Read global variables such as $ _ Get \ $ _ post in PHP Kernel

1. Get global variables such as $ _ Get \ $ _ post \ $ _ Server \ $ _ files \ $ _ cookie in the kernel
Hashtable is the basis for many PHP implementations, such as $ _ Get \ $ _ post and other global variable implementations.
Then, read the global variables in the extension, and of course operate hashtable.
Initialize environment variables in the kernel through php_hash_environment (tsrmls_d) in main/php_variables.c)

When initializing environment variables, PHP registers a read-only environment variable through php_startup_auto_globals of main/php_variables.c, taking into account the reading performance of large variables.

void php_startup_auto_globals(TSRMLS_D){zend_register_auto_global("_GET", sizeof("_GET")-1, NULL TSRMLS_CC);zend_register_auto_global("_POST", sizeof("_POST")-1, NULL TSRMLS_CC);zend_register_auto_global("_COOKIE", sizeof("_COOKIE")-1, NULL TSRMLS_CC);zend_register_auto_global("_SERVER", sizeof("_SERVER")-1, php_auto_globals_create_server TSRMLS_CC);zend_register_auto_global("_ENV", sizeof("_ENV")-1, php_auto_globals_create_env TSRMLS_CC);zend_register_auto_global("_REQUEST", sizeof("_REQUEST")-1, php_auto_globals_create_request TSRMLS_CC);zend_register_auto_global("_FILES", sizeof("_FILES")-1, NULL TSRMLS_CC);}

Read-Only environment variables:

&PG(http_globals)[TRACK_VARS_GET];&PG(http_globals)[TRACK_VARS_POST];&PG(http_globals)[TRACK_VARS_REQUEST];&PG(http_globals)[TRACK_VARS_COOKIE];&PG(http_globals)[TRACK_VARS_ENV];&PG(http_globals)[TRACK_VARS_FILES];

The macros are used to provide the kernel

/*main/php_globals.h*/#define TRACK_VARS_POST0#define TRACK_VARS_GET1#define TRACK_VARS_COOKIE2#define TRACK_VARS_SERVER3#define TRACK_VARS_ENV4#define TRACK_VARS_FILES5#define TRACK_VARS_REQUEST6

If you need to modify the environment variables, you can search for them in the global scope:

(void)zend_hash_find(&EG(symbol_table), ZEND_STRS("_GET"), (void **)&carrier);(void)zend_hash_find(&EG(symbol_table), ZEND_STRS("_POST"), (void **)&carrier);(void)zend_hash_find(&EG(symbol_table), ZEND_STRS("_REQUEST"), (void **)&carrier);(void)zend_hash_find(&EG(symbol_table), ZEND_STRS("_COOKIE"), (void **)&carrier);(void)zend_hash_find(&EG(symbol_table), ZEND_STRS("_FILES"), (void **)&carrier);(void)zend_hash_find(&EG(symbol_table), ZEND_STRS("_ENV"), (void **)&carrier);

2. Now let's look at the case and define a request class, which has the getquery and getpost methods to read $ _ Get and $ _ post.

/** Fw_request.c ** created on: 2012-6-19 * Author: JY */# ifdef have_config_h # include "config. H "# endif # include" php. H "# include" php_ini.h "# include" Main/SAPI. H "# include" Zend/zend_exceptions.h "# include" Zend/zend_alloc.h "# include" php_f1_h "# include" fw_request.h "zend_class_entry * request; /*** class request {public mixed getlang (void); Public mixed getquery (string $ name = NULL);} * // defines the Class Method Parameter type. The kernel automatically verifies the parameter type token (getqueryargs, 1) zend_arg_info (0, name) zend_end_arg_info () token (getpostargs, 1) zend_arg_info (0, name) zend_end_arg_info () zend_method (request, getquery) {zval ** carrier; zval * Key, * ret; If (zend_parse_parameters (zend_num_args () tsrmls_cc, "Z", & Key) = failure) {return_false;} ret = request_query (track_vars_get, z_strval_p (key), z_strlen_p (key) tsrmls_cc ); Return_zval (Ret, 0, null);} zend_method (request, getpost) {zval ** carrier; zval * Key, * ret; If (zend_parse_parameters (zend_num_args () tsrmls_cc, "Z", & Key) = failure) {return_false;} ret = request_query (track_vars_post, z_strval_p (key), z_strlen_p (key) tsrmls_cc); return_zval (Ret, 0, null);} zend_function_entry functions_entry [] = {php_me (request, getquery, getqueryargs, zend_acc_public) php_me (request, Ge Tpost, getpostargs, zend_acc_public)}; sums (fw_request) {zend_class_entry CE; init_class_entry (CE, "request", functions_entry); Request = sums (& ce, null, null tsrmls_cc ); return success ;} /* define request_query to read $ _ Get \ $ _ post \ $ _ Server \ $ _ files \ $ _ cookie \ $ _ request in the kernel. Only the value of $ _ request is */zval * request_query (uint type, char * Name, uint Len tsrmls_dc) {zval ** carrier, ** Ret; zend_bool jit_initialization = (PG (auto_globals_jit )&&! PG (register_globals )&&! PG (Rack); Switch (type) {Case track_vars_post: Case track_vars_get: Case track_vars_files: Case track_vars_cookie: Carrier = & PG (http_globals) [type]; break; Case track_vars_env: if (jit_initialization) {constraint (zend_strl ("_ env") tsrmls_cc);} carrier = & PG (http_globals) [type]; break; Case track_vars_server: If (jit_initialization) {zend_is_auto_global (zend_strl ("_ server") tsrmls_cc) ;} Carrier = & PG (http_globals) [type]; break; Case track_vars_request: If (jit_initialization) {zend_is_auto_global (zend_strl ("_ request") tsrmls_cc) zend_hash_find (& EG (symbol_table), zend_strs ("_ request"), (void **) & carrier); break; default: break;} If (! Carrier |! (* Carrier) {zval * empty; make_std_zval (empty); zval_null (empty); return empty;} If (! Len) {z_addref_p (* carrier); return * carrier;} If (zend_hash_find (z_arrval_pp (carrier), name, Len + 1, (void **) & RET) = failure) {zval * empty; make_std_zval (empty); zval_null (empty); return empty;} z_addref_p (* RET); return * ret ;}

Iii. Web page access PHP Testing

Http: // localhost/test. php? Get = test. This URL is determined by your local environment.

$_GET['test'] = "abc";$obj = new request();echo $obj->getQuery('test')."<br>";echo $obj->getPost('test');

Output result:
Test
Null

This also proves that request_query reads read-only global variables.