Since the info command in cat-file --batch-command prints object
info for a given object, it is natural to add another command in
cat-file --batch-command to print object info for a given object
from a remote.
Add remote-object-info command to cat-file --batch-command.
While info takes object ids one at a time, this creates overhead when
making requests to a server. So remote-object-info instead can take
multiple object ids at once.
The cat-file --batch-command command is generally implemented in the
following manner:
- Receive and parse input from user
- Call respective function attached to command
- Get object info, print object info
In --buffer mode, this changes to:
- Receive and parse input from user
- Store respective function attached to command in a queue
- After flush, loop through commands in queue
- Call respective function attached to command
- Get object info, print object info
Notice how the getting and printing of object info is accomplished one
at a time. As described above, this creates a problem for making
requests to a server. Therefore, remote-object-info is implemented in
the following manner:
- Receive and parse input from user
If command is remote-object-info:
- Get object info from remote
- Loop through and print each object info
Else:
- Call respective function attached to command
- Parse input, get object info, print object info
And finally for --buffer mode remote-object-info:
- Receive and parse input from user
- Store respective function attached to command in a queue
- After flush, loop through commands in queue:
If command is remote-object-info:
- Get object info from remote
- Loop through and print each object info
Else:
- Call respective function attached to command
- Get object info, print object info
To summarize, remote-object-info gets object info from the remote and
then loops through the object info passed in, printing the info.
In order for remote-object-info to avoid remote communication
overhead in the non-buffer mode, the objects are passed in as such:
remote-object-info <remote> <oid> <oid> ... <oid>
rather than
remote-object-info <remote> <oid>
remote-object-info <remote> <oid>
...
remote-object-info <remote> <oid>
Placeholders in the format are validated against an allow-list of the
atoms the remote path supports: "objectname" and "objectsize".
Unsupported atoms expand to an empty string, honoring how for-each-ref
handles known but inapplicable atoms.
Without this, atoms like %(objecttype) would mark data->info.typep and
because the server only sends size, type_name() would later crash.
As extra safety, even outside of the remote path, initialize
expand_data's type to OBJ_BAD and handle type_name() returning NULL.
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Eric Ju <eric.peijian@gmail.com>
[pablo: added the atom allow-list validation]
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
0ae93f56ec