_new_index
  0.00    0.000077          77         1 __gmp_set_memory_functions
  0.00    0.000076          76         1 ERR_load_EVP_strings
  0.00    0.000076          76         1 pcre_version
  0.00    0.000075          75         1 X509_get_default_cert_area
  0.00    0.000075          75         1 strstr
  0.00    0.000074          74         1 sigemptyset
  0.00    0.000074          74         1 __xmlParserVersion
  0.00    0.000074          74         1 time
  0.00    0.000074          74         1 xmlResetLastError
  0.00    0.000074          74         1 strncmp
  0.00    0.000073          73         1 sigaddset
------ ----------- ----------- --------- --------------------
100.00  331.614442               1000662 total
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We found that strtol takes up a lot of time

Check the library functions

/*
函数名: strtol 
功  能: 将串转换为长整数 
用  法: long strtol(char *str, char **endptr, int base); 
程序例: 
*/

#include <stdlib.h> 
#include <stdio.h> 

int main(void) 
{ 
   char *string = "87654321", *endptr; 
   long lnumber; 

   /* strtol converts string to long integer  */ 
   lnumber = strtol(string, &endptr, 10); 
   printf("string = %s  long = %ld\n", string, lnumber); 

   return 0; 
}
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So there should be a lot of type conversions in the source code

About in_array

in_array looks like this

bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )
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Searches for haystack within needle , using a relaxed comparison if strict is not set.

needle

The value to search for. If needle is a string, the comparison is case-sensitive.

haystack

This array.

strict

If the value of the third parameter strict is TRUE, then the in_array() function will also check whether the type of needle is the same as the one in haystack.

Then let me take a look at the source code

The first step is in the ext/standard/array.c file 

/* }}} */                                                      
                                                               
/* {{{ proto bool in_array(mixed needle, array haystack [, bool strict])
   Checks if the given value exists in the array */            
PHP_FUNCTION(in_array)                                         
{                                                              
    php_search_array(INTERNAL_FUNCTION_PARAM_PASSTHRU, 0);     
}                                                              
/* }}} */                                                      
                                                               
/* {{{ proto mixed array_search(mixed needle, array haystack [, bool strict])
   Searches the array for a given value and returns the corresponding key if successful */
PHP_FUNCTION(array_search)                                     
{                                                              
    php_search_array(INTERNAL_FUNCTION_PARAM_PASSTHRU, 1);     
}                                                              
/* }}} */
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By the way, I saw array_search, which turns out to be basically the same as the internal implementation of in_array

The parameters of the function are in ./zend.h

#define INTERNAL_FUNCTION_PARAM_PASSTHRU ht, return_value, return_value_ptr, this_ptr, return_value_used TSRMLS_CC
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The second step is to view the php_search_array prototype in the ext/standard/array.c file

/* void php_search_array(INTERNAL_FUNCTION_PARAMETERS, int behavior)
 * 0 = return boolean
 * 1 = return key
 */      
static void php_search_array(INTERNAL_FUNCTION_PARAMETERS, int behavior) /* {{{ */
{        
    zval *value,            /* value to check for */
         *array,            /* array to check in */
         **entry,           /* pointer to array entry */
         res;              /* comparison result */
    HashPosition pos;        /* hash iterator */
    zend_bool strict = 0;     /* strict comparison or not */
    ulong num_key;
    uint str_key_len;
    char *string_key;
    int (*is_equal_func)(zval *, zval *, zval * TSRMLS_DC) = is_equal_function;
         
    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "za|b", &value, &array, &strict) == FAILURE) {
        return;
    }    
         
    if (strict) {
        is_equal_func = is_identical_function;
    }    
         
    zend_hash_internal_pointer_reset_ex(Z_ARRVAL_P(array), &pos);
    while (zend_hash_get_current_data_ex(Z_ARRVAL_P(array), (void **)&entry, &pos) == SUCCESS) {
        is_equal_func(&res, value, *entry TSRMLS_CC);
        if (Z_LVAL(res)) {
            if (behavior == 0) {
                RETURN_TRUE;
            } else {
                /* Return current key */
                switch (zend_hash_get_current_key_ex(Z_ARRVAL_P(array), &string_key, &str_key_len, &num_key, 0, &pos)) {
                    case HASH_KEY_IS_STRING:
                        RETURN_STRINGL(string_key, str_key_len - 1, 1);
                        break;
                    case HASH_KEY_IS_LONG:
                        RETURN_LONG(num_key);
                        break;
                }
            }
        }
        zend_hash_move_forward_ex(Z_ARRVAL_P(array), &pos);
    }    
         
