root/ext/interbase/ibase_events.c

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DEFINITIONS

This source file includes following definitions.
  1. _php_ibase_event_free
  2. _php_ibase_free_event
  3. _php_ibase_free_event_rsrc
  4. php_ibase_events_minit
  5. _php_ibase_event_block
  6. PHP_FUNCTION
  7. _php_ibase_callback
  8. PHP_FUNCTION
  9. PHP_FUNCTION

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2008 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 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_01.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.               |
   +----------------------------------------------------------------------+
   | Authors: Ard Biesheuvel <a.k.biesheuvel@its.tudelft.nl>              |
   +----------------------------------------------------------------------+
 */

/* $Id: ibase_events.c,v 1.8.2.1.2.2 2007/12/31 07:20:07 sebastian Exp $ */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"

#if HAVE_IBASE

#include "php_interbase.h"
#include "php_ibase_includes.h"

static int le_event;

static void _php_ibase_event_free(char *event_buf, char *result_buf) /* {{{ */
{
        isc_free(event_buf);
        isc_free(result_buf);
}
/* }}} */

void _php_ibase_free_event(ibase_event *event TSRMLS_DC) /* {{{ */
{
        unsigned short i;

        event->state = DEAD;

        if (event->link != NULL) {
                ibase_event **node;

                if (event->link->handle != NULL &&
                                isc_cancel_events(IB_STATUS, &event->link->handle, &event->event_id)) {
                        _php_ibase_error(TSRMLS_C);
                }

                /* delete this event from the link struct */
                for (node = &event->link->event_head; *node != event; node = &(*node)->event_next);
                *node = event->event_next;
        }

        if (event->callback) {
                zval_dtor(event->callback);
                FREE_ZVAL(event->callback);
                event->callback = NULL;

                _php_ibase_event_free(event->event_buffer,event->result_buffer);

                for (i = 0; i < event->event_count; ++i) {
                        efree(event->events[i]);
                }
                efree(event->events);
        }
}
/* }}} */

static void _php_ibase_free_event_rsrc(zend_rsrc_list_entry *rsrc TSRMLS_DC) /* {{{ */
{
        ibase_event *e = (ibase_event *) rsrc->ptr;

        _php_ibase_free_event(e TSRMLS_CC);

        efree(e);
}
/* }}} */

void php_ibase_events_minit(INIT_FUNC_ARGS) /* {{{ */
{
        le_event = zend_register_list_destructors_ex(_php_ibase_free_event_rsrc, NULL, 
            "interbase event", module_number);
}
/* }}} */

static void _php_ibase_event_block(ibase_db_link *ib_link, unsigned short count, /* {{{ */
        char **events, unsigned short *l, char **event_buf, char **result_buf)
{
        ISC_STATUS dummy_result[20];
        unsigned long dummy_count[15];

        /**
         * Unfortunately, there's no clean and portable way in C to pass arguments to
         * a variadic function if you don't know the number of arguments at compile time.
         * (And even if there were a way, the Interbase API doesn't provide a version of
         * this function that takes a va_list as an argument)
         *
         * In this case, the number of arguments is limited to 18 by the underlying API,
         * so we can work around it.
         */

        *l = (unsigned short) isc_event_block(event_buf, result_buf, count, events[0],
                events[1], events[2], events[3], events[4], events[5], events[6], events[7],
                events[8], events[9], events[10], events[11], events[12], events[13], events[14]);

        /**
         * Currently, this is the only way to correctly initialize an event buffer.
         * This is clearly something that should be fixed, cause the semantics of
         * isc_wait_for_event() indicate that it blocks until an event occurs.
         * If the Firebird people ever fix this, these lines should be removed,
         * otherwise, events will have to fire twice before ibase_wait_event() returns.
         */

        isc_wait_for_event(dummy_result, &ib_link->handle, *l, *event_buf, *result_buf);
        isc_event_counts(dummy_count, *l, *event_buf, *result_buf);
}
/* }}} */

/* {{{ proto string ibase_wait_event([resource link_identifier,] string event [, string event [, ...]])
   Waits for any one of the passed Interbase events to be posted by the database, and returns its name */
PHP_FUNCTION(ibase_wait_event)
{
        zval **args[16];
        ibase_db_link *ib_link;
        char *event_buffer, *result_buffer, *events[15];
        unsigned short i = 0, event_count = 0, buffer_size;
        unsigned long occurred_event[15];

