Re: [PATCH 1/3] unpack: replace xwrite() loop with write_in_full()
On Sat, Mar 02, 2024 at 11:03:46AM -0800, Junio C Hamano wrote:
Show 58 quoted lines
> We have two packfile stream consumers, index-pack and
> unpack-objects, that allow excess payload after the packfile stream
> data. Their code to relay excess data hasn't changed significantly
> since their original implementation that appeared in 67e5a5ec
> (git-unpack-objects: re-write to read from stdin, 2005-06-28) and
> 9bee2478 (mimic unpack-objects when --stdin is used with index-pack,
> 2006-10-25).
>
> These code blocks contain hand-rolled loops using xwrite(), written
> before our write_in_full() helper existed. This helper now provides
> the same functionality.
>
> Replace these loops with write_in_full() for shorter, clearer
> code. Update related variables accordingly.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
> builtin/index-pack.c | 17 +++--------------
> builtin/unpack-objects.c | 8 +-------
> 2 files changed, 4 insertions(+), 21 deletions(-)
>
> diff --git a/builtin/index-pack.c b/builtin/index-pack.c
> index a3a37bd215..856428fef9 100644
> --- a/builtin/index-pack.c
> +++ b/builtin/index-pack.c
> @@ -1524,14 +1524,12 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
> struct strbuf pack_name = STRBUF_INIT;
> struct strbuf index_name = STRBUF_INIT;
> struct strbuf rev_index_name = STRBUF_INIT;
> - int err;
>
> if (!from_stdin) {
> close(input_fd);
> } else {
> fsync_component_or_die(FSYNC_COMPONENT_PACK, output_fd, curr_pack_name);
> - err = close(output_fd);
> - if (err)
> + if (close(output_fd))
> die_errno(_("error while closing pack file"));
> }
>
> @@ -1566,17 +1564,8 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
> write_or_die(1, buf.buf, buf.len);
> strbuf_release(&buf);
>
> - /*
> - * Let's just mimic git-unpack-objects here and write
> - * the last part of the input buffer to stdout.
> - */
> - while (input_len) {
> - err = xwrite(1, input_buffer + input_offset, input_len);
> - if (err <= 0)
> - break;
> - input_len -= err;
> - input_offset += err;
> - }
> + /* Write the last part of the buffer to stdout */
> + write_in_full(1, input_buffer + input_offset, input_len);With this change we stop updating `input_len` and `input_offset`, both of which are global variables. Assuming that tests pass this must be okay right now given that this is the final part of what we are writing. But I wonder whether we shouldn't update those regardless just so that these remain consistent?
Show 19 quoted lines
> }
>
> strbuf_release(&rev_index_name);
> diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
> index e0a701f2b3..f1c85a00ae 100644
> --- a/builtin/unpack-objects.c
> +++ b/builtin/unpack-objects.c
> @@ -679,13 +679,7 @@ int cmd_unpack_objects(int argc, const char **argv, const char *prefix UNUSED)
> use(the_hash_algo->rawsz);
>
> /* Write the last part of the buffer to stdout */
> - while (len) {
> - int ret = xwrite(1, buffer + offset, len);
> - if (ret <= 0)
> - break;
> - len -= ret;
> - offset += ret;
> - }
> + write_in_full(1, buffer + offset, len);Show 6 quoted lines
> /* All done */
> return has_errors;
> --
> 2.44.0-84-gb387623c12
>
>
Junio C Hamano