    RETURN_FALSE;
}        
/* }}} */
         
/* {{{ proto bool in_array(mixed needle, array haystack [, bool strict])
   Checks if the given value exists in the array */
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We found that there are two comparison methods for the difference in the value of strict. Let’s take a look at the difference between the two functions

is_identical_function Check if the types are the same

ZEND_API int is_identical_function(zval *result, zval *op1, zval *op2 TSRMLS_DC) /* {{{ */
{        
   Z_TYPE_P(result) = IS_BOOL;
   if (Z_TYPE_P(op1) != Z_TYPE_P(op2)) {
      Z_LVAL_P(result) = 0;
      return SUCCESS;
   }    
   switch (Z_TYPE_P(op1)) {
      case IS_NULL:
         Z_LVAL_P(result) = 1;
         break;
      case IS_BOOL:
      case IS_LONG:
      case IS_RESOURCE:
         Z_LVAL_P(result) = (Z_LVAL_P(op1) == Z_LVAL_P(op2));
         break;
      case IS_DOUBLE:
         Z_LVAL_P(result) = (Z_DVAL_P(op1) == Z_DVAL_P(op2));
         break;
      case IS_STRING:
         Z_LVAL_P(result) = ((Z_STRLEN_P(op1) == Z_STRLEN_P(op2))
            && (!memcmp(Z_STRVAL_P(op1), Z_STRVAL_P(op2), Z_STRLEN_P(op1))));
         break;
      case IS_ARRAY:
         Z_LVAL_P(result) = (Z_ARRVAL_P(op1) == Z_ARRVAL_P(op2) 
            zend_hash_compare(Z_ARRVAL_P(op1), Z_ARRVAL_P(op2), (compare_func_t) hash_zval_identical_function, 1 TSRMLS_CC)==0);
         break;
      case IS_OBJECT:
         if (Z_OBJ_HT_P(op1) == Z_OBJ_HT_P(op2)) {
            Z_LVAL_P(result) = (Z_OBJ_HANDLE_P(op1) == Z_OBJ_HANDLE_P(op2));
         } else {
            Z_LVAL_P(result) = 0;
         }
         break;
      default:
         Z_LVAL_P(result) = 0;
         return FAILURE;
   }    
   return SUCCESS;
}        
/* }}} */
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is_equal_function does not check whether the types are the same, so implicit conversion is required 

ZEND_API int is_equal_function(zval *result, zval *op1, zval *op2 TSRMLS_DC) /* {{{ */
{        
   if (compare_function(result, op1, op2 TSRMLS_CC) == FAILURE) {
      return FAILURE;
   }    
   ZVAL_BOOL(result, (Z_LVAL_P(result) == 0));
   return SUCCESS;
}        
/* }}} */
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==》compare_function

ZEND_API int compare_function(zval *result, zval *op1, zval *op2 TSRMLS_DC) /* {{{ */
{            
   int ret; 
   int converted = 0;
   zval op1_copy, op2_copy;
   zval *op_free;
             
   while (1) {
      switch (TYPE_PAIR(Z_TYPE_P(op1), Z_TYPE_P(op2))) {
         case TYPE_PAIR(IS_LONG, IS_LONG):
            ZVAL_LONG(result, Z_LVAL_P(op1)>Z_LVAL_P(op2)?1:(Z_LVAL_P(op1)<Z_LVAL_P(op2)?-1:0)); 
            return SUCCESS;
              
         case TYPE_PAIR(IS_DOUBLE, IS_LONG):
            Z_DVAL_P(result) = Z_DVAL_P(op1) - (double)Z_LVAL_P(op2);
            ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result)));
            return SUCCESS;
             
         case TYPE_PAIR(IS_LONG, IS_DOUBLE):
            Z_DVAL_P(result) = (double)Z_LVAL_P(op1) - Z_DVAL_P(op2);
            ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result)));
            return SUCCESS;
             
         case TYPE_PAIR(IS_DOUBLE, IS_DOUBLE):
            if (Z_DVAL_P(op1) == Z_DVAL_P(op2)) {
               ZVAL_LONG(result, 0);
            } else {
               Z_DVAL_P(result) = Z_DVAL_P(op1) - Z_DVAL_P(op2);
               ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result)));
            }
            return SUCCESS;
            
