PHP_GINIT_FUNCTION(test)
{
  /** 初始化全局变量 */
}
//对应的C代码
void zm_globals_ctor_test (zend_test_globals *test_globals TSRMLS_DC)
{
  /** 初始化全局变量 */
}
//在线程退出时，需要将之前自己申请的资源释放时，可以使用 PHP_GSHUTDOWN_FUNCTION来注册析构函数。
PHP_GSHUTDOWN_FUNCTION(test)
{
  /** 清除全局变量 */
}
//对应的C代码
void zm_globals_dtor_test (zend_test_globals *test_globals TSRMLS_DC)
{
  /** 清除全局变量 */
}

int minit_time;
PHP_MINIT_FUNCTION(test)
{
  minit_time = time(NULL);
  return SUCCESS;
}
PHP_MSHUTDOWN_FUNCTION(test)
{
  FILE *fp=fopen("mshutdown.txt","a+");
  fprintf(fp,"%ld\n",time(NULL));
  fclose(fp);
  return SUCCESS;
}
int rinit_time;
PHP_RINIT_FUNCTION(test)
{
  rinit_time = time(NULL);
  return SUCCESS;
}
PHP_RSHUTDOWN_FUNCTION(test)
{
  FILE *fp=fopen("rshutdown.txt","a+");
  fprintf(fp,"%ld\n",time(NULL));
  fclose(fp);
  return SUCCESS;
}
PHP_MINFO_FUNCTION(test)
{
  php_info_print_table_start();
  php_info_print_table_header(, "module info", "enabled");
  php_info_print_table_end();
  /* Remove comments if you have entries in php.ini
  DISPLAY_INI_ENTRIES();
  */
}
PHP_FUNCTION(test)
{
  php_printf("%d",time_of_minit);
  php_printf("%d",time_of_rinit);
  return;
}

typedef struct _sapi_globals_struct {
  void *server_context;
  sapi_request_info request_info;
  sapi_headers_struct sapi_headers;
  int read_post_bytes;
  unsigned char headers_sent;
  struct stat global_stat;
  char *default_mimetype;
  char *default_charset;
  HashTable *rfc1867_uploaded_files;
  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;
  zend_bool callback_run;
} sapi_globals_struct;

static int sapi_cgi_send_headers(sapi_headers_struct *sapi_headers TSRMLS_DC)
{
  char buf[SAPI_CGI_MAX_HEADER_LENGTH];
  sapi_header_struct *h;
  zend_llist_position pos;
  long rfc2616_headers = 0;
  if(SG(request_info).no_headers == 1) {
    return SAPI_HEADER_SENT_SUCCESSFULLY;
  }
  if (SG(sapi_headers).http_response_code != 200) {
    int len;
    len = sprintf(buf, "Status: %d\r\n", SG(sapi_headers).http_response_code);
    PHPWRITE_H(buf, len);
  }
  if (SG(sapi_headers).send_default_content_type) {
    char *hd;
    hd = sapi_get_default_content_type(TSRMLS_C);
    PHPWRITE_H("Content-type:", sizeof("Content-type: ")-1);
    PHPWRITE_H(hd, strlen(hd));
    PHPWRITE_H("\r\n", 2);
    efree(hd);
  }
  h = zend_llist_get_first_ex(&sapi_headers->headers, &pos);
  while (h) {
    PHPWRITE_H(h->header, h->header_len);
    PHPWRITE_H("\r\n", 2);
    h = zend_llist_get_next_ex(&sapi_headers->headers, &pos);
  }
  PHPWRITE_H("\r\n", 2);
  return SAPI_HEADER_SENT_SUCCESSFULLY;
}

struct _zend_execution_globals {
 ...
 HashTable symbol_table;  /* 全局作用域，如果没有进入函数内部，全局＝活动 */
 HashTable *active_symbol_table; /* 活动作用域，当前作用域 */
 ...
}

void describe_zval(zval *foo)
{
  if ( Z_TYPE_P(foo) == IS_NULL )
  {
    php_printf("这个变量的数据类型是： NULL");
  }
  else
  {
    php_printf("这个变量的数据类型不是NULL，这种数据类型对应的数字是： %d", Z_TYPE_P(foo));
  }
}

