[PATCH 2/3] lib: migrate from Xapian ValueRangeProcessor to RangeProcessor

[David Bremner <david@tethera.net>]

This will be mandatory as of Xapian 1.5.  The API is also more
consistent with the FieldProcessor API, which helps code re-use a bit.

Note that this switches to using the built-in Xapian support for
prefixes on ranges (i.e. deleted code at beginning of
ParseTimeRangeProcessor::operator(), added prefix to constructor).

Another side effect of the migration is that we are generating smaller
queries, using one OP_VALUE_RANGE instead of an AND of two OP_VALUE_*
queries.
---
 lib/database-private.h |  6 ++--
 lib/database.cc        | 21 ++++++-------
 lib/parse-time-vrp.cc  | 69 +++++++++++++++++++++---------------------
 lib/parse-time-vrp.h   | 18 +++++------
 4 files changed, 56 insertions(+), 58 deletions(-)

diff --git a/lib/database-private.h b/lib/database-private.h
index 87ae1bdf..76359007 100644
--- a/lib/database-private.h
+++ b/lib/database-private.h
@@ -218,9 +218,9 @@ struct _notmuch_database {
     unsigned long view;
     Xapian::QueryParser *query_parser;
     Xapian::TermGenerator *term_gen;
-    Xapian::ValueRangeProcessor *value_range_processor;
-    Xapian::ValueRangeProcessor *date_range_processor;
-    Xapian::ValueRangeProcessor *last_mod_range_processor;
+    Xapian::RangeProcessor *value_range_processor;
+    Xapian::RangeProcessor *date_range_processor;
+    Xapian::RangeProcessor *last_mod_range_processor;
 
     /* XXX it's slightly gross to use two parallel string->string maps
      * here, but at least they are small */
diff --git a/lib/database.cc b/lib/database.cc
index 43bfac4e..2f794164 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -385,8 +385,8 @@ _setup_query_field (const prefix_t *prefix, notmuch_database_t *notmuch)
 	Xapian::FieldProcessor *fp;
 
 	if (STRNCMP_LITERAL (prefix->name, "date") == 0)
-	    fp = (new DateFieldProcessor ())->release ();
-	else if (STRNCMP_LITERAL (prefix->name, "query") == 0)
+	    fp = (new DateFieldProcessor(NOTMUCH_VALUE_TIMESTAMP))->release ();
+	else if (STRNCMP_LITERAL(prefix->name, "query") == 0)
 	    fp = (new QueryFieldProcessor (*notmuch->query_parser, notmuch))->release ();
 	else if (STRNCMP_LITERAL (prefix->name, "thread") == 0)
 	    fp = (new ThreadFieldProcessor (*notmuch->query_parser, notmuch))->release ();
@@ -1036,17 +1036,16 @@ notmuch_database_open_verbose (const char *path,
 	notmuch->query_parser = new Xapian::QueryParser;
 	notmuch->term_gen = new Xapian::TermGenerator;
 	notmuch->term_gen->set_stemmer (Xapian::Stem ("english"));
-	notmuch->value_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_TIMESTAMP);
-	notmuch->date_range_processor = new ParseTimeValueRangeProcessor (NOTMUCH_VALUE_TIMESTAMP);
-	notmuch->last_mod_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_LAST_MOD, "lastmod:");
-
+	notmuch->value_range_processor = new Xapian::NumberRangeProcessor (NOTMUCH_VALUE_TIMESTAMP);
+	notmuch->date_range_processor = new ParseTimeRangeProcessor (NOTMUCH_VALUE_TIMESTAMP, "date:");
+	notmuch->last_mod_range_processor = new Xapian::NumberRangeProcessor (NOTMUCH_VALUE_LAST_MOD, "lastmod:");
 	notmuch->query_parser->set_default_op (Xapian::Query::OP_AND);
 	notmuch->query_parser->set_database (*notmuch->xapian_db);
 	notmuch->query_parser->set_stemmer (Xapian::Stem ("english"));
 	notmuch->query_parser->set_stemming_strategy (Xapian::QueryParser::STEM_SOME);
-	notmuch->query_parser->add_valuerangeprocessor (notmuch->value_range_processor);
-	notmuch->query_parser->add_valuerangeprocessor (notmuch->date_range_processor);
-	notmuch->query_parser->add_valuerangeprocessor (notmuch->last_mod_range_processor);
+	notmuch->query_parser->add_rangeprocessor (notmuch->value_range_processor);
+	notmuch->query_parser->add_rangeprocessor (notmuch->date_range_processor);
+	notmuch->query_parser->add_rangeprocessor (notmuch->last_mod_range_processor);
 
 	for (i = 0; i < ARRAY_SIZE (prefix_table); i++) {
 	    const prefix_t *prefix = &prefix_table[i];
@@ -1401,8 +1400,8 @@ handle_sigalrm (unused (int signal))
  */
 notmuch_status_t
 notmuch_database_upgrade (notmuch_database_t *notmuch,
-			  void (*progress_notify)(void *closure,
-						  double progress),
+			  void (*progress_notify) (void *closure,
+						   double progress),
 			  void *closure)
 {
     void *local = talloc_new (NULL);
diff --git a/lib/parse-time-vrp.cc b/lib/parse-time-vrp.cc
index 168d5810..10809aa3 100644
--- a/lib/parse-time-vrp.cc
+++ b/lib/parse-time-vrp.cc
@@ -24,64 +24,63 @@
 #include "parse-time-vrp.h"
 #include "parse-time-string.h"
 
