From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Beller Subject: [PATCH v4 09/16] refs.c: write updates to packed refs when a transaction has more than one ref Date: Mon, 17 Nov 2014 17:44:50 -0800 Message-ID: <1416275097-3616-10-git-send-email-sbeller@google.com> References: <1416275097-3616-1-git-send-email-sbeller@google.com> Cc: Ronnie Sahlberg , Stefan Beller To: git@vger.kernel.org, gitster@pobox.com, mhagger@alum.mit.edu X-From: git-owner@vger.kernel.org Tue Nov 18 02:46:01 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XqXri-00040h-BR for gcvg-git-2@plane.gmane.org; Tue, 18 Nov 2014 02:45:58 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753670AbaKRBpS (ORCPT ); Mon, 17 Nov 2014 20:45:18 -0500 Received: from mail-ie0-f179.google.com ([209.85.223.179]:35076 "EHLO mail-ie0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753642AbaKRBpO (ORCPT ); Mon, 17 Nov 2014 20:45:14 -0500 Received: by mail-ie0-f179.google.com with SMTP id rp18so3100816iec.10 for ; Mon, 17 Nov 2014 17:45:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=fhBZJCTyMrqP4/7nYeFxbSKSiHqxQOP6WOJ7XyYCCM0=; b=EoeEuM4jXiTBHg7VRQM5vPz/PTqx1lmYTpx4d2/ZO5aKazdB0TwmJkDMR09nefqZ34 s5bniP754LvOmCYwQ9pokHGyUTBbABdABQ9NdF4pNsFmbkac2EMfeFnkKMczHOVuQkoJ FGcVso/6HEsQEeW8OL4cD2qZaChnkBiwQEvtjDgCwI6hTMnVzUUVPt9WbpwTB7GMJQDQ k3xFiepuWkkdqHGyDa/7yZiZNEz8TPMoolToBnXyo6uhg/lV3GF0wCote4OnBpVQpLxk LbCusu4r+KmIHIsPEw5ug5RiUUXb1/Zeh3djrxd/S/OANGD3TUa5PcQwJg2GV71Je/cE vcCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=fhBZJCTyMrqP4/7nYeFxbSKSiHqxQOP6WOJ7XyYCCM0=; b=USgDM8GPCsTIC2Nh5/t42AgVzPebq1F1MTvysaCEPAq2d5VqurdLXY4w8AYT3RLkn9 /Btt3FlhuvXhu66mRz26dH4H7DKKZg5tIBQ4VTCVTMyejEQGvqGx9f8HaDrn8+KXuFVX fTK3gzJ/Ozq0ikptTI+re/IBTFkfBpyqHdge6iWJXiHA2iygljHgW1DJ/ymunK5NaK4u NBspf6ltmQATD/rqYymZcKJojGSrkr93hm8uh2eKsU3exRWowm5K3TKKCGSTZSLFKyE9 eG6yO3SNmeN6KVgSbqoib8665JIDzfjLjIrludFQj8HESNSUZIB3JJ0Mf5K7DRqypq9Z Ngnw== X-Gm-Message-State: ALoCoQnbSKXeB80SRr5b2abFAZHnYz/1LNFW1X5vQ6DOI9iXxmRtSph6qVDPtMJ6QV0YLJu+gAdg X-Received: by 10.107.172.68 with SMTP id v65mr6711467ioe.60.1416275113280; Mon, 17 Nov 2014 17:45:13 -0800 (PST) Received: from localhost ([2620:0:1000:5b00:c9d9:b6de:cff4:3fc7]) by mx.google.com with ESMTPSA id zy11sm6883868igc.4.2014.11.17.17.45.12 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 17 Nov 2014 17:45:12 -0800 (PST) X-Mailer: git-send-email 2.2.0.rc2.5.gf7b9fb2 In-Reply-To: <1416275097-3616-1-git-send-email-sbeller@google.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Ronnie Sahlberg When we are updating more than one single ref, i.e. not a commit, then write the updated refs directly to the packed refs file instead of writing them as loose refs. Change clone to use a transaction instead of using the packed refs API. This changes the behavior of clone slightly. Previously clone would always clone all refs into a packed refs file. With this change clone will only clone into packed refs iff there are two or more refs being cloned. If the repository we are cloning from only contains exactly one single ref then clone will now store this as a loose ref. The benefit here is that we no longer need to export a bunch of API functions to clone to access packed refs directly. Clone can now just use a normal transaction and all the packed refs goodness will happen automatically. Update the t5516 test to cope with the fact that clone now only uses packed refs if there are more than one ref being cloned. We still use loose refs for single ref transactions, such as are used by 'git commit' and