reftable/system: introduce `reftable_rand()`

Introduce a new system-level `reftable_rand()` function that generates a
single unsigned integer for us. The implementation of this function is
to be provided by the calling codebase, which allows us to more easily
hook into pre-seeded random number generators.

Adapt the two callsites where we generated random data.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/reftable/system.h b/reftable/system.h
index d02eacea8f..bb6a7e6285 100644
--- a/reftable/system.h
+++ b/reftable/system.h
@@ -15,6 +15,12 @@ https://developers.google.com/open-source/licenses/bsd
 #include "compat/zlib-compat.h"
 
 /*
+ * Return a random 32 bit integer. This function is expected to return
+ * pre-seeded data.
+ */
+uint32_t reftable_rand(void);
+
+/*
  * An implementation-specific temporary file. By making this specific to the
  * implementation it becomes possible to tie temporary files into any kind of
  * signal or atexit handlers for cleanup on abnormal situations.