1/*
2 * time.c:  time/date utilities
3 *
4 * ====================================================================
5 *    Licensed to the Apache Software Foundation (ASF) under one
6 *    or more contributor license agreements.  See the NOTICE file
7 *    distributed with this work for additional information
8 *    regarding copyright ownership.  The ASF licenses this file
9 *    to you under the Apache License, Version 2.0 (the
10 *    "License"); you may not use this file except in compliance
11 *    with the License.  You may obtain a copy of the License at
12 *
13 *      http://www.apache.org/licenses/LICENSE-2.0
14 *
15 *    Unless required by applicable law or agreed to in writing,
16 *    software distributed under the License is distributed on an
17 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18 *    KIND, either express or implied.  See the License for the
19 *    specific language governing permissions and limitations
20 *    under the License.
21 * ====================================================================
22 */
23
24
25
26#include <string.h>
27#include <stdlib.h>
28#include <apr_pools.h>
29#include <apr_time.h>
30#include <apr_strings.h>
31#include "svn_io.h"
32#include "svn_time.h"
33#include "svn_utf.h"
34#include "svn_error.h"
35#include "svn_private_config.h"
36
37#include "private/svn_string_private.h"
38
39
40
41/*** Code. ***/
42
43/* Our timestamp strings look like this:
44 *
45 *    "2002-05-07Thh:mm:ss.uuuuuuZ"
46 *
47 * The format is conformant with ISO-8601 and the date format required
48 * by RFC2518 for creationdate. It is a direct conversion between
49 * apr_time_t and a string, so converting to string and back retains
50 * the exact value.
51 */
52#define TIMESTAMP_FORMAT "%04d-%02d-%02dT%02d:%02d:%02d.%06dZ"
53
54/* Our old timestamp strings looked like this:
55 *
56 *    "Tue 3 Oct 2000 HH:MM:SS.UUU (day 277, dst 1, gmt_off -18000)"
57 *
58 * The idea is that they are conventionally human-readable for the
59 * first part, and then in parentheses comes everything else required
60 * to completely fill in an apr_time_exp_t: tm_yday, tm_isdst,
61 * and tm_gmtoff.
62 *
63 * This format is still recognized on input, for backward
64 * compatibility, but no longer generated.
65 */
66#define OLD_TIMESTAMP_FORMAT \
67        "%3s %d %3s %d %02d:%02d:%02d.%06d (day %03d, dst %d, gmt_off %06d)"
68
69/* Our human representation of dates looks like this:
70 *
71 *    "2002-06-23 11:13:02 +0300 (Sun, 23 Jun 2002)"
72 *
73 * This format is used whenever time is shown to the user. It consists
74 * of a machine parseable, almost ISO-8601, part in the beginning -
75 * and a human explanatory part at the end. The machine parseable part
76 * is generated strictly by APR and our code, with a apr_snprintf. The
77 * human explanatory part is generated by apr_strftime, which means
78 * that its generation can be affected by locale, it can fail and it
79 * doesn't need to be constant in size. In other words, perfect to be
80 * converted to a configuration option later on.
81 */
82/* Maximum length for the date string. */
83#define SVN_TIME__MAX_LENGTH 80
84/* Machine parseable part, generated by apr_snprintf. */
85#define HUMAN_TIMESTAMP_FORMAT "%.4d-%.2d-%.2d %.2d:%.2d:%.2d %+.2d%.2d"
86/* Human explanatory part, generated by apr_strftime as "Sat, 01 Jan 2000" */
87#define HUMAN_TIMESTAMP_FORMAT_SUFFIX _(" (%a, %d %b %Y)")
88
89const char *
90svn_time_to_cstring(apr_time_t when, apr_pool_t *pool)
91{
92  apr_time_exp_t exploded_time;
93
94  /* We toss apr_status_t return value here -- for one thing, caller
95     should pass in good information.  But also, where APR's own code
96     calls these functions it tosses the return values, and
97     furthermore their current implementations can only return success
98     anyway. */
99
100  /* We get the date in GMT now -- and expect the tm_gmtoff and
101     tm_isdst to be not set. We also ignore the weekday and yearday,
102     since those are not needed. */
103
104  apr_time_exp_gmt(&exploded_time, when);
105
106  /* It would be nice to use apr_strftime(), but APR doesn't give a
107     way to convert back, so we wouldn't be able to share the format
108     string between the writer and reader. */
109  return apr_psprintf(pool,
110                      TIMESTAMP_FORMAT,
111                      exploded_time.tm_year + 1900,
112                      exploded_time.tm_mon + 1,
113                      exploded_time.tm_mday,
114                      exploded_time.tm_hour,
115                      exploded_time.tm_min,
116                      exploded_time.tm_sec,
117                      exploded_time.tm_usec);
118}
119
120
121static apr_int32_t
122find_matching_string(char *str, apr_size_t size, const char strings[][4])
123{
124  apr_size_t i;
125
126  for (i = 0; i < size; i++)
127    if (strings[i] && (strcmp(str, strings[i]) == 0))
128      return (apr_int32_t) i;
129
130  return -1;
131}
132
133
134svn_error_t *
