The server can handle type requests but does not advertise the
capability yet. Prepare the client to know how to parse the server
response once the server advertises the type capability.
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Every failure in fetch_object_info() dies except one: a short read while
parsing the attribute lines returns -1. That -1 is then passed through
fetch_object_info_via_pack() and get_remote_info() up to cat-file, only
to die() with a generic message.
Die in fetch_object_info() instead, consistently with the rest of its
error paths, and make fetch_object_info() void.
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch_object_info() collects information about N objects, but it stores
the results in an array of object_info. That struct holds the extended
parameters of read_object_info() (The optional outputs the caller wants
filled). Its pointers tell that function where to write the answers for
a single object. object_info is not meant to be the final storage, and
since fetch_object_info() does not call read_object_info(), there is no
reason to use it. Using it means allocating one scalar per object per
attribute just to have those pointers somewhere to point at.
Add struct fetch_object_info_results. The caller sets the wants_* flags
to say what it is interested in, and fetch_object_info() allocates one
array per attribute. A set wants_* flag means "asked for", while a
non-NULL array means "available". The caller releases the arrays with
free_fetch_object_info_results().
The object_info_options string list is no longer needed. Filtering
against the server's advertisement now sets local ask_* flags, and
send_object_info_request() turns those into the v2 protocol option
strings. remote_atom_map[] existed only to map those strings back into
atom names, so drop it and build remote_allowed_atoms from the result
arrays.
Currently for wants_* and ask_* there is only the 'size' variant but a
subsequent commit will add '*_type'.
free_object_info_contents() loses its only caller and is dropped.
Dropping the allow-list check makes the final else reachable from the
wire, so die() instead of BUG(): an unknown attribute is the server's
error, not ours.
Helped-by: Jeff King <peff@peff.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
struct object_info_args groups three pointers that already live in the
transport and are given to fetch_object_info().
Grouping them into a struct reduces the number of parameters, but it
suggests that the three belong together, when they are unrelated and end
up being accessed as args->* independently.
Drop the struct and pass those parameters directly to
fetch_object_info() and send_object_info_request(). This should have no
change in behavior.
Helped-by: Jeff King <peff@peff.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The loop reading the object-info response stops as soon as the reader
returns something other than PACKET_READ_NORMAL, or once it has read as
many lines as we requested. Neither end is checked.
A server that answers with fewer objects leaves the end of the result
arrays empty, and the caller trusts that every requested object was
filled in. A server that answers with more leaves the extra packets
unread. On stateless transports check_stateless_delimiter() notices, but
on the others it passes unnoticed.
Check both limits by extracting the packet_reader_read() from the loop
condition, so the loop no longer consumes the last packet (flush). If
while looping the read is different from a PACKET_READ_NORMAL, die()
meaning there are fewer objects than expected. After iterating, we only
expect a flush, so if the last packet is not a flush, die().
Helped-by: Junio C Hamano <gitster@pobox.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The static allow-list in expand_atom() is hardcoded to allow only
"objectname" and "objectsize" for remote queries. This works because,
up to this point, servers will either support object-info with name
and size or they do not support them at all.
As object-info gains new capabilities, we cannot expect different
servers with different Git versions to have the same object-info
capabilities. Therefore, the client needs to adapt its allow-list to
what the server advertises.
The client now:
1. Requests the protocol option that the placeholder refers to (i.e.
"size" for "%(objectsize)").
2. Drops any requested option that the server does not advertise in
fetch_object_info().
3. Maps the remaining advertised options back to their placeholders and
populates remote_allowed_atoms.
4. Uses remote_allowed_atoms in expand_atom(), preserving the previous
behavior for supported placeholders.
For example, if the client requests "%(objectsize) %(objecttype)" and
the server only supports 'size', then the client only requests 'size'.
The server returns the size (i.e "42") "%(objectsize)" is expanded
normally while "%(objecttype)" expands to an empty string:
"42 "
Note that the empty string expansion is only for known but unsupported
placeholders. "%(objectcolor)" which doesn't exist would die().
This honors what for-each-ref does for known but inapplicable atoms
(placeholders).
Move object_info_options out of get_remote_info() so the caller which
has data can select what options will be requested instead of requesting
always size.
Move batch_object_write() out so output is always produced.
If there are no supported attributes, the output is a blank line.
Include "type" in the object_info_options even though the client does
not yet know how to parse the server's "type" capability.
As a result, "type" is always filtered out, allowing the tests to verify
that known but unsupported placeholders expand to an empty string.
Since the filter removes options by swapping with the last element,
the list is no longer kept sorted. Drop the pre-sort in
fetch_object_info_via_pack() and use the unsorted string_list lookup
for the response header. This has no effect in performance as the list
can only be two entries long ('size' and 'type').
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Sometimes, it is beneficial to retrieve information about an object
without downloading it entirely. The server-side logic for this
functionality was implemented in commit "a2ba162cda (object-info:
support for retrieving object info, 2021-04-20)." And the wire
format is documented at
https://git-scm.com/docs/protocol-v2#_object_info.
Introduce client-side support for the object-info capability.
Add its own function for object-info separate from existing fetch
infrastructure.
Currently, the client supports requesting a list of OIDs with the size
attribute from a v2 server. If the server does not advertise this
feature (i.e., transfer.advertiseobjectinfo is set to false), the client
returns an error and exits.
Note that:
1. The entire request is written into req_buf before being sent to the
remote. This approach follows the pattern used in the
send_fetch_request() logic within 'fetch-pack.c'. Streaming the
request is not addressed in this patch.
2. A new field 'unrecognized' has been added to object_info. This new
field is set at fetch_object_info() when the object is unrecognized
by the server.
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Eric Ju <eric.peijian@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
