diff --git a/src/matches.c b/src/matches.c
new file mode 100644
index 0000000..b1fae2a
--- /dev/null
+++ b/src/matches.c
@@ -0,0 +1,51 @@
+#include "common.h"
+#include "matches.h"
+
+bool
+f2b_matches_create(f2b_matches_t *m, size_t max) {
+  assert(m != NULL);
+  assert(max != 0);
+
+  if ((m->times = calloc(max, sizeof(time_t))) == NULL)
+    return false;
+
+  m->used = 0;
+  m->max  = max;
+  return true;
+}
+
+void
+f2b_matches_destroy(f2b_matches_t *m) {
+  assert(m != NULL);
+
+  FREE(m->times);
+  m->used = 0;
+  m->max  = 0;
+}
+
+bool
+f2b_matches_append(f2b_matches_t *m, time_t t) {
+  assert(m != NULL);
+
+  if (m->used >= m->max)
+    return false;
+
+  m->times[m->used] = t;
+  m->used++;
+  return true;
+}
+
+void
+f2b_matches_expire(f2b_matches_t *m, time_t t) {
+  assert(m != NULL);
+
+  for (size_t i = 0; i < m->used; ) {
+    if (m->times[i] > t) {
+      i++;
+      continue;
+    }
+    m->used--;
+    m->times[i] = m->times[m->used];
+    m->times[m->used] = 0;
+  }
+}
diff --git a/src/matches.h b/src/matches.h
new file mode 100644
index 0000000..89f3de0
--- /dev/null
+++ b/src/matches.h
@@ -0,0 +1,16 @@
+#ifndef F2B_MATCHES_H_
+#define F2B_MATCHES_H_
+
+typedef struct {
+  size_t max;
+  size_t used;
+  time_t *times;
+} f2b_matches_t;
+
+bool f2b_matches_create (f2b_matches_t *m, size_t max);
+void f2b_matches_destroy(f2b_matches_t *m);
+
+bool f2b_matches_append (f2b_matches_t *m, time_t t);
+void f2b_matches_expire (f2b_matches_t *m, time_t t);
+
+#endif /* F2B_MATCHES_H_ */