Re: [WIP] Shift rev-list enumeration from upload-pack to pack-objects

> instead of using the internal revision walker and piping object refs
> to pack-objects this patch passes only the revs to pack-objects, which
> in turn handles both enumeration and packing.
>
> Signed-off-by: Sam Vilain <sam@vilain.net>
> ---
>   Submitted on behalf of Nick in order to get wider feedback on this.
>   This version passes the test suite.
>
>  upload-pack.c |   54 +++++++++++++++++++++++++++++++++++++++++++++---------
>  1 files changed, 45 insertions(+), 9 deletions(-)
>
> diff --git a/upload-pack.c b/upload-pack.c
> index edc7861..7eda8fd 100644
> --- a/upload-pack.c
> +++ b/upload-pack.c
> @@ -155,13 +155,27 @@ static void create_pack_file(void)
>  	const char *argv[10];
>  	int arg = 0;
>  
> -	rev_list.proc = do_rev_list;
> -	/* .data is just a boolean: any non-NULL value will do */
> -	rev_list.data = create_full_pack ? &rev_list : NULL;
> -	if (start_async(&rev_list))
> -		die("git upload-pack: unable to fork git-rev-list");
> -
> -	argv[arg++] = "pack-objects";
> +	/* sending rev params to pack-objects directly is great, but unfortunately pack-objects 
> +	 * has no way of turning off thin pack generation.  this would be a relatively simple 
> +	 * addition, but as we also have to deal with shallow grafts and all it's simplest to 
> +	 * just resort to piping object refs.
> +	 */
> +	if (!use_thin_pack) {
> +		rev_list.proc = do_rev_list;
> +		/* .data is just a boolean: any non-NULL value will do */
> +		rev_list.data = create_full_pack ? &rev_list : NULL;
> +		if (start_async(&rev_list))
> +			die("git upload-pack: unable to fork git-rev-list");
> +		
> +		argv[arg++] = "pack-objects";
> +	} else {
> +		argv[arg++] = "pack-objects";
> +		argv[arg++] = "--revs";
> +		argv[arg++] = "--include-tag";
> +		if (create_full_pack)
> +			argv[arg++] = "--all";
> +	}
> +	
>  	argv[arg++] = "--stdout";
>  	if (!no_progress)
>  		argv[arg++] = "--progress";
> @@ -172,7 +186,7 @@ static void create_pack_file(void)
>  	argv[arg++] = NULL;
>  
>  	memset(&pack_objects, 0, sizeof(pack_objects));
> -	pack_objects.in = rev_list.out;	/* start_command closes it */
> +	pack_objects.in = !use_thin_pack ? rev_list.out : -1;
>  	pack_objects.out = -1;
>  	pack_objects.err = -1;
>  	pack_objects.git_cmd = 1;
> @@ -181,6 +195,28 @@ static void create_pack_file(void)
>  	if (start_command(&pack_objects))
>  		die("git upload-pack: unable to fork git-pack-objects");
>  
> +	/* pass on revisions we (don't) want 
> +	 * (do we need to check the validity of pack_objects.in?)
> +	 */
> +	if (use_thin_pack) {
> +		FILE *pipe_fd = fdopen(pack_objects.in, "w");
> +		if (!create_full_pack) {
> +			int i;
> +			for (i = 0; i < want_obj.nr; i++) {
> +				fprintf(pipe_fd, "%s\n", sha1_to_hex(want_obj.objects[i].item->sha1));
> +			}
> +			fprintf(pipe_fd, "--not\n");
> +			for (i = 0; i < have_obj.nr; i++) {
> +				fprintf(pipe_fd, "%s\n", sha1_to_hex(have_obj.objects[i].item->sha1));
> +			}
> +		}
> +		
> +		fprintf(pipe_fd, "\n");
> +		fflush(pipe_fd);
> +		fclose(pipe_fd);
> +	}
> +
> +
>  	/* We read from pack_objects.err to capture stderr output for
>  	 * progress bar, and pack_objects.out to capture the pack data.
>  	 */
> @@ -276,7 +312,7 @@ static void create_pack_file(void)
>  		error("git upload-pack: git-pack-objects died with error.");
>  		goto fail;
>  	}
> -	if (finish_async(&rev_list))
> +	if (!use_thin_pack && finish_async(&rev_list))
>  		goto fail;	/* error was already reported */
>  
>  	/* flush the data */
>