         case TYPE_PAIR(IS_ARRAY, IS_ARRAY):
            zend_compare_arrays(result, op1, op2 TSRMLS_CC);
            return SUCCESS;
            
         case TYPE_PAIR(IS_NULL, IS_NULL):
            ZVAL_LONG(result, 0);
            return SUCCESS;
            
         case TYPE_PAIR(IS_NULL, IS_BOOL):
            ZVAL_LONG(result, Z_LVAL_P(op2) ? -1 : 0);
            return SUCCESS;
             
         case TYPE_PAIR(IS_BOOL, IS_NULL):
            ZVAL_LONG(result, Z_LVAL_P(op1) ? 1 : 0);
            return SUCCESS;
             
         case TYPE_PAIR(IS_BOOL, IS_BOOL):
            ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(op1) - Z_LVAL_P(op2)));
            return SUCCESS;
             
         case TYPE_PAIR(IS_STRING, IS_STRING):
            zendi_smart_strcmp(result, op1, op2);
            return SUCCESS;
             
         case TYPE_PAIR(IS_NULL, IS_STRING):
            ZVAL_LONG(result, zend_binary_strcmp("", 0, Z_STRVAL_P(op2), Z_STRLEN_P(op2)));
            return SUCCESS;
             
         case TYPE_PAIR(IS_STRING, IS_NULL):
            ZVAL_LONG(result, zend_binary_strcmp(Z_STRVAL_P(op1), Z_STRLEN_P(op1), "", 0));
            return SUCCESS;
             
         case TYPE_PAIR(IS_OBJECT, IS_NULL):
            ZVAL_LONG(result, 1);
            return SUCCESS;
             
         case TYPE_PAIR(IS_NULL, IS_OBJECT):
            ZVAL_LONG(result, -1);
            return SUCCESS;
             
         case TYPE_PAIR(IS_OBJECT, IS_OBJECT):
            /* If both are objects sharing the same comparision handler then use is */
            if (Z_OBJ_HANDLER_P(op1,compare_objects) == Z_OBJ_HANDLER_P(op2,compare_objects)) {
               if (Z_OBJ_HANDLE_P(op1) == Z_OBJ_HANDLE_P(op2)) {
                  /* object handles are identical, apparently this is the same object */
                  ZVAL_LONG(result, 0);
                  return SUCCESS;
               }
               ZVAL_LONG(result, Z_OBJ_HT_P(op1)->compare_objects(op1, op2 TSRMLS_CC));
               return SUCCESS;
            }
            /* break missing intentionally */
             
