Re: [PATCH 02/14] upload-pack.c: Refactor capability advertising
- From
Junio C Hamano <gitster@pobox.com>
- Date
- May 4, 2016, 20:05 UTC
- Message-ID
- <xmqq37pxh9ll.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <1461972887-22100-3-git-send-email-sbeller@google.com>
Stefan Beller <sbeller@google.com> writes:
Show 6 quoted lines
> Instead of having the capabilities in a local string, keep them > in a struct outside the function. This will allow us in a later patch > to easily reuse the capabilities in version 2 of the protocol. > > Signed-off-by: Stefan Beller <sbeller@google.com> > ---
Between a flat string and a list, you may be able to enumerate the elements in a list more easily, but my knee-jerk reaction is that this does not go far enough, if you are to introduce a table. It for example does not allow us to lose the conditional writing of some capabilties based on allow_*_request and replace that with a more table-driven approach.
Perhaps that can come in a later step (in other words, the above is not a basis for rejecting this change; just pointing it out that this does not have to be the end of the story).
Show 85 quoted lines
> upload-pack.c | 59 ++++++++++++++++++++++++++++++++++++++++-------------------
> 1 file changed, 40 insertions(+), 19 deletions(-)
>
> diff --git a/upload-pack.c b/upload-pack.c
> index aaaf883..85381d5 100644
> --- a/upload-pack.c
> +++ b/upload-pack.c
> @@ -719,37 +719,58 @@ static void format_symref_info(struct strbuf *buf, struct string_list *symref)
> strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
> }
>
> +static int advertise_capabilities = 1;
> +const char *all_capabilities[] = {
> + "multi_ack",
> + "thin-pack",
> + "side-band",
> + "side-band-64k",
> + "ofs-delta",
> + "shallow",
> + "no-progress",
> + "include-tag",
> + "multi_ack_detailed",
> + "allow-tip-sha1-in-want",
> + "allow-reachable-sha1-in-want",
> + "no-done",
> +};
> +
> static int send_ref(const char *refname, const struct object_id *oid,
> int flag, void *cb_data)
> {
> - static const char *capabilities = "multi_ack thin-pack side-band"
> - " side-band-64k ofs-delta shallow no-progress"
> - " include-tag multi_ack_detailed";
> const char *refname_nons = strip_namespace(refname);
> struct object_id peeled;
>
> if (mark_our_ref(refname_nons, refname, oid))
> return 0;
>
> - if (capabilities) {
> - struct strbuf symref_info = STRBUF_INIT;
> -
> - format_symref_info(&symref_info, cb_data);
> - packet_write(1, "%s %s%c%s%s%s%s%s agent=%s\n",
> - oid_to_hex(oid), refname_nons,
> - 0, capabilities,
> - (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
> - " allow-tip-sha1-in-want" : "",
> - (allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1) ?
> - " allow-reachable-sha1-in-want" : "",
> - stateless_rpc ? " no-done" : "",
> - symref_info.buf,
> - git_user_agent_sanitized());
> - strbuf_release(&symref_info);
> + if (advertise_capabilities) {
> + int i;
> + struct strbuf capabilities = STRBUF_INIT;
> +
> + for (i = 0; i < ARRAY_SIZE(all_capabilities); i++) {
> + const char *cap = all_capabilities[i];
> + if (!strcmp(cap, "allow-tip-sha1-in-want")
> + && !(allow_unadvertised_object_request & ALLOW_TIP_SHA1))
> + continue;
> + if (!strcmp(cap, "allow-reachable-sha1-in-want")
> + && !(allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1))
> + continue;
> + if (!strcmp(cap, "no-done") && !stateless_rpc)
> + continue;
> + strbuf_addf(&capabilities, " %s", cap);
> + }
> +
> + format_symref_info(&capabilities, cb_data);
> + strbuf_addf(&capabilities, " agent=%s", git_user_agent_sanitized());
> +
> + packet_write(1, "%s %s%c%s\n", oid_to_hex(oid), refname_nons,
> + 0, capabilities.buf);
> + strbuf_release(&capabilities);
> + advertise_capabilities = 0;
> } else {
> packet_write(1, "%s %s\n", oid_to_hex(oid), refname_nons);
> }
> - capabilities = NULL;
> if (!peel_ref(refname, peeled.hash))
> packet_write(1, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
> return 0;