git.notmuchmail.org Git - notmuch/blob - lib/parse-sexp.cc

   1 #include "database-private.h"
   2
   3 #if HAVE_SFSEXP
   4 #include "sexp.h"
   5 #include "unicode-util.h"
   6
   7 /* _sexp is used for file scope symbols to avoid clashing with
   8  * definitions from sexp.h */
   9
  10 typedef enum {
  11     SEXP_FLAG_NONE      = 0,
  12     SEXP_FLAG_FIELD     = 1 << 0,
  13 } _sexp_flag_t;
  14
  15 typedef struct  {
  16     const char *name;
  17     Xapian::Query::op xapian_op;
  18     Xapian::Query initial;
  19     _sexp_flag_t flags;
  20 } _sexp_prefix_t;
  21
  22 static _sexp_prefix_t prefixes[] =
  23 {
  24     { "and",            Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
  25       SEXP_FLAG_NONE },
  26     { "not",            Xapian::Query::OP_AND_NOT,      Xapian::Query::MatchAll,
  27       SEXP_FLAG_NONE },
  28     { "or",             Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
  29       SEXP_FLAG_NONE },
  30     { "subject",        Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
  31       SEXP_FLAG_FIELD },
  32     { }
  33 };
  34
  35 static notmuch_status_t _sexp_to_xapian_query (notmuch_database_t *notmuch,
  36                                                const _sexp_prefix_t *parent,
  37                                                const sexp_t *sx,
  38                                                Xapian::Query &output);
  39
  40 static notmuch_status_t
  41 _sexp_combine_query (notmuch_database_t *notmuch,
  42                      const _sexp_prefix_t *parent,
  43                      Xapian::Query::op operation,
  44                      Xapian::Query left,
  45                      const sexp_t *sx,
  46                      Xapian::Query &output)
  47 {
  48     Xapian::Query subquery;
  49
  50     notmuch_status_t status;
  51
  52     /* if we run out elements, return accumulator */
  53
  54     if (! sx) {
  55         output = left;
  56         return NOTMUCH_STATUS_SUCCESS;
  57     }
  58
  59     status = _sexp_to_xapian_query (notmuch, parent, sx, subquery);
  60     if (status)
  61         return status;
  62
  63     return _sexp_combine_query (notmuch,
  64                                 parent,
  65                                 operation,
  66                                 Xapian::Query (operation, left, subquery),
  67                                 sx->next, output);
  68 }
  69
  70 static notmuch_status_t
  71 _sexp_parse_phrase (std::string term_prefix, const char *phrase, Xapian::Query &output)
  72 {
  73     Xapian::Utf8Iterator p (phrase);
  74     Xapian::Utf8Iterator end;
  75     std::vector<std::string> terms;
  76
  77     while (p != end) {
  78         Xapian::Utf8Iterator start;
  79         while (p != end && ! Xapian::Unicode::is_wordchar (*p))
  80             p++;
  81
  82         if (p == end)
  83             break;
  84
  85         start = p;
  86
  87         while (p != end && Xapian::Unicode::is_wordchar (*p))
  88             p++;
  89
  90         if (p != start) {
  91             std::string word (start, p);
  92             word = Xapian::Unicode::tolower (word);
  93             terms.push_back (term_prefix + word);
  94         }
  95     }
  96     output = Xapian::Query (Xapian::Query::OP_PHRASE, terms.begin (), terms.end ());
  97     return NOTMUCH_STATUS_SUCCESS;
  98 }
  99
 100 /* Here we expect the s-expression to be a proper list, with first
 101  * element defining and operation, or as a special case the empty
 102  * list */
 103
 104 static notmuch_status_t
 105 _sexp_to_xapian_query (notmuch_database_t *notmuch, const _sexp_prefix_t *parent, const sexp_t *sx,
 106                        Xapian::Query &output)
 107 {
 108
 109     if (sx->ty == SEXP_VALUE) {
 110         std::string term = Xapian::Unicode::tolower (sx->val);
 111         Xapian::Stem stem = *(notmuch->stemmer);
 112         std::string term_prefix = parent ? _find_prefix (parent->name) : "";
 113         if (sx->aty == SEXP_BASIC && unicode_word_utf8 (sx->val)) {
 114             output = Xapian::Query ("Z" + term_prefix + stem (term));
 115             return NOTMUCH_STATUS_SUCCESS;
 116         } else {
 117             return _sexp_parse_phrase (term_prefix, sx->val, output);
 118         }
 119     }
 120
 121     /* Empty list */
 122     if (! sx->list) {
 123         output = Xapian::Query::MatchAll;
 124         return NOTMUCH_STATUS_SUCCESS;
 125     }
 126
 127     if (sx->list->ty == SEXP_LIST) {
 128         _notmuch_database_log (notmuch, "unexpected list in field/operation position\n",
 129                                sx->list->val);
 130         return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 131     }
 132
 133     for (_sexp_prefix_t *prefix = prefixes; prefix && prefix->name; prefix++) {
 134         if (strcmp (prefix->name, sx->list->val) == 0) {
 135             if (prefix->flags & SEXP_FLAG_FIELD) {
 136                 if (parent) {
 137                     _notmuch_database_log (notmuch, "nested field: '%s' inside '%s'\n",
 138                                            prefix->name, parent->name);
 139                     return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 140                 }
 141                 parent = prefix;
 142             }
 143
 144             return _sexp_combine_query (notmuch, parent, prefix->xapian_op, prefix->initial,
 145                                         sx->list->next, output);
 146         }
 147     }
 148
 149     _notmuch_database_log (notmuch, "unknown prefix '%s'\n", sx->list->val);
 150
 151     return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 152 }
 153
 154 notmuch_status_t
 155 _notmuch_sexp_string_to_xapian_query (notmuch_database_t *notmuch, const char *querystr,
 156                                       Xapian::Query &output)
 157 {
 158     const sexp_t *sx = NULL;
 159     char *buf = talloc_strdup (notmuch, querystr);
 160
 161     sx = parse_sexp (buf, strlen (querystr));
 162     if (! sx) {
 163         _notmuch_database_log (notmuch, "invalid s-expression: '%s'\n", querystr);
 164         return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 165     }
 166
 167     return _sexp_to_xapian_query (notmuch, NULL, sx, output);
 168 }
 169 #endif