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From: Jeff King <peff@peff•net>
To: "René Scharfe" <l.s.r@web•de>
Cc: Git List <git@vger•kernel.org>
Subject: Re: [PATCH 2/3] prio-queue: add prio_queue_replace()
Date: Wed, 16 Jul 2025 01:09:33 -0400	[thread overview]
Message-ID: <20250716050933.GC1396022@coredump.intra.peff.net> (raw)
In-Reply-To: <cbabed69-b44a-4920-9a56-e81b404be2de@web.de>

On Tue, Jul 15, 2025 at 04:51:22PM +0200, René Scharfe wrote:

> Add a function to replace the top element of the queue that basically
> does the same as prio_queue_get() followed by prio_queue_put(), but
> without the work by prio_queue_get() to rebalance the heap.  It can be
> used to optimize loops that get one element and then immediately add
> another one.  That's common e.g., with commit history traversal, where
> we get out a commit and then put in its parents.

Hmm. But surely we still need to rebalance the heap after adding an
element? And indeed, we still call the new sift_down_root() function.

But I guess we are getting away without the "bubble up" operation that
put would do? So we are doing half as much work (but still big-O the
same)?

-Peff

  reply	other threads:[~2025-07-16  5:09 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-15 14:35 [PATCH 0/3] commit: convert pop_most_recent_commit() to prio_queue René Scharfe
2025-07-15 14:51 ` [PATCH 1/3] " René Scharfe
2025-07-15 19:23   ` Junio C Hamano
2025-07-15 20:47   ` Justin Tobler
2025-07-16  9:39     ` René Scharfe
2025-07-16  5:05   ` Jeff King
2025-07-16  9:39     ` René Scharfe
2025-07-17  8:22       ` René Scharfe
2025-07-19  6:55       ` Jeff King
2025-07-19  6:57         ` Jeff King
2025-07-19 11:15         ` René Scharfe
2025-07-20  0:03           ` Jeff King
2025-07-20  1:22             ` Junio C Hamano
2025-07-16 22:23   ` Junio C Hamano
2025-07-17  8:22     ` René Scharfe
2025-07-15 14:51 ` [PATCH 2/3] prio-queue: add prio_queue_replace() René Scharfe
2025-07-16  5:09   ` Jeff King [this message]
2025-07-16  9:38     ` René Scharfe
2025-07-17  9:20       ` René Scharfe
2025-07-19  7:02         ` Jeff King
2025-07-15 14:51 ` [PATCH 3/3] commit: use prio_queue_replace() in pop_most_recent_commit() René Scharfe
2025-07-15 20:43   ` Junio C Hamano
2025-07-16  9:38     ` René Scharfe
2025-07-16  0:07 ` [PATCH 0/3] commit: convert pop_most_recent_commit() to prio_queue Junio C Hamano
2025-07-16  5:15   ` Jeff King
2025-07-16  9:38     ` René Scharfe
2025-07-19  6:45       ` Jeff King
2025-07-16 14:49     ` Junio C Hamano
2025-07-18  9:09 ` [PATCH v2 " René Scharfe
2025-07-18  9:39   ` [PATCH v2 1/3] " René Scharfe
2025-07-21 14:02     ` Lidong Yan
2025-08-03  9:54       ` René Scharfe
2025-08-03 16:48         ` Junio C Hamano
2025-08-04 19:56           ` René Scharfe
2025-07-18  9:39   ` [PATCH v2 3/3] commit: use prio_queue_replace() in pop_most_recent_commit(),MIME-Version: 1.0 René Scharfe
2025-08-03 11:12     ` Johannes Schindelin
2025-08-03 11:33       ` René Scharfe
2025-07-18  9:39   ` [PATCH v2 2/3] prio-queue: add prio_queue_replace() René Scharfe
2025-07-19  7:04   ` [PATCH v2 0/3] commit: convert pop_most_recent_commit() to prio_queue Jeff King
2025-07-22  6:26   ` SZEDER Gábor
2025-07-22 14:27     ` Junio C Hamano

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