服务器之家:专注于服务器技术及软件下载分享
分类导航

PHP教程|ASP.NET教程|Java教程|ASP教程|编程技术|正则表达式|C/C++|IOS|C#|Swift|Android|VB|R语言|JavaScript|易语言|vb.net|

服务器之家 - 编程语言 - PHP教程 - 深入php内核之php in array

深入php内核之php in array

2020-11-30 16:19PHP教程网 PHP教程

这篇文章主要介绍了深入php内核之php in array的相关资料,需要的朋友可以参考下

先给大家介绍php in array函数基本知识热热身。

定义和用法

in_array() 函数在数组中搜索给定的值。

语法
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。

 

 说明

如果给定的值 value 存在于数组 array 中则返回 true。如果第三个参数设置为 true,函数只有在元素存在于数组中且数据类型与给定值相同时才返回 true。

如果没有在数组中找到参数,函数返回 false。

注释:如果 value 参数是字符串,且 type 参数设置为 true,则搜索区分大小写。

无意中看到一段代码

?
1
2
3
4
5
6
7
8
9
10
11
<?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;
 }
}

测试了一下

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

竟然需要9s

in_array是这个样子的

 

复制代码 代码如下:

bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )

 

在 haystack 中搜索 needle,如果没有设置 strict 则使用宽松的比较。

needle

待搜索的值。如果 needle 是字符串,则比较是区分大小写的。

haystack

这个数组。

strict

如果第三个参数 strict 的值为 TRUE 则 in_array() 函数还会检查 needle 的类型是否和 haystack 中的相同。

那么我看一下源代码

第一步 在ext/standard/array.c 文件中

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
/* }}} */             
/* {{{ 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);
}               
/* }}} */

顺便看到了array_search,原来和in_array的内部实现基本一致

其中函数的参数 在./zend.h中

#define INTERNAL_FUNCTION_PARAM_PASSTHRU ht, return_value, return_value_ptr, this_ptr, return_value_used TSRMLS_CC

第二步 在ext/standard/array.c 文件中 查看php_search_array原型

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/* 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 */

我们发现 strict  这个值的不同有两种比较方式,看一下两个函数的不同之处

is_identical_function 检查类型是否相同

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
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 不检查类型是否相同,所以需要隐式转换

 

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
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)?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;
   }
  }
 
}  
/* }}} */

延伸 · 阅读

精彩推荐