        RESET_ERRMSG;

        /* no more than 15 events */
        if (ZEND_NUM_ARGS() < 1 || ZEND_NUM_ARGS() > 16) {
                WRONG_PARAM_COUNT;
        }

        if (zend_get_parameters_array_ex(ZEND_NUM_ARGS(), args) == FAILURE) {
                RETURN_FALSE;
        }

        if (Z_TYPE_PP(args[0]) == IS_RESOURCE) {

                ZEND_FETCH_RESOURCE2(ib_link, ibase_db_link *, args[0], -1, "InterBase link", le_link, le_plink);
                i = 1;

        } else {

                if (ZEND_NUM_ARGS() > 15) {
                        WRONG_PARAM_COUNT;
                }

                ZEND_FETCH_RESOURCE2(ib_link, ibase_db_link *, NULL, IBG(default_link), "InterBase link", le_link, le_plink);
        }

        for (; i < ZEND_NUM_ARGS(); ++i) {
                convert_to_string_ex(args[i]);
                events[event_count++] = Z_STRVAL_PP(args[i]);
        }

        /* fills the required data structure with information about the events */
        _php_ibase_event_block(ib_link, event_count, events, &buffer_size, &event_buffer, &result_buffer);

        /* now block until an event occurs */
        if (isc_wait_for_event(IB_STATUS, &ib_link->handle, buffer_size, event_buffer, result_buffer)) {
                _php_ibase_error(TSRMLS_C);
                _php_ibase_event_free(event_buffer,result_buffer);
                RETURN_FALSE;
        }

        /* find out which event occurred */
        isc_event_counts(occurred_event, buffer_size, event_buffer, result_buffer);
        for (i = 0; i < event_count; ++i) {
                if (occurred_event[i]) {
                        char *result = estrdup(events[i]);
                        _php_ibase_event_free(event_buffer,result_buffer);
                        RETURN_STRING(result,0);
                }
        }

        /* If we reach this line, isc_wait_for_event() did return, but we don't know
           which event fired. */
        _php_ibase_event_free(event_buffer,result_buffer);
        RETURN_FALSE;
}
/* }}} */

static isc_callback _php_ibase_callback(ibase_event *event, /* {{{ */
        unsigned short buffer_size, char *result_buf)
{
        /* this function is called asynchronously by the Interbase client library. */
        TSRMLS_FETCH_FROM_CTX(event->thread_ctx);

        /**
         * The callback function is called when the event is first registered and when the event
         * is cancelled. I consider this is a bug. By clearing event->callback first and setting
         * it to -1 later, we make sure nothing happens if no event was actually posted.
         */
        switch (event->state) {
                unsigned short i;
                unsigned long occurred_event[15];
                zval event_name, link_id, return_value, *args[2];

                default: /* == DEAD */
                        break;
                case ACTIVE:
                        args[0] = &event_name;
                        args[1] = &link_id;

                        /* copy the updated results into the result buffer */
                        memcpy(event->result_buffer, result_buf, buffer_size);

                        INIT_ZVAL(event_name);
                        INIT_ZVAL(link_id);
                        ZVAL_RESOURCE(&link_id, event->link_res_id);

                        /* find out which event occurred */
                        isc_event_counts(occurred_event, buffer_size, event->event_buffer, event->result_buffer);
                        for (i = 0; i < event->event_count; ++i) {
                                if (occurred_event[i]) {
                                        ZVAL_STRING(&event_name,event->events[i],0);
                                        break;
                                }
                        }

                        /* call the callback provided by the user */
                        if (SUCCESS != call_user_function(EG(function_table), NULL,
                                        event->callback, &return_value, 2, args TSRMLS_CC)) {
                                _php_ibase_module_error("Error calling callback %s" TSRMLS_CC, Z_STRVAL_P(event->callback));
                                break;
                        }

                        if (Z_TYPE(return_value) == IS_BOOL && !Z_BVAL(return_value)) {
                                event->state = DEAD;
                                break;
                        }
                case NEW:
                        /* re-register the event */
                        if (isc_que_events(IB_STATUS, &event->link->handle, &event->event_id, buffer_size,
                                event->event_buffer,(isc_callback)_php_ibase_callback, (void *)event)) {

                                _php_ibase_error(TSRMLS_C);
                        }
                        event->state = ACTIVE;
        }
        return 0;
}
/* }}} */

