/* *********************
   * Cookie Management *
   ********************* */
 
#define COOKIE_SET_COOKIE "Set-Cookie: "
#define COOKIE_EXPIRES	"; expires="
#define COOKIE_PATH	"; path="
#define COOKIE_DOMAIN	"; domain="
#define COOKIE_SECURE	"; secure"
#define COOKIE_HTTPONLY	"; HttpOnly"
 
static void php_session_send_cookie(TSRMLS_D) /* {{{ */
{
	smart_str ncookie = {0};
	char *date_fmt = NULL;
	char *e_session_name, *e_id;
 
	if (SG(headers_sent)) {
		char *output_start_filename = php_get_output_start_filename(TSRMLS_C);
		int output_start_lineno = php_get_output_start_lineno(TSRMLS_C);
 
		if (output_start_filename) {
			php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot send session cookie - headers already sent by (output started at %s:%d)", output_start_filename, output_start_lineno);
		} else {
			php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot send session cookie - headers already sent");
		}
		return;
	}
 
	/* URL encode session_name and id because they might be user supplied */
	e_session_name = php_url_encode(PS(session_name), strlen(PS(session_name)), NULL);
	e_id = php_url_encode(PS(id), strlen(PS(id)), NULL);
 
	smart_str_appends(&ncookie, COOKIE_SET_COOKIE);
	smart_str_appends(&ncookie, e_session_name);
	smart_str_appendc(&ncookie, '=');
	smart_str_appends(&ncookie, e_id);
 
	efree(e_session_name);
	efree(e_id);
 
	if (PS(cookie_lifetime) > 0) {
		struct timeval tv;
		time_t t;
 
		gettimeofday(&tv, NULL);
		t = tv.tv_sec + PS(cookie_lifetime);
 
		if (t > 0) {
			date_fmt = php_format_date("D, d-M-Y H:i:s T", sizeof("D, d-M-Y H:i:s T")-1, t, 0 TSRMLS_CC);
			smart_str_appends(&ncookie, COOKIE_EXPIRES);
			smart_str_appends(&ncookie, date_fmt);
			efree(date_fmt);
		}
	}
 
	if (PS(cookie_path)[0]) {
		smart_str_appends(&ncookie, COOKIE_PATH);
		smart_str_appends(&ncookie, PS(cookie_path));
	}
 
	if (PS(cookie_domain)[0]) {
		smart_str_appends(&ncookie, COOKIE_DOMAIN);
		smart_str_appends(&ncookie, PS(cookie_domain));
	}
 
	if (PS(cookie_secure)) {
		smart_str_appends(&ncookie, COOKIE_SECURE);
	}
 
	if (PS(cookie_httponly)) {
		smart_str_appends(&ncookie, COOKIE_HTTPONLY);
	}
 
	smart_str_0(&ncookie);
 
	/*	'replace' must be 0 here, else a previous Set-Cookie
		header, probably sent with setcookie() will be replaced! */
	sapi_add_header_ex(ncookie.c, ncookie.len, 0, 0 TSRMLS_CC);
}
/* }}} */

bool setcookie ( string $name [, string $value [, int $expire = 0 [, string $path [, string $domain [, bool $secure = false [, bool $httponly = false ]]]]]] )

typedef struct {
	char *name;	
	void (*func)(TSRMLS_D);
} php_session_cache_limiter_t;

static php_session_cache_limiter_t php_session_cache_limiters[] = {
	CACHE_LIMITER_ENTRY(public)
	CACHE_LIMITER_ENTRY(private)
	CACHE_LIMITER_ENTRY(private_no_expire)
	CACHE_LIMITER_ENTRY(nocache)
	{0}
};

	for (lim = php_session_cache_limiters; lim->name; lim++) {
		if (!strcasecmp(lim->name, PS(cache_limiter))) {
			lim->func(TSRMLS_C);
			return 0;
		}
	}

#define MAX_SERIALIZERS 10
#define PREDEFINED_SERIALIZERS 2
 
static ps_serializer ps_serializers[MAX_SERIALIZERS + 1] = {
	PS_SERIALIZER_ENTRY(php),
	PS_SERIALIZER_ENTRY(php_binary)
};

