Re: [PATCH 2/4] receive-pack: implement advertising and receiving push options
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jul 7, 2016, 20:37 UTC
- Message-ID
- <xmqqa8htp4kc.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <20160707011218.3690-3-sbeller@google.com>
Stefan Beller <sbeller@google.com> writes:
Show 13 quoted lines
> While documenting > this, fix a nit in the `receive.advertiseAtomic` wording. > > receive.advertiseAtomic:: > By default, git-receive-pack will advertise the atomic push > - capability to its clients. If you don't want to this capability > + capability to its clients. If you don't want this capability > + to be advertised, set this variable to false. > + > +receive.advertisePushOptions:: > + By default, git-receive-pack will advertise the push options capability > + to its clients. If you don't want this capability > to be advertised, set this variable to false.
I think we correcting the nit by avoiding passive voice, i.e.
If you don't want to advertise this capability, set this variable to false.
would make it easier to read.
Show 5 quoted lines
> in packet-line format to the client, followed by a flush-pkt. The only > real difference is that the capability listing is different - the only > -possible values are 'report-status', 'delete-refs' and 'ofs-delta'. > +possible values are 'report-status', 'delete-refs', 'ofs-delta' and > +'push-options'.
OK.
> +push-options > +------------ > + > +If the server sends the 'push-options' capability it is capable to accept
Two nits:
- A comma would make it easier to read. - "capable" goes with "of <gerund>", while "able" goes with "to <infinitive>".
i.e. "... capability, it is capable of accepting..."
> +push options after the update commands have been sent. If the pushing client > +requests this capability, the server will pass the options to the pre and post > +receive hooks that process this push request.
Missing dashes, i.e. "pre- and post-receive hooks"?
Show 9 quoted lines
> @@ -207,6 +214,8 @@ static void show_ref(const char *path, const unsigned char *sha1) > "report-status delete-refs side-band-64k quiet"); > if (advertise_atomic_push) > strbuf_addstr(&cap, " atomic"); > + if (advertise_push_options) > + strbuf_addstr(&cap, " push-options"); > if (prefer_ofs_delta) > strbuf_addstr(&cap, " ofs-delta"); > if (push_cert_nonce)
Hmph, was there a good reason to add it in the middle (contrast to the previous addition to the "only possible values are..." enumeration)?
> +static struct string_list *read_push_options()
static struct string_list *read_push_options(void)
Show 17 quoted lines
> +{
> + int i;
> + struct string_list *ret = xmalloc(sizeof(*ret));
> + string_list_init(ret, 1);
> +
> + /* NEEDSWORK: expose the limitations to be configurable. */
> + int max_options = 32;
> +
> + /*
> + * NEEDSWORK: expose the limitations to be configurable;
> + * Once the limit can be lifted, include a way for payloads
> + * larger than one pkt, e.g allow a payload of up to
> + * LARGE_PACKET_MAX - 1 only, and reserve the last byte
> + * to indicate whether the next pkt continues with this
> + * push option.
> + */
> + int max_size = 1024;Good NEEDSWORK comments; perhaps also hint that the configuration must not come from the repository level configuration file (i.e. Peff's "scoped configuration" from jk/upload-pack-hook topic)?
Show 21 quoted lines
> + for (i = 0; i < max_options; i++) {
> + char *line;
> + int len;
> +
> + line = packet_read_line(0, &len);
> +
> + if (!line)
> + break;
> +
> + if (len > max_size)
> + die("protocol error: server configuration allows push "
> + "options of size up to %d bytes", max_size);
> +
> + len = strcspn(line, "\n");
> + line[len] = '\0';
> +
> + string_list_append(ret, line);
> + }
> + if (i == max_options)
> + die("protocol error: server configuration only allows up "
> + "to %d push options", max_options);When not going over ssh://, does the user sees these messages?
More importantly, if we plan to make this configurable and not make the limit a hardwired constant of the wire protocol, it may be better to advertise push-options capability with the limit, e.g. "push-options=32" (or even "push-options=1024/32"), so that the client side can count and abort early?
I wondered how well the extra flush works with the extra framing smart-http does to wrap the wire protocol; as I do not see any change to the http side, I'd assume that there is no issue.
Show 17 quoted lines
> +
> + return ret;
> +}
> +
> static const char *parse_pack_header(struct pack_header *hdr)
> {
> switch (read_pack_header(0, hdr)) {
> @@ -1773,6 +1829,9 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
> const char *unpack_status = NULL;
> struct string_list *push_options = NULL;
>
> + if (use_push_options)
> + push_options = read_push_options();
> +
> prepare_shallow_info(&si, &shallow);
> if (!si.nr_ours && !si.nr_theirs)
> shallow_update = 0;