lib: factor out lastmod range handling from sexp parser.

This will permit the re-use of the same logic in the infix query
parser. The location of the shared code in the infix side is for
consistency with the other shared parsing logic. It will make more
sense when a Xapian field processor is added for the lastmod prefix.

lib/Makefile.local

@@ -65,7 +65,8 @@ libnotmuch_cxx_srcs =		\
 	$(dir)/open.cc		\
 	$(dir)/init.cc		\
 	$(dir)/parse-sexp.cc	\
-	$(dir)/sexp-fp.cc
+	$(dir)/sexp-fp.cc	\
+	$(dir)/lastmod-fp.cc
 
 libnotmuch_modules := $(libnotmuch_c_srcs:.c=.o) $(libnotmuch_cxx_srcs:.cc=.o)
 

lib/database-private.h

@@ -381,5 +381,11 @@ _notmuch_sexp_string_to_xapian_query (notmuch_database_t *notmuch, const char *q
 notmuch_status_t
 _notmuch_date_strings_to_query (Xapian::valueno slot, const std::string &from, const std::string &to,
 				Xapian::Query &output, std::string &msg);
+
+/* lastmod-fp.h */
+notmuch_status_t
+_notmuch_lastmod_strings_to_query (notmuch_database_t *notmuch,
+				   const std::string &from, const std::string &to,
+				   Xapian::Query &output, std::string &msg);
 #endif
 #endif

lib/lastmod-fp.cc

@@ -0,0 +1,68 @@
+/* lastmod-fp.cc - lastmod range query glue
+ *
+ * This file is part of notmuch.
+ *
+ * Copyright © 2022 David Bremner
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see https://www.gnu.org/licenses/ .
+ *
+ * Author: David Bremner <david@tethera.net>
+ */
+
+#include "database-private.h"
+
+notmuch_status_t
+_notmuch_lastmod_strings_to_query (notmuch_database_t *notmuch,
+				   const std::string &from, const std::string &to,
+				   Xapian::Query &output, std::string &msg)
+{
+    long from_idx = 0L, to_idx = LONG_MAX;
+    long current;
+    std::string str;
+
+    /* revision should not change, but for the avoidance of doubt,
+     * grab for both ends of range, if needed*/
+    current = notmuch_database_get_revision (notmuch, NULL);
+
+    try {
+	if (from.empty ())
+	    from_idx = 0L;
+	else
+	    from_idx = std::stol (from);
+    } catch (std::logic_error &e) {
+	msg = "bad 'from' revision: '" + from + "'";
+	return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
+    }
+
+    if (from_idx < 0)
+	from_idx += current;
+
+    try {
+	if (EMPTY_STRING (to))
+	    to_idx = LONG_MAX;
+	else
+	    to_idx = std::stol (to);
+    } catch (std::logic_error &e) {
+	msg = "bad 'to' revision: '" + to + "'";
+	return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
+    }
+
+    if (to_idx < 0)
+	to_idx += current;
+
+    output = Xapian::Query (Xapian::Query::OP_VALUE_RANGE, NOTMUCH_VALUE_LAST_MOD,
+			    Xapian::sortable_serialise (from_idx),
+			    Xapian::sortable_serialise (to_idx));
+    return NOTMUCH_STATUS_SUCCESS;
+}

lib/parse-sexp.cc

@@ -563,38 +563,13 @@ _sexp_parse_range (notmuch_database_t *notmuch,  const _sexp_prefix_t *prefix,
     }
 
     if (strcmp (prefix->name, "lastmod") == 0) {
-	long from_idx, to_idx;
+	notmuch_status_t status;
-
+	status = _notmuch_lastmod_strings_to_query (notmuch, from, to, output, msg);
-	try {
+	if (status) {
-	    if (EMPTY_STRING (from))
+	    if (! msg.empty ())
-		from_idx = 0L;
+		_notmuch_database_log (notmuch, "%s\n", msg.c_str ());
-	    else
-		from_idx = std::stol (from);
-	} catch (std::logic_error &e) {
-	    _notmuch_database_log (notmuch, "bad 'from' revision: '%s'\n", from);
-	    return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 	}
-
+	return status;
-	if (from_idx < 0)
-	    from_idx += notmuch_database_get_revision (notmuch, NULL);
-
-	try {
-	    if (EMPTY_STRING (to))
-		to_idx = LONG_MAX;
-	    else
-		to_idx = std::stol (to);
-	} catch (std::logic_error &e) {
-	    _notmuch_database_log (notmuch, "bad 'to' revision: '%s'\n", to);
-	    return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
-	}
-
-	if (to_idx < 0)
-	    to_idx += notmuch_database_get_revision (notmuch, NULL);
-
-	output = Xapian::Query (Xapian::Query::OP_VALUE_RANGE, NOTMUCH_VALUE_LAST_MOD,
-				Xapian::sortable_serialise (from_idx),
-				Xapian::sortable_serialise (to_idx));
-	return NOTMUCH_STATUS_SUCCESS;
     }
 
     _notmuch_database_log (notmuch, "unimplimented range prefix: '%s'\n", prefix->name);