odb: prepare `struct odb_transaction` to become generic
An ODB transaction handles how objects are stored temporarily and eventually committed. Due to object storage being implemented differently for a given ODB source, the ODB transactions must be implemented in a manner specific to the source the objects are being written to. To provide generic transactions, `struct odb_transaction` is updated to store a commit callback that can be configured to support a specific ODB source. For now `struct odb_transaction_files` is the only transaction type and what is always returned when starting a transaction. Signed-off-by: Justin Tobler <jltobler@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Justin Tobler committed
Feb 2, 2026 at 18:10 UTC
fa7d067923a342c298b7723935c60217a5244e4e
4 files changed
+65
-43
object-file.c
+44
-36
@@ -710,15 +710,17 @@ struct transaction_packfile {
710
uint32_t nr_written;
711
};
712
713
-struct odb_transaction {
714
- struct odb_source *source;
713
+struct odb_transaction_files {
714
+ struct odb_transaction base;
715
716
struct tmp_objdir *objdir;
717
struct transaction_packfile packfile;
718
};
719
720
-static void prepare_loose_object_transaction(struct odb_transaction *transaction)
720
+static void prepare_loose_object_transaction(struct odb_transaction *base)
721
{
722
+ struct odb_transaction_files *transaction = (struct odb_transaction_files *)base;
723
+
724
/*
725
* We lazily create the temporary object directory
726
* the first time an object might be added, since
@@ -728,14 +730,16 @@ static void prepare_loose_object_transaction(struct odb_transaction *transaction
730
if (!transaction || transaction->objdir)
731
return;
732
731
- transaction->objdir = tmp_objdir_create(transaction->source->odb->repo, "bulk-fsync");
733
+ transaction->objdir = tmp_objdir_create(base->source->odb->repo, "bulk-fsync");
734
if (transaction->objdir)
735
tmp_objdir_replace_primary_odb(transaction->objdir, 0);
736
}
737
736
-static void fsync_loose_object_transaction(struct odb_transaction *transaction,
738
+static void fsync_loose_object_transaction(struct odb_transaction *base,
739
int fd, const char *filename)
740
{
741
+ struct odb_transaction_files *transaction = (struct odb_transaction_files *)base;
742
+
743
/*
744
* If we have an active ODB transaction, we issue a call that
745
* cleans the filesystem page cache but avoids a hardware flush
@@ -754,7 +758,7 @@ static void fsync_loose_object_transaction(struct odb_transaction *transaction,
758
/*
759
* Cleanup after batch-mode fsync_object_files.
760
*/
757
-static void flush_loose_object_transaction(struct odb_transaction *transaction)
761
+static void flush_loose_object_transaction(struct odb_transaction_files *transaction)
762
{
763
struct strbuf temp_path = STRBUF_INIT;
764
struct tempfile *temp;
@@ -772,7 +776,7 @@ static void flush_loose_object_transaction(struct odb_transaction *transaction)
776
* the final name is visible.