friends. The reason for this is that if you have very many refs then having to re-write the whole packed refs file for every common operation like commit would have a performance impact. That said, with these changes it should now be fairly straightforward to add support to optionally start using packed refs for ALL updates which could solve existing issues with name clashes in case insensitive filesystems. This change also means that multi-ref updates will now appear as a single atomic change to any external observers instead of a sequence of discreete changes. Signed-off-by: Ronnie Sahlberg Signed-off-by: Stefan Beller --- builtin/clone.c | 16 ++++++--- refs.c | 89 ++++++++++++++++++++++++++++++++++----------------- t/t5516-fetch-push.sh | 2 +- 3 files changed, 72 insertions(+), 35 deletions(-) diff --git a/builtin/clone.c b/builtin/clone.c index d5e7532..9e4c42b 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -495,17 +495,25 @@ static struct ref *wanted_peer_refs(const struct ref *refs, static void write_remote_refs(const struct ref *local_refs) { const struct ref *r; + struct transaction *transaction; + struct strbuf err = STRBUF_INIT; - lock_packed_refs(LOCK_DIE_ON_ERROR); + transaction = transaction_begin(&err); + if (!transaction) + die("%s", err.buf); for (r = local_refs; r; r = r->next) { if (!r->peer_ref) continue; - add_packed_ref(r->peer_ref->name, r->old_sha1); + if (transaction_update_ref(transaction, r->peer_ref->name, + r->old_sha1, NULL, 0, 0, NULL, + &err)) + die("%s", err.buf); } - if (commit_packed_refs()) - die_errno("unable to overwrite old ref-pack file"); + if (transaction_commit(transaction, &err)) + die("%s", err.buf); + transaction_free(transaction); } static void write_followtags(const struct ref *refs, const char *msg) diff --git a/refs.c b/refs.c index 75c6d3b..130d240 100644 --- a/refs.c +++ b/refs.c @@ -2673,36 +2673,15 @@ int repack_without_refs(struct string_list *without, struct strbuf *err) struct ref_dir *packed; struct string_list refs_to_delete = STRING_LIST_INIT_DUP; struct string_list_item *ref_to_delete; - int count, ret, removed = 0; + int ret; assert(err); - /* Look for a packed ref */ - count = 0; - for_each_string_list_item(ref_to_delete, without) - if (get_packed_ref(ref_to_delete->string)) - count++; - - /* No refname exists in packed refs */ - if (!count) { - rollback_packed_refs(); - return 0; - } - packed = get_packed_refs(&ref_cache); /* Remove refnames from the cache */ for_each_string_list_item(ref_to_delete, without) - if (remove_entry(packed, ref_to_delete->string) != -1) - removed = 1; - if (!removed) { - /* - * All packed entries disappeared while we were - * acquiring the lock. - */ - rollback_packed_refs(); - return 0; - } + remove_entry(packed, ref_to_delete->string); /* Remove any other accumulated cruft */ do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete); @@ -3791,6 +3770,7 @@ int transaction_commit(struct transaction *transaction, struct strbuf *err) { int ret = 0, i, need_repack = 0; + int num_updates = 0; int n = transaction->nr; struct packed_ref_cache *packed_ref_cache; struct ref_update **updates = transaction->updates; @@ -3824,14 +3804,30 @@ int transaction_commit(struct transaction *transaction, goto cleanup; } - /* any loose refs are to be deleted are first copied to packed refs */ + /* count how many refs we are updating (not deleting) */ + for (i = 0; i < n; i++) { + struct ref_update *update = updates[i]; + + if (update->update_type != UPDATE_SHA1) + continue; + if (is_null_sha1(update->new_sha1)) + continue; + + num_updates++; + } + + /* + * Always copy loose refs that are to be deleted to the packed refs. + * If we are updating multiple refs then copy all refs to the packed + * refs file. + */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; unsigned char sha1[20]; if (update->update_type != UPDATE_SHA1) continue; - if (!is_null_sha1(update->new_sha1)) + if (num_updates < 2 && !is_null_sha1(update->new_sha1)) continue; if (get_packed_ref(update->refname)) continue; @@ -3843,7 +3839,7 @@ int transaction_commit(struct transaction *transaction, need_repack = 1; } if (need_repack) { - packed = get_packed_refs(&ref_cache);; + packed = get_packed_refs(&ref_cache); sort_ref_dir(packed); if (commit_packed_refs()){ strbuf_addf(err, "unable to overwrite old ref-pack " @@ -3860,13 +3856,15 @@ int transaction_commit(struct transaction *transaction, goto cleanup; } } + need_repack = 0; /* * At this stage any refs that are to be deleted have been moved to the - * packed refs file anf the packed refs file is deleted. We can now + * packed refs file and the packed refs file is committed. We can now * safely delete these loose refs. + * If we are updating multiple refs then those will also be in the + * packed refs file so we can delete those too. */ - /* Unlink any loose refs scheduled for deletion */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; @@ -3905,7 +3903,10 @@ int transaction_commit(struct transaction *transaction, update->lock = NULL; } - /* Acquire all ref locks for updates while verifying old values */ + /* + * Acquire all ref locks for updates while verifying old values. + * If we are multi-updating then update them in packed refs. + */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; @@ -3928,6 +3929,30 @@ int transaction_commit(struct transaction *transaction, update->refname); goto cleanup; } + if (num_updates < 2) + continue; + + if (delete_ref_loose(update->lock, update->type, err)) { + ret = -1; + goto cleanup; + } + if (write_sha1_update_reflog(update->lock, update->new_sha1, + update->msg)) { + if (err) + strbuf_addf(err, "Failed to update log '%s'.", + update->refname); + ret = -1; + goto cleanup; + } + unlock_ref(update->lock); + update->lock = NULL; + + packed = get_packed_refs(&ref_cache); + remove_entry(packed, update->refname); + add_packed_ref(update->refname, update->new_sha1); + need_repack = 1; + + try_remove_empty_parents((char *)update->refname); } /* delete reflog for all deleted refs */ @@ -3976,7 +4001,7 @@ int transaction_commit(struct transaction *transaction, if (update->update_type != UPDATE_SHA1) continue; - if (!is_null_sha1(update->new_sha1)) { + if (update->lock && !is_null_sha1(update->new_sha1)) { if (write_ref_sha1(update->lock, update->new_sha1, update->msg)) { update->lock = NULL; /* freed by write_ref_sha1 */ @@ -4049,6 +4074,10 @@ int transaction_commit(struct transaction *transaction, } } + if (need_repack) { + packed = get_packed_refs(&ref_cache); + sort_ref_dir(packed); + } if (repack_without_refs(&refs_to_delete, err)) ret = TRANSACTION_GENERIC_ERROR; clear_loose_ref_cache(&ref_cache); diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh index f4da20a..5d422a8 100755 --- a/t/t5516-fetch-push.sh +++ b/t/t5516-fetch-push.sh @@ -593,7 +593,7 @@ test_expect_success 'push updates up-to-date local refs' ' test_expect_success 'push preserves up-to-date packed refs' ' - mk_test testrepo heads/master && + mk_test testrepo heads/master heads/foo heads/bar && mk_child testrepo child && ( cd child && -- 2.2.0.rc2.5.gf7b9fb2