谈谈你对Zend SAPIs(Zend SAPI Internals)的理解

 */static sapi_module_struct cgi_sapi_module = {#if PHP_FASTCGI "cgi-fcgi",      /* name */ "CGI/FastCGI",     /* pretty name */#else "cgi",       /* name */ "CGI",       /* pretty name */#endif  php_cgi_startup,    /* startup */ php_module_shutdown_wrapper, /* shutdown */  NULL,       /* activate */ sapi_cgi_deactivate,   /* deactivate */  sapi_cgibin_ub_write,   /* unbuffered write */ sapi_cgibin_flush,    /* flush */ NULL,       /* get uid */ sapi_cgibin_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 */  STANDARD_SAPI_MODULE_PROPERTIES};

 static int php_cgi_startup(sapi_module_struct *sapi_module){ if (php_module_startup(sapi_module, NULL, 0) == FAILURE) {  return FAILURE; } return SUCCESS;}

 static int sapi_cgi_deactivate(TSRMLS_D){ /* flush only when SAPI was started. The reasons are:  1. SAPI Deactivate is called from two places: module init and request shutdown  2. When the first call occurs and the request is not set up, flush fails on   FastCGI. */ if (SG(sapi_started)) {  sapi_cgibin_flush(SG(server_context)); } return SUCCESS;}

static inline size_t sapi_cgibin_single_write(const char *str, uint str_length TSRMLS_DC){#ifdef PHP_WRITE_STDOUT long ret;#else size_t ret;#endif#if PHP_FASTCGI if (fcgi_is_fastcgi()) {  fcgi_request *request = (fcgi_request*) SG(server_context);  long ret = fcgi_write(request, FCGI_STDOUT, str, str_length);  if (ret <= 0) {   return 0;  }  return ret; }#endif#ifdef PHP_WRITE_STDOUT ret = write(STDOUT_FILENO, str, str_length); if (ret <= 0) return 0; return ret;#else ret = fwrite(str, 1, MIN(str_length, 16384), stdout); return ret;#endif}static int sapi_cgibin_ub_write(const char *str, uint str_length TSRMLS_DC){ const char *ptr = str; uint remaining = str_length; size_t ret; while (remaining > 0) {  ret = sapi_cgibin_single_write(ptr, remaining TSRMLS_CC);  if (!ret) {   php_handle_aborted_connection();   return str_length - remaining;  }  ptr += ret;  remaining -= ret; } return str_length;}

static char *sapi_cgibin_getenv(char *name, size_t name_len TSRMLS_DC){#if PHP_FASTCGI /* when php is started by mod_fastcgi, no regular environment  is provided to PHP. It is always sent to PHP at the start  of a request. So we have to do our own lookup to get env  vars. This could probably be faster somehow. */ if (fcgi_is_fastcgi()) {  fcgi_request *request = (fcgi_request*) SG(server_context);  return fcgi_getenv(request, name, name_len); }#endif /* if cgi, or fastcgi and not found in fcgi env  check the regular environment */ return getenv(name);}

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; if (SG(request_info).no_headers == 1) {  return SAPI_HEADER_SENT_SUCCESSFULLY; } if (cgi_nph || SG(sapi_headers).http_response_code != 200) {  int len;  if (rfc2616_headers && SG(sapi_headers).http_status_line) {   len = snprintf(buf, SAPI_CGI_MAX_HEADER_LENGTH,       "%s\r\n", SG(sapi_headers).http_status_line);   if (len > SAPI_CGI_MAX_HEADER_LENGTH) {    len = SAPI_CGI_MAX_HEADER_LENGTH;   }  } else {   len = sprintf(buf, "Status: %d\r\n", SG(sapi_headers).http_response_code);  }  PHPWRITE_H(buf, len); } h = (sapi_header_struct*)zend_llist_get_first_ex(&sapi_headers->headers, &pos); while (h) {  /* prevent CRLFCRLF */  if (h->header_len) {   PHPWRITE_H(h->header, h->header_len);   PHPWRITE_H("\r\n", 2);  }  h = (sapi_header_struct*)zend_llist_get_next_ex(&sapi_headers->headers, &pos); } PHPWRITE_H("\r\n", 2); return SAPI_HEADER_SENT_SUCCESSFULLY; }

static int sapi_cgi_read_post(char *buffer, uint count_bytes TSRMLS_DC){ uint read_bytes=0, tmp_read_bytes;#if PHP_FASTCGI char *pos = buffer;#endif count_bytes = MIN(count_bytes, (uint) SG(request_info).content_length - SG(read_post_bytes)); while (read_bytes < count_bytes) {#if PHP_FASTCGI  if (fcgi_is_fastcgi()) {   fcgi_request *request = (fcgi_request*) SG(server_context);   tmp_read_bytes = fcgi_read(request, pos, count_bytes - read_bytes);   pos += tmp_read_bytes;  } else {   tmp_read_bytes = read(0, buffer + read_bytes, count_bytes - read_bytes);  }#else  tmp_read_bytes = read(0, buffer + read_bytes, count_bytes - read_bytes);#endif  if (tmp_read_bytes <= 0) {   break;  }  read_bytes += tmp_read_bytes; } return read_bytes;}

static char *sapi_cgi_read_cookies(TSRMLS_D){ return sapi_cgibin_getenv((char *) "HTTP_COOKIE", sizeof("HTTP_COOKIE")-1 TSRMLS_CC);}

static void sapi_cgi_register_variables(zval *track_vars_array TSRMLS_DC){ /* In CGI mode, we consider the environment to be a part of the server  * variables  */ php_import_environment_variables(track_vars_array TSRMLS_CC); /* Build the special-case PHP_SELF variable for the CGI version */ php_register_variable("PHP_SELF", (SG(request_info).request_uri ? SG(request_info).request_uri : ""), track_vars_array TSRMLS_CC);}

static void sapi_cgi_log_message(char *message){#if PHP_FASTCGI if (fcgi_is_fastcgi() && fcgi_logging) {  fcgi_request *request;  TSRMLS_FETCH();  request = (fcgi_request*) SG(server_context);  if (request) {   int len = strlen(message);   char *buf = malloc(len+2);   memcpy(buf, message, len);   memcpy(buf + len, "\n", sizeof("\n"));   fcgi_write(request, FCGI_STDERR, buf, len+1);   free(buf);  } else {   fprintf(stderr, "%s\n", message);  }  /* ignore return code */ } else#endif /* PHP_FASTCGI */ fprintf(stderr, "%s\n", message);}