         default:
            if (Z_TYPE_P(op1) == IS_OBJECT) {
               if (Z_OBJ_HT_P(op1)->get) {
                  op_free = Z_OBJ_HT_P(op1)->get(op1 TSRMLS_CC);
                  ret = compare_function(result, op_free, op2 TSRMLS_CC);
                  zend_free_obj_get_result(op_free TSRMLS_CC);
                  return ret;
               } else if (Z_TYPE_P(op2) != IS_OBJECT && Z_OBJ_HT_P(op1)->cast_object) {
                  ALLOC_INIT_ZVAL(op_free);
                  if (Z_OBJ_HT_P(op1)->cast_object(op1, op_free, Z_TYPE_P(op2) TSRMLS_CC) == FAILURE) {
                     ZVAL_LONG(result, 1);
                     zend_free_obj_get_result(op_free TSRMLS_CC);
                     return SUCCESS;
                  }
                  ret = compare_function(result, op_free, op2 TSRMLS_CC);
                  zend_free_obj_get_result(op_free TSRMLS_CC);
                  return ret;
               }
            }
            if (Z_TYPE_P(op2) == IS_OBJECT) {
               if (Z_OBJ_HT_P(op2)->get) {
                  op_free = Z_OBJ_HT_P(op2)->get(op2 TSRMLS_CC);
                  ret = compare_function(result, op1, op_free TSRMLS_CC);
                  zend_free_obj_get_result(op_free TSRMLS_CC);
                  return ret;
               } else if (Z_TYPE_P(op1) != IS_OBJECT && Z_OBJ_HT_P(op2)->cast_object) {
                  ALLOC_INIT_ZVAL(op_free);
                  if (Z_OBJ_HT_P(op2)->cast_object(op2, op_free, Z_TYPE_P(op1) TSRMLS_CC) == FAILURE) {
                     ZVAL_LONG(result, -1);
                     zend_free_obj_get_result(op_free TSRMLS_CC);
                     return SUCCESS;
                  }
                  ret = compare_function(result, op1, op_free TSRMLS_CC);
                  zend_free_obj_get_result(op_free TSRMLS_CC);
                  return ret;
               } else if (Z_TYPE_P(op1) == IS_OBJECT) {
                  ZVAL_LONG(result, 1);
                  return SUCCESS;
               }
            }
            if (!converted) {
               if (Z_TYPE_P(op1) == IS_NULL) {
                  zendi_convert_to_boolean(op2, op2_copy, result);
                  ZVAL_LONG(result, Z_LVAL_P(op2) ? -1 : 0);
                  return SUCCESS;
               } else if (Z_TYPE_P(op2) == IS_NULL) {
                  zendi_convert_to_boolean(op1, op1_copy, result);
                  ZVAL_LONG(result, Z_LVAL_P(op1) ? 1 : 0);
                  return SUCCESS;
               } else if (Z_TYPE_P(op1) == IS_BOOL) {
                  zendi_convert_to_boolean(op2, op2_copy, result);
                  ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(op1) - Z_LVAL_P(op2)));
                  return SUCCESS;
               } else if (Z_TYPE_P(op2) == IS_BOOL) {
                  zendi_convert_to_boolean(op1, op1_copy, result);
                  ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(op1) - Z_LVAL_P(op2)));
                  return SUCCESS;
               } else {
                  zendi_convert_scalar_to_number(op1, op1_copy, result);
                  zendi_convert_scalar_to_number(op2, op2_copy, result);
                  converted = 1;
               }
            } else if (Z_TYPE_P(op1)==IS_ARRAY) {
               ZVAL_LONG(result, 1);
               return SUCCESS;
            } else if (Z_TYPE_P(op2)==IS_ARRAY) {
               ZVAL_LONG(result, -1);
               return SUCCESS;
            } else if (Z_TYPE_P(op1)==IS_OBJECT) {
               ZVAL_LONG(result, 1);
               return SUCCESS;
            } else if (Z_TYPE_P(op2)==IS_OBJECT) {
               ZVAL_LONG(result, -1);
               return SUCCESS;
            } else {
               ZVAL_LONG(result, 0);
               return FAILURE;
            }
      }     
   }         
}             
/* }}} */
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Let’s take a look at how array and string compare

==》zend_hash_compare in Zend/zend_hash.c

ZEND_API int zend_hash_compare(HashTable *ht1, HashTable *ht2, compare_func_t compar, zend_bool ordered TSRMLS_DC)
{            
     Bucket *p1, *p2 = NULL;
     int result;
     void *pData2;
             
     IS_CONSISTENT(ht1);
     IS_CONSISTENT(ht2);
             
     HASH_PROTECT_RECURSION(ht1);.
     HASH_PROTECT_RECURSION(ht2);.
             
     result = ht1->nNumOfElements - ht2->nNumOfElements;
     if (result!=0) {
          HASH_UNPROTECT_RECURSION(ht1);.
          HASH_UNPROTECT_RECURSION(ht2);.
          return result;
     }        
             
     p1 = ht1->pListHead;
     if (ordered) {
          p2 = ht2->pListHead;
     }         
             
     while (p1) {
          if (ordered && !p2) {
               HASH_UNPROTECT_RECURSION(ht1);.
               HASH_UNPROTECT_RECURSION(ht2);.
               return 1; /* That's not supposed to happen */
          }    
          if (ordered) {
               if (p1->nKeyLength==0 && p2->nKeyLength==0) { /* numeric indices */
                    result = p1->h - p2->h;
                    if (result!=0) {
                         HASH_UNPROTECT_RECURSION(ht1);.
                         HASH_UNPROTECT_RECURSION(ht2);.
                         return result;
                    }
               } else { /* string indices */
                    result = p1->nKeyLength - p2->nKeyLength;
                    if (result!=0) {
                         HASH_UNPROTECT_RECURSION(ht1);.
                         HASH_UNPROTECT_RECURSION(ht2);.
                         return result;
                    }
                    result = memcmp(p1->arKey, p2->arKey, p1->nKeyLength);
                    if (result!=0) {
                         HASH_UNPROTECT_RECURSION(ht1);.
                         HASH_UNPROTECT_RECURSION(ht2);.
                         return result;
                    }
               }
               pData2 = p2->pData;
          } else {
               if (p1->nKeyLength==0) { /* numeric index */
                    if (zend_hash_index_find(ht2, p1->h, &pData2)==FAILURE) {
                         HASH_UNPROTECT_RECURSION(ht1);.
                         HASH_UNPROTECT_RECURSION(ht2);.
                         return 1;
                    }
               } else { /* string index */
                    if (zend_hash_quick_find(ht2, p1->arKey, p1->nKeyLength, p1->h, &pData2)==FAILURE) { 
                         HASH_UNPROTECT_RECURSION(ht1);.
                         HASH_UNPROTECT_RECURSION(ht2);.
                         return 1;
                    }
               } 
          }     
          result = compar(p1->pData, pData2 TSRMLS_CC);
          if (result!=0) {
               HASH_UNPROTECT_RECURSION(ht1);.
               HASH_UNPROTECT_RECURSION(ht2);.
               return result;
          }     
          p1 = p1->pListNext;
          if (ordered) {
               p2 = p2->pListNext;
          }     
     }         
               