//开始定义php语言中的函数gettype
PHP_FUNCTION(gettype)
{
  //arg间接指向调用gettype函数时所传递的参数。是一个zval**结构
  //所以我们要对他使用__PP后缀的宏。
  zval **arg;
  //这个if的操作主要是让arg指向参数～
  if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "Z", &arg) == FAILURE) {
    return;
  }
  //调用Z_TYPE_PP宏来获取arg指向zval的类型。
  //然后是一个switch结构，RETVAL_STRING宏代表这gettype函数返回的字符串类型的值
  switch (Z_TYPE_PP(arg)) {
    case IS_NULL:
      RETVAL_STRING("NULL", 1);
      break;
    case IS_BOOL:
      RETVAL_STRING("boolean", 1);
      break;
    case IS_LONG:
      RETVAL_STRING("integer", 1);
      break;
    case IS_DOUBLE:
      RETVAL_STRING("double", 1);
      break;
    case IS_STRING:
      RETVAL_STRING("string", 1);
      break;
    case IS_ARRAY:
      RETVAL_STRING("array", 1);
      break;
    case IS_OBJECT:
      RETVAL_STRING("object", 1);
      break;
    case IS_RESOURCE:
      {
        char *type_name;
        type_name = zend_rsrc_list_get_rsrc_type(Z_LVAL_PP(arg) TSRMLS_CC);
        if (type_name) {
          RETVAL_STRING("resource", 1);
          break;
        }
      }
    default:
      RETVAL_STRING("unknown type", 1);
  }
}

PHP_FUNCTION(rot13)
{
 zval **arg;
 char *ch, cap;
 int i;
  
 if (ZEND_NUM_ARGS( ) != 1 || zend_get_parameters_ex(1, &arg) == FAILURE) {
   WRONG_PARAM_COUNT;
 }
 *return_value = **arg;
 zval_copy_ctor(return_value);
 convert_to_string(return_value);
  
 for(i=0, ch=return_value->value.str.val;
   i<return_value->value.str.len; i++, ch++) {
    cap = *ch & 32;
    *ch &= ~cap;
    *ch = ((*ch>='A') && (*ch<='Z') "htmlcode">

void display_values(zval boolzv, zval *longpzv, zval **doubleppzv)
{
 if (Z_TYPE(boolzv) == IS_BOOL) {
  php_printf("The value of the boolean is : %s\n", Z_BVAL(boolzv) "true" : "false");
 }
 if(Z_TYPE_P(longpzv) == IS_LONG) {
  php_printf("The value of the long is: %ld\n", Z_LVAL_P(longpzv));
 }
 if(Z_TYPE_PP(doubleppzv) == IS_DOUBLE) {
  php_printf("The value of the double is : %f\n", Z_DVAL_PP(doubleppzv));
 }
}


对于字符串类型，因为它含有两个字段char * (Z_STRVAL) 和 int (Z_STRLEN)，因此需要用两个宏来进行取值，因为需要二进制安全的输出这个字符串


void display_string(zval *zstr)
{
 if (Z_TYPE_P(zstr) != IS_STRING) {
  php_printf("The wronng datatype was passed!\n");
  return ;
 }
 PHPWRITE(Z_STRVAL_P(zstr), Z_STRLEN_P(zstr));
}


因为数组在zval中是以HashTable形式存在的，因此使用Z_ARRVAL()进行访问


void display_zval(zval *value)
{
  switch (Z_TYPE_P(value)) {
    case IS_NULL:
      /* 如果是NULL，则不输出任何东西 */
      break;
 
