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From: David Turner <dturner@twopensource.com>
To: git@vger.kernel.org, pclouds@gmail.com
Subject: Re: [PATCH] refs: document transaction semantics
Date: Thu, 25 Feb 2016 15:10:13 -0500	[thread overview]
Message-ID: <1456431013.18017.50.camel@twopensource.com> (raw)
In-Reply-To: <1456430746-5565-1-git-send-email-dturner@twopensource.com>

I thought it would be better in the api docs, since it's a design
decision that all backends should follow.

On Thu, 2016-02-25 at 15:05 -0500, David Turner wrote:
> Add some comments on ref transaction semantics to refs.h
> 
> Signed-off-by: David Turner <dturner@twopensource.com>
> ---
>  refs.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/refs.h b/refs.h
> index c0964f5..9b3eaf3 100644
> --- a/refs.h
> +++ b/refs.h
> @@ -112,6 +112,11 @@ 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
> @@ -127,6 +132,13 @@ 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;
>  

  reply	other threads:[~2016-02-25 20:10 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-18  5:17 [PATCH v5 00/27] refs backends David Turner
2016-02-18  5:17 ` [PATCH v5 01/27] refs: Move head_ref{,_submodule} to the common code David Turner
2016-02-18  5:17 ` [PATCH v5 02/27] refs: move for_each_*ref* functions into " David Turner
2016-02-18  5:17 ` [PATCH v5 03/27] refs: add a backend method structure with transaction functions David Turner
2016-02-18  5:17 ` [PATCH v5 04/27] refs: add methods for misc ref operations David Turner
2016-02-18  5:17 ` [PATCH v5 05/27] refs: add method for do_for_each_ref David Turner
2016-02-18  5:17 ` [PATCH v5 06/27] refs: add do_for_each_per_worktree_ref David Turner
2016-02-18  5:17 ` [PATCH v5 07/27] refs: add methods for reflog David Turner
2016-02-18  5:17 ` [PATCH v5 08/27] refs: add method for initial ref transaction commit David Turner
2016-02-18  5:17 ` [PATCH v5 09/27] refs: add method for delete_refs David Turner
2016-02-18  5:17 ` [PATCH v5 10/27] refs: add methods to init refs db David Turner
2016-02-18  5:17 ` [PATCH v5 11/27] refs: add method to rename refs David Turner
2016-02-18  5:17 ` [PATCH v5 12/27] refs: forbid cross-backend ref renames David Turner
2016-02-20  4:30   ` Duy Nguyen
2016-02-24 20:48     ` David Turner
2016-02-18  5:17 ` [PATCH v5 13/27] refs: make lock generic David Turner
2016-02-18  5:17 ` [PATCH v5 14/27] refs: move duplicate check to common code David Turner
2016-02-18  5:17 ` [PATCH v5 15/27] refs: allow log-only updates David Turner
2016-02-18  5:17 ` [PATCH v5 16/27] refs: don't dereference on rename David Turner
2016-02-18  5:17 ` [PATCH v5 17/27] refs: on symref reflog expire, lock symref not referrent David Turner
2016-02-18  5:17 ` [PATCH v5 18/27] refs: resolve symbolic refs first David Turner
2016-02-18  5:17 ` [PATCH v5 19/27] refs: always handle non-normal refs in files backend David Turner
2016-02-18  5:17 ` [PATCH v5 20/27] init: allow alternate ref strorage to be set for new repos David Turner
2016-02-18  5:17 ` [PATCH v5 21/27] refs: check submodules' ref storage config David Turner
2016-02-18  5:17 ` [PATCH v5 22/27] clone: allow ref storage backend to be set for clone David Turner
2016-02-18  5:17 ` [PATCH v5 23/27] svn: learn ref-storage argument David Turner
2016-02-20 23:55   ` Eric Wong
2016-02-23 18:08     ` David Turner
2016-02-18  5:17 ` [PATCH v5 24/27] refs: add register_ref_storage_backends() David Turner
2016-02-18  5:17 ` [PATCH v5 25/27] refs: add LMDB refs storage backend David Turner
2016-02-18  8:50   ` Duy Nguyen
2016-02-18 20:23     ` David Turner
2016-02-18 21:15       ` Junio C Hamano
2016-02-19  2:54       ` Duy Nguyen
2016-02-19 19:10         ` David Turner
2016-02-20 13:14       ` Duy Nguyen
2016-02-24 20:41         ` David Turner
2016-02-20 21:32       ` Junio C Hamano
2016-02-19 22:49     ` David Turner
2016-02-19 23:08       ` Junio C Hamano
2016-02-20  2:58       ` Duy Nguyen
2016-02-24 20:43         ` David Turner
2016-02-25 10:07           ` Duy Nguyen
2016-02-20  8:59   ` Duy Nguyen
2016-02-24 20:37     ` David Turner
2016-02-25 10:12       ` Duy Nguyen
2016-02-25 20:05         ` [PATCH] refs: document transaction semantics David Turner
2016-02-25 20:10           ` David Turner [this message]
2016-02-25 20:34             ` Junio C Hamano
2016-02-25 20:50               ` David Turner
2016-02-18  5:17 ` [PATCH v5 26/27] refs: tests for lmdb backend David Turner
2016-02-18  5:17 ` [PATCH v5 27/27] tests: add ref-storage argument David Turner

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