In-depth PHP kernel php in array, phparray_PHP tutorial

Deep into the php kernel of php in array, phparray

I will first introduce you to the basic knowledge of php in array function to warm up.

Definition and usage

in_array() function searches an array for a given value.

Grammar
in_array(value,array,type)

参数	描述
value	必需。规定要在数组搜索的值。
array	必需。规定要搜索的数组。
type	可选。如果设置该参数为 true，则检查搜索的数据与数组的值的类型是否相同。

Description

Returns true if the given value value exists in the array array. If the third parameter is set to true, the function returns true only if the element exists in the array and has the same data type as the given value.

If the parameter is not found in the array, the function returns false.

Note: If the value parameter is a string and the type parameter is set to true, the search is case-sensitive.

I accidentally saw a piece of code

<&#63;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;
 } 
}

Tested it

[root@dev tmp]# time php b.php
real 0m9.517s
user 0m4.486s
sys 0m0.015s

It actually takes 9s

in_array looks like this

Copy code The code is as follows:
bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )

Search for needle in haystack, using 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, the in_array() function will also check whether the type of needle is the same as that 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); 
}                
/* }}} */ 

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

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 */

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 checks whether 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;
}  
/* }}} */

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;
}  
/* }}} */
==》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)&#63;1:(Z_LVAL_P(op1)<Z_LVAL_P(op2)&#63;-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) &#63; -1 : 0);
   return SUCCESS;
   case TYPE_PAIR(IS_BOOL, IS_NULL):
   ZVAL_LONG(result, Z_LVAL_P(op1) &#63; 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) &#63; -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) &#63; 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;
   }
  } 
 }  
}   
/* }}} */

http://www.bkjia.com/PHPjc/1069341.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/1069341.htmlTechArticleDeep into the php kernel of php in array, phparray I will first introduce you to the basic knowledge of php in array function to warm up. Definition and Usage The in_array() function searches an array for a given value. Grammar in_...