/src/httpd/server/util_time.c

Source
/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "util_time.h"
#include "apr_env.h"



/* Number of characters needed to format the microsecond part of a timestamp.
 * Microseconds have 6 digits plus one separator character makes 7.
 *   */
#define AP_CTIME_USEC_LENGTH      7

/* Number of characters needed to format the millisecond part of a timestamp.
 * Milliseconds have 3 digits plus one separator character makes 4.
 *   */
#define AP_CTIME_MSEC_LENGTH      4

/* Length of ISO 8601 date/time (including trailing '\0') */
#define AP_CTIME_COMPACT_LEN      20

/* Length of timezone offset from GMT ([+-]hhmm) plus leading space */
#define AP_CTIME_GMTOFF_LEN       6

/* Cache for exploded values of recent timestamps
 */

struct exploded_time_cache_element {
    apr_int64_t t;
    apr_time_exp_t xt;
    apr_int64_t t_validate; /* please see comments in cached_explode() */
};

/* the "+ 1" is for the current second: */
#define TIME_CACHE_SIZE (AP_TIME_RECENT_THRESHOLD + 1)

/* Note that AP_TIME_RECENT_THRESHOLD is defined to
 * be a power of two minus one in util_time.h, so that
 * we can replace a modulo operation with a bitwise AND
 * when hashing items into a cache of size
 * AP_TIME_RECENT_THRESHOLD+1
 */
#define TIME_CACHE_MASK (AP_TIME_RECENT_THRESHOLD)

static struct exploded_time_cache_element exploded_cache_localtime[TIME_CACHE_SIZE];
static struct exploded_time_cache_element exploded_cache_gmt[TIME_CACHE_SIZE];


static apr_status_t cached_explode(apr_time_exp_t *xt, apr_time_t t,
                                   struct exploded_time_cache_element *cache,
                                   int use_gmt)
{
    apr_int64_t seconds = apr_time_sec(t);
    struct exploded_time_cache_element *cache_element =
        &(cache[seconds & TIME_CACHE_MASK]);
    struct exploded_time_cache_element cache_element_snapshot;

    /* The cache is implemented as a ring buffer.  Each second,
     * it uses a different element in the buffer.  The timestamp
     * in the element indicates whether the element contains the
     * exploded time for the current second (vs the time
     * 'now - AP_TIME_RECENT_THRESHOLD' seconds ago).  If the
     * cached value is for the current time, we use it.  Otherwise,
     * we compute the apr_time_exp_t and store it in this
     * cache element. Note that the timestamp in the cache
     * element is updated only after the exploded time.  Thus
     * if two threads hit this cache element simultaneously
     * at the start of a new second, they'll both explode the
     * time and store it.  I.e., the writers will collide, but
     * they'll be writing the same value.
     */
    if (cache_element->t >= seconds) {
        /* There is an intentional race condition in this design:
         * in a multithreaded app, one thread might be reading
         * from this cache_element to resolve a timestamp from
         * TIME_CACHE_SIZE seconds ago at the same time that
         * another thread is copying the exploded form of the
         * current time into the same cache_element.  (I.e., the
         * first thread might hit this element of the ring buffer
         * just as the element is being recycled.)  This can
         * also happen at the start of a new second, if a
         * reader accesses the cache_element after a writer
         * has updated cache_element.t but before the writer
         * has finished updating the whole cache_element.
         *
         * Rather than trying to prevent this race condition
         * with locks, we allow it to happen and then detect
         * and correct it.  The detection works like this:
         *   Step 1: Take a "snapshot" of the cache element by
         *           copying it into a temporary buffer.
         *   Step 2: Check whether the snapshot contains consistent
         *           data: the timestamps at the start and end of
         *           the cache_element should both match the 'seconds'
         *           value that we computed from the input time.
         *           If these three don't match, then the snapshot
         *           shows the cache_element in the middle of an
         *           update, and its contents are invalid.
         *   Step 3: If the snapshot is valid, use it.  Otherwise,
         *           just give up on the cache and explode the
         *           input time.
         */
        memcpy(&cache_element_snapshot, cache_element,
               sizeof(struct exploded_time_cache_element));
        if ((seconds != cache_element_snapshot.t) ||
            (seconds != cache_element_snapshot.t_validate)) {
            /* Invalid snapshot */
            if (use_gmt) {
                return apr_time_exp_gmt(xt, t);
            }
            else {
                return apr_time_exp_lt(xt, t);
            }
        }
        else {
            /* Valid snapshot */
            memcpy(xt, &(cache_element_snapshot.xt),
                   sizeof(apr_time_exp_t));
        }
    }
    else {
        apr_status_t r;
        if (use_gmt) {
            r = apr_time_exp_gmt(xt, t);
        }
        else {
            r = apr_time_exp_lt(xt, t);
        }
        if (r != APR_SUCCESS) {
            return r;
        }
        cache_element->t = seconds;
        memcpy(&(cache_element->xt), xt, sizeof(apr_time_exp_t));
        cache_element->t_validate = seconds;
    }
    xt->tm_usec = (int)apr_time_usec(t);
    return APR_SUCCESS;
}


