From: Junio C Hamano <gitster@pobox.com>
To: "Eric Rannaud" <e@nanocritical.com>, Elijah Newren <newren@gmail.com>
Cc: git@vger.kernel.org, Jeremy Serror <jeremy.serror@gmail.com>
Subject: Re: [PATCH v3] fast-import: checkpoint: only write out refs and tags if we changed them
Date: Wed, 15 May 2019 14:30:25 +0900 [thread overview]
Message-ID: <xmqq8sv8709a.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <ad63393c24c7346c5b606b29579dfacad4d307f3.1557477247.git.e@nanocritical.com> (Eric Rannaud's message of "Fri, 10 May 2019 01:41:15 -0700")
"Eric Rannaud" <e@nanocritical.com> writes:
> We now keep track of whether branches and tags have been changed by this
> fast-import process since our last checkpoint (or startup). At the next
> checkpoint, only refs and tags that new commands have changed are
> written to disk.
And when we notice that we have been competing with some other
process and the ref that we wanted to update has already been
updated to a different value, what happens? That should be part of
the description of the new behaviour (aka "fix") written here.
> ---
Missing sign-off.
It sounds like a worthwhile thing to do.
It seems that Elijah has been active in fast-import/export area in
the last 12 months, so let's borrow a second set of eyes from him.
Thanks.
> fast-import.c | 14 ++++++
> t/t9300-fast-import.sh | 106 ++++++++++++++++++++++++++++++++++-------
> 2 files changed, 104 insertions(+), 16 deletions(-)
>
>
> v2 and v1 were sent in Oct 2018. Only difference since is that the new
> test cases in t9300 don't use sleep to implement the asynchronous dance.
>
> Thanks.
>
>
> diff --git a/fast-import.c b/fast-import.c
> index f38d04fa5851..e9c3ea23ae42 100644
> --- a/fast-import.c
> +++ b/fast-import.c
> @@ -103,6 +103,7 @@ struct branch {
> uintmax_t num_notes;
> unsigned active : 1;
> unsigned delete : 1;
> + unsigned changed : 1;
> unsigned pack_id : PACK_ID_BITS;
> struct object_id oid;
> };
> @@ -110,6 +111,7 @@ struct branch {
> struct tag {
> struct tag *next_tag;
> const char *name;
> + unsigned changed : 1;
> unsigned int pack_id;
> struct object_id oid;
> };
> @@ -581,6 +583,7 @@ static struct branch *new_branch(const char *name)
> b->branch_tree.versions[1].mode = S_IFDIR;
> b->num_notes = 0;
> b->active = 0;
> + b->changed = 0;
> b->pack_id = MAX_PACK_ID;
> branch_table[hc] = b;
> branch_count++;
> @@ -1571,6 +1574,10 @@ static int update_branch(struct branch *b)
> struct object_id old_oid;
> struct strbuf err = STRBUF_INIT;
>
> + if (!b->changed)
> + return 0;
> + b->changed = 0;
> +
> if (is_null_oid(&b->oid)) {
> if (b->delete)
> delete_ref(NULL, b->name, NULL, 0);
> @@ -1636,6 +1643,10 @@ static void dump_tags(void)
> goto cleanup;
> }
> for (t = first_tag; t; t = t->next_tag) {
> + if (!t->changed)
> + continue;
> + t->changed = 0;
> +
> strbuf_reset(&ref_name);
> strbuf_addf(&ref_name, "refs/tags/%s", t->name);
>
> @@ -2679,6 +2690,7 @@ static void parse_new_commit(const char *arg)
>
> if (!store_object(OBJ_COMMIT, &new_data, NULL, &b->oid, next_mark))
> b->pack_id = pack_id;
> + b->changed = 1;
> b->last_commit = object_count_by_type[OBJ_COMMIT];
> }
>
> @@ -2763,6 +2775,7 @@ static void parse_new_tag(const char *arg)
> t->pack_id = MAX_PACK_ID;
> else
> t->pack_id = pack_id;
> + t->changed = 1;
> }
>
> static void parse_reset_branch(const char *arg)
> @@ -2783,6 +2796,7 @@ static void parse_reset_branch(const char *arg)
> b = new_branch(arg);
> read_next_command();
> parse_from(b);
> + b->changed = 1;
> if (command_buf.len > 0)
> unread_command_buf = 1;
> }
> diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
> index 3668263c4046..12abaebb22b6 100755
> --- a/t/t9300-fast-import.sh
> +++ b/t/t9300-fast-import.sh
> @@ -3121,14 +3121,23 @@ test_expect_success 'U: validate root delete result' '
> ### series V (checkpoint)
> ###
>
> -# The commands in input_file should not produce any output on the file
> -# descriptor set with --cat-blob-fd (or stdout if unspecified).
> +# Instructions can be sent from $input_file to background_import() loop via the
> +# fast-import progress command.
> +#
> +# progress do: shell
> +# Parse the next progress line and invoke it as a shell command.
> +#
> +# progress do: checkpoint and stop
> +# Send checkpoint and wait for its completion.
> +#
> +# progress do: stop
> +# Internal instruction.
> #
> # To make sure you're observing the side effects of checkpoint *before*
> # fast-import terminates (and thus writes out its state), check that the
> # fast-import process is still running using background_import_still_running
> # *after* evaluating the test conditions.