777
*/
778
strbuf_addf(&temp_path, "%s/bulk_fsync_XXXXXX",
775
- repo_get_object_directory(transaction->source->odb->repo));
779
+ repo_get_object_directory(transaction->base.source->odb->repo));
780
temp = xmks_tempfile(temp_path.buf);
781
fsync_or_die(get_tempfile_fd(temp), get_tempfile_path(temp));
782
delete_tempfile(&temp);
@@ -1340,11 +1344,11 @@ static int index_core(struct index_state *istate,
1344
return ret;
1345
}
1346
1343
-static int already_written(struct odb_transaction *transaction,
1347
+static int already_written(struct odb_transaction_files *transaction,
1348
struct object_id *oid)
1349
{
1350
/* The object may already exist in the repository */
1347
- if (odb_has_object(transaction->source->odb, oid,
1351
+ if (odb_has_object(transaction->base.source->odb, oid,
1352
HAS_OBJECT_RECHECK_PACKED | HAS_OBJECT_FETCH_PROMISOR))
1353
return 1;
1354
@@ -1358,14 +1362,14 @@ static int already_written(struct odb_transaction *transaction,
1362
}
1363
1364
/* Lazily create backing packfile for the state */
1361
-static void prepare_packfile_transaction(struct odb_transaction *transaction,
1365
+static void prepare_packfile_transaction(struct odb_transaction_files *transaction,
1366
unsigned flags)
1367
{
1368
struct transaction_packfile *state = &transaction->packfile;
1369
if (!(flags & INDEX_WRITE_OBJECT) || state->f)
1370
return;
1371
1368
- state->f = create_tmp_packfile(transaction->source->odb->repo,
1372
+ state->f = create_tmp_packfile(transaction->base.source->odb->repo,
1373
&state->pack_tmp_name);
1374
reset_pack_idx_option(&state->pack_idx_opts);
1375
@@ -1466,10 +1470,10 @@ static int stream_blob_to_pack(struct transaction_packfile *state,
1470
return 0;
1471
}
1472
1469
-static void flush_packfile_transaction(struct odb_transaction *transaction)
1473
+static void flush_packfile_transaction(struct odb_transaction_files *transaction)
1474
{
1475
struct transaction_packfile *state = &transaction->packfile;
1472
- struct repository *repo = transaction->source->odb->repo;
1476
+ struct repository *repo = transaction->base.source->odb->repo;
1477
unsigned char hash[GIT_MAX_RAWSZ];
1478
struct strbuf packname = STRBUF_INIT;
1479
char *idx_tmp_name = NULL;
@@ -1494,7 +1498,7 @@ static void flush_packfile_transaction(struct odb_transaction *transaction)
1498
}
1499
1500
strbuf_addf(&packname, "%s/pack/pack-%s.",
1497
- repo_get_object_directory(transaction->source->odb->repo),
1501
+ repo_get_object_directory(transaction->base.source->odb->repo),
1502
hash_to_hex_algop(hash, repo->hash_algo));
1503
1504
stage_tmp_packfiles(repo, &packname, state->pack_tmp_name,
@@ -1534,7 +1538,7 @@ clear_exit:
1538
* binary blobs, they generally do not want to get any conversion, and
1539
* callers should avoid this code path when filters are requested.
1540
*/
1537
-static int index_blob_packfile_transaction(struct odb_transaction *transaction,
1541
+static int index_blob_packfile_transaction(struct odb_transaction_files *transaction,
1542
struct object_id *result_oid, int fd,
1543
size_t size, const char *path,
1544
unsigned flags)
@@ -1553,7 +1557,7 @@ static int index_blob_packfile_transaction(struct odb_transaction *transaction,
1557
1558
header_len = format_object_header((char *)obuf, sizeof(obuf),
1559
OBJ_BLOB, size);
1556
- transaction->source->odb->repo->hash_algo->init_fn(&ctx);
1560
+ transaction->base.source->odb->repo->hash_algo->init_fn(&ctx);
1561
git_hash_update(&ctx, obuf, header_len);
1562
1563
/* Note: idx is non-NULL when we are writing */
@@ -1629,10 +1633,11 @@ int index_fd(struct index_state *istate, struct object_id *oid,
1633
ret = index_core(istate, oid, fd, xsize_t(st->st_size),
1634
type, path, flags);
1635
} else {
1636
+ struct object_database *odb = the_repository->objects;
1637
struct odb_transaction *transaction;
1638
1634
- transaction = odb_transaction_begin(the_repository->objects);
1635
- ret = index_blob_packfile_transaction(the_repository->objects->transaction,
1639
+ transaction = odb_transaction_begin(odb);
1640
+ ret = index_blob_packfile_transaction((struct odb_transaction_files *)odb->transaction,
1641
oid, fd,
1642
xsize_t(st->st_size),
1643
path, flags);
@@ -1985,35 +1990,38 @@ out:
1990
return ret;
1991
}
1992
1988
-struct odb_transaction *odb_transaction_files_begin(struct odb_source *source)
1993
+static void odb_transaction_files_commit(struct odb_transaction *base)
1994
{
1990
- struct object_database *odb = source->odb;
1991
-
1992
- if (odb->transaction)
1993
- return NULL;
1994
-
1995
- CALLOC_ARRAY(odb->transaction, 1);
1996
- odb->transaction->source = source;
1997
-
1998
- return odb->transaction;
1999
-}
2000
-
2001
-void odb_transaction_files_commit(struct odb_transaction *transaction)
2002
-{
2003
- if (!transaction)
2004
- return;
1995
+ struct odb_transaction_files *transaction = (struct odb_transaction_files *)base;
1996
1997
/*
1998
* Ensure the transaction ending matches the pending transaction.
