sha256: recycle I/O buffer used in stream hash.

* chksum.c (sha256_stream): Use iobuf_get and iobuf_put.

* gc.c (gc): Do not mark the list of recycled buffers; just
consider them to be garbage and clear the list, like we do
with recycled conses via rcyc_empty.

* stream.c (iobuf_free_list): New static variable.
(iobuf_get, iobuf_put, iobuf_list_empty): New functions.

* stream.h (iobuf_get, iobuf_put, iobuf_list_empty): Declared.

1 files changed, 1 insertions, 0 deletions

diff --git a/gc.c b/gc.c
index 178e1cc6..4c8d9f6d 100644
--- a/gc.c
+++ b/gc.c
@@ -754,6 +754,7 @@ void gc(void)
   save_context(mc);
   gc_enabled = 0;
   rcyc_empty();
+  iobuf_list_empty();
   mark(&mc, &gc_stack_top);
   hash_process_weak();
   prepare_finals();