The call to apr_explode_localtime() in mod_log_config is one of the more

expensive operations in the httpd.  This patch attempts to reduce the
overhead by caching the result for 15 seconds.

Submitted by:	Brian Pane <bpane@pacbell.net>
Reviewed by:	Cliff Woolley, Ryan Bloom, Dean Gaudet, Justin Erenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91083 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 111 insertions, 0 deletions

diff --git a/include/util_time.h b/include/util_time.h
new file mode 100644
index 0000000000..704d0e02d5
--- /dev/null
+++ b/include/util_time.h
@@ -0,0 +1,111 @@
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    nor may "Apache" appear in their name, without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+#ifndef APACHE_UTIL_TIME_H
+#define APACHE_UTIL_TIME_H
+
+#include "apr.h"
+#include "apr_time.h"
+#include "httpd.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @package Apache date/time handling functions
+ */
+
+/* Maximum delta from the current time, in seconds, for a past time
+ * to qualify as "recent" for use in the ap_explode_recent_*() functions:
+ */
+#define AP_TIME_RECENT_THRESHOLD 15
+
+/**
+ * convert a recent time to its human readable components in local timezone
+ * @param tm the exploded time
+ * @param t the time to explode: MUST be within the last
+ *          AP_TIME_RECENT_THRESHOLD seconds
+ * @note This is a faster alternative to apr_explode_localtime that uses
+ *       a cache of pre-exploded time structures.  It is useful for things
+ *       that need to explode the current time multiple times per second,
+ *       like loggers.
+ * @return APR_SUCCESS iff successful
+ * @deffunc apr_status_t ap_explode_recent_localtime(apr_exploded_time_t *tm, apr_time_t t);
+ */
+AP_DECLARE(apr_status_t) ap_explode_recent_localtime(apr_exploded_time_t *tm,
+                                                     apr_time_t t);
+
+/**
+ * convert a recent time to its human readable components in GMT timezone
+ * @param tm the exploded time
+ * @param t the time to explode: MUST be within the last
+ *          AP_TIME_RECENT_THRESHOLD seconds
+ * @note This is a faster alternative to apr_explode_gmt that uses
+ *       a cache of pre-exploded time structures.  It is useful for things
+ *       that need to explode the current time multiple times per second,
+ *       like loggers.
+ * @return APR_SUCCESS iff successful
+ * @deffunc apr_status_t ap_explode_recent_gmt(apr_exploded_time_t *tm, apr_time_t t);
+ */
+AP_DECLARE(apr_status_t) ap_explode_recent_gmt(apr_exploded_time_t *tm,
+                                               apr_time_t t);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* !APACHE_UTIL_TIME_H */