The temporary directory used by git-receive-pack(1) to write objects is
managed slightly differently than how it is done via ODB transactions:
- The temporary directory is eagerly created upfront, instead of
waiting for the first object write.
- The prefix name of the temporary directory is "incoming" instead of
"bulk-fsync".
In a subsequent commit, git-receive-pack(1) will use ODB transactions
instead of `tmp_objdir` directly. To provide a means to configure the
same transaction behavior, introduce `enum odb_transaction_flags` and
the ODB_TRANSACTION_RECEIVE flag intended as a signal for ODB
transactions using the "files" backend to be set up for
git-receive-pack(1). Transaction call sites are updated accordingly to
provide the required flag parameter.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The ODB transaction backend is responsible for creating/managing its own
staging area for writing objects. Other child processes spawned by Git
may need access to uncommitted objects or write new objects in the
staging area though.
Introduce `odb_transaction_env()` which is expected to provide the set
of environment variables needed by a child process to access the
transaction's staging area.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When `odb_transaction_commit()` is invoked, the return value of the
backend commit callback is silently discarded. A backend has no way
to signal that committing failed, such as when the "files" backend
cannot migrate its temporary object directory into the permanent
ODB.
In a subsequent commit, git-receive-pack(1) starts using ODB transaction
to stage objects and consequently cares about such failures so it can
handle the error appropriately. Change the commit callback signature to
return an int error code and have `odb_transaction_commit()` forward it
accordingly.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When `odb_transaction_begin()` is invoked, the function returns the
transaction pointer directly. There is no way for the backend to
signal that it failed to set up its state, such as when creating the
temporary object directory backing the transaction.
In a subsequent commit, git-receive-pack(1) starts using ODB
transactions and needs to be able to report such failures rather
than silently ignore them. Refactor `odb_transaction_begin()` to
return an int error code and write the resulting transaction into an
out parameter. Also introduce `odb_transaction_begin_or_die()` as a
convenience for callsites that do not need to handle errors
explicitly.
Note that `odb_transaction_begin()` now returns an error when the ODB
already has an inflight transaction pending. ODB transaction call sites
that may encounter an inflight transaction are updated to explicitly
handle this case.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
How an ODB transaction handles writing objects is expected to vary
between implementations. Introduce a new `write_object_stream()`
callback in `struct odb_transaction` to make this function pluggable.
Rename `index_blob_packfile_transaction()` to
`odb_transaction_files_write_object_stream()` and wire it up for use
with `struct odb_transaction_files` accordingly.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each ODB source is expected to provide an ODB transaction implementation
that should be used when starting a transaction. With d6fc6fe6f8
(odb/source: make `begin_transaction()` function pluggable, 2026-03-05),
the `struct odb_source` now provides a pluggable callback for beginning
transactions. Use the callback provided by the ODB source accordingly.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current ODB transaction interface is colocated with other ODB
interfaces in "odb.{c,h}". Subsequent commits will expand `struct
odb_transaction` to support write operations on the transaction
directly. To keep things organized and prevent "odb.{c,h}" from becoming
more unwieldy, split out `struct odb_transaction` into a separate
header.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Justin Tobler