Re: [PATCH v1] convert: add "status=delayed" to filter process protocol

[Lars Schneider <larsxschneider@gmail.com>]

> On 08 Jan 2017, at 21:14, Torsten Bögershausen <tboegi@web.de> wrote:
> 
> On Sun, Jan 08, 2017 at 08:17:36PM +0100, larsxschneider@gmail.com wrote:
>> From: Lars Schneider <larsxschneider@gmail.com>
>> 
>> Some `clean` / `smudge` filters might require a significant amount of
>> time to process a single blob. During this process the Git checkout
>> operation is blocked and Git needs to wait until the filter is done to
>> continue with the checkout.
>> 
>> Teach the filter process protocol (introduced in edcc858) to accept the
>> status "delayed" as response to a filter request. Upon this response Git
>> continues with the checkout operation and asks the filter to process the
>> blob again after all other blobs have been processed.
>> 
>> Git has a multiple code paths that checkout a blob. Support delayed
>> checkouts only in `clone` (in unpack-trees.c) and `checkout` operations.
>> 
>> Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
>> ---
>> 
> 
> Some feeling tells me that it may be better to leave convert_to_working_tree() as it is.
> And change convert_to_working_tree_internal as suggested:
> 
> int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
> {
> -	return convert_to_working_tree_internal(path, src, len, dst, 0);
> +	return convert_to_working_tree_internal(path, src, len, dst, NULL, 0);
> }

If I do this then I would have no way to communicate to the caller that the
processing is delayed. Consequently the caller would not know that an additional
call is necessary to fetch the result.

Thanks,
Lars