odb/transaction: make `write_object_stream()` pluggable

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>

Justin Tobler committed May 14, 2026 at 13:37 UTC 08b6afb2a2dbf762e3d9fa7abd78090b9afbd1a8
3 files changed +38 -10
object-file.c
+9 -7
@@ -1578,9 +1578,10 @@ clear_exit:
1578 * binary blobs, they generally do not want to get any conversion, and
1579 * callers should avoid this code path when filters are requested.
1580 */
1581 -static int index_blob_packfile_transaction(struct odb_transaction *base,
1582 - struct odb_write_stream *stream,
1583 - size_t size, struct object_id *result_oid)
1581 +static int odb_transaction_files_write_object_stream(struct odb_transaction *base,
1582 + struct odb_write_stream *stream,
1583 + size_t size,
1584 + struct object_id *result_oid)
1585 {
1586 struct odb_transaction_files *transaction = container_of(base,
1587 struct odb_transaction_files,
@@ -1664,10 +1665,10 @@ int index_fd(struct index_state *istate, struct object_id *oid,
1665 struct object_database *odb = the_repository->objects;
1666 struct odb_transaction *transaction = odb_transaction_begin(odb);
1667
1667 - ret = index_blob_packfile_transaction(odb->transaction,
1668 - &stream,
1669 - xsize_t(st->st_size),
1670 - oid);
1668 + ret = odb_transaction_write_object_stream(odb->transaction,
1669 + &stream,
1670 + xsize_t(st->st_size),
1671 + oid);
1672 odb_transaction_commit(transaction);
1673 } else {
1674 ret = hash_blob_stream(&stream,
@@ -2132,6 +2133,7 @@ struct odb_transaction *odb_transaction_files_begin(struct odb_source *source)
2133 transaction = xcalloc(1, sizeof(*transaction));
2134 transaction->base.source = source;
2135 transaction->base.commit = odb_transaction_files_commit;
2136 + transaction->base.write_object_stream = odb_transaction_files_write_object_stream;
2137
2138 return &transaction->base;
2139 }
odb/transaction.c
+7
@@ -26,3 +26,10 @@ void odb_transaction_commit(struct odb_transaction *transaction)
26 transaction->source->odb->transaction = NULL;
27 free(transaction);
28 }
29 +
30 +int odb_transaction_write_object_stream(struct odb_transaction *transaction,
31 + struct odb_write_stream *stream,
32 + size_t len, struct object_id *oid)
33 +{
34 + return transaction->write_object_stream(transaction, stream, len, oid);
35 +}
odb/transaction.h
+22 -3
@@ -12,14 +12,24 @@
12 *
13 * Each ODB source is expected to implement its own transaction handling.
14 */
15 -struct odb_transaction;
16 -typedef void (*odb_transaction_commit_fn)(struct odb_transaction *transaction);
15 struct odb_transaction {
16 /* The ODB source the transaction is opened against. */
17 struct odb_source *source;
18
19 /* The ODB source specific callback invoked to commit a transaction. */
22 - odb_transaction_commit_fn commit;
20 + void (*commit)(struct odb_transaction *transaction);
21 +
22 + /*
23 + * This callback is expected to write the given object stream into
24 + * the ODB transaction. Note that for now, only blobs support streaming.
25 + *
26 + * The resulting object ID shall be written into the out pointer. The
27 + * callback is expected to return 0 on success, a negative error code
28 + * otherwise.
29 + */
30 + int (*write_object_stream)(struct odb_transaction *transaction,
31 + struct odb_write_stream *stream, size_t len,
32 + struct object_id *oid);
33 };
34
35 /*
@@ -35,4 +45,13 @@ struct odb_transaction *odb_transaction_begin(struct object_database *odb);
45 */
46 void odb_transaction_commit(struct odb_transaction *transaction);
47
48 +/*
49 + * Writes the object in the provided stream into the transaction. The resulting
50 + * object ID is written into the out pointer. Returns 0 on success, a negative
51 + * error code otherwise.
52 + */
53 +int odb_transaction_write_object_stream(struct odb_transaction *transaction,
54 + struct odb_write_stream *stream,
55 + size_t len, struct object_id *oid);
56 +
57 #endif