1 files changed, 136 insertions, 0 deletions
diff --git a/ccan/ccan/likely/likely.c b/ccan/ccan/likely/likely.c
new file mode 100644
index 0000000..83e8d6f
--- /dev/null
+++ b/ccan/ccan/likely/likely.c
@@ -0,0 +1,136 @@
+/* CC0 (Public domain) - see LICENSE file for details. */
+#ifdef CCAN_LIKELY_DEBUG
+#include <ccan/likely/likely.h>
+#include <ccan/hash/hash.h>
+#include <ccan/htable/htable_type.h>
+#include <stdlib.h>
+#include <stdio.h>
+struct trace {
+	const char *condstr;
+	const char *file;
+	unsigned int line;
+	bool expect;
+	unsigned long count, right;
+};
+
+static size_t hash_trace(const struct trace *trace)
+{
+	return hash(trace->condstr, strlen(trace->condstr),
+		    hash(trace->file, strlen(trace->file),
+			 trace->line + trace->expect));
+}
+
+static bool trace_eq(const struct trace *t1, const struct trace *t2)
+{
+	return t1->condstr == t2->condstr
+		&& t1->file == t2->file
+		&& t1->line == t2->line
+		&& t1->expect == t2->expect;
+}
+
+/* struct thash */
+HTABLE_DEFINE_TYPE(struct trace, (const struct trace *), hash_trace, trace_eq,
+		   thash);
+
+static struct thash htable
+= { HTABLE_INITIALIZER(htable.raw, thash_hash, NULL) };
+
+static void init_trace(struct trace *trace,
+		       const char *condstr, const char *file, unsigned int line,
+		       bool expect)
+{
+	trace->condstr = condstr;
+	trace->file = file;
+	trace->line = line;
+	trace->expect = expect;
+	trace->count = trace->right = 0;
+}
+
+static struct trace *add_trace(const struct trace *t)
+{
+	struct trace *trace = malloc(sizeof(*trace));
+	*trace = *t;
+	thash_add(&htable, trace);
+	return trace;
+}
+
+long _likely_trace(bool cond, bool expect,
+		   const char *condstr,
+		   const char *file, unsigned int line)
+{
+	struct trace *p, trace;
+
+	init_trace(&trace, condstr, file, line, expect);
+	p = thash_get(&htable, &trace);
+	if (!p)
+		p = add_trace(&trace);
+
+	p->count++;
+	if (cond == expect)
+		p->right++;
+
+	return cond;
+}
+
+static double right_ratio(const struct trace *t)
+{
+	return (double)t->right / t->count;
+}
+
+char *likely_stats(unsigned int min_hits, unsigned int percent)
+{
+	struct trace *worst;
+	double worst_ratio;
+	struct thash_iter i;
+	char *ret;
+	struct trace *t;
+
+	worst = NULL;
+	worst_ratio = 2;
+
+	/* This is O(n), but it's not likely called that often. */
+	for (t = thash_first(&htable, &i); t; t = thash_next(&htable, &i)) {
+		if (t->count >= min_hits) {
+			if (right_ratio(t) < worst_ratio) {
+				worst = t;
+				worst_ratio = right_ratio(t);
+			}
+		}
+	}
+
+	if (worst_ratio * 100 > percent)
+		return NULL;
+
+	ret = malloc(strlen(worst->condstr) +
+		     strlen(worst->file) +
+		     sizeof(long int) * 8 +
+		     sizeof("%s:%u:%slikely(%s) correct %u%% (%lu/%lu)"));
+	sprintf(ret, "%s:%u:%slikely(%s) correct %u%% (%lu/%lu)",
+		worst->file, worst->line,
+		worst->expect ? "" : "un", worst->condstr,
+		(unsigned)(worst_ratio * 100),
+		worst->right, worst->count);
+
+	thash_del(&htable, worst);
+	free(worst);
+
+	return ret;
+}
+
+void likely_stats_reset(void)
+{
+	struct thash_iter i;
+	struct trace *t;
+
+	/* This is a bit better than O(n^2), but we have to loop since
+	 * first/next during delete is unreliable. */
+	while ((t = thash_first(&htable, &i)) != NULL) {
+		for (; t; t = thash_next(&htable, &i)) {
+			thash_del(&htable, t);
+			free(t);
+		}
+	}
+
+	thash_clear(&htable);
+}
+#endif /*CCAN_LIKELY_DEBUG*/