1999
*/
2009
- ASSERT(transaction == transaction->source->odb->transaction);
2000
+ ASSERT(base == base->source->odb->transaction);
2001
2002
flush_loose_object_transaction(transaction);
2003
flush_packfile_transaction(transaction);
2013
- transaction->source->odb->transaction = NULL;
2004
+ base->source->odb->transaction = NULL;
2005
free(transaction);
2006
}
2007
2008
+struct odb_transaction *odb_transaction_files_begin(struct odb_source *source)
2009
+{
2010
+ struct odb_transaction_files *transaction;
2011
+ struct object_database *odb = source->odb;
2012
+
2013
+ if (odb->transaction)
2014
+ return NULL;
2015
+
2016
+ transaction = xcalloc(1, sizeof(*transaction));
2017
+ transaction->base.source = source;
2018
+ transaction->base.commit = odb_transaction_files_commit;
2019
+
2020
+ odb->transaction = &transaction->base;
2021
+
2022
+ return &transaction->base;
2023
+}
2024
+
2025
struct odb_source_loose *odb_source_loose_new(struct odb_source *source)
2026
{
2027
struct odb_source_loose *loose;
object-file.h
-6
@@ -208,10 +208,4 @@ struct odb_transaction;
208
*/
209
struct odb_transaction *odb_transaction_files_begin(struct odb_source *source);
210
211
-/*
212
- * Tell the object database to make any objects from the
213
- * current transaction visible.
214
- */
215
-void odb_transaction_files_commit(struct odb_transaction *transaction);
216
-
211
#endif /* OBJECT_FILE_H */
odb.c
+4
-1
@@ -1158,5 +1158,8 @@ struct odb_transaction *odb_transaction_begin(struct object_database *odb)
1158
1159
void odb_transaction_commit(struct odb_transaction *transaction)
1160
{
1161
- odb_transaction_files_commit(transaction);
1161
+ if (!transaction)
1162
+ return;
1163
+
1164
+ transaction->commit(transaction);
1165
}
odb.h
+17
@@ -77,7 +77,24 @@ struct odb_source {
77
struct packed_git;
78
struct packfile_store;
79
struct cached_object_entry;
80
+
81
+/*
82
+ * A transaction may be started for an object database prior to writing new
83
+ * objects via odb_transaction_begin(). These objects are not committed until
84
+ * odb_transaction_commit() is invoked. Only a single transaction may be pending
85
+ * at a time.
86
+ *
87
+ * Each ODB source is expected to implement its own transaction handling.
88
+ */
89
struct odb_transaction;
90
+typedef void (*odb_transaction_commit_fn)(struct odb_transaction *transaction);
91
+struct odb_transaction {
92
+ /* The ODB source the transaction is opened against. */
93
+ struct odb_source *source;
94
+
95
+ /* The ODB source specific callback invoked to commit a transaction. */
96
+ odb_transaction_commit_fn commit;
97
+};
98
99
/*
100
* The object database encapsulates access to objects in a repository. It