    case IS_BOOL:
      /* 如果是bool类型，并且true，则输出1，否则什么也不干 */
      if (Z_BVAL_P(value)) {
        php_printf("1");
      }
      break;
    case IS_LONG:
      /* 如果是long整型，则输出数字形式 */
      php_printf("%ld", Z_LVAL_P(value));
      break;
    case IS_DOUBLE:
      /* 如果是double型，则输出浮点数 */
      php_printf("%f", Z_DVAL_P(value));
      break;
    case IS_STRING:
      /* 如果是string型，则二进制安全的输出这个字符串 */
      PHPWRITE(Z_STRVAL_P(value), Z_STRLEN_P(value));
      break;
    case IS_RESOURCE:
      /* 如果是资源，则输出Resource #10 格式的东东 */
      php_printf("Resource #%ld", Z_RESVAL_P(value));
      break;
    case IS_ARRAY:
      /* 如果是Array，则输出Array5个字母！ */
      php_printf("Array");
      break;
    case IS_OBJECT:
      php_printf("Object");
      break;
    default:
      /* Should never happen in practice,
       * but it's dangerous to make assumptions
       */
       php_printf("Unknown");
       break;
  }
} 


一些类型转换函数
ZEND_API void convert_to_long(zval *op);

ZEND_API void convert_to_double(zval *op);

ZEND_API void convert_to_null(zval *op);

ZEND_API void convert_to_boolean(zval *op);

ZEND_API void convert_to_array(zval *op);

ZEND_API void convert_to_object(zval *op);

ZEND_API void _convert_to_string(zval *op ZEND_FILE_LINE_DC);
6、常量的实例化
我们可以这样实例化


PHP_MINIT_FUNCTION(consts) //模块初始化时定义常量
{
  REGISTER_LONG_CONSTANT("CONSTS_MEANING_OF_LIFE", 42, CONST_CS | CONST_PERSISTENT);
  REGISTER_DOUBLE_CONSTANT("CONSTS_PI", 3.1415926, CONST_PERSISTENT);
  REGISTER_STRING_CONSTANT("CONSTS_NAME", "leon", CONST_CS|CONST_PERSISTENT);
}
PHP_RINIT_FUNCTION(consts) //每次请求时定义常量
{
  char buffer[40];
  srand((int)time(NULL));
  snprintf(buffer, sizeof(buffer), "%d", rand());
  REGISTER_STRING_CONSTANT("CONSTS_RAND", estrdup(buffer), CONST_CS);
  return SUCCESS;
}


常见的宏
/*注册LONG类型常量*/

#define REGISTER_LONG_CONSTANT(name, lval, flags)  zend_register_long_constant((name), sizeof(name), (lval), (flags), module_number TSRMLS_CC)


 /*注册double类型常量*/

#define REGISTER_DOUBLE_CONSTANT(name, dval, flags)  zend_register_double_constant((name), sizeof(name), (dval), (flags), module_number TSRMLS_CC)


/*注册STRING类型常量*/

#define REGISTER_STRING_CONSTANT(name, str, flags)  zend_register_string_constant((name), sizeof(name), (str), (flags), module_number TSRMLS_CC)


/*注册STRING类型常量*/

#define REGISTER_STRINGL_CONSTANT(name, str, len, flags)  zend_register_stringl_constant((name), sizeof(name), (str), (len), (flags), module_number TSRMLS_CC)
7、全局变量


#php-fpm 生成 POST|GET|COOKIE|SERVER|ENV|REQUEST|FILES全局变量的流程
php_cgi_startup() -> php_module_startup() -> php_startup_auto_globals() -> 保存变量到symbol_table符号表
php_cgi_startup()在 fpm/fpm/fpm_main.c中定义
php_module_startup() 在main/main.c中定义
php_startup_auto_globals() 在main/php_variables.h中定义
zend_hash_update(&EG(symbol_table), "_GET", sizeof("_GET") + 1, &vars, sizeof(zval *), NULL);
/* 读取$_SERVER变量 */
static PHP_FUNCTION(print_server_vars) {
  zval **val;
  if (zend_hash_find(&EG(symbol_table), "_SERVER", sizeof("_SERVER"), (void **)&val) == SUCCESS) {
    RETURN_ZVAL(*val, 1, 0);
  }else{
   RETURN_FALSE;
  }
}
/* 读取$_SERVER[$name] */
ZEND_BEGIN_ARG_INFO(print_server_var_arginfo, 0)
  ZEND_ARG_INFO(0, "name")
ZEND_END_ARG_INFO()
static PHP_FUNCTION(print_server_var) {
  char *name;
  int name_len;
  zval **val;
  HashTable *ht_vars = NULL;
  HashPosition pos;
  zval **ret_val;
  if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|s!", &name, &name_len) == FAILURE) {
    RETURN_NULL();
  }
  if (zend_hash_find(&EG(symbol_table), "_SERVER", sizeof("_SERVER"), (void **)&val) == SUCCESS) {
    ht_vars = Z_ARRVAL_PP(val);
    //此处需传入大于name长度+1的值，因为字符串值后面需要'\0'
    if (zend_hash_find(ht_vars, name, name_len+1, (void **)&ret_val) == SUCCESS) {       RETURN_STRING(Z_STRVAL_PP(ret_val), 0);
    }else{
      RETURN_NULL();
    }
  }else{
    RETURN_NULL();
  }
}


