From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fout-b6-smtp.messagingengine.com (fout-b6-smtp.messagingengine.com [202.12.124.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5550E63D for ; Mon, 25 Nov 2024 00:39:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.149 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732495197; cv=none; b=Y4JiOO/VPwY46adM2/fUE27jVhsNS1RrI8eTNy/9WSdhVvNs1vfu6nH6hG/6gFX9DTxbP2KFCcW9Hr1nvj+w/z7E/SDa38IFiLfMdaMqXwHx612zEsQdCpKCF2va4+JDVPO4pctxt4QexxLBCMhHa5M3f0C18yGWuFSok9FE9X0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732495197; c=relaxed/simple; bh=qadNTea8eJKGqpzf50F6e6TWxMcb8AWLDOklxxAgJWY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=bm5SUlCSwO8ryvFxPU38W8HXxZhLp0QCDmFh5r3/EYIcwlSpnreAC2r+8VCHI1LijleR9sSfYhcaoZzwVEbk8vz5s7thyHSimEg3zTlKIzeu/J4bNtqMlbKp4+6ldyf75kRdopkYAhS8XeYYTQ8GKRB992LNbSzh5U3jCE/jjP8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com; spf=pass smtp.mailfrom=pobox.com; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=Hsa/74f6; arc=none smtp.client-ip=202.12.124.149 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pobox.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="Hsa/74f6" Received: from phl-compute-04.internal (phl-compute-04.phl.internal [10.202.2.44]) by mailfout.stl.internal (Postfix) with ESMTP id 1E8081140134; Sun, 24 Nov 2024 19:39:54 -0500 (EST) Received: from phl-frontend-01 ([10.202.2.160]) by phl-compute-04.internal (MEProxy); Sun, 24 Nov 2024 19:39:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t= 1732495193; x=1732581593; bh=u9ezfYOLgUw+UsTXJ1HaAmbiRSbITyuAn41 6TmMM9VM=; b=Hsa/74f6D/+minwuW3ARfgcw2k2XZOM0Fy7+qUVeQOoWClGq2GH JBi4dHCGCRobUnCflKHNfZyyIUFVm4K5ph9Lo566PKCdafHTl6pvL0H87gIHmQ8D btH9T0FM9gE3Pm1XjvxKj+m9fMMS46m9nfFsiD/CoWDLPuFMgoEPsjVaQEV60CpC 51v2FGIiBoZqMQrsLNlRIUUwlWKneoHDy88GiAdCr4zQyyT2vKE3b0dw25a41ez4 byZOLqVxEbVIhgVd9iBHDL6ZKroel5e0nyBjYCydd1tG6snrsOWAY8+3YELKNAoi qpuAylbslQ6Zyqu9uqBnLywOrCILwltTYlA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrgeeggddvgecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdpuffr tefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnth hsucdlqddutddtmdenucfjughrpefhvfevufgjfhffkfgfgggtsehttdertddtredtnecu hfhrohhmpefluhhnihhoucevucfjrghmrghnohcuoehgihhtshhtvghrsehpohgsohigrd gtohhmqeenucggtffrrghtthgvrhhnpeefveetteejheeugeffledvteeiveffueefjeel ueffteeigffgfedthfefieegieenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmh epmhgrihhlfhhrohhmpehgihhtshhtvghrsehpohgsohigrdgtohhmpdhnsggprhgtphht thhopeduuddpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepjhhonhgrthhhrghnth grnhhmhiesghhoohhglhgvrdgtohhmpdhrtghpthhtohepghhithhgihhtghgrughgvght sehgmhgrihhlrdgtohhmpdhrtghpthhtohepghhithesvhhgvghrrdhkvghrnhgvlhdroh hrghdprhgtphhtthhopehjohhhrghnnhgvshdrshgthhhinhguvghlihhnsehgmhigrdgu vgdprhgtphhtthhopehpvghffhesphgvfhhfrdhnvghtpdhrtghpthhtohepphhssehpkh hsrdhimhdprhgtphhtthhopehmvgesthhtrgihlhhorhhrrdgtohhmpdhrtghpthhtohep jhhohhhntggrihekieesghhmrghilhdrtghomhdprhgtphhtthhopehnvgifrhgvnhesgh hmrghilhdrtghomh X-ME-Proxy: Feedback-ID: if26b431b:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 24 Nov 2024 19:39:53 -0500 (EST) From: Junio C Hamano To: Jonathan Tan Cc: Derrick Stolee via GitGitGadget , git@vger.kernel.org, johannes.schindelin@gmx.de, peff@peff.net, ps@pks.im, me@ttaylorr.com, johncai86@gmail.com, newren@gmail.com, Derrick Stolee Subject: Re: [PATCH 3/7] pack-objects: add GIT_TEST_FULL_NAME_HASH In-Reply-To: <20241122180144.523048-1-jonathantanmy@google.com> (Jonathan Tan's message of "Fri, 22 Nov 2024 10:01:44 -0800") References: <20241122180144.523048-1-jonathantanmy@google.com> Date: Mon, 25 Nov 2024 09:39:51 +0900 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Jonathan Tan writes: > Junio C Hamano writes: >> It is sad that it is a (probably unfixable) flaw in the "promisor >> object" concept that the "promisor object"-ness of blobA depends on >> the lazy-fetch status of treeA. This is not merely a test failure, >> but it would cause blobA pruned if such a lazy fetch happens in the >> wild and then "git gc" triggers, no? > > Right now, it won't be pruned since we never prune promisor objects > (we just concatenate all of them into one file). Sorry, but I am lost. In the scenario discussed, you have two commits A and B with their trees and blobs. You initially only have commit A because the partial clone is done with "tree:0". Then you fetch commit B (A's child), tree B in non-delta form, and blob B contained within tree B. Due to the tweak in the name hash function, we do not know of tree A (we used to learn about it because tree B was sent as a delta against it with the old name hash). If blob B was sent as a delta against blob A, lazy fetch would later materialize blob A even if you do not still have tree A, no? I thought the story was that we would not know who refers to blobA when treeA hasn't been lazily fetched, hence we cannot tell if blobA is a "promisor object" to begin with, no? The blob in such a scenario may be reclaimed by GC and we may still be able to refetch from the promisor, so it may not be the end of the world, but feels suboptimal.