     HASH_UNPROTECT_RECURSION(ht1);.
     HASH_UNPROTECT_RECURSION(ht2);.
     return 0; 
}
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==》There is also a zendi_smart_strcmp in Zend/zend_operators.c

ZEND_API void zendi_smart_strcmp(zval *result, zval *s1, zval *s2) /* {{{ */
{    
     int ret1, ret2;
     int oflow1, oflow2;
     long lval1, lval2;
     double dval1, dval2;
     
     if ((ret1=is_numeric_string_ex(Z_STRVAL_P(s1), Z_STRLEN_P(s1), &lval1, &dval1, 0, &oflow1)) &&
          (ret2=is_numeric_string_ex(Z_STRVAL_P(s2), Z_STRLEN_P(s2), &lval2, &dval2, 0, &oflow2))) {
#if ULONG_MAX == 0xFFFFFFFF
          if (oflow1 != 0 && oflow1 == oflow2 && dval1 - dval2 == 0. &&
               ((oflow1 == 1 && dval1 > 9007199254740991. /*0x1FFFFFFFFFFFFF*/)
                    (oflow1 == -1 && dval1 < -9007199254740991.))) {
#else
          if (oflow1 != 0 && oflow1 == oflow2 && dval1 - dval2 == 0.) {
#endif
               /* both values are integers overflown to the same side, and the
                * double comparison may have resulted in crucial accuracy lost */
               goto string_cmp;
          }
          if ((ret1==IS_DOUBLE)      (ret2==IS_DOUBLE)) {
               if (ret1!=IS_DOUBLE) {
                    if (oflow2) {
                         /* 2nd operand is integer > LONG_MAX (oflow2==1) or < LONG_MIN (-1) */
                         ZVAL_LONG(result, -1 * oflow2);
                         return;
                    }
                    dval1 = (double) lval1;
               } else if (ret2!=IS_DOUBLE) {
                    if (oflow1) {
                         ZVAL_LONG(result, oflow1);
                         return;
                    }
                    dval2 = (double) lval2;
               } else if (dval1 == dval2 && !zend_finite(dval1)) {
                    /* Both values overflowed and have the same sign,
                     * so a numeric comparison would be inaccurate */
                    goto string_cmp;
               }
               Z_DVAL_P(result) = dval1 - dval2;
               ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result)));
          } else { /* they both have to be long's */
               ZVAL_LONG(result, lval1 > lval2 ? 1 : (lval1 < lval2 ? -1 : 0));
          }
     } else {
string_cmp:
          Z_LVAL_P(result) = zend_binary_zval_strcmp(s1, s2);
          ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(result)));
     }
}   
/* }}} *
Copy after login

Our type conversion function is_numeric_string_ex is in Zend/zend_operators.h

Continue to follow

==》is_numeric_string_ex

static inline zend_uchar is_numeric_string_ex(const char *str, int length, long *lval, double *dval, int allow_errors, int *oflow_info)
{
     const char *ptr;
     int base = 10, digits = 0, dp_or_e = 0;
     double local_dval;
     zend_uchar type;
 
     if (!length) {
          return 0;
     }
 
     if (oflow_info != NULL) {
          *oflow_info = 0;
     }
 
     /* Skip any whitespace
      * This is much faster than the isspace() function */
     while (*str == ' '      *str == '\t'      *str == '\n'      *str == '\r'      *str == '\v'      *str == '\f') {
          str++;
          length--;
     }
     ptr = str;
 
     if (*ptr == '-'      *ptr == '+') {
          ptr++;
     }
 
     if (ZEND_IS_DIGIT(*ptr)) {
          /* Handle hex numbers
           * str is used instead of ptr to disallow signs and keep old behavior */
          if (length > 2 && *str == '0' && (str[1] == 'x'      str[1] == 'X')) {
               base = 16;
               ptr += 2;
          }
 
