zend引擎分析.md

#Zend引擎分析 ##基础变量类型(zend_value)

• zend_long

typedef int64_t zend_long;64位有符号整型

• zend_uchar

typedef unsigned char zend_uchar;无符号字符型

• zend_bool

typedef unsigned char zend_bool;bool其实是无符号字符型

• double
• zend_refcounted

typedef struct _zend_refcounted zend_refcounted;
struct _zend_refcounted {
	uint32_t         refcount; /*  32位整型的引用计数 */
	union {
		struct {
			ZEND_ENDIAN_LOHI_3(
				zend_uchar    type,
				zend_uchar    flags,    /* used for strings & objects */
				uint16_t      gc_info)  /* keeps GC root number (or 0) and color */
		} v;
		uint32_t type_info;
	} u;
};

• zend_string

typedef struct _zend_string     zend_string;
struct _zend_string {
	zend_refcounted   gc;
	zend_ulong        h;                /* hash value */
	size_t            len; /* 长度 */
	char              val[1];
};

• zend_array

typedef struct _zend_array      zend_array;
struct _zend_array {
	zend_refcounted   gc;
	HashTable         ht;
};

• HashTable

typedef struct _HashTable {	
	uint32_t          nTableSize; /* 大小 */
	uint32_t          nTableMask;
	uint32_t          nNumUsed;
	uint32_t          nNumOfElements;
	zend_long         nNextFreeElement;
	Bucket           *arData;
	uint32_t         *arHash;
	dtor_func_t       pDestructor;
	uint32_t          nInternalPointer; 
	union {
		struct {
			ZEND_ENDIAN_LOHI_3(
				zend_uchar    flags,
				zend_uchar    nApplyCount,
				uint16_t      reserve)
		} v;
		uint32_t flags;
	} u;
} HashTable;

• Bucket

typedef struct _Bucket {
	zval              val;
	zend_ulong        h;                /* hash value (or numeric index)   */
	zend_string      *key;              /* string key or NULL for numerics */
} Bucket;

• zend_object

typedef struct _zend_object     zend_object;
struct _zend_object {
	zend_refcounted   gc;
	uint32_t          handle; // TODO: may be removed ???
	zend_class_entry *ce;
	const zend_object_handlers *handlers;
	HashTable        *properties;
	HashTable        *guards; /* protects from __get/__set ... recursion */
	zval              properties_table[1];
};

• zend_class_entry

typedef struct _zend_class_entry     zend_class_entry;
struct _zend_class_entry {
	char type;
	zend_string *name;
	struct _zend_class_entry *parent;
	int refcount;
	uint32_t ce_flags;

	int default_properties_count;
	int default_static_members_count;
	zval *default_properties_table;
	zval *default_static_members_table;
	zval *static_members_table;
	HashTable function_table;
	HashTable properties_info;
	HashTable constants_table;

	union _zend_function *constructor;
	union _zend_function *destructor;
	union _zend_function *clone;
	union _zend_function *__get;
	union _zend_function *__set;
	union _zend_function *__unset;
	union _zend_function *__isset;
	union _zend_function *__call;
	union _zend_function *__callstatic;
	union _zend_function *__tostring;
	union _zend_function *__debugInfo;
	union _zend_function *serialize_func;
	union _zend_function *unserialize_func;

	zend_class_iterator_funcs iterator_funcs;

	/* handlers */
	zend_object* (*create_object)(zend_class_entry *class_type TSRMLS_DC);
	zend_object_iterator *(*get_iterator)(zend_class_entry *ce, zval *object, int by_ref TSRMLS_DC);
	int (*interface_gets_implemented)(zend_class_entry *iface, zend_class_entry *class_type TSRMLS_DC); /* a class implements this interface */
	union _zend_function *(*get_static_method)(zend_class_entry *ce, zend_string* method TSRMLS_DC);

	/* serializer callbacks */
	int (*serialize)(zval *object, unsigned char **buffer, size_t *buf_len, zend_serialize_data *data TSRMLS_DC);
	int (*unserialize)(zval *object, zend_class_entry *ce, const unsigned char *buf, size_t buf_len, zend_unserialize_data *data TSRMLS_DC);

	uint32_t num_interfaces;
	uint32_t num_traits;
	zend_class_entry **interfaces;
	
	zend_class_entry **traits;
	zend_trait_alias **trait_aliases;
	zend_trait_precedence **trait_precedences;

	union {
		struct {
			zend_string *filename;
			uint32_t line_start;
			uint32_t line_end;
			zend_string *doc_comment;
		} user;
		struct {
			const struct _zend_function_entry *builtin_functions;
			struct _zend_module_entry *module;
		} internal;
	} info;
};

• zend_resource

typedef struct _zend_resource   zend_resource;
struct _zend_resource {
	zend_refcounted   gc;
	zend_long         handle; // TODO: may be removed ???
	int               type;
	void             *ptr;
};

• zend_reference

typedef struct _zend_reference  zend_reference;
struct _zend_reference {
	zend_refcounted   gc;
	zval              val;
};

• zend_ast_ref

typedef struct _zend_ast_ref    zend_ast_ref;
struct _zend_ast_ref {
	zend_refcounted   gc;
	zend_ast         *ast;
};

• zval

• zend_function

• zend_ast

typedef struct _zend_ast        zend_ast;
struct _zend_ast {
	zend_ast_kind kind; /* Type of the node (ZEND_AST_* enum constant) */
	zend_ast_attr attr; /* Additional attribute, use depending on node type */
	uint32_t lineno;    /* Line number */
	zend_ast *child[1]; /* Array of children (using struct hack) */
};