8、包装第三方库
配置(config.m4)


SEARCH_PATH="/usr/local /usr"   #lib搜索的目录
SEARCH_FOR="/include/curl/curl.h" #lib头文件的路径
if test -r $PHP_LIBS/$SEARCH_FOR; then
  LIBS_DIR=$PHP_LIBS
else # search default path list
  AC_MSG_CHECKING([for libs files in default path])
  for i in $SEARCH_PATH ; do
    if test -r $i/$SEARCH_FOR; then
      LIBS_DIR=$i        #搜索到的lib的路径
      AC_MSG_RESULT(found in $i)
    fi
  done
fi
/*验证lib是否存在*/
if test -z "$LIBS_DIR"; then
  AC_MSG_RESULT([not found])
  AC_MSG_ERROR([Please reinstall the libs distribution])
fi
/*编译的时候添加lib的include目录, -I/usr/include*/
PHP_ADD_INCLUDE($LIBS_DIR/include)
LIBNAME=curl      #lib名称 
LIBSYMBOL=curl_version #lib的一个函数，用来PHP_CHECK_LIBRARY验证lib
/*验证lib*/
PHP_CHECK_LIBRARY($LIBNAME,$LIBSYMBOL, 
[
  PHP_ADD_LIBRARY_WITH_PATH($LIBNAME, $LIBS_DIR/$PHP_LIBDIR, LIBS_SHARED_LIBADD) #编译的时候链接lib, -llibcurl
  AC_DEFINE(HAVE_LIBSLIB,1,[ ])
],[
  AC_MSG_ERROR([wrong libs lib version or lib not found])
],[
  -L$LIBS_DIR/$PHP_LIBDIR -lm
]) 
PHP_SUBST(LIBS_SHARED_LIBADD)


9、用于返回的宏
//这些宏都定义在Zend/zend_API.h文件里

#define RETVAL_RESOURCE(l)              ZVAL_RESOURCE(return_value, l)

#define RETVAL_BOOL(b)                  ZVAL_BOOL(return_value, b)

#define RETVAL_NULL()                   ZVAL_NULL(return_value)

#define RETVAL_LONG(l)                  ZVAL_LONG(return_value, l)

#define RETVAL_DOUBLE(d)                ZVAL_DOUBLE(return_value, d)

#define RETVAL_STRING(s, duplicate)         ZVAL_STRING(return_value, s, duplicate)

#define RETVAL_STRINGL(s, l, duplicate)     ZVAL_STRINGL(return_value, s, l, duplicate)

#define RETVAL_EMPTY_STRING()           ZVAL_EMPTY_STRING(return_value)

#define RETVAL_ZVAL(zv, copy, dtor)     ZVAL_ZVAL(return_value, zv, copy, dtor)

#define RETVAL_FALSE                    ZVAL_BOOL(return_value, 0)

#define RETVAL_TRUE                     ZVAL_BOOL(return_value, 1)

