PHP8 の基礎となるカーネル ソース コードである SAPI の詳細な分析 (1)

[root@a951700e857d cui-php]# php -v
PHP 8.0.2 (cli) (built: Mar  2 2021 02:40:03) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.2, Copyright (c) Zend Technologies
[root@a951700e857d cui-php]#

//* sapi_module_struct cgi_sapi_module 
static sapi_module_struct cgi_sapi_module = {
	"cgi-fcgi",						/* name */
	"CGI/FastCGI",					/* pretty name */

	php_cgi_startup,				/* startup */
	php_module_shutdown_wrapper,	/* shutdown */

	sapi_cgi_activate,				/* activate */
	sapi_cgi_deactivate,			/* deactivate */

	sapi_cgi_ub_write,				/* unbuffered write */
	sapi_cgi_flush,					/* flush */
	NULL,							/* get uid */
	sapi_cgi_getenv,				/* getenv */

	php_error,						/* error handler */

	NULL,							/* header handler */
	sapi_cgi_send_headers,			/* send headers handler */
	NULL,							/* send header handler */

	sapi_cgi_read_post,				/* read POST data */
	sapi_cgi_read_cookies,			/* read Cookies */

	sapi_cgi_register_variables,	/* register server variables */
	sapi_cgi_log_message,			/* Log message */
	NULL,							/* Get request time */
	NULL,							/* Child terminate */

	STANDARD_SAPI_MODULE_PROPERTIES
};

struct _sapi_module_struct {
	char *name;
	char *pretty_name;

	int (*startup)(struct _sapi_module_struct *sapi_module);
	int (*shutdown)(struct _sapi_module_struct *sapi_module);

	int (*activate)(void);
	int (*deactivate)(void);

	size_t (*ub_write)(const char *str, size_t str_length);
	void (*flush)(void *server_context);
	zend_stat_t *(*get_stat)(void);
	char *(*getenv)(const char *name, size_t name_len);

	void (*sapi_error)(int type, const char *error_msg, ...) ZEND_ATTRIBUTE_FORMAT(printf, 2, 3);

	int (*header_handler)(sapi_header_struct *sapi_header, sapi_header_op_enum op, sapi_headers_struct *sapi_headers);
	int (*send_headers)(sapi_headers_struct *sapi_headers);
	void (*send_header)(sapi_header_struct *sapi_header, void *server_context);

	size_t (*read_post)(char *buffer, size_t count_bytes);
	char *(*read_cookies)(void);

	void (*register_server_variables)(zval *track_vars_array);
	void (*log_message)(const char *message, int syslog_type_int);
	double (*get_request_time)(void);
	void (*terminate_process)(void);

	char *php_ini_path_override;

	void (*default_post_reader)(void);
	void (*treat_data)(int arg, char *str, zval *destArray);
	char *executable_location;

	int php_ini_ignore;
	int php_ini_ignore_cwd; /* don't look for php.ini in the current directory */

	int (*get_fd)(int *fd);

	int (*force_http_10)(void);

	int (*get_target_uid)(uid_t *);
	int (*get_target_gid)(gid_t *);

	unsigned int (*input_filter)(int arg, const char *var, char **val, size_t val_len, size_t *new_val_len);

	void (*ini_defaults)(HashTable *configuration_hash);
	int phpinfo_as_text;

	char *ini_entries;
	const zend_function_entry *additional_functions;
	unsigned int (*input_filter_init)(void);
};

struct _sapi_module_struct {
        char ＊name; // 名字，如cli、 fpm-fcgi等
        char ＊pretty_name; // 更易理解的名字，比如fpm-fcgi对应的为FPM/FastCGI
        int (＊startup)(struct _sapi_module_struct ＊sapi_module);
        //模块启动时调用的函数
        int (＊shutdown)(struct _sapi_module_struct ＊sapi_module);
        //模块结束时调用的函数
        int (＊activate)(void); // 处理request时，激活需要调用的函数指针
        int (＊deactivate)(void); // 处理完request时，使要调用的函数指针无效
        size_t (＊ub_write)(const char ＊str, size_t str_length);
        // 这个函数指针用于输出数据
        void (＊flush)(void ＊server_context); // 刷新缓存的函数指针
        zend_stat_t ＊(＊get_stat)(void); // 判断对执行文件是否有执行权限
        char ＊(＊getenv)(char ＊name, size_t name_len); // 获取环境变量的函数指针
        void (＊sapi_error)(int type, const char ＊error_msg, ...)
            ZEND_ATTRIBUTE_FORMAT(printf, 2, 3); // 错误处理函数指针
        int (＊header_handler)(sapi_header_struct ＊sapi_header,
            sapi_header_op_enum op, sapi_headers_struct ＊sapi_headers);
            //调用header()时被调用的函数指针
        int (＊send_headers)(sapi_headers_struct ＊sapi_headers);
        // 发送全部header的函数指针
        void (＊send_header)(sapi_header_struct ＊sapi_header, void ＊server_context);
        // 发送某一个header的函数指针
        size_t (＊read_post)(char ＊buffer, size_t count_bytes);
        // 获取HTTP POST中数据的函数指针
        char ＊(＊read_cookies)(void);  // 获取cookie中数据的函数指针
        void (＊register_server_variables)(zval ＊track_vars_array);
        // 从$_SERVER中获取变量的函数指针
        void (＊log_message)(char ＊message, int syslog_type_int);
        // 输出错误信息函数指针
        double (＊get_request_time)(void); // 获取请求时间的函数指针
        void (＊terminate_process)(void);  // 调用exit退出时的函数指针
        char ＊php_ini_path_override;  // PHP的ini文件被复写的地址

