From: Derrick Stolee <dsto...@microsoft.com>
In anticipation of a new commit-graph file format version, create
a flag for the write_commit_graph() and write_commit_graph_reachable()
methods to take a version number.
When there is no specified version, the implementation selects a
default value. Currently, the only valid value is 1.
The file format will change the header information, so place the
existing header logic inside a switch statement with only one case.
Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
commit-graph.c | 58 +++++++++++++++++++++++++++++++++-----------------
commit-graph.h | 1 +
2 files changed, 40 insertions(+), 19 deletions(-)
diff --git a/commit-graph.c b/commit-graph.c
index b16c71fd82..e75e1655fb 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -25,9 +25,6 @@
#define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
-#define GRAPH_VERSION_1 0x1
-#define GRAPH_VERSION GRAPH_VERSION_1
-
#define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
#define GRAPH_EDGE_LAST_MASK 0x7fffffff
#define GRAPH_PARENT_NONE 0x70000000
@@ -173,30 +170,35 @@ struct commit_graph *parse_commit_graph(void *graph_map,
int fd,
}
graph_version = *(unsigned char*)(data + 4);
- if (graph_version != GRAPH_VERSION) {
+ if (graph_version != 1) {
error(_("commit-graph version %X does not match version %X"),
- graph_version, GRAPH_VERSION);
- return NULL;
- }
-
- hash_version = *(unsigned char*)(data + 5);
- if (hash_version != oid_version()) {
- error(_("commit-graph hash version %X does not match version
%X"),
- hash_version, oid_version());
+ graph_version, 1);
return NULL;
}
graph = alloc_commit_graph();
+ switch (graph_version) {
+ case 1:
+ hash_version = *(unsigned char*)(data + 5);
+ if (hash_version != oid_version()) {
+ error(_("commit-graph hash version %X does not match
version %X"),
+ hash_version, oid_version());
+ return NULL;
+ }
+
+ graph->num_chunks = *(unsigned char*)(data + 6);
+ chunk_lookup = data + 8;
+ break;
+ }
+
graph->hash_len = the_hash_algo->rawsz;
- graph->num_chunks = *(unsigned char*)(data + 6);
graph->graph_fd = fd;
graph->data = graph_map;
graph->data_len = graph_size;
last_chunk_id = 0;
last_chunk_offset = 8;
- chunk_lookup = data + 8;
for (i = 0; i < graph->num_chunks; i++) {
uint32_t chunk_id;
uint64_t chunk_offset;
@@ -888,10 +890,22 @@ int write_commit_graph(const char *obj_dir,
int res = 0;
int append = flags & COMMIT_GRAPH_APPEND;
int report_progress = flags & COMMIT_GRAPH_PROGRESS;
+ int version = 0;
+ int header_size = 0;
if (!commit_graph_compatible(the_repository))
return 0;
+ if (flags & COMMIT_GRAPH_VERSION_1)
+ version = 1;
+ if (!version)
+ version = 1;
+ if (version != 1) {
+ error(_("unsupported commit-graph version %d"),
+ version);
+ return 1;
+ }
+
oids.nr = 0;
approx_nr_objects = approximate_object_count();
oids.alloc = approx_nr_objects / 32;
@@ -1076,10 +1090,16 @@ int write_commit_graph(const char *obj_dir,
hashwrite_be32(f, GRAPH_SIGNATURE);
- hashwrite_u8(f, GRAPH_VERSION);
- hashwrite_u8(f, oid_version());
- hashwrite_u8(f, num_chunks);
- hashwrite_u8(f, 0); /* unused padding byte */
+ hashwrite_u8(f, version);
+
+ switch (version) {
+ case 1:
+ hashwrite_u8(f, oid_version());
+ hashwrite_u8(f, num_chunks);
+ hashwrite_u8(f, 0); /* unused padding byte */
+ header_size = 8;
+ break;
+ }
chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
@@ -1090,7 +1110,7 @@ int write_commit_graph(const char *obj_dir,
chunk_ids[3] = 0;
chunk_ids[4] = 0;
- chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
+ chunk_offsets[0] = header_size + (num_chunks + 1) *
GRAPH_CHUNKLOOKUP_WIDTH;
chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
diff --git a/commit-graph.h b/commit-graph.h
index 390474047c..d7cd13deb3 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -67,6 +67,7 @@ int generation_numbers_enabled(struct repository *r);
#define COMMIT_GRAPH_APPEND (1 << 0)
#define COMMIT_GRAPH_PROGRESS (1 << 1)
+#define COMMIT_GRAPH_VERSION_1 (1 << 2)
int write_commit_graph_reachable(const char *obj_dir, int flags);
int write_commit_graph(const char *obj_dir,
--
gitgitgadget