AP_DECLARE(apr_status_t) ap_explode_recent_localtime(apr_time_exp_t * tm,
                                                     apr_time_t t)
{
    return cached_explode(tm, t, exploded_cache_localtime, 0);
}

AP_DECLARE(apr_status_t) ap_explode_recent_gmt(apr_time_exp_t * tm,
                                               apr_time_t t)
{
    return cached_explode(tm, t, exploded_cache_gmt, 1);
}

AP_DECLARE(apr_status_t) ap_recent_ctime(char *date_str, apr_time_t t)
{
    int len = APR_CTIME_LEN;
    return ap_recent_ctime_ex(date_str, t, AP_CTIME_OPTION_NONE, &len);
}

AP_DECLARE(apr_status_t) ap_recent_ctime_ex(char *date_str, apr_time_t t,
                                            int option, int *len)
{
    /* ### This code is a clone of apr_ctime(), except that it
     * uses ap_explode_recent_localtime() instead of apr_time_exp_lt().
     */
    apr_time_exp_t xt;
    const char *s;
    int real_year;
    int needed;


    /* Calculate the needed buffer length */
    if (option & AP_CTIME_OPTION_COMPACT)
        needed = AP_CTIME_COMPACT_LEN;
    else
        needed = APR_CTIME_LEN;

    if (option & AP_CTIME_OPTION_USEC) {
        needed += AP_CTIME_USEC_LENGTH;
    }
    else if (option & AP_CTIME_OPTION_MSEC) {
        needed += AP_CTIME_MSEC_LENGTH;
    }

    if (option & AP_CTIME_OPTION_GMTOFF) {
        needed += AP_CTIME_GMTOFF_LEN;
    }

    /* Check the provided buffer length (note: above AP_CTIME_COMPACT_LEN
     * and APR_CTIME_LEN include the trailing '\0'; so does 'needed' then).
     */
    if (len && *len >= needed) {
        *len = needed;
    }
    else {
        if (len != NULL) {
            *len = 0;
        }
        return APR_ENOMEM;
    }

    /* example without options: "Wed Jun 30 21:49:08 1993" */
    /* example for compact format: "1993-06-30 21:49:08" */
    /* example for compact+usec+gmtoff format:
     *     "1993-06-30 22:49:08.123456 +0100"
     */

