From patchwork Mon Feb 21 08:02:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Steinhardt X-Patchwork-Id: 12753226 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA25BC433EF for ; Mon, 21 Feb 2022 08:02:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346753AbiBUIDD (ORCPT ); Mon, 21 Feb 2022 03:03:03 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:57182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346770AbiBUICx (ORCPT ); Mon, 21 Feb 2022 03:02:53 -0500 Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AF75B7DD for ; Mon, 21 Feb 2022 00:02:30 -0800 (PST) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id C94CA5C01BB; Mon, 21 Feb 2022 03:02:29 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Mon, 21 Feb 2022 03:02:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pks.im; h=cc:cc :content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm3; bh=V4tjAGBbHvpLW7pnlVDcdjMx04NRXmr1D98T/F ietXU=; b=CoEYWlmUHEjQdcMqdWB1GDiTE1j63lpiTREychvSlVp/FW+WngcX5+ 8Kn0QqrwsCwFjELoP3tRto+74XXu9G6xj38ps0PapBRo7JVNzVUi5nYX94p/6Ygo VugcfLr5edi7+5S3Jgdro7E4QcvYkHmohe+lDfuKpN/avT3xxdW/apYIq1Bo+9Pf vZlo4lrZHerFrnyDdRUDoPuIvlFyA7ul6WqmRJ/pag36LKs1JE8++tU4dlQTKyno kNCPppsVXG4vLBPKaKSuQHwiIsVDX9zuYE/RkwMqOZSB2GaBc3nXb4ulDe/uCzZJ K8njUg4zW/EM0SHG8iUSRu7e+XFYPldw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=V4tjAGBbHvpLW7pnl VDcdjMx04NRXmr1D98T/FietXU=; b=PqRoGxeWQmqT8WyNCabJ0InNUhVDfwbI6 ZNVueSdRtjmNBw2VBy7hWX/2/ebDx9ztNkbkw7qiwWOdLyTemB7ShXeMBM+pTaeN DniIWPHUP30R4Ebg34Nm+Dr5zJ7LS/z6DId2J2e/yY6ug9oo6PaVqk6ltFNjyNPg S+34lHmvzaJDsqRlPJACkbzuLbQXNp0phJX4/B6sy0DrVrQggnTqmgEqEkoaL01/ mbDp9pEV05tXSwWHvAiNMaZ0vGWNPu7rmN0Dwh8BYqUU1TfENlvv7fqLd4l4gBGi yNNLsOr8hKKx+5KfZIWttXNXdSoH63ASzzgaVbiNWcTVOvfsH3xBA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrkeehgdduuddvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehgtderredttddvnecuhfhrohhmpefrrghtrhhi tghkucfuthgvihhnhhgrrhguthcuoehpshesphhkshdrihhmqeenucggtffrrghtthgvrh hnpeehgefhtdefueffheekgfffudelffejtdfhvdejkedthfehvdelgfetgfdvtedthfen ucevlhhushhtvghrufhiiigvpedunecurfgrrhgrmhepmhgrihhlfhhrohhmpehpshesph hkshdrihhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 21 Feb 2022 03:02:28 -0500 (EST) Received: from localhost (ncase [10.192.0.11]) by vm-mail.pks.im (OpenSMTPD) with ESMTPSA id a12ce5fc (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Mon, 21 Feb 2022 08:02:27 +0000 (UTC) Date: Mon, 21 Feb 2022 09:02:26 +0100 From: Patrick Steinhardt To: git@vger.kernel.org Cc: Christian Couder , Jonathan Tan , Elijah Newren , Junio C Hamano Subject: [PATCH v3 5/7] refs: add interface to iterate over queued transactional updates Message-ID: <0316d770e9590641a942370c84e4d8a42df2ffcd.1645430423.git.ps@pks.im> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org There is no way for a caller to see whether a reference update has already been queued up for a given reference transaction. There are multiple alternatives to provide this functionality: - We may add a function that simply tells us whether a specific reference has already been queued. If implemented naively then this would potentially be quadratic in runtime behaviour if this question is asked repeatedly because we have to iterate over all references every time. The alternative would be to add a hashmap of all queued reference updates to speed up the lookup, but this adds overhead to all callers. - We may add a flag to `ref_transaction_add_update()` that causes it to skip duplicates, but this has the same runtime concerns as the first alternative. - We may add an interface which lets callers collect all updates which have already been queued such that he can avoid re-adding them. This is the most flexible approach and puts the burden on the caller, but also allows us to not impact any of the existing callsites which don't need this information. This commit implements the last approach: it allows us to compute the map of already-queued updates once up front such that we can then skip all subsequent references which are already part of this map. Signed-off-by: Patrick Steinhardt --- refs.c | 16 ++++++++++++++++ refs.h | 14 ++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/refs.c b/refs.c index d680de3bc0..35d4e69687 100644 --- a/refs.c +++ b/refs.c @@ -2417,6 +2417,22 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction, return refs->be->initial_transaction_commit(refs, transaction, err); } +void ref_transaction_for_each_queued_update(struct ref_transaction *transaction, + ref_transaction_for_each_queued_update_fn cb, + void *cb_data) +{ + int i; + + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + + cb(update->refname, + (update->flags & REF_HAVE_OLD) ? &update->old_oid : NULL, + (update->flags & REF_HAVE_NEW) ? &update->new_oid : NULL, + cb_data); + } +} + int refs_delete_refs(struct ref_store *refs, const char *logmsg, struct string_list *refnames, unsigned int flags) { diff --git a/refs.h b/refs.h index ff859d5951..1ae12c410a 100644 --- a/refs.h +++ b/refs.h @@ -776,6 +776,20 @@ int ref_transaction_abort(struct ref_transaction *transaction, int initial_ref_transaction_commit(struct ref_transaction *transaction, struct strbuf *err); +/* + * Execute the given callback function for each of the reference updates which + * have been queued in the given transaction. `old_oid` and `new_oid` may be + * `NULL` pointers depending on whether the update has these object IDs set or + * not. + */ +typedef void ref_transaction_for_each_queued_update_fn(const char *refname, + const struct object_id *old_oid, + const struct object_id *new_oid, + void *cb_data); +void ref_transaction_for_each_queued_update(struct ref_transaction *transaction, + ref_transaction_for_each_queued_update_fn cb, + void *cb_data); + /* * Free `*transaction` and all associated data. */