[patch v5 3/6] lib: create field processors from prefix table

[David Bremner]

This is a bit more code than hardcoding the two existing field
processors, but it should make it easy to add more.
---
 lib/database-private.h |  3 ++-
 lib/database.cc        | 45 +++++++++++++++++++++++++++++++--------------
 2 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/lib/database-private.h b/lib/database-private.h
index 2fb60f5e..60d1fead 100644
--- a/lib/database-private.h
+++ b/lib/database-private.h
@@ -153,7 +153,8 @@ operator&=(_notmuch_features &a, _notmuch_features b)
 typedef enum notmuch_field_flags {
     NOTMUCH_FIELD_NO_FLAGS = 0,
     NOTMUCH_FIELD_EXTERNAL = 1 << 0,
-    NOTMUCH_FIELD_PROBABILISTIC = 1 << 1
+    NOTMUCH_FIELD_PROBABILISTIC = 1 << 1,
+    NOTMUCH_FIELD_PROCESSOR = 1 << 2
 } notmuch_field_flag_t;
 
 /*
diff --git a/lib/database.cc b/lib/database.cc
index 8016c4df..450ee295 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -270,6 +270,12 @@ prefix_t prefix_table[] = {
      * discussion.
      */
     { "folder",			"XFOLDER:",	NOTMUCH_FIELD_EXTERNAL },
+#if HAVE_XAPIAN_FIELD_PROCESSOR
+    { "date",			NULL,		NOTMUCH_FIELD_EXTERNAL |
+						NOTMUCH_FIELD_PROCESSOR },
+    { "query",			NULL,		NOTMUCH_FIELD_EXTERNAL |
+						NOTMUCH_FIELD_PROCESSOR },
+#endif
     { "from",			"XFROM",	NOTMUCH_FIELD_EXTERNAL |
 						NOTMUCH_FIELD_PROBABILISTIC },
     { "to",			"XTO",		NOTMUCH_FIELD_EXTERNAL |
@@ -282,6 +288,20 @@ prefix_t prefix_table[] = {
 						NOTMUCH_FIELD_PROBABILISTIC },
 };
 
+#if HAVE_XAPIAN_FIELD_PROCESSOR
+static Xapian::FieldProcessor *
+_make_field_processor (const char *name, notmuch_database_t *notmuch) {
+    if (STRNCMP_LITERAL (name, "date") == 0)
+	return (new DateFieldProcessor())->release ();
+    else if (STRNCMP_LITERAL(name, "query") == 0)
+	return (new QueryFieldProcessor (*notmuch->query_parser, notmuch))->release ();
+
+    INTERNAL_ERROR ("no field processor for prefix '%s'\n", name);
+}
+#else
+#define _make_field_processor(name, db) NULL
+#endif
+
 const char *
 _find_prefix (const char *name)
 {
@@ -1027,18 +1047,6 @@ notmuch_database_open_verbose (const char *path,
 	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);
-#if HAVE_XAPIAN_FIELD_PROCESSOR
-	/* This currently relies on the query parser to pass anything
-	 * with a .. to the range processor */
-	{
-	    Xapian::FieldProcessor * date_fp = new DateFieldProcessor();
-	    Xapian::FieldProcessor * query_fp =
-		new QueryFieldProcessor (*notmuch->query_parser, notmuch);
-
-	    notmuch->query_parser->add_boolean_prefix("date", date_fp->release ());
-	    notmuch->query_parser->add_boolean_prefix("query", query_fp->release ());
-	}
-#endif
 	notmuch->last_mod_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_LAST_MOD, "lastmod:");
 
 	notmuch->query_parser->set_default_op (Xapian::Query::OP_AND);
@@ -1052,8 +1060,17 @@ notmuch_database_open_verbose (const char *path,
 	for (i = 0; i < ARRAY_SIZE (prefix_table); i++) {
 	    const prefix_t *prefix = &prefix_table[i];
 	    if (prefix->flags & NOTMUCH_FIELD_EXTERNAL) {
-		if (prefix->flags & NOTMUCH_FIELD_PROBABILISTIC) {
-		    notmuch->query_parser->add_prefix (prefix->name, prefix->prefix);
+		/* we treat all field-processor fields as boolean in order
+		   to get the raw input */
+		if (HAVE_XAPIAN_FIELD_PROCESSOR &&
+		    (prefix->flags & NOTMUCH_FIELD_PROCESSOR)) {
+		    Xapian::FieldProcessor *fp = _make_field_processor (prefix->name,
+									notmuch);
+
+		    notmuch->query_parser->add_boolean_prefix (prefix->name, fp);
+		} else if (prefix->flags & NOTMUCH_FIELD_PROBABILISTIC) {
+			notmuch->query_parser->add_prefix (prefix->name,
+							   prefix->prefix);
 		} else {
 		    notmuch->query_parser->add_boolean_prefix (prefix->name,
 							       prefix->prefix);
-- 
2.11.0