    ap_explode_recent_localtime(&xt, t);
    real_year = 1900 + xt.tm_year;
    if (option & AP_CTIME_OPTION_COMPACT) {
        int real_month = xt.tm_mon + 1;
        *date_str++ = real_year / 1000 + '0';
        *date_str++ = real_year % 1000 / 100 + '0';
        *date_str++ = real_year % 100 / 10 + '0';
        *date_str++ = real_year % 10 + '0';
        *date_str++ = '-';
        *date_str++ = real_month / 10 + '0';
        *date_str++ = real_month % 10 + '0';
        *date_str++ = '-';
    }
    else {
        s = &apr_day_snames[xt.tm_wday][0];
        *date_str++ = *s++;
        *date_str++ = *s++;
        *date_str++ = *s++;
        *date_str++ = ' ';
        s = &apr_month_snames[xt.tm_mon][0];
        *date_str++ = *s++;
        *date_str++ = *s++;
        *date_str++ = *s++;
        *date_str++ = ' ';
    }
    *date_str++ = xt.tm_mday / 10 + '0';
    *date_str++ = xt.tm_mday % 10 + '0';
    *date_str++ = ' ';
    *date_str++ = xt.tm_hour / 10 + '0';
    *date_str++ = xt.tm_hour % 10 + '0';
    *date_str++ = ':';
    *date_str++ = xt.tm_min / 10 + '0';
    *date_str++ = xt.tm_min % 10 + '0';
    *date_str++ = ':';
    *date_str++ = xt.tm_sec / 10 + '0';
    *date_str++ = xt.tm_sec % 10 + '0';
    if (option & (AP_CTIME_OPTION_USEC|AP_CTIME_OPTION_MSEC)) {
        int div;
        int usec = (int)xt.tm_usec;
        *date_str++ = '.';
        div = 100000;
        if (!(option & AP_CTIME_OPTION_USEC)) {
            usec = usec / 1000;
            div = 100;
        }
        for (; div>0; div=div/10) {
            *date_str++ = usec / div + '0';
            usec = usec % div;
        }
    }
    if (!(option & AP_CTIME_OPTION_COMPACT)) {
        *date_str++ = ' ';
        *date_str++ = real_year / 1000 + '0';
        *date_str++ = real_year % 1000 / 100 + '0';
        *date_str++ = real_year % 100 / 10 + '0';
        *date_str++ = real_year % 10 + '0';
    }
    if (option & AP_CTIME_OPTION_GMTOFF) {
        int off = xt.tm_gmtoff, off_hh, off_mm;
        char sign = '+';
        if (off < 0) {
            off = -off;
            sign = '-';
        }
        off_hh = off / 3600;
        off_mm = off % 3600 / 60;
        *date_str++ = ' ';
        *date_str++ = sign;
        *date_str++ = off_hh / 10 + '0';
        *date_str++ = off_hh % 10 + '0';
        *date_str++ = off_mm / 10 + '0';
        *date_str++ = off_mm % 10 + '0';
    }
    *date_str = 0;

    return APR_SUCCESS;
}

AP_DECLARE(apr_status_t) ap_recent_rfc822_date(char *date_str, apr_time_t t)
{
    /* ### This code is a clone of apr_rfc822_date(), except that it
     * uses ap_explode_recent_gmt() instead of apr_time_exp_gmt().
     */
    apr_time_exp_t xt;
    const char *s;
    int real_year;

    ap_explode_recent_gmt(&xt, t);

    /* example: "Sat, 08 Jan 2000 18:31:41 GMT" */
    /*           12345678901234567890123456789  */

    s = &apr_day_snames[xt.tm_wday][0];
    *date_str++ = *s++;
    *date_str++ = *s++;
    *date_str++ = *s++;
    *date_str++ = ',';
    *date_str++ = ' ';
    *date_str++ = xt.tm_mday / 10 + '0';
    *date_str++ = xt.tm_mday % 10 + '0';
    *date_str++ = ' ';
    s = &apr_month_snames[xt.tm_mon][0];
    *date_str++ = *s++;
    *date_str++ = *s++;
    *date_str++ = *s++;
    *date_str++ = ' ';
    real_year = 1900 + xt.tm_year;
    /* This routine isn't y10k ready. */
    *date_str++ = real_year / 1000 + '0';
    *date_str++ = real_year % 1000 / 100 + '0';
    *date_str++ = real_year % 100 / 10 + '0';
    *date_str++ = real_year % 10 + '0';
    *date_str++ = ' ';
    *date_str++ = xt.tm_hour / 10 + '0';
    *date_str++ = xt.tm_hour % 10 + '0';
    *date_str++ = ':';
    *date_str++ = xt.tm_min / 10 + '0';
    *date_str++ = xt.tm_min % 10 + '0';
    *date_str++ = ':';
    *date_str++ = xt.tm_sec / 10 + '0';
    *date_str++ = xt.tm_sec % 10 + '0';
    *date_str++ = ' ';
    *date_str++ = 'G';
    *date_str++ = 'M';
    *date_str++ = 'T';
    *date_str++ = 0;
    return APR_SUCCESS;
}