        void (＊default_post_reader)(void); //负责解析POST数据的函数指针
        void (＊treat_data)(int arg, char ＊str, zval ＊destArray);
        // 对数据进行处理的函数指针
        char ＊executable_location; // 执行的地理位置
        int php_ini_ignore; // 是否不使用任何ini配置文件
        int php_ini_ignore_cwd; // 忽略当前路径的php.ini
        int (＊get_fd)(int ＊fd); // 获取执行文件的fd的函数指针
        int (＊force_http_10)(void); // 强制使用http 1.0版本的函数指针
        int (＊get_target_uid)(uid_t ＊); // 获取执行程序的uid的函数指针
        int (＊get_target_gid)(gid_t ＊); // 获取执行程序的gid的函数指针
        unsigned int (＊input_filter)(int arg, char ＊var, char ＊＊val, size_t val_len,
            size_t ＊new_val_len);
        // 对输入进行过滤的函数指针。比如将输入参数填充到自动全局变量$_GET、$_POST、$_COOKIE中
        void (＊ini_defaults)(HashTable ＊configuration_hash);
        // 默认的ini配置的函数指针，把ini配置信息存在HashTable中
        int phpinfo_as_text; // 是否输出phpinfo信息

        char ＊ini_entries; // 执行时附带的ini配置，可以使用php -d设置
        const zend_function_entry ＊additional_functions;
        // 每个SAPI模块特有的一些函数注册，比如cli的cli_get_process_title
        unsigned int (*input_filter_init)(void);
};

typedef struct _sapi_globals_struct {
	void *server_context;
	sapi_request_info request_info;
	sapi_headers_struct sapi_headers;
	int64_t read_post_bytes;
	unsigned char post_read;
	unsigned char headers_sent;
	zend_stat_t global_stat;
	char *default_mimetype;
	char *default_charset;
	HashTable *rfc1867_uploaded_files;
	zend_long post_max_size;
	int options;
	zend_bool sapi_started;
	double global_request_time;
	HashTable known_post_content_types;
	zval callback_func;
	zend_fcall_info_cache fci_cache;
} sapi_globals_struct;

...
        sapi_startup(&cgi_sapi_module);
	fastcgi = fcgi_is_fastcgi();
	cgi_sapi_module.php_ini_path_override = NULL;

static void sapi_globals_ctor(sapi_globals_struct *sapi_globals)
{
	memset(sapi_globals, 0, sizeof(*sapi_globals));
	zend_hash_init(&sapi_globals->known_post_content_types, 8, NULL, _type_dtor, 1);
	php_setup_sapi_content_types();
}

/* {{{ php_startup_sapi_content_types */
int php_startup_sapi_content_types(void)
{
	sapi_register_default_post_reader(php_default_post_reader);
	sapi_register_treat_data(php_default_treat_data);
	sapi_register_input_filter(php_default_input_filter, NULL);
	return SUCCESS;
}

	sapi_startup(&cgi_sapi_module);
	fastcgi = fcgi_is_fastcgi();
	cgi_sapi_module.php_ini_path_override = NULL;

int fcgi_is_fastcgi(void)
{
	if (!is_initialized) {
		return fcgi_init();
	} else {
		return is_fastcgi;
	}
}

int fcgi_init(void)
{
	if (!is_initialized) {
#ifndef _WIN32
		sa_t sa;
		socklen_t len = sizeof(sa);
#endif
		zend_hash_init(&fcgi_mgmt_vars, 8, NULL, fcgi_free_mgmt_var_cb, 1);
		fcgi_set_mgmt_var("FCGI_MPXS_CONNS", sizeof("FCGI_MPXS_CONNS")-1, "0", sizeof("0")-1);

		is_initialized = 1;
#ifdef _WIN32
# if 0
		/* TODO: Support for TCP sockets */
		WSADATA wsaData;

		if (WSAStartup(MAKEWORD(2,0), &wsaData)) {
			fprintf(stderr, "Error starting Windows Sockets.  Error: %d", WSAGetLastError());
			return 0;
		}
# endif
		if ((GetStdHandle(STD_OUTPUT_HANDLE) == INVALID_HANDLE_VALUE) &&
		    (GetStdHandle(STD_ERROR_HANDLE)  == INVALID_HANDLE_VALUE) &&
		    (GetStdHandle(STD_INPUT_HANDLE)  != INVALID_HANDLE_VALUE)) {
			char *str;
			DWORD pipe_mode = PIPE_READMODE_BYTE | PIPE_WAIT;
			HANDLE pipe = GetStdHandle(STD_INPUT_HANDLE);

			SetNamedPipeHandleState(pipe, &pipe_mode, NULL, NULL);

			str = getenv("_FCGI_SHUTDOWN_EVENT_");
			if (str != NULL) {
				zend_long ev;
				HANDLE shutdown_event;

				ZEND_ATOL(ev, str);
				shutdown_event = (HANDLE) ev;
				if (!CreateThread(NULL, 0, fcgi_shutdown_thread,
				                  shutdown_event, 0, NULL)) {
					return -1;
				}
			}
			str = getenv("_FCGI_MUTEX_");
			if (str != NULL) {
				zend_long mt;
				ZEND_ATOL(mt, str);
				fcgi_accept_mutex = (HANDLE) mt;
			}
			return is_fastcgi = 1;
		} else {
			return is_fastcgi = 0;
		}
#else
		errno = 0;
		if (getpeername(0, (struct sockaddr *)&sa, &len) != 0 && errno == ENOTCONN) {
			fcgi_setup_signals();
			return is_fastcgi = 1;
		} else {
			return is_fastcgi = 0;
		}
#endif
	}
	return is_fastcgi;
}