From: Andre Noll <maan@systemlinux.org>
Date: Thu, 9 Jul 2009 18:11:55 +0000 (+0200)
Subject: Add the new "year" mood method.
X-Git-Tag: v0.4.0~52^2~1
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=5f540c5a4793a704bbdd4e7aaf117b8a3e642002

Add the new "year" mood method.

This includes a Y2K heuristic for year tags that contain only two digits. If that two-digit
number N is less or equal than the current year minus 2000, assume that it means 2000 + N.
Otherwise, assume 1900 + N.

Examples: 0 -> 2000, 42 -> 1942, 9->2009.
---

diff --git a/mood.c b/mood.c
index f16d9c4c..239911fd 100644
--- a/mood.c
+++ b/mood.c
@@ -6,6 +6,7 @@
 
 /** \file mood.c Paraslash's mood handling functions. */
 
+#include <time.h>
 #include <regex.h>
 #include <fnmatch.h>
 #include <osl.h>
@@ -167,6 +168,122 @@ static uint64_t int_sqrt(uint64_t x)
 	return res;
 }
 
+#define MOOD_COMPARATORS \
+	MC(LESS, <) \
+	MC(LESS_OR_EQUAL, <=) \
+	MC(EQUAL, =) \
+	MC(EQUAL2, ==) \
+	MC(NOT_EQUAL, !=) \
+	MC(NOT_EQUAL2, <>) \
+	MC(GREATER, >) \
+	MC(GREATER_OR_EQUAL, >=) \
+
+#define MC(a, b) MC_ ## a,
+enum mood_comparator_id {MOOD_COMPARATORS NUM_MOOD_COMPARATORS};
+#undef MC
+#define MC(a, b) # b,
+const char const *mood_comparators[] = {MOOD_COMPARATORS};
+#undef MC
+
+static int parse_mood_comparator(const char *word)
+{
+	int i;
+
+	for (i = 0; i < NUM_MOOD_COMPARATORS; i++)
+		if (!strcmp(word, mood_comparators[i]))
+			return i;
+	return -E_MOOD_SYNTAX;
+}
+
+static int compare_int32(int32_t a, int32_t b, enum mood_comparator_id id)
+{
+	int res;
+
+	switch (id) {
+	case MC_LESS:
+		res = a < b; break;
+	case MC_LESS_OR_EQUAL:
+		res = a <= b; break;
+	case MC_EQUAL:
+	case MC_EQUAL2:
+		res = a == b; break;
+	case MC_NOT_EQUAL:
+	case MC_NOT_EQUAL2:
+		res = a != b; break;
+	case MC_GREATER:
+		res = a > b; break;
+	case MC_GREATER_OR_EQUAL:
+		res = a >= b; break;
+	default:
+		PARA_EMERG_LOG("BUG: invalid mood comparator\n");
+		exit(EXIT_FAILURE);
+	}
+	return res? 100 : -100;
+}
+
+struct mm_year_data {
+	/** The year given at the mood line. */
+	int32_t year;
+	/** Used to detect Y2K issues. */
+	int32_t current_year;
+	/** <, <=, =, !=, >=, or >. */
+	enum mood_comparator_id id;
+};
+
+static int mm_year_parser(int argc, char **argv, void **private)
+{
+	int ret = -E_MOOD_SYNTAX;
+	struct mm_year_data *mmyd = para_malloc(sizeof(*mmyd));
+	time_t current_time;
+	struct tm *gmt;
+
+	if (argc != 2)
+		goto err;
+	ret = parse_mood_comparator(argv[1]);
+	mmyd->id = ret;
+	if (ret < 0)
+		goto err;
+	ret = para_atoi32(argv[2], &mmyd->year);
+	if (ret < 0)
+		goto err;
+	current_time = time(NULL);
+	gmt = gmtime(&current_time);
+	/* tm_year is the number of years since 1900 */
+	mmyd->current_year = gmt->tm_year + 1900;
+	*private = mmyd;
+	return 1;
+err:
+	free(mmyd);
+	return ret;
+}
+
+static int mm_year_score_function(__a_unused const char *path,
+		__a_unused const struct afs_info *afsi,
+		const struct afh_info *afhi,
+		const void *private)
+{
+	const struct mm_year_data *mmyd = private;
+	int32_t tag_year;
+	int ret = para_atoi32(afhi->tags.year, &tag_year);
+
+	if (ret < 0) /* year tag not present or not a number */
+		return -100;
+	if (tag_year < 0)
+		return -100;
+	/* try to work around Y2K issues */
+	if (tag_year < 100) {
+		tag_year += 1900;
+		if (tag_year + 100 <= mmyd->current_year)
+			tag_year += 100; /* assume tag_year >= 2000 */
+	}
+	return compare_int32(tag_year, mmyd->year, mmyd->id);
+}
+
+static void mm_year_cleanup(void *private)
+{
+	free(private);
+}
+
 static int mm_no_attributes_set_parser(int argc, __a_unused char **argv,
 		__a_unused void **ignored)
 {
@@ -329,6 +446,7 @@ static const struct mood_method mood_methods[] = {
 	{DEFINE_MOOD_METHOD(played_rarely)},
 	{DEFINE_MOOD_METHOD(is_set)},
 	{DEFINE_MOOD_METHOD_WITH_CLEANUP(path_matches)},
+	{DEFINE_MOOD_METHOD_WITH_CLEANUP(year)},
 	{.parser = NULL}
 };