AP_DECLARE(void) ap_force_set_tz(apr_pool_t *p) {
    /* If the TZ variable is unset, many operating systems,
     * such as Linux, will at runtime read from /etc/localtime
     * and call fstat on it.
     *
     * By forcing the time zone to UTC if it is unset, we gain
     * about 2% in raw requests/second (since we format log files
     * in the local time, if present)
     *
     * For more info, see:
     *   <http://www.gnu.org/s/hello/manual/libc/TZ-Variable.html>
     */
    char *v = NULL;

    if (apr_env_get(&v, "TZ", p) != APR_SUCCESS) {
        apr_env_set("TZ", "UTC+0", p);
    }
}

Coverage Report

Created: 2026-02-26 06:18

Line	Count	Source
1		/* Licensed to the Apache Software Foundation (ASF) under one or more
2		* contributor license agreements. See the NOTICE file distributed with
3		* this work for additional information regarding copyright ownership.
4		* The ASF licenses this file to You under the Apache License, Version 2.0
5		* (the "License"); you may not use this file except in compliance with
6		* the License. You may obtain a copy of the License at
7		*
8		* http://www.apache.org/licenses/LICENSE-2.0
9		*
10		* Unless required by applicable law or agreed to in writing, software
11		* distributed under the License is distributed on an "AS IS" BASIS,
12		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13		* See the License for the specific language governing permissions and
14		* limitations under the License.
15		*/
16
17		#include "util_time.h"
18		#include "apr_env.h"
19
20
21
22		/* Number of characters needed to format the microsecond part of a timestamp.
23		* Microseconds have 6 digits plus one separator character makes 7.
24		* */
25	0	#define AP_CTIME_USEC_LENGTH 7
26
27		/* Number of characters needed to format the millisecond part of a timestamp.
28		* Milliseconds have 3 digits plus one separator character makes 4.
29		* */
30	0	#define AP_CTIME_MSEC_LENGTH 4
31
32		/* Length of ISO 8601 date/time (including trailing '\0') */
33	0	#define AP_CTIME_COMPACT_LEN 20
34
35		/* Length of timezone offset from GMT ([+-]hhmm) plus leading space */
36	0	#define AP_CTIME_GMTOFF_LEN 6
37
38		/* Cache for exploded values of recent timestamps
39		*/
40
41		struct exploded_time_cache_element {
42		apr_int64_t t;
43		apr_time_exp_t xt;
44		apr_int64_t t_validate; /* please see comments in cached_explode() */
45		};
46
47		/* the "+ 1" is for the current second: */
48		#define TIME_CACHE_SIZE (AP_TIME_RECENT_THRESHOLD + 1)
49
50		/* Note that AP_TIME_RECENT_THRESHOLD is defined to
51		* be a power of two minus one in util_time.h, so that
52		* we can replace a modulo operation with a bitwise AND
53		* when hashing items into a cache of size
54		* AP_TIME_RECENT_THRESHOLD+1
55		*/
56	0	#define TIME_CACHE_MASK (AP_TIME_RECENT_THRESHOLD)
57
58		static struct exploded_time_cache_element exploded_cache_localtime[TIME_CACHE_SIZE];
59		static struct exploded_time_cache_element exploded_cache_gmt[TIME_CACHE_SIZE];
60
61
62		static apr_status_t cached_explode(apr_time_exp_t *xt, apr_time_t t,
63		struct exploded_time_cache_element *cache,
64		int use_gmt)
65	0	{
66	0	apr_int64_t seconds = apr_time_sec(t);
67	0	struct exploded_time_cache_element *cache_element =
68	0	&(cache[seconds & TIME_CACHE_MASK]);