          /* Skip any leading 0s */
          while (*ptr == '0') {
               ptr++;
          }
 
          /* Count the number of digits. If a decimal point/exponent is found,
           * it's a double. Otherwise, if there's a dval or no need to check for
           * a full match, stop when there are too many digits for a long */
          for (type = IS_LONG; !(digits >= MAX_LENGTH_OF_LONG && (dval      allow_errors == 1)); digits++, ptr++) {
check_digits:
               if (ZEND_IS_DIGIT(*ptr)      (base == 16 && ZEND_IS_XDIGIT(*ptr))) {
                    continue;
               } else if (base == 10) {
                    if (*ptr == '.' && dp_or_e < 1) {
                         goto process_double;
                    } else if ((*ptr == 'e'      *ptr == 'E') && dp_or_e < 2) {
                         const char *e = ptr + 1;
 
                         if (*e == '-'      *e == '+') {
                              ptr = e++;
                         }
                         if (ZEND_IS_DIGIT(*e)) {
                              goto process_double;
                         }
                    }
               }
 
               break;
          }
 
          if (base == 10) {
               if (digits >= MAX_LENGTH_OF_LONG) {
                    if (oflow_info != NULL) {
                         *oflow_info = *str == '-' ? -1 : 1;
                    }
                    dp_or_e = -1;
                    goto process_double;
               }
          } else if (!(digits < SIZEOF_LONG * 2      (digits == SIZEOF_LONG * 2 && ptr[-digits] <= '7'))) {
               if (dval) {
                    local_dval = zend_hex_strtod(str, &ptr);
               }
               if (oflow_info != NULL) {
                    *oflow_info = 1;
               }
               type = IS_DOUBLE;
          }
     } else if (*ptr == '.' && ZEND_IS_DIGIT(ptr[1])) {
process_double:
          type = IS_DOUBLE;
 
          /* If there's a dval, do the conversion; else continue checking
           * the digits if we need to check for a full match */
          if (dval) {
               local_dval = zend_strtod(str, &ptr);
          } else if (allow_errors != 1 && dp_or_e != -1) {
               dp_or_e = (*ptr++ == '.') ? 1 : 2;
               goto check_digits;
          }
     } else {
          return 0;
     }
 
     if (ptr != str + length) {
          if (!allow_errors) {
               return 0;
          }
          if (allow_errors == -1) {
               zend_error(E_NOTICE, "A non well formed numeric value encountered");
          }
     }
 
     if (type == IS_LONG) {
          if (digits == MAX_LENGTH_OF_LONG - 1) {
               int cmp = strcmp(&ptr[-digits], long_min_digits);
 
               if (!(cmp < 0      (cmp == 0 && *str == '-'))) {
                    if (dval) {
                         *dval = zend_strtod(str, NULL);
                    }
                    if (oflow_info != NULL) {
                         *oflow_info = *str == '-' ? -1 : 1;
                    }
 
                    return IS_DOUBLE;
               }
          }
 
          if (lval) {
               *lval = strtol(str, NULL, base);
          }
 
          return IS_LONG;
     } else {
          if (dval) {
               *dval = local_dval;
          }
 
          return IS_DOUBLE;
     }
}
Copy after login

There is indeed this code when type == IS_LONG

Intercept this piece of code

&hellip;&hellip;
if (type == IS_LONG) {
     if (digits == MAX_LENGTH_OF_LONG - 1) {
          int cmp = strcmp(&ptr[-digits], long_min_digits);

          if (!(cmp < 0      (cmp == 0 && *str == '-'))) {
               if (dval) {
                    *dval = zend_strtod(str, NULL);
               }
               if (oflow_info != NULL) {
                    *oflow_info = *str == '-' ? -1 : 1;
               }

               return IS_DOUBLE;
          }
     }

     if (lval) {
          *lval = strtol(str, NULL, base);
     }

     return IS_LONG;
}
&hellip;&hellip;
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That’s it strtol here

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