-#define PREFIX "date:"
-
-/* See *ValueRangeProcessor in xapian-core/api/valuerangeproc.cc */
-Xapian::valueno
-ParseTimeValueRangeProcessor::operator() (std::string &begin, std::string &end)
+Xapian::Query
+ParseTimeRangeProcessor::operator() (const std::string &begin, const std::string &end)
 {
-    time_t t, now;
-    std::string b;
-
-    /* Require date: prefix in start of the range... */
-    if (STRNCMP_LITERAL (begin.c_str (), PREFIX))
-	return Xapian::BAD_VALUENO;
-
-    /* ...and remove it. */
-    begin.erase (0, sizeof (PREFIX) - 1);
-    b = begin;
+    double from = DBL_MIN, to = DBL_MAX;
+    time_t parsed_time, now;
+    std::string str;
 
     /* Use the same 'now' for begin and end. */
     if (time (&now) == (time_t) -1)
-	return Xapian::BAD_VALUENO;
-
-    if (! begin.empty ()) {
-	if (parse_time_string (begin.c_str (), &t, &now, PARSE_TIME_ROUND_DOWN))
-	    return Xapian::BAD_VALUENO;
+	throw Xapian::QueryParserError ("unable to get current time");
 
-	begin.assign (Xapian::sortable_serialise ((double) t));
+    if (!begin.empty ()) {
+	if (parse_time_string (begin.c_str (), &parsed_time, &now, PARSE_TIME_ROUND_DOWN))
+	    throw Xapian::QueryParserError ("Didn't understand date specification '" + begin + "'");
+	else
+	    from = (double) parsed_time;
     }
 
-    if (! end.empty ()) {
-	if (end == "!" && ! b.empty ())
-	    end = b;
-
-	if (parse_time_string (end.c_str (), &t, &now, PARSE_TIME_ROUND_UP_INCLUSIVE))
-	    return Xapian::BAD_VALUENO;
+    if (!end.empty ()) {
+	if (end == "!" && ! begin.empty ())
+	    str = begin;
+	else
+	    str = end;
 
-	end.assign (Xapian::sortable_serialise ((double) t));
+	if (parse_time_string (str.c_str (), &parsed_time, &now, PARSE_TIME_ROUND_UP_INCLUSIVE))
+	    throw Xapian::QueryParserError ("Didn't understand date specification '" + str + "'");
+	else
+	    to = (double) parsed_time;
     }
 
-    return valno;
+    return Xapian::Query (Xapian::Query::OP_VALUE_RANGE, slot,
+			  Xapian::sortable_serialise (from),
+			  Xapian::sortable_serialise (to));
 }
 
 /* XXX TODO: is throwing an exception the right thing to do here? */
 Xapian::Query
 DateFieldProcessor::operator() (const std::string & str)
 {
-    time_t from, to, now;
+    double from = DBL_MIN, to = DBL_MAX;
+    time_t parsed_time, now;
 
     /* Use the same 'now' for begin and end. */
     if (time (&now) == (time_t) -1)
 	throw Xapian::QueryParserError ("Unable to get current time");
 
-    if (parse_time_string (str.c_str (), &from, &now, PARSE_TIME_ROUND_DOWN))
+    if (parse_time_string (str.c_str (), &parsed_time, &now, PARSE_TIME_ROUND_DOWN))
 	throw Xapian::QueryParserError ("Didn't understand date specification '" + str + "'");
+    else
+	from = (double) parsed_time;
 
-    if (parse_time_string (str.c_str (), &to, &now, PARSE_TIME_ROUND_UP_INCLUSIVE))
+    if (parse_time_string (str.c_str (), &parsed_time, &now, PARSE_TIME_ROUND_UP_INCLUSIVE))
 	throw Xapian::QueryParserError ("Didn't understand date specification '" + str + "'");
+    else
+	to = (double) parsed_time;
 
-    return Xapian::Query (Xapian::Query::OP_AND,
-			  Xapian::Query (Xapian::Query::OP_VALUE_GE, 0, Xapian::sortable_serialise ((double) from)),
-			  Xapian::Query (Xapian::Query::OP_VALUE_LE, 0, Xapian::sortable_serialise ((double) to)));
+    return Xapian::Query (Xapian::Query::OP_VALUE_RANGE, slot,
+			  Xapian::sortable_serialise (from),
+			  Xapian::sortable_serialise (to));
 }
diff --git a/lib/parse-time-vrp.h b/lib/parse-time-vrp.h
index 9fb1af60..f495e716 100644
--- a/lib/parse-time-vrp.h
+++ b/lib/parse-time-vrp.h
@@ -26,21 +26,21 @@
 #include <xapian.h>
 
 /* see *ValueRangeProcessor in xapian-core/include/xapian/queryparser.h */
-class ParseTimeValueRangeProcessor : public Xapian::ValueRangeProcessor {
-protected:
-    Xapian::valueno valno;
+class ParseTimeRangeProcessor : public Xapian::RangeProcessor {
 
 public:
-    ParseTimeValueRangeProcessor (Xapian::valueno slot_)
-	: valno (slot_)
-    {
-    }
+    ParseTimeRangeProcessor (Xapian::valueno slot_, const std::string prefix_)
+	:  Xapian::RangeProcessor(slot_, prefix_, 0) { }
 
-    Xapian::valueno operator() (std::string &begin, std::string &end);
+    Xapian::Query operator() (const std::string &begin, const std::string &end);
 };
 
 class DateFieldProcessor : public Xapian::FieldProcessor {
-    Xapian::Query operator() (const std::string & str);
+private:
+    Xapian::valueno slot;
+public:
+    DateFieldProcessor(Xapian::valueno slot_) : slot(slot_) { };
+    Xapian::Query operator()(const std::string & str);
 };
 
 #endif /* NOTMUCH_PARSE_TIME_VRP_H */
-- 
2.27.0