69	0	struct exploded_time_cache_element cache_element_snapshot;
70
71		/* The cache is implemented as a ring buffer. Each second,
72		* it uses a different element in the buffer. The timestamp
73		* in the element indicates whether the element contains the
74		* exploded time for the current second (vs the time
75		* 'now - AP_TIME_RECENT_THRESHOLD' seconds ago). If the
76		* cached value is for the current time, we use it. Otherwise,
77		* we compute the apr_time_exp_t and store it in this
78		* cache element. Note that the timestamp in the cache
79		* element is updated only after the exploded time. Thus
80		* if two threads hit this cache element simultaneously
81		* at the start of a new second, they'll both explode the
82		* time and store it. I.e., the writers will collide, but
83		* they'll be writing the same value.
84		*/
85	0	if (cache_element->t >= seconds) {
86		/* There is an intentional race condition in this design:
87		* in a multithreaded app, one thread might be reading
88		* from this cache_element to resolve a timestamp from
89		* TIME_CACHE_SIZE seconds ago at the same time that
90		* another thread is copying the exploded form of the
91		* current time into the same cache_element. (I.e., the
92		* first thread might hit this element of the ring buffer
93		* just as the element is being recycled.) This can
94		* also happen at the start of a new second, if a
95		* reader accesses the cache_element after a writer
96		* has updated cache_element.t but before the writer
97		* has finished updating the whole cache_element.
98		*
99		* Rather than trying to prevent this race condition
100		* with locks, we allow it to happen and then detect
101		* and correct it. The detection works like this:
102		* Step 1: Take a "snapshot" of the cache element by
103		* copying it into a temporary buffer.
104		* Step 2: Check whether the snapshot contains consistent
105		* data: the timestamps at the start and end of
106		* the cache_element should both match the 'seconds'
107		* value that we computed from the input time.
108		* If these three don't match, then the snapshot
109		* shows the cache_element in the middle of an
110		* update, and its contents are invalid.
111		* Step 3: If the snapshot is valid, use it. Otherwise,
112		* just give up on the cache and explode the
113		* input time.
114		*/
115	0	memcpy(&cache_element_snapshot, cache_element,
116	0	sizeof(struct exploded_time_cache_element));
117	0	if ((seconds != cache_element_snapshot.t) \|\|
118	0	(seconds != cache_element_snapshot.t_validate)) {
119		/* Invalid snapshot */
120	0	if (use_gmt) {
121	0	return apr_time_exp_gmt(xt, t);
122	0	}
123	0	else {
124	0	return apr_time_exp_lt(xt, t);
125	0	}
126	0	}
127	0	else {
128		/* Valid snapshot */
129	0	memcpy(xt, &(cache_element_snapshot.xt),
130	0	sizeof(apr_time_exp_t));
131	0	}
132	0	}
133	0	else {
134	0	apr_status_t r;
135	0	if (use_gmt) {
136	0	r = apr_time_exp_gmt(xt, t);
137	0	}
138	0	else {
139	0	r = apr_time_exp_lt(xt, t);
140	0	}
141	0	if (r != APR_SUCCESS) {
142	0	return r;
143	0	}
144	0	cache_element->t = seconds;
145	0	memcpy(&(cache_element->xt), xt, sizeof(apr_time_exp_t));
146	0	cache_element->t_validate = seconds;
147	0	}
148	0	xt->tm_usec = (int)apr_time_usec(t);
