xapian-applications/omega/date.cc

   1 /** @file
   2  * @brief date range parsing routines for omega
   3  */
   4 /* Copyright 1999,2000,2001 BrightStation PLC
   5  * Copyright 2001 James Aylett
   6  * Copyright 2001,2002 Ananova Ltd
   7  * Copyright 2002 Intercede 1749 Ltd
   8  * Copyright 2002,2003,2006,2014,2016,2017,2018 Olly Betts
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of the
  13  * License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  23  * USA
  24  */
  25
  26 #include <config.h>
  27
  28 #include "date.h"
  29
  30 #include <vector>
  31
  32 #include <cstdlib>
  33 #include <ctime>
  34
  35 using namespace std;
  36
  37 static int
  38 last_day(int y, int m)
  39 {
  40     static const int l[13] = {
  41         0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  42     };
  43     if (m != 2) return l[m];
  44     return 28 + (y % 4 == 0 && (y % 100 != 0 || y % 400 == 0));
  45 }
  46
  47 // Write exactly w chars to buffer p representing integer v.
  48 //
  49 // The result is left padded with zeros if v < pow(10, w - 1).
  50 //
  51 // If v >= pow(10, w), then the output will show v % pow(10, w) (i.e. the
  52 // most significant digits are lost).
  53 static void
  54 format_int_fixed_width(char * p, int v, int w)
  55 {
  56     while (--w >= 0) {
  57         p[w] = '0' + (v % 10);
  58         v /= 10;
  59     }
  60 }
  61
  62 static Xapian::Query
  63 date_range_filter(int y1, int m1, int d1, int y2, int m2, int d2)
  64 {
  65     if (y1 > y2 || (y1 == y2 && (m1 > m2 || (m1 == m2 && d1 > d2)))) {
  66         // Start is after end.
  67         return Xapian::Query::MatchNothing;
  68     }
  69     char buf[10];
  70     format_int_fixed_width(buf + 1, y1, 4);
  71     format_int_fixed_width(buf + 5, m1, 2);
  72     vector<Xapian::Query> v;
  73
  74     int d_last = last_day(y1, m1);
  75     int d_end = d_last;
  76     if (d1 == 1 && m1 == 1 && y1 != y2) {
  77         --y1;
  78         goto whole_year_at_start;
  79     }
  80     if (y1 == y2 && m1 == m2 && d2 < d_last) {
  81         d_end = d2;
  82     }
  83     // Deal with any initial partial month
  84     if (d1 > 1 || d_end < d_last) {
  85         buf[0] = 'D';
  86         for ( ; d1 <= d_end; ++d1) {
  87             format_int_fixed_width(buf + 7, d1, 2);
  88             v.push_back(Xapian::Query(string(buf, 9)));
  89         }
  90     } else {
  91         buf[0] = 'M';
  92         v.push_back(Xapian::Query(string(buf, 7)));
  93     }
  94
  95     if (y1 == y2 && m1 == m2) {
  96         return Xapian::Query(Xapian::Query::OP_OR, v.begin(), v.end());
  97     }
  98
  99     {
 100         int m_last = (y1 < y2) ? 12 : m2 - 1;
 101         while (++m1 <= m_last) {
 102             format_int_fixed_width(buf + 5, m1, 2);
 103             buf[0] = 'M';
 104             v.push_back(Xapian::Query(string(buf, 7)));
 105         }
 106     }
 107
 108     if (y1 < y2) {
 109 whole_year_at_start:
 110         while (++y1 < y2) {
 111             format_int_fixed_width(buf + 1, y1, 4);
 112             buf[0] = 'Y';
 113             v.push_back(Xapian::Query(string(buf, 5)));
 114         }
 115         format_int_fixed_width(buf + 1, y2, 4);
 116         if (m2 == 12 && d2 >= 31) {
 117             v.push_back(Xapian::Query(string(buf, 5)));
 118             goto whole_year_at_end;
 119         }
 120         buf[0] = 'M';
 121         for (m1 = 1; m1 < m2; ++m1) {
 122             format_int_fixed_width(buf + 5, m1, 2);
 123             v.push_back(Xapian::Query(string(buf, 7)));
 124         }
 125     }
 126
 127     format_int_fixed_width(buf + 5, m2, 2);
 128
 129     // Deal with any final partial month
 130     if (d2 < last_day(y2, m2)) {
 131         buf[0] = 'D';
 132         for (d1 = 1; d1 <= d2; ++d1) {
 133             format_int_fixed_width(buf + 7, d1, 2);
 134             v.push_back(Xapian::Query(string(buf, 9)));
 135         }
 136     } else {
 137         buf[0] = 'M';
 138         v.push_back(Xapian::Query(string(buf, 7)));
 139     }
 140
 141 whole_year_at_end:
 142     return Xapian::Query(Xapian::Query::OP_OR, v.begin(), v.end());
 143 }
 144
 145 static int DIGIT(char ch) { return ch - '0'; }
 146
 147 static int DIGIT2(const char *p) {
 148     return DIGIT(p[0]) * 10 + DIGIT(p[1]);
 149 }
 150
 151 static int DIGIT4(const char *p) {
 152     return DIGIT2(p) * 100 + DIGIT2(p + 2);
 153 }
 154
 155 static void
 156 parse_date(const string & date, int *y, int *m, int *d, bool start)
 157 {
 158     // Support YYYYMMDD, YYYYMM and YYYY.
