commit-slab: provide a static initializer

Callers currently must use init_foo_slab() at runtime before
accessing a slab. For global slabs, it's much nicer if we
can initialize them in BSS, so that each user does not have
to add code to check-and-initialize.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/commit-slab.h b/commit-slab.h
index cc114b53b0..375c9c751a 100644
--- a/commit-slab.h
+++ b/commit-slab.h
@@ -117,4 +117,16 @@ static int stat_ ##slabname## realloc
  * catch because GCC silently parses it by default.
  */
 
+/*
+ * Statically initialize a commit slab named "var". Note that this
+ * evaluates "stride" multiple times! Example:
+ *
+ *   struct indegree indegrees = COMMIT_SLAB_INIT(1, indegrees);
+ *
+ */
+#define COMMIT_SLAB_INIT(stride, var) { \
+	COMMIT_SLAB_SIZE / sizeof(**((var).slab)) / (stride), \
+	(stride), 0, NULL \
+}
+
 #endif /* COMMIT_SLAB_H */