Re: [PATCH v7 15/16] remote-svn: add marks-file regeneration

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 28, 2012, 17:59 UTC
Message-ID: <7vpq6a28tp.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1346143790-23491-16-git-send-email-florian.achleitner.2.6.31@gmail.com>

Florian Achleitner <florian.achleitner.2.6.31@gmail.com> writes:

Show 40 quoted lines

> fast-import mark files are stored outside the object database and are
> therefore not fetched and can be lost somehow else.  marks provide a
> svn revision --> git sha1 mapping, while the notes that are attached
> to each commit when it is imported provide a git sha1 --> svn revision
> mapping.
>
> If the marks file is not available or not plausible, regenerate it by
> walking through the notes tree.  , i.e.  The plausibility check tests
> if the highest revision in the marks file matches the revision of the
> top ref. It doesn't ensure that the mark file is completely correct.
> This could only be done with an effort equal to unconditional
> regeneration.
>
> Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>  remote-testsvn.c |   68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
>
> diff --git a/remote-testsvn.c b/remote-testsvn.c
> index e90d221..d0b81d5 100644
> --- a/remote-testsvn.c
> +++ b/remote-testsvn.c
> @@ -86,6 +86,73 @@ static int parse_rev_note(const char *msg, struct rev_note *res) {
>  	return 0;
>  }
>  
> +static int note2mark_cb(const unsigned char *object_sha1,
> +		const unsigned char *note_sha1, char *note_path,
> +		void *cb_data) {
> +	FILE *file = (FILE *)cb_data;
> +	char *msg;
> +	unsigned long msglen;
> +	enum object_type type;
> +	struct rev_note note;
> +	if (!(msg = read_sha1_file(note_sha1, &type, &msglen)) ||
> +			!msglen || type != OBJ_BLOB) {
> +		free(msg);
> +		return 1;
> +	}

The same comments as an earlier patch in the series applies here, regarding chained assignments in coditional, whether each case is an error that needs to be reported, and the sign of the error return value.

Show 21 quoted lines

> +	if (parse_rev_note(msg, &note))
> +		return 2;
> +	if (fprintf(file, ":%d %s\n", note.rev_nr, sha1_to_hex(object_sha1)) < 1)
> +		return 3;
> +	return 0;
> +}
> +
> +static void regenerate_marks(void)
> +{
> +	int ret;
> +	FILE *marksfile;
> +	marksfile = fopen(marksfilename, "w+");
> +	if (!marksfile)
> +		die_errno("Couldn't create mark file %s.", marksfilename);
> +	ret = for_each_note(NULL, 0, note2mark_cb, marksfile);
> +	if (ret)
> +		die("Regeneration of marks failed, returned %d.", ret);
> +	fclose(marksfile);
> +}
> +
> +static void check_or_regenerate_marks(int latestrev) {

Style.

Show 7 quoted lines

> +	FILE *marksfile;
> +	struct strbuf sb = STRBUF_INIT;
> +	struct strbuf line = STRBUF_INIT;
> +	int found = 0;
> +
> +	if (latestrev < 1)
> +		return;

It's more pleasant to read to have a blank line between the end of decls and the first statement, like this function does. Please fix two functions that appear before this function in this file to match.

Show 36 quoted lines

> +	init_notes(NULL, notes_ref, NULL, 0);
> +	marksfile = fopen(marksfilename, "r");
> +	if (!marksfile) {
> +		regenerate_marks();
> +		marksfile = fopen(marksfilename, "r");
> +		if (!marksfile)
> +			die_errno("cannot read marks file %s!", marksfilename);
> +		fclose(marksfile);
> +	} else {
> +		strbuf_addf(&sb, ":%d ", latestrev);
> +		while (strbuf_getline(&line, marksfile, '\n') != EOF) {
> +			if (!prefixcmp(line.buf, sb.buf)) {
> +				found++;
> +				break;
> +			}
> +		}
> +		fclose(marksfile);
> +		if (!found)
> +			regenerate_marks();
> +	}
> +	free_notes(NULL);
> +	strbuf_release(&sb);
> +	strbuf_release(&line);
> +}
> +
>  static int cmd_import(const char *line)
>  {
>  	int code;
> @@ -111,6 +178,7 @@ static int cmd_import(const char *line)
>  			free(note_msg);
>  		}
>  	}
> +	check_or_regenerate_marks(startrev - 1);
>  
>  	if (dump_from_file) {
>  		dumpin_fd = open(url, O_RDONLY);