Add sample zipf distribution randomizer
[fio.git] / io_u.c
diff --git a/io_u.c b/io_u.c
index b049b61..8f2ce30 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -157,8 +157,8 @@ static int get_next_free_block(struct thread_data *td, struct fio_file *f,
        return 1;
 }
 
-static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
-                               enum fio_ddir ddir, unsigned long long *b)
+static int __get_next_rand_offset(struct thread_data *td, struct fio_file *f,
+                                 enum fio_ddir ddir, unsigned long long *b)
 {
        unsigned long long rmax, r, lastb;
        int loops = 5;
@@ -234,6 +234,25 @@ ret:
        return 0;
 }
 
+static int __get_next_rand_offset_zipf(struct thread_data *td, struct fio_file *f,
+                                 enum fio_ddir ddir, unsigned long long *b)
+{
+       *b = zipf_next(&td->zipf);
+       return 0;
+}
+
+static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
+                               enum fio_ddir ddir, unsigned long long *b)
+{
+       if (td->o.random_distribution == FIO_RAND_DIST_RANDOM)
+               return __get_next_rand_offset(td, f, ddir, b);
+       else if (td->o.random_distribution == FIO_RAND_DIST_ZIPF)
+               return __get_next_rand_offset_zipf(td, f, ddir, b);
+
+       log_err("fio: unknown random distribution: %d\n", td->o.random_distribution);
+       return 1;
+}
+
 static int get_next_rand_block(struct thread_data *td, struct fio_file *f,
                               enum fio_ddir ddir, unsigned long long *b)
 {