135svn_time_from_cstring(apr_time_t *when, const char *data, apr_pool_t *pool)
136{
137  apr_time_exp_t exploded_time;
138  apr_status_t apr_err;
139  char wday[4], month[4];
140  const char *c;
141
142  /* Open-code parsing of the new timestamp format, as this
143     is a hot path for reading the entries file.  This format looks
144     like:  "2001-08-31T04:24:14.966996Z"  */
145  exploded_time.tm_year = (apr_int32_t) svn__strtoul(data, &c);
146  if (*c++ != '-') goto fail;
147  exploded_time.tm_mon = (apr_int32_t) svn__strtoul(c, &c);
148  if (*c++ != '-') goto fail;
149  exploded_time.tm_mday = (apr_int32_t) svn__strtoul(c, &c);
150  if (*c++ != 'T') goto fail;
151  exploded_time.tm_hour = (apr_int32_t) svn__strtoul(c, &c);
152  if (*c++ != ':') goto fail;
153  exploded_time.tm_min = (apr_int32_t) svn__strtoul(c, &c);
154  if (*c++ != ':') goto fail;
155  exploded_time.tm_sec = (apr_int32_t) svn__strtoul(c, &c);
156  if (*c++ != '.') goto fail;
157  exploded_time.tm_usec = (apr_int32_t) svn__strtoul(c, &c);
158  if (*c++ != 'Z') goto fail;
159
160  exploded_time.tm_year  -= 1900;
161  exploded_time.tm_mon   -= 1;
162  exploded_time.tm_wday   = 0;
163  exploded_time.tm_yday   = 0;
164  exploded_time.tm_isdst  = 0;
165  exploded_time.tm_gmtoff = 0;
166
167  apr_err = apr_time_exp_gmt_get(when, &exploded_time);
168  if (apr_err == APR_SUCCESS)
169    return SVN_NO_ERROR;
170
171  return svn_error_create(SVN_ERR_BAD_DATE, NULL, NULL);
172
173 fail:
174  /* Try the compatibility option.  This does not need to be fast,
175     as this format is no longer generated and the client will convert
176     an old-format entries file the first time it reads it.  */
177  if (sscanf(data,
178             OLD_TIMESTAMP_FORMAT,
179             wday,
180             &exploded_time.tm_mday,
181             month,
182             &exploded_time.tm_year,
183             &exploded_time.tm_hour,
184             &exploded_time.tm_min,
185             &exploded_time.tm_sec,
186             &exploded_time.tm_usec,
187             &exploded_time.tm_yday,
188             &exploded_time.tm_isdst,
189             &exploded_time.tm_gmtoff) == 11)
190    {
191      exploded_time.tm_year -= 1900;
192      exploded_time.tm_yday -= 1;
193      /* Using hard coded limits for the arrays - they are going away
194         soon in any case. */
195      exploded_time.tm_wday = find_matching_string(wday, 7, apr_day_snames);
196      exploded_time.tm_mon = find_matching_string(month, 12, apr_month_snames);
197
198      apr_err = apr_time_exp_gmt_get(when, &exploded_time);
199      if (apr_err != APR_SUCCESS)
200        return svn_error_create(SVN_ERR_BAD_DATE, NULL, NULL);
201
202      return SVN_NO_ERROR;
203    }
204  /* Timestamp is something we do not recognize. */
205  else
206    return svn_error_create(SVN_ERR_BAD_DATE, NULL, NULL);
207}
208
209
210const char *
211svn_time_to_human_cstring(apr_time_t when, apr_pool_t *pool)
212{
213  apr_time_exp_t exploded_time;
214  apr_size_t len, retlen;
215  apr_status_t ret;
216  char *datestr, *curptr, human_datestr[SVN_TIME__MAX_LENGTH];
217
218  /* Get the time into parts */
219  ret = apr_time_exp_lt(&exploded_time, when);
220  if (ret)
221    return NULL;
222
223  /* Make room for datestring */
224  datestr = apr_palloc(pool, SVN_TIME__MAX_LENGTH);
225
226  /* Put in machine parseable part */
227  len = apr_snprintf(datestr,
228                     SVN_TIME__MAX_LENGTH,
229                     HUMAN_TIMESTAMP_FORMAT,
230                     exploded_time.tm_year + 1900,
231                     exploded_time.tm_mon + 1,
232                     exploded_time.tm_mday,
233                     exploded_time.tm_hour,
234                     exploded_time.tm_min,
235                     exploded_time.tm_sec,
236                     exploded_time.tm_gmtoff / (60 * 60),
237                     (abs(exploded_time.tm_gmtoff) / 60) % 60);
238
239  /* If we overfilled the buffer, just return what we got. */
240  if (len >= SVN_TIME__MAX_LENGTH)
241    return datestr;
242
243  /* Calculate offset to the end of the machine parseable part. */
244  curptr = datestr + len;
245
246  /* Put in human explanatory part */
247  ret = apr_strftime(human_datestr,
248                     &retlen,
249                     SVN_TIME__MAX_LENGTH - len,
250                     HUMAN_TIMESTAMP_FORMAT_SUFFIX,
251                     &exploded_time);
252
253  /* If there was an error, ensure that the string is zero-terminated. */
254  if (ret || retlen == 0)
255    *curptr = '\0';
256  else
257    {
258      const char *utf8_string;
259      svn_error_t *err;
260
261      err = svn_utf_cstring_to_utf8(&utf8_string, human_datestr, pool);
262      if (err)
263        {
264          *curptr = '\0';
265          svn_error_clear(err);
266        }
267      else
268        apr_cpystrn(curptr, utf8_string, SVN_TIME__MAX_LENGTH - len);
269    }
270
271  return datestr;
272}
273
274
275void
276svn_sleep_for_timestamps(void)
277{
278  svn_io_sleep_for_timestamps(NULL, NULL);
279}
280