PHP原理、源码1

//Zend/zend_hash.h
    typedef struct bucket {
        ulong h;                        /* Used for numeric indexing */
        uint nKeyLength;
        void *pData;
        void *pDataPtr;
        struct bucket *pListNext;
        struct bucket *pListLast;
        struct bucket *pNext;
        struct bucket *pLast;
        const char *arKey;
    } Bucket;

    typedef struct _hashtable {
        uint nTableSize;
        uint nTableMask;
        uint nNumOfElements;
        ulong nNextFreeElement;
        Bucket *pInternalPointer;    /* Used for element traversal */
        Bucket *pListHead;
        Bucket *pListTail;
        Bucket **arBuckets;
        dtor_func_t pDestructor;
        zend_bool persistent;
        unsigned char nApplyCount;
        zend_bool bApplyProtection;
    #if ZEND_DEBUG
        int inconsistent;
    #endif
    } HashTable;
    
// Zend/zend.h php的弱类型原理：
typedef union _zvalue_value {
    long lval;                    /* long value */
    double dval;                /* double value */
    struct {
        char *val;
        int len;
    } str;
    HashTable *ht;                /* hash table value */
    zend_object_value obj;
} zvalue_value;

struct _zval_struct {
    /* Variable information */
    zvalue_value value;        /* value */
    zend_uint refcount__gc;
    zend_uchar type;    /* active type */
    zend_uchar is_ref__gc;
};

/* data types */
/* All data types <= IS_BOOL have their constructor/destructors skipped */
#define IS_NULL        0
#define IS_LONG        1
#define IS_DOUBLE    2
#define IS_BOOL        3
#define IS_ARRAY    4
#define IS_OBJECT    5
#define IS_STRING    6
#define IS_RESOURCE    7
#define IS_CONSTANT    8
#define IS_CONSTANT_ARRAY    9
#define IS_CALLABLE    10

//php.ini相关的源码：
//main/php_globals.h
struct _php_core_globals {
zend_bool implicit_flush;

long output_buffering;

zend_bool sql_safe_mode;
zend_bool enable_dl;

char *output_handler;

char *unserialize_callback_func;
long serialize_precision;

long memory_limit;
long max_input_time;

zend_bool track_errors;
zend_bool display_errors;
zend_bool display_startup_errors;
zend_bool log_errors;
long      log_errors_max_len;
zend_bool ignore_repeated_errors;
zend_bool ignore_repeated_source;
zend_bool report_memleaks;
char *error_log;

char *doc_root;
char *user_dir;
char *include_path;
char *open_basedir;
char *extension_dir;
char *php_binary;
char *sys_temp_dir;

char *upload_tmp_dir;
long upload_max_filesize;

char *error_append_string;
char *error_prepend_string;

char *auto_prepend_file;
char *auto_append_file;

arg_separators arg_separator;

char *variables_order;

HashTable rfc1867_protected_variables;

short connection_status;
short ignore_user_abort;

unsigned char header_is_being_sent;

zend_llist tick_functions;

zval *http_globals[6];

zend_bool expose_php;

zend_bool register_argc_argv;
zend_bool auto_globals_jit;

char *docref_root;
char *docref_ext;

zend_bool html_errors;
zend_bool xmlrpc_errors;

long xmlrpc_error_number;

zend_bool activated_auto_globals[8];

zend_bool modules_activated;
zend_bool file_uploads;
zend_bool during_request_startup;
zend_bool allow_url_fopen;
zend_bool enable_post_data_reading;
zend_bool always_populate_raw_post_data;
zend_bool report_zend_debug;

int last_error_type;
char *last_error_message;
char *last_error_file;
int  last_error_lineno;

char *disable_functions;
char *disable_classes;
zend_bool allow_url_include;
zend_bool exit_on_timeout;
#ifdef PHP_WIN32
zend_bool com_initialized;
#endif
long max_input_nesting_level;
long max_input_vars;
zend_bool in_user_include;

char *user_ini_filename;
long user_ini_cache_ttl;

char *request_order;

zend_bool mail_x_header;
char *mail_log;

zend_bool in_error_log;

#ifdef PHP_WIN32
zend_bool windows_show_crt_warning;
#endif
};