Initial revision of PHP/Interbase UDF lib

# This will allow users running the embedded engine
# to call PHP functions from inside their SQL statements

diff --git a/ext/interbase/php_ibase_udf.c b/ext/interbase/php_ibase_udf.c
new file mode 100644 (file)
index 0000000..a05f2c8
--- /dev/null
+++ b/ext/interbase/php_ibase_udf.c
@@ -0,0 +1,127 @@
+/*
+   +----------------------------------------------------------------------+
+   | PHP Version 5                                                        |
+   +----------------------------------------------------------------------+
+   | Copyright (c) 1997-2004 The PHP Group                                |
+   +----------------------------------------------------------------------+
+   | This source file is subject to version 3.0 of the PHP license,       |
+   | that is bundled with this package in the file LICENSE, and is        |
+   | available through the world-wide-web at the following url:           |
+   | http://www.php.net/license/3_0.txt.                                  |
+   | If you did not receive a copy of the PHP license and are unable to   |
+   | obtain it through the world-wide-web, please send a note to          |
+   | license@php.net so we can mail you a copy immediately.               |
+   +----------------------------------------------------------------------+
+   | Author: Ard Biesheuvel <a.k.biesheuvel@ewi.tudelft.nl>               |
+   +----------------------------------------------------------------------+
+ */
+
+/* $Id$ */
+
+/**
+* This UDF library adds the ability to call PHP functions from your SQL
+* statement. You will have to declare a different external function for 
+* each number of parameters you require. Currently, only string arguments
+* are supported as both input arguments as well as the result.
+* 
+* Declare the functions like this:
+* 
+*     DECLARE EXTERNAL FUNCTION CALL_PHP1
+*         CSTRING(xx),CSTRING(xx) RETURNS VARCHAR(4096)
+*         ENTRY_POINT 'udf_call_php1' MODULE_NAME 'php_ibase_udf'
+* 
+*     DECLARE EXTERNAL FUNCTION CALL_PHP2
+*         CSTRING(xx),CSTRING(xx),CSTRING(256) RETURNS VARCHAR(4096)
+*         ENTRY_POINT 'udf_call_php1' MODULE_NAME 'php_ibase_udf'
+* 
+*     ... and so on.
+* 
+* The first input parameter contains the function you want to call. Subsequent
+* arguments are passed to the called function. The lengths of the input strings can
+* have any value >1. The length of the output is restricted to 4k.
+* 
+* The declared functions can be called from SQL like:
+* 
+*     SELECT CALL_PHP1('strtolower',rdb$relation_name) FROM rdb$relations
+* 
+* THIS UDF WILL ONLY WORK IF YOU ARE RUNNING THE EMBEDDED 'CLASSIC' SERVER
+* IN-PROCESS WITH YOUR PHP ENGINE. NETWORK CONNECTIONS TO 'LOCALHOST' ARE 
+* NOT SUPPORTED. 
+* 
+* Compile with:
+*     gcc -shared `php-config --includes` `php-config --ldflags` -o php_ibase_udf.so php_ibase_udf.c
+* 
+* and copy the resulting file to the folder where your database expects to find it.
+*/
+
+#include "zend.h"
+#include "zend_API.h"
+
+#include "stdarg.h"
+
+#ifdef ZTS
+#error This functionality is not available in ZTS mode
+#endif
+
+/* VARCHAR result ignores first short, but must not be 0 */
+static char result[4096] = { 1, 1 };
+
+static void call_php(char *name, int argc, ...)
+{
+       zval callback, args[4], *argp[4], return_value;
+       va_list va;
+       int i;
+
+       INIT_ZVAL(callback);
+       ZVAL_STRING(&callback,name,0);
+
+       /* check if the requested function exists */
+       if (!zend_is_callable(&callback, 0, NULL)) {
+               return;
+       }
+
+       va_start(va, argc);
+
+       /* create the argument array */
+       for (i = 0; i < argc; ++i) {
+               char *arg = va_arg(va, char*);
+               
+               INIT_ZVAL(args[i]);
+               argp[i] = &args[i];
+               ZVAL_STRING(argp[i] = &args[i], arg, 0);
+       }
+       
+       /* now call the function */
+       if (FAILURE == call_user_function(EG(function_table), NULL,
+                       &callback, &return_value, argc, argp)) {
+               return;
+       }
+
+       convert_to_string(&return_value);
+
+       memcpy(&result[2], Z_STRVAL(return_value), Z_STRLEN(return_value)+1);
+}
+
+char *udf_call_php1(char *name, char *arg1)
+{
+       call_php(name, 1, arg1);
+       return result;
+}
+
+char *udf_call_php2(char *name, char *arg1, char *arg2)
+{
+       call_php(name, 2, arg1, arg2);
+       return result;
+}
+
+char *udf_call_php3(char *name, char *arg1, char *arg2, char *arg3)
+{
+       call_php(name, 3, arg1, arg2, arg3);
+       return result;
+}
+
+char *udf_call_php4(char *name, char *arg1, char *arg2, char *arg3, char *arg4)
+{
+       call_php(name, 4, arg1, arg2, arg3, arg4);
+       return result;
+}