commit: integrate commit graph with commit parsing
[gitweb.git] / commit-graph.c
index ea29c5c2d86ae69f7ea0a5ac1a5fb4dfafec9660..f745186e7f5ebaaea7852e7c6bfa3a275762c343 100644 (file)
@@ -38,7 +38,6 @@
 #define GRAPH_MIN_SIZE (5 * GRAPH_CHUNKLOOKUP_WIDTH + GRAPH_FANOUT_SIZE + \
                        GRAPH_OID_LEN + 8)
 
-
 char *get_commit_graph_filename(const char *obj_dir)
 {
        return xstrfmt("%s/info/commit-graph", obj_dir);
@@ -179,6 +178,145 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
        exit(1);
 }
 
+/* global storage */
+static struct commit_graph *commit_graph = NULL;
+
+static void prepare_commit_graph_one(const char *obj_dir)
+{
+       char *graph_name;
+
+       if (commit_graph)
+               return;
+
+       graph_name = get_commit_graph_filename(obj_dir);
+       commit_graph = load_commit_graph_one(graph_name);
+
+       FREE_AND_NULL(graph_name);
+}
+
+static int prepare_commit_graph_run_once = 0;
+static void prepare_commit_graph(void)
+{
+       struct alternate_object_database *alt;
+       char *obj_dir;
+
+       if (prepare_commit_graph_run_once)
+               return;
+       prepare_commit_graph_run_once = 1;
+
+       obj_dir = get_object_directory();
+       prepare_commit_graph_one(obj_dir);
+       prepare_alt_odb();
+       for (alt = alt_odb_list; !commit_graph && alt; alt = alt->next)
+               prepare_commit_graph_one(alt->path);
+}
+
+static void close_commit_graph(void)
+{
+       if (!commit_graph)
+               return;
+
+       if (commit_graph->graph_fd >= 0) {
+               munmap((void *)commit_graph->data, commit_graph->data_len);
+               commit_graph->data = NULL;
+               close(commit_graph->graph_fd);
+       }
+
+       FREE_AND_NULL(commit_graph);
+}
+
+static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
+{
+       return bsearch_hash(oid->hash, g->chunk_oid_fanout,
+                           g->chunk_oid_lookup, g->hash_len, pos);
+}
+
+static struct commit_list **insert_parent_or_die(struct commit_graph *g,
+                                                uint64_t pos,
+                                                struct commit_list **pptr)
+{
+       struct commit *c;
+       struct object_id oid;
+       hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
+       c = lookup_commit(&oid);
+       if (!c)
+               die("could not find commit %s", oid_to_hex(&oid));
+       c->graph_pos = pos;
+       return &commit_list_insert(c, pptr)->next;
+}
+
+static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
+{
+       struct object_id oid;
+       uint32_t edge_value;
+       uint32_t *parent_data_ptr;
+       uint64_t date_low, date_high;
+       struct commit_list **pptr;
+       const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
+
+       item->object.parsed = 1;
+       item->graph_pos = pos;
+
+       hashcpy(oid.hash, commit_data);
+       item->tree = lookup_tree(&oid);
+
+       date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
+       date_low = get_be32(commit_data + g->hash_len + 12);
+       item->date = (timestamp_t)((date_high << 32) | date_low);
+
+       pptr = &item->parents;
+
+       edge_value = get_be32(commit_data + g->hash_len);
+       if (edge_value == GRAPH_PARENT_NONE)
+               return 1;
+       pptr = insert_parent_or_die(g, edge_value, pptr);
+
+       edge_value = get_be32(commit_data + g->hash_len + 4);
+       if (edge_value == GRAPH_PARENT_NONE)
+               return 1;
+       if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
+               pptr = insert_parent_or_die(g, edge_value, pptr);
+               return 1;
+       }
+
+       parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
+                         4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
+       do {
+               edge_value = get_be32(parent_data_ptr);
+               pptr = insert_parent_or_die(g,
+                                           edge_value & GRAPH_EDGE_LAST_MASK,
+                                           pptr);
+               parent_data_ptr++;
+       } while (!(edge_value & GRAPH_LAST_EDGE));
+
+       return 1;
+}
+
+int parse_commit_in_graph(struct commit *item)
+{
+       if (!core_commit_graph)
+               return 0;
+       if (item->object.parsed)
+               return 1;
+
+       prepare_commit_graph();
+       if (commit_graph) {
+               uint32_t pos;
+               int found;
+               if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
+                       pos = item->graph_pos;
+                       found = 1;
+               } else {
+                       found = bsearch_graph(commit_graph, &(item->object.oid), &pos);
+               }
+
+               if (found)
+                       return fill_commit_in_graph(item, commit_graph, pos);
+       }
+
+       return 0;
+}
+
 static void write_graph_chunk_fanout(struct hashfile *f,
                                     struct commit **commits,
                                     int nr_commits)
@@ -530,6 +668,7 @@ void write_commit_graph(const char *obj_dir)
        write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
        write_graph_chunk_large_edges(f, commits.list, commits.nr);
 
+       close_commit_graph();
        finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
        commit_lock_file(&lk);