#define PS_SERIALIZER_ENCODE_ARGS char **newstr, int *newlen TSRMLS_DC
#define PS_SERIALIZER_DECODE_ARGS const char *val, int vallen TSRMLS_DC
 
typedef struct ps_serializer_struct {
	const char *name;
	int (*encode)(PS_SERIALIZER_ENCODE_ARGS);
	int (*decode)(PS_SERIALIZER_DECODE_ARGS);
} ps_serializer;

typedef struct _php_ps_globals {
	char *save_path;	//	保存路径 
	char *session_name;	//	session名称 默认为PHPSESSID 这个在cookie中会看到
	char *id;		//	session ID
	char *extern_referer_chk;	//	请求头中的"Referer"字段不包含此处指定的字符串则会话ID将被视为无效
	char *entropy_file;	// 指定这里建立 session id
	char *cache_limiter;	// 可以设为{nocache,private,public},以决定 HTTP 的缓存问题
	long entropy_length;	//	 从文件中读取多少字节 
	long cookie_lifetime;	//	为按秒记的cookie的保存时间
	char *cookie_path;	//	cookie的有效路径
	char *cookie_domain;	//	cookie的有效域 
	zend_bool  cookie_secure;	//	是否仅仅通过安全连接(https)发送cookie。
	zend_bool  cookie_httponly;	//是否在cookie中添加httpOnly标志(仅允许HTTP协议访问)
	ps_module *mod;	//	session的处理方式
	void *mod_data;
	php_session_status session_status;	//	session的状态
	long gc_probability;	//	在每次 session 初始化的时候开始的可能性。 
	long gc_divisor;	// 收集概率计算公式：gc_probability/gc_divisor
	long gc_maxlifetime;	// 在这里数字所指的秒数后，保存的数据将被视为´碎片(garbage)´并由gc 进程清理掉。 
	int module_number;	//	存储方式编号
	long cache_expire;	//	过期时间，单位为分钟 
	union {
		zval *names[6];
		struct {
			zval *ps_open;
			zval *ps_close;
			zval *ps_read;
			zval *ps_write;
			zval *ps_destroy;
			zval *ps_gc;
		} name;
	} mod_user_names;	//	用户自定义函数 你懂的
	zend_bool bug_compat; /* Whether to behave like PHP 4.2 and earlier */
	zend_bool bug_compat_warn; /* Whether to warn about it */
	const struct ps_serializer_struct *serializer;	//	序列化处理函数
	zval *http_session_vars;	//	存放session变量
	zend_bool auto_start;	//	是否自动开始 默认为0
	zend_bool use_cookies;	//	是否使用cookies 
	zend_bool use_only_cookies;	//	是否仅仅使用cookie在客户端保存会话ID
	zend_bool use_trans_sid;	/* contains the INI value of whether to use trans-sid */
	zend_bool apply_trans_sid;	/* whether or not to enable trans-sid for the current request */
 
	long hash_func;	//	生成SID的散列算法。SHA-1的安全性更高一些
#if defined(HAVE_HASH_EXT) && !defined(COMPILE_DL_HASH)
	php_hash_ops *hash_ops;
#endif
	long hash_bits_per_character;	//指定在SID字符串中的每个字符内保存多少bit，
	int send_cookie;	//	是否发送cookie头
	int define_sid;		//	session常量id
	zend_bool invalid_session_id;	/* allows the driver to report about an invalid session id and request id regeneration */
} php_ps_globals;

 
static PHP_RINIT_FUNCTION(session) /* {{{ */
{
	php_rinit_session_globals(TSRMLS_C);
 
	if (PS(mod) == NULL) {
		char *value;
 
		value = zend_ini_string("session.save_handler", sizeof("session.save_handler"), 0);
		if (value) {
			PS(mod) = _php_find_ps_module(value TSRMLS_CC);
		}
	}
 
	if (PS(serializer) == NULL) {
		char *value;
 