149	0	return APR_SUCCESS;
150	0	}
151
152
153		AP_DECLARE(apr_status_t) ap_explode_recent_localtime(apr_time_exp_t * tm,
154		apr_time_t t)
155	0	{
156	0	return cached_explode(tm, t, exploded_cache_localtime, 0);
157	0	}
158
159		AP_DECLARE(apr_status_t) ap_explode_recent_gmt(apr_time_exp_t * tm,
160		apr_time_t t)
161	0	{
162	0	return cached_explode(tm, t, exploded_cache_gmt, 1);
163	0	}
164
165		AP_DECLARE(apr_status_t) ap_recent_ctime(char *date_str, apr_time_t t)
166	0	{
167	0	int len = APR_CTIME_LEN;
168	0	return ap_recent_ctime_ex(date_str, t, AP_CTIME_OPTION_NONE, &len);
169	0	}
170
171		AP_DECLARE(apr_status_t) ap_recent_ctime_ex(char *date_str, apr_time_t t,
172		int option, int *len)
173	0	{
174		/* ### This code is a clone of apr_ctime(), except that it
175		* uses ap_explode_recent_localtime() instead of apr_time_exp_lt().
176		*/
177	0	apr_time_exp_t xt;
178	0	const char *s;
179	0	int real_year;
180	0	int needed;
181
182
183		/* Calculate the needed buffer length */
184	0	if (option & AP_CTIME_OPTION_COMPACT)
185	0	needed = AP_CTIME_COMPACT_LEN;
186	0	else
187	0	needed = APR_CTIME_LEN;
188
189	0	if (option & AP_CTIME_OPTION_USEC) {
190	0	needed += AP_CTIME_USEC_LENGTH;
191	0	}
192	0	else if (option & AP_CTIME_OPTION_MSEC) {
193	0	needed += AP_CTIME_MSEC_LENGTH;
194	0	}
195
196	0	if (option & AP_CTIME_OPTION_GMTOFF) {
197	0	needed += AP_CTIME_GMTOFF_LEN;
198	0	}
199
200		/* Check the provided buffer length (note: above AP_CTIME_COMPACT_LEN
201		* and APR_CTIME_LEN include the trailing '\0'; so does 'needed' then).
202		*/
203	0	if (len && *len >= needed) {
204	0	*len = needed;
205	0	}
206	0	else {
207	0	if (len != NULL) {
208	0	*len = 0;
209	0	}
210	0	return APR_ENOMEM;
211	0	}
212
213		/* example without options: "Wed Jun 30 21:49:08 1993" */
214		/* example for compact format: "1993-06-30 21:49:08" */
215		/* example for compact+usec+gmtoff format:
216		* "1993-06-30 22:49:08.123456 +0100"
217		*/
218
219	0	ap_explode_recent_localtime(&xt, t);
220	0	real_year = 1900 + xt.tm_year;
221	0	if (option & AP_CTIME_OPTION_COMPACT) {
222	0	int real_month = xt.tm_mon + 1;
223	0	*date_str++ = real_year / 1000 + '0';
224	0	*date_str++ = real_year % 1000 / 100 + '0';
225	0	*date_str++ = real_year % 100 / 10 + '0';
226	0	*date_str++ = real_year % 10 + '0';
227	0	*date_str++ = '-';
228	0	*date_str++ = real_month / 10 + '0';
229	0	*date_str++ = real_month % 10 + '0';
230	0	*date_str++ = '-';
231	0	}
232	0	else {
233	0	s = &apr_day_snames[xt.tm_wday][0];
234	0	date_str++ = s++;
235	0	date_str++ = s++;
236	0	date_str++ = s++;
237	0	*date_str++ = ' ';
238	0	s = &apr_month_snames[xt.tm_mon][0];
239	0	date_str++ = s++;
240	0	date_str++ = s++;
241	0	date_str++ = s++;
242	0	*date_str++ = ' ';
243	0	}
244	0	*date_str++ = xt.tm_mday / 10 + '0';
245	0	*date_str++ = xt.tm_mday % 10 + '0';
246	0	*date_str++ = ' ';
247	0	*date_str++ = xt.tm_hour / 10 + '0';
248	0	*date_str++ = xt.tm_hour % 10 + '0';
249	0	*date_str++ = ':';
250	0	*date_str++ = xt.tm_min / 10 + '0';
251	0	*date_str++ = xt.tm_min % 10 + '0';
252	0	*date_str++ = ':';
253	0	*date_str++ = xt.tm_sec / 10 + '0';
254	0	*date_str++ = xt.tm_sec % 10 + '0';
255	0	if (option & (AP_CTIME_OPTION_USEC\|AP_CTIME_OPTION_MSEC)) {
256	0	int div;
257	0	int usec = (int)xt.tm_usec;
