From 49386868de1cebebfb1e9f9527560e17197ad94f Mon Sep 17 00:00:00 2001 From: David Turner Date: Thu, 25 Feb 2016 15:05:46 -0500 Subject: [PATCH] refs: document transaction semantics Add some comments on ref transaction semantics to refs.h Signed-off-by: David Turner Signed-off-by: Junio C Hamano --- refs.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/refs.h b/refs.h index 7a0407748..19ebebcce 100644 --- a/refs.h +++ b/refs.h @@ -109,6 +109,11 @@ extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref); * If this succeeds, the ref updates will have taken place and * the transaction cannot be rolled back. * + * - Instead of `ref_transaction_commit`, use + * `initial_ref_transaction_commit()` if the ref database is known + * to be empty (e.g. during clone). This is likely to be much + * faster. + * * - At any time call `ref_transaction_free()` to discard the * transaction and free associated resources. In particular, * this rolls back the transaction if it has not been @@ -124,6 +129,13 @@ extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref); * * The message is appended to err without first clearing err. * err will not be '\n' terminated. + * + * Caveats + * ------- + * + * Note that no locks are taken, and no refs are read, until + * `ref_transaction_commit` is called. So `ref_transaction_verify` + * won't report a verification failure until the commit is attempted. */ struct ref_transaction;