 159     if (date.size() < 4) {
 160         // We default to the start of 1970 when START isn't specified, so it
 161         // seems logical to here do that here too.
 162         *y = 1970;
 163     } else {
 164         *y = DIGIT4(date.c_str());
 165     }
 166     if (date.size() < 6) {
 167         if (start) {
 168             *m = 1;
 169             *d = 1;
 170         } else {
 171             *m = 12;
 172             *d = 31;
 173         }
 174         return;
 175     }
 176     *m = DIGIT2(date.c_str() + 4);
 177     if (date.size() < 8) {
 178         if (start) {
 179             *d = 1;
 180         } else {
 181             *d = last_day(*y, *m);
 182         }
 183         return;
 184     }
 185     *d = DIGIT2(date.c_str() + 6);
 186 }
 187
 188 Xapian::Query
 189 date_range_filter(const string & date_start, const string & date_end,
 190                   const string & date_span)
 191 {
 192     int y1, m1, d1, y2, m2, d2;
 193     if (!date_span.empty()) {
 194         time_t secs = atoi(date_span.c_str()) * (24 * 60 * 60);
 195         if (!date_end.empty()) {
 196             parse_date(date_end, &y2, &m2, &d2, false);
 197             struct tm t;
 198             t.tm_year = y2 - 1900;
 199             t.tm_mon = m2 - 1;
 200             t.tm_mday = d2;
 201             t.tm_hour = 12;
 202             t.tm_min = t.tm_sec = 0;
 203             t.tm_isdst = -1;
 204             time_t then = mktime(&t) - secs;
 205             struct tm *t2 = localtime(&then);
 206             y1 = t2->tm_year + 1900;
 207             m1 = t2->tm_mon + 1;
 208             d1 = t2->tm_mday;
 209         } else if (!date_start.empty()) {
 210             parse_date(date_start, &y1, &m1, &d1, true);
 211             struct tm t;
 212             t.tm_year = y1 - 1900;
 213             t.tm_mon = m1 - 1;
 214             t.tm_mday = d1;
 215             t.tm_hour = 12;
 216             t.tm_min = t.tm_sec = 0;
 217             t.tm_isdst = -1;
 218             time_t end = mktime(&t) + secs;
 219             struct tm *t2 = localtime(&end);
 220             y2 = t2->tm_year + 1900;
 221             m2 = t2->tm_mon + 1;
 222             d2 = t2->tm_mday;
 223         } else {
 224             time_t end = time(NULL);
 225             struct tm *t = localtime(&end);
 226             y2 = t->tm_year + 1900;
 227             m2 = t->tm_mon + 1;
 228             d2 = t->tm_mday;
 229             time_t then = end - secs;
 230             struct tm *t2 = localtime(&then);
 231             y1 = t2->tm_year + 1900;
 232             m1 = t2->tm_mon + 1;
 233             d1 = t2->tm_mday;
 234         }
 235     } else {
 236         if (date_start.empty()) {
 237             y1 = 1970;
 238             m1 = 1;
 239             d1 = 1;
 240         } else {
 241             parse_date(date_start, &y1, &m1, &d1, true);
 242         }
 243         if (date_end.empty()) {
 244             time_t now = time(NULL);
 245             struct tm *t = localtime(&now);
 246             y2 = t->tm_year + 1900;
 247             m2 = t->tm_mon + 1;
 248             d2 = t->tm_mday;
 249         } else {
 250             parse_date(date_end, &y2, &m2, &d2, false);
 251         }
 252     }
 253     return date_range_filter(y1, m1, d1, y2, m2, d2);
 254 }