> -background_import_then_checkpoint () {
> +background_import () {
> options=$1
> input_file=$2
>
> @@ -3153,22 +3162,30 @@ background_import_then_checkpoint () {
> # pipes writing sequence. We want to assume that the write below could
> # block, e.g. if fast-import blocks writing its own output to &9
> # because there is no reader on &9 yet.
> - (
> - cat "$input_file"
> - echo "checkpoint"
> - echo "progress checkpoint"
> - ) >&8 &
> + cat "$input_file" >&8 &
>
> error=1 ;# assume the worst
> while read output <&9
> do
> - if test "$output" = "progress checkpoint"
> + if test "$output" = "progress do: shell"
> + then
> + read output <&9
> + shell_cmd="$(echo $output |sed -e 's/^progress //')"
> + $shell_cmd
> + elif test "$output" = "progress do: checkpoint and stop"
> + then
> + (
> + echo "checkpoint"
> + echo "progress do: stop"
> + ) >&8 &
> + elif test "$output" = "progress do: stop"
> then
> error=0
> break
> + else
> + # otherwise ignore cruft
> + echo >&2 "cruft: $output"
> fi
> - # otherwise ignore cruft
> - echo >&2 "cruft: $output"
> done
>
> if test $error -eq 1
> @@ -3189,10 +3206,11 @@ test_expect_success PIPE 'V: checkpoint helper does not get stuck with extra out
> cat >input <<-INPUT_END &&
> progress foo
> progress bar
> + progress do: checkpoint and stop
>
> INPUT_END
>
> - background_import_then_checkpoint "" input &&
> + background_import "" input &&
> background_import_still_running
> '
>
> @@ -3201,9 +3219,11 @@ test_expect_success PIPE 'V: checkpoint updates refs after reset' '
> reset refs/heads/V
> from refs/heads/U
>
> + progress do: checkpoint and stop
> +
> INPUT_END
>
> - background_import_then_checkpoint "" input &&
> + background_import "" input &&
> test "$(git rev-parse --verify V)" = "$(git rev-parse --verify U)" &&
> background_import_still_running
> '
> @@ -3216,9 +3236,11 @@ test_expect_success PIPE 'V: checkpoint updates refs and marks after commit' '
> data 0
> from refs/heads/U
>
> + progress do: checkpoint and stop
> +
> INPUT_END
>
> - background_import_then_checkpoint "--export-marks=marks.actual" input &&
> + background_import "--export-marks=marks.actual" input &&
>
> echo ":1 $(git rev-parse --verify V)" >marks.expected &&
>
> @@ -3237,9 +3259,11 @@ test_expect_success PIPE 'V: checkpoint updates refs and marks after commit (no
> data 0
> from refs/heads/U
>
> + progress do: checkpoint and stop
> +
> INPUT_END
>
> - background_import_then_checkpoint "--export-marks=marks.actual" input &&
> + background_import "--export-marks=marks.actual" input &&
>
> echo ":2 $(git rev-parse --verify V2)" >marks.expected &&
>
> @@ -3255,13 +3279,63 @@ test_expect_success PIPE 'V: checkpoint updates tags after tag' '
> tagger $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
> data 0
>
> + progress do: checkpoint and stop
> +
> INPUT_END
>
> - background_import_then_checkpoint "" input &&
> + background_import "" input &&
> git show-ref -d Vtag &&
> background_import_still_running
> '
>
> +test_expect_success PIPE 'V: checkpoint only resets changed branches' '
> + cat >input <<-INPUT_END &&
> + reset refs/heads/V3
> + from refs/heads/U
> +
> + checkpoint
> +
> + progress do: shell
> + progress git branch -f V3 V
> +
> + reset refs/heads/V4
> + from refs/heads/U
> +
> + progress do: checkpoint and stop
> +
> + INPUT_END
> +
> + background_import "--force" input &&
> + test "$(git rev-parse --verify V3)" = "$(git rev-parse --verify V)" &&
> + background_import_still_running
> +'
> +
> +test_expect_success PIPE 'V: checkpoint only updates changed tags' '
> + cat >input <<-INPUT_END &&
> + tag Vtag2
> + from refs/heads/U
> + tagger $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
> + data 0
> +
> + checkpoint
> +
> + progress do: shell
> + progress git tag -f Vtag2 V
> +
> + tag Vtag3
> + from refs/heads/U
> + tagger $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
> + data 0
> +
> + progress do: checkpoint and stop
> +
> + INPUT_END
> +
> + background_import "" input &&
> + test "$(git show-ref -d Vtag2 |tail -1 |awk \{print\ \$1\})" = "$(git rev-parse --verify V)" &&
> + background_import_still_running
> +'
> +
> ###
> ### series W (get-mark and empty orphan commits)
> ###
next prev parent reply other threads:[~2019-05-15 5:30 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 8:41 [PATCH v3] fast-import: checkpoint: only write out refs and tags if we changed them Eric Rannaud
2019-05-15 5:30 ` Junio C Hamano [this message]
2019-05-15 6:57 ` Eric Rannaud
2019-05-16 0:35 ` Elijah Newren
2019-05-16 5:54 ` Eric Rannaud
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