/* {{{ proto resource ibase_set_event_handler([resource link_identifier,] callback handler, string event [, string event [, ...]])
   Register the callback for handling each of the named events */
PHP_FUNCTION(ibase_set_event_handler)
{
        /**
         * The callback passed to this function should take an event name (string) and a
         * link resource id (int) as arguments. The value returned from the function is
         * used to determine if the event handler should remain set.
         */

        zval **args[17], **cb_arg;
        ibase_db_link *ib_link;
        ibase_event *event;
        unsigned short i = 1, buffer_size;
        int link_res_id;

        RESET_ERRMSG;

        /* no more than 15 events */
        if (ZEND_NUM_ARGS() < 2 || ZEND_NUM_ARGS() > 17) {
                WRONG_PARAM_COUNT;
        }

        if (zend_get_parameters_array_ex(ZEND_NUM_ARGS(), args) == FAILURE) {
                RETURN_FALSE;
        }

        /* get a working link */
        if (Z_TYPE_PP(args[0]) != IS_STRING) {

                cb_arg = args[1];
                i = 2;

                ZEND_FETCH_RESOURCE2(ib_link, ibase_db_link *, args[0], -1,
                        "InterBase link", le_link, le_plink);

                convert_to_long_ex(args[0]);
                link_res_id = Z_LVAL_PP(args[0]);

        } else {

                if (ZEND_NUM_ARGS() > 16) {
                        WRONG_PARAM_COUNT;
                }

                cb_arg = args[0];

                ZEND_FETCH_RESOURCE2(ib_link, ibase_db_link *, NULL, IBG(default_link),
                        "InterBase link", le_link, le_plink);
                link_res_id = IBG(default_link);
        }

        /* get the callback */
        if (!zend_is_callable(*cb_arg, 0, NULL)) {
                _php_ibase_module_error("Callback argument %s is not a callable function"
                        TSRMLS_CC, Z_STRVAL_PP(cb_arg));
                RETURN_FALSE;
        }

        /* allocate the event resource */
        event = (ibase_event *) safe_emalloc(sizeof(ibase_event), 1, 0);
        TSRMLS_SET_CTX(event->thread_ctx);
        event->link_res_id = link_res_id;
        event->link = ib_link;
        event->event_count = 0;
        event->state = NEW;
        event->events = (char **) safe_emalloc(sizeof(char *),ZEND_NUM_ARGS()-i,0);

        ALLOC_ZVAL(event->callback);
        *event->callback = **cb_arg;
        INIT_PZVAL(event->callback);
        zval_copy_ctor(event->callback);

        for (; i < ZEND_NUM_ARGS(); ++i) {
                convert_to_string_ex(args[i]);
                event->events[event->event_count++] = estrdup(Z_STRVAL_PP(args[i]));
        }

        /* fills the required data structure with information about the events */
        _php_ibase_event_block(ib_link, event->event_count, event->events,
                &buffer_size, &event->event_buffer, &event->result_buffer);

        /* now register the events with the Interbase API */
        if (isc_que_events(IB_STATUS, &ib_link->handle, &event->event_id, buffer_size,
                event->event_buffer,(isc_callback)_php_ibase_callback, (void *)event)) {

                _php_ibase_error(TSRMLS_C);
                efree(event);
                RETURN_FALSE;
        }

        event->event_next = ib_link->event_head;
        ib_link->event_head = event;

        ZEND_REGISTER_RESOURCE(return_value, event, le_event);
        zend_list_addref(Z_LVAL_P(return_value));
}
/* }}} */

/* {{{ proto bool ibase_free_event_handler(resource event)
   Frees the event handler set by ibase_set_event_handler() */
PHP_FUNCTION(ibase_free_event_handler)
{
        zval *event_arg;

        RESET_ERRMSG;

        if (SUCCESS == zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "r", &event_arg)) {
                ibase_event *event;

                ZEND_FETCH_RESOURCE(event, ibase_event *, &event_arg, -1, "Interbase event", le_event);

                event->state = DEAD;

                zend_list_delete(Z_LVAL_P(event_arg));
                RETURN_TRUE;
        } else {
                RETURN_FALSE;
        }
}
/* }}} */

#endif /* HAVE_IBASE */

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: sw=4 ts=4 fdm=marker
 * vim<600: sw=4 ts=4
 */

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