		value = zend_ini_string("session.serialize_handler", sizeof("session.serialize_handler"), 0);
		if (value) {
			PS(serializer) = _php_find_ps_serializer(value TSRMLS_CC);
		}
	}
 
	if (PS(mod) == NULL || PS(serializer) == NULL) {
		/* current status is unusable */
		PS(session_status) = php_session_disabled;
		return SUCCESS;
	}
 
	if (PS(auto_start)) {
		php_session_start(TSRMLS_C);
	}
 
	return SUCCESS;
}
/* }}} */

/* Dispatched by RINIT and by php_session_destroy */
static inline void php_rinit_session_globals(TSRMLS_D) /* {{{ */
{
	PS(id) = NULL;
	PS(session_status) = php_session_none;
	PS(mod_data) = NULL;
	/* Do NOT init PS(mod_user_names) here! */
	PS(http_session_vars) = NULL;
}
/* }}} */

	if (PS(mod_data) && PS(gc_probability) > 0) {
		int nrdels = -1;
 
		nrand = (int) ((float) PS(gc_divisor) * php_combined_lcg(TSRMLS_C));
		if (nrand < PS(gc_probability)) {
			PS(mod)->s_gc(&PS(mod_data), PS(gc_maxlifetime), &nrdels TSRMLS_CC);
#ifdef SESSION_DEBUG
			if (nrdels != -1) {
				php_error_docref(NULL TSRMLS_CC, E_NOTICE, "purged %d expired session objects", nrdels);
			}
#endif
		}
	}

#define PS_OPEN_ARGS void **mod_data, const char *save_path, const char *session_name TSRMLS_DC
#define PS_CLOSE_ARGS void **mod_data TSRMLS_DC
#define PS_READ_ARGS void **mod_data, const char *key, char **val, int *vallen TSRMLS_DC
#define PS_WRITE_ARGS void **mod_data, const char *key, const char *val, const int vallen TSRMLS_DC
#define PS_DESTROY_ARGS void **mod_data, const char *key TSRMLS_DC
#define PS_GC_ARGS void **mod_data, int maxlifetime, int *nrdels TSRMLS_DC
#define PS_CREATE_SID_ARGS void **mod_data, int *newlen TSRMLS_DC
 
/* default create id function */
PHPAPI char *php_session_create_id(PS_CREATE_SID_ARGS);
 
typedef struct ps_module_struct {
	const char *s_name;	// session存储方式的名字 如默认的files
	int (*s_open)(PS_OPEN_ARGS);
	int (*s_close)(PS_CLOSE_ARGS);
	int (*s_read)(PS_READ_ARGS);
	int (*s_write)(PS_WRITE_ARGS);
	int (*s_destroy)(PS_DESTROY_ARGS);
	int (*s_gc)(PS_GC_ARGS);
	char *(*s_create_sid)(PS_CREATE_SID_ARGS);
} ps_module;

#define PS_OPEN_FUNC(x) 	int ps_open_##x(PS_OPEN_ARGS)
#define PS_CLOSE_FUNC(x) 	int ps_close_##x(PS_CLOSE_ARGS)
#define PS_READ_FUNC(x) 	int ps_read_##x(PS_READ_ARGS)
#define PS_WRITE_FUNC(x) 	int ps_write_##x(PS_WRITE_ARGS)
#define PS_DESTROY_FUNC(x) 	int ps_delete_##x(PS_DESTROY_ARGS)
#define PS_GC_FUNC(x) 		int ps_gc_##x(PS_GC_ARGS)
#define PS_CREATE_SID_FUNC(x)	char *ps_create_sid_##x(PS_CREATE_SID_ARGS)

#define MAX_MODULES 10
#define PREDEFINED_MODULES 2
 
static ps_module *ps_modules[MAX_MODULES + 1] = {
	ps_files_ptr,
	ps_user_ptr
};
 
PHPAPI int php_session_register_module(ps_module *ptr) /* {{{ */
{
	int ret = -1;
	int i;
 
	for (i = 0; i < MAX_MODULES; i++) {
		if (!ps_modules[i]) {
			ps_modules[i] = ptr;
			ret = 0;
			break;
		}
	}
	return ret;
}
/* }}} */