#define RETURN_RESOURCE(l)              { RETVAL_RESOURCE(l); return; }

#define RETURN_BOOL(b)                  { RETVAL_BOOL(b); return; }

#define RETURN_NULL()                   { RETVAL_NULL(); return;}

#define RETURN_LONG(l)                  { RETVAL_LONG(l); return; }

#define RETURN_DOUBLE(d)                { RETVAL_DOUBLE(d); return; }

#define RETURN_STRING(s, duplicate)     { RETVAL_STRING(s, duplicate); return; }

#define RETURN_STRINGL(s, l, duplicate) { RETVAL_STRINGL(s, l, duplicate); return; }

#define RETURN_EMPTY_STRING()           { RETVAL_EMPTY_STRING(); return; }

#define RETURN_ZVAL(zv, copy, dtor)     { RETVAL_ZVAL(zv, copy, dtor); return; }

#define RETURN_FALSE                    { RETVAL_FALSE; return; }

#define RETURN_TRUE                     { RETVAL_TRUE; return; }
其实，除了这些标量类型，还有很多php语言中的复合类型我们需要在函数中返回，如数组和对象，我们可以通过RETVAL_ZVAL与RETURN_ZVAL来操作它们
10、hashTable的遍历函数
//基于long key的操作函数

zval *v3;

MAKE_STD_ZVAL(v3);

ZVAL_STRING(v3, "value3", 1);

zend_hash_index_update(names, 0, &v3, sizeof(zval *), NULL);//按数字索引键更新HashTable元素的值

zval **v4;

zend_hash_index_find(names, 1, &v4); //按数字索引获取HashTable元素的值

php_printf("v4 : ");

PHPWRITE(Z_STRVAL_PP(v4), Z_STRLEN_PP(v4));

php_printf("\n");

ulong idx;

idx = zend_hash_index_exists(names, 10);//按数字索引查找HashTable，如果找到返回 1， 反之则返回 0

zend_hash_index_del(names, 2);    //按数字索引删除HashTable元素

//hashTable的遍历函数

zend_hash_internal_pointer_reset(names); //初始化hash指针

zend_hash_internal_pointer_reset_ex(names, &pos);//初始化hash指针，并付值给pos

zend_hash_get_current_data(names, (void**) &val); //获取当前hash存储值,data should be cast to void**, ie: (void**) &data

zend_hash_get_current_data_ex(names, (void**) &val, &pos) == SUCCESS; //获取当前hash存储值

zend_hash_get_current_key(names, &key, &klen, &index, 0) == HASH_KEY_IS_LONG

zend_hash_get_current_key_ex(names, &key, &klen, &index, 0, &pos) == HASH_KEY_IS_LONG; //读取hashtable当前的KEY，返回值会有两种 HASH_KEY_IS_LONG | HASH_KEY_IS_STRING ，分别对应array("value")，array("key"=>"value")两种hashtable

zend_hash_move_forward(names);

zend_hash_move_forward_ex(names, &pos); //hash指针移至下一位

//HashTable长度

php_printf("%*carray(%d) {\n", depth * 2, ' ', zend_hash_num_elements(Z_ARRVAL_P(zv))
一个简单的函数


function hello_array_strings($arr) {
  if (!is_array($arr)) return NULL;
  printf("The array passed contains %d elements ", count($arr));
  foreach($arr as $data) {
    if (is_string($data)) echo "$data ";
  }
}


PHP内核实现


PHP_FUNCTION(hello_array_strings)
{
  zval *arr, **data;
  HashTable *arr_hash;
  HashPosition pointer;
  int array_count;
  if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a", &arr) == FAILURE) {
    RETURN_NULL();
  }
  arr_hash = Z_ARRVAL_P(arr);
  array_count = zend_hash_num_elements(arr_hash);
  php_printf("The array passed contains %d elements ", array_count);
  for(zend_hash_internal_pointer_reset_ex(arr_hash, &pointer); zend_hash_get_current_data_ex(arr_hash, (void**) &data, &pointer) == SUCCESS; zend_hash_move_forward_ex(arr_hash, &pointer)) {
    if (Z_TYPE_PP(data) == IS_STRING) {
      PHPWRITE(Z_STRVAL_PP(data), Z_STRLEN_PP(data));
      php_printf(" ");
    }
  }
  RETURN_TRUE;
}


以上所述就是本文给大家介绍的PHP扩展开发教程，希望大家喜欢。