258	0	*date_str++ = '.';
259	0	div = 100000;
260	0	if (!(option & AP_CTIME_OPTION_USEC)) {
261	0	usec = usec / 1000;
262	0	div = 100;
263	0	}
264	0	for (; div>0; div=div/10) {
265	0	*date_str++ = usec / div + '0';
266	0	usec = usec % div;
267	0	}
268	0	}
269	0	if (!(option & AP_CTIME_OPTION_COMPACT)) {
270	0	*date_str++ = ' ';
271	0	*date_str++ = real_year / 1000 + '0';
272	0	*date_str++ = real_year % 1000 / 100 + '0';
273	0	*date_str++ = real_year % 100 / 10 + '0';
274	0	*date_str++ = real_year % 10 + '0';
275	0	}
276	0	if (option & AP_CTIME_OPTION_GMTOFF) {
277	0	int off = xt.tm_gmtoff, off_hh, off_mm;
278	0	char sign = '+';
279	0	if (off < 0) {
280	0	off = -off;
281	0	sign = '-';
282	0	}
283	0	off_hh = off / 3600;
284	0	off_mm = off % 3600 / 60;
285	0	*date_str++ = ' ';
286	0	*date_str++ = sign;
287	0	*date_str++ = off_hh / 10 + '0';
288	0	*date_str++ = off_hh % 10 + '0';
289	0	*date_str++ = off_mm / 10 + '0';
290	0	*date_str++ = off_mm % 10 + '0';
291	0	}
292	0	*date_str = 0;
293
294	0	return APR_SUCCESS;
295	0	}
296
297		AP_DECLARE(apr_status_t) ap_recent_rfc822_date(char *date_str, apr_time_t t)
298	0	{
299		/* ### This code is a clone of apr_rfc822_date(), except that it
300		* uses ap_explode_recent_gmt() instead of apr_time_exp_gmt().
301		*/
302	0	apr_time_exp_t xt;
303	0	const char *s;
304	0	int real_year;
305
306	0	ap_explode_recent_gmt(&xt, t);
307
308		/* example: "Sat, 08 Jan 2000 18:31:41 GMT" */
309		/* 12345678901234567890123456789 */
310
311	0	s = &apr_day_snames[xt.tm_wday][0];
312	0	date_str++ = s++;
313	0	date_str++ = s++;
314	0	date_str++ = s++;
315	0	*date_str++ = ',';
316	0	*date_str++ = ' ';
317	0	*date_str++ = xt.tm_mday / 10 + '0';
318	0	*date_str++ = xt.tm_mday % 10 + '0';
319	0	*date_str++ = ' ';
320	0	s = &apr_month_snames[xt.tm_mon][0];
321	0	date_str++ = s++;
322	0	date_str++ = s++;
323	0	date_str++ = s++;
324	0	*date_str++ = ' ';
325	0	real_year = 1900 + xt.tm_year;
326		/* This routine isn't y10k ready. */
327	0	*date_str++ = real_year / 1000 + '0';
328	0	*date_str++ = real_year % 1000 / 100 + '0';
329	0	*date_str++ = real_year % 100 / 10 + '0';
330	0	*date_str++ = real_year % 10 + '0';
331	0	*date_str++ = ' ';
332	0	*date_str++ = xt.tm_hour / 10 + '0';
333	0	*date_str++ = xt.tm_hour % 10 + '0';
334	0	*date_str++ = ':';
335	0	*date_str++ = xt.tm_min / 10 + '0';
336	0	*date_str++ = xt.tm_min % 10 + '0';
337	0	*date_str++ = ':';
338	0	*date_str++ = xt.tm_sec / 10 + '0';
339	0	*date_str++ = xt.tm_sec % 10 + '0';
340	0	*date_str++ = ' ';
341	0	*date_str++ = 'G';
342	0	*date_str++ = 'M';
343	0	*date_str++ = 'T';
344	0	*date_str++ = 0;
345	0	return APR_SUCCESS;
346	0	}
347
348	0	AP_DECLARE(void) ap_force_set_tz(apr_pool_t *p) {
349		/* If the TZ variable is unset, many operating systems,
350		* such as Linux, will at runtime read from /etc/localtime
351		* and call fstat on it.
352		*
353		* By forcing the time zone to UTC if it is unset, we gain
354		* about 2% in raw requests/second (since we format log files
355		* in the local time, if present)
356		*
357		* For more info, see:
358		* <http://www.gnu.org/s/hello/manual/libc/TZ-Variable.html>
359		*/
360	0	char *v = NULL;
361
362	0	if (apr_env_get(&v, "TZ", p) != APR_SUCCESS) {
363	0	apr_env_set("TZ", "UTC+0", p);
364	0	}
365	0	}