Re: [PATCH v2 1/6] archive: optionally add "virtual" files

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

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Hi René,

On Mon, 7 Feb 2022, René Scharfe wrote:

> Am 06.02.22 um 23:39 schrieb Johannes Schindelin via GitGitGadget:
> > From: Johannes Schindelin <johannes.schindelin@gmx.de>
> >
> > With the `--add-file-with-content=<path>:<content>` option, `git
> > archive` now supports use cases where relatively trivial files need to
> > be added that do not exist on disk.
> >
> > Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> > ---
> >  Documentation/git-archive.txt | 11 ++++++++
> >  archive.c                     | 51 +++++++++++++++++++++++++++++------
> >  t/t5003-archive-zip.sh        | 12 +++++++++
> >  3 files changed, 66 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
> > index bc4e76a7834..1b52a0a65a1 100644
> > --- a/Documentation/git-archive.txt
> > +++ b/Documentation/git-archive.txt
> > @@ -61,6 +61,17 @@ OPTIONS
> >  	by concatenating the value for `--prefix` (if any) and the
> >  	basename of <file>.
> >
> > +--add-file-with-content=<path>:<content>::
> > +	Add the specified contents to the archive.  Can be repeated to add
> > +	multiple files.  The path of the file in the archive is built
> > +	by concatenating the value for `--prefix` (if any) and the
> > +	basename of <file>.
> > ++
> > +The `<path>` cannot contain any colon, the file mode is limited to
> > +a regular file, and the option may be subject platform-dependent
>
> s/subject/& to/

Thanks.

> > +command-line limits. For non-trivial cases, write an untracked file
> > +and use `--add-file` instead.
> > +
>
> We could use that option in Git's own Makefile to add the file named
> "version", which contains $GIT_VERSION.

We could do that, that opportunity is a side effect of this patch series.

> Hmm, but it also contains a terminating newline, which would be a bit
> tricky (but not impossible) to add.  Would it make sense to add one
> automatically if it's missing (e.g. with strbuf_complete_line)?  Not
> sure.

It is really easy:

	LF='
	'

	git archive --add-file-with-content=version:"$GIT_VERSION$LF" ...

(That's shell script, in the Makefile it would need those `\`
continuations.)

> >  --worktree-attributes::
> >  	Look for attributes in .gitattributes files in the working tree
> >  	as well (see <<ATTRIBUTES>>).
> > diff --git a/archive.c b/archive.c
> > index a3bbb091256..172efd690c3 100644
> > --- a/archive.c
> > +++ b/archive.c
> > @@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
> >  struct extra_file_info {
> >  	char *base;
> >  	struct stat stat;
> > +	void *content;
> >  };
> >
> >  int write_archive_entries(struct archiver_args *args,
> > @@ -337,7 +338,13 @@ int write_archive_entries(struct archiver_args *args,
> >  		strbuf_addstr(&path_in_archive, basename(path));
> >
> >  		strbuf_reset(&content);
> > -		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
> > +		if (info->content)
> > +			err = write_entry(args, &fake_oid, path_in_archive.buf,
> > +					  path_in_archive.len,
> > +					  info->stat.st_mode,
> > +					  info->content, info->stat.st_size);
> > +		else if (strbuf_read_file(&content, path,
> > +					  info->stat.st_size) < 0)
> >  			err = error_errno(_("could not read '%s'"), path);
> >  		else
> >  			err = write_entry(args, &fake_oid, path_in_archive.buf,
> > @@ -493,6 +500,7 @@ static void extra_file_info_clear(void *util, const char *str)
> >  {
> >  	struct extra_file_info *info = util;
> >  	free(info->base);
> > +	free(info->content);
> >  	free(info);
> >  }
> >
> > @@ -514,14 +522,38 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
> >  	if (!arg)
> >  		return -1;
> >
> > -	path = prefix_filename(args->prefix, arg);
> > -	item = string_list_append_nodup(&args->extra_files, path);
> > -	item->util = info = xmalloc(sizeof(*info));
> > +	info = xmalloc(sizeof(*info));
> >  	info->base = xstrdup_or_null(base);
> > -	if (stat(path, &info->stat))
> > -		die(_("File not found: %s"), path);
> > -	if (!S_ISREG(info->stat.st_mode))
> > -		die(_("Not a regular file: %s"), path);
> > +
> > +	if (strcmp(opt->long_name, "add-file-with-content")) {
>
> Equivalent to:
>
> 	if (!strcmp(opt->long_name, "add-file")) {
>
> I mention that because the inequality check confused me a bit at first.

Good point. For some reason I thought it would be clearer to handle
everything but `--add-file-with-content` here, but that "everything but"
is only `--add-file`, so I sowed more confusion. Sorry about that.

>
> > +		path = prefix_filename(args->prefix, arg);
> > +		if (stat(path, &info->stat))
> > +			die(_("File not found: %s"), path);
> > +		if (!S_ISREG(info->stat.st_mode))
> > +			die(_("Not a regular file: %s"), path);
> > +		info->content = NULL; /* read the file later */
> > +	} else {
> > +		const char *colon = strchr(arg, ':');
> > +		char *p;
> > +
> > +		if (!colon)
> > +			die(_("missing colon: '%s'"), arg);
> > +
> > +		p = xstrndup(arg, colon - arg);
> > +		if (!args->prefix)
> > +			path = p;
> > +		else {
> > +			path = prefix_filename(args->prefix, p);
> > +			free(p);
> > +		}
> > +		memset(&info->stat, 0, sizeof(info->stat));
> > +		info->stat.st_mode = S_IFREG | 0644;
> > +		info->content = xstrdup(colon + 1);
> > +		info->stat.st_size = strlen(info->content);
> > +	}
> > +	item = string_list_append_nodup(&args->extra_files, path);
> > +	item->util = info;
> > +
> >  	return 0;
> >  }
> >
> > @@ -554,6 +586,9 @@ static int parse_archive_args(int argc, const char **argv,
> >  		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
> >  		  N_("add untracked file to archive"), 0, add_file_cb,
> >  		  (intptr_t)&base },
> > +		{ OPTION_CALLBACK, 0, "add-file-with-content", args,
> > +		  N_("file"), N_("add untracked file to archive"), 0,
>                       ^^^^
> "<file>" seems wrong, because there is no actual file.  It should rather
> be "<name>:<content>" for the virtual one, right?

Or `<path>:<content>`. Yes.

Again, thank you for your clear and helpful review,
Dscho