commit-graph: verify generation number
[gitweb.git] / commit-graph.c
index f83f6d2373af6b356295ee1686a8813695801723..de656ebbaff88d692fc26b3f8a57d3d8798070ba 100644 (file)
@@ -11,6 +11,7 @@
 #include "sha1-lookup.h"
 #include "commit-graph.h"
 #include "object-store.h"
+#include "alloc.h"
 
 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
@@ -242,6 +243,10 @@ static struct commit_list **insert_parent_or_die(struct commit_graph *g,
 {
        struct commit *c;
        struct object_id oid;
+
+       if (pos >= g->num_commits)
+               die("invalid parent position %"PRIu64, pos);
+
        hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
        c = lookup_commit(&oid);
        if (!c)
@@ -314,7 +319,7 @@ static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uin
        }
 }
 
-int parse_commit_in_graph(struct commit *item)
+static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
 {
        uint32_t pos;
 
@@ -322,9 +327,21 @@ int parse_commit_in_graph(struct commit *item)
                return 0;
        if (item->object.parsed)
                return 1;
+
+       if (find_commit_in_graph(item, g, &pos))
+               return fill_commit_in_graph(item, g, pos);
+
+       return 0;
+}
+
+int parse_commit_in_graph(struct commit *item)
+{
+       if (!core_commit_graph)
+               return 0;
+
        prepare_commit_graph();
-       if (commit_graph && find_commit_in_graph(item, commit_graph, &pos))
-               return fill_commit_in_graph(item, commit_graph, pos);
+       if (commit_graph)
+               return parse_commit_in_graph_one(commit_graph, item);
        return 0;
 }
 
@@ -350,14 +367,20 @@ static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *
        return c->maybe_tree;
 }
 
-struct tree *get_commit_tree_in_graph(const struct commit *c)
+static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
+                                                const struct commit *c)
 {
        if (c->maybe_tree)
                return c->maybe_tree;
        if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
-               BUG("get_commit_tree_in_graph called from non-commit-graph commit");
+               BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 
-       return load_tree_for_commit(commit_graph, (struct commit *)c);
+       return load_tree_for_commit(g, (struct commit *)c);
+}
+
+struct tree *get_commit_tree_in_graph(const struct commit *c)
+{
+       return get_commit_tree_in_graph_one(commit_graph, c);
 }
 
 static void write_graph_chunk_fanout(struct hashfile *f,
@@ -809,3 +832,161 @@ void write_commit_graph(const char *obj_dir,
        oids.alloc = 0;
        oids.nr = 0;
 }
+
+static int verify_commit_graph_error;
+
+static void graph_report(const char *fmt, ...)
+{
+       va_list ap;
+
+       verify_commit_graph_error = 1;
+       va_start(ap, fmt);
+       vfprintf(stderr, fmt, ap);
+       fprintf(stderr, "\n");
+       va_end(ap);
+}
+
+#define GENERATION_ZERO_EXISTS 1
+#define GENERATION_NUMBER_EXISTS 2
+
+int verify_commit_graph(struct repository *r, struct commit_graph *g)
+{
+       uint32_t i, cur_fanout_pos = 0;
+       struct object_id prev_oid, cur_oid;
+       int generation_zero = 0;
+
+       if (!g) {
+               graph_report("no commit-graph file loaded");
+               return 1;
+       }
+
+       verify_commit_graph_error = 0;
+
+       if (!g->chunk_oid_fanout)
+               graph_report("commit-graph is missing the OID Fanout chunk");
+       if (!g->chunk_oid_lookup)
+               graph_report("commit-graph is missing the OID Lookup chunk");
+       if (!g->chunk_commit_data)
+               graph_report("commit-graph is missing the Commit Data chunk");
+
+       if (verify_commit_graph_error)
+               return verify_commit_graph_error;
+
+       for (i = 0; i < g->num_commits; i++) {
+               struct commit *graph_commit;
+
+               hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
+
+               if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
+                       graph_report("commit-graph has incorrect OID order: %s then %s",
+                                    oid_to_hex(&prev_oid),
+                                    oid_to_hex(&cur_oid));
+
+               oidcpy(&prev_oid, &cur_oid);
+
+               while (cur_oid.hash[0] > cur_fanout_pos) {
+                       uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
+
+                       if (i != fanout_value)
+                               graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
+                                            cur_fanout_pos, fanout_value, i);
+                       cur_fanout_pos++;
+               }
+
+               graph_commit = lookup_commit(&cur_oid);
+               if (!parse_commit_in_graph_one(g, graph_commit))
+                       graph_report("failed to parse %s from commit-graph",
+                                    oid_to_hex(&cur_oid));
+       }
+
+       while (cur_fanout_pos < 256) {
+               uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
+
+               if (g->num_commits != fanout_value)
+                       graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
+                                    cur_fanout_pos, fanout_value, i);
+
+               cur_fanout_pos++;
+       }
+
+       if (verify_commit_graph_error)
+               return verify_commit_graph_error;
+
+       for (i = 0; i < g->num_commits; i++) {
+               struct commit *graph_commit, *odb_commit;
+               struct commit_list *graph_parents, *odb_parents;
+               uint32_t max_generation = 0;
+
+               hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
+
+               graph_commit = lookup_commit(&cur_oid);
+               odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
+               if (parse_commit_internal(odb_commit, 0, 0)) {
+                       graph_report("failed to parse %s from object database",
+                                    oid_to_hex(&cur_oid));
+                       continue;
+               }
+
+               if (oidcmp(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
+                          get_commit_tree_oid(odb_commit)))
+                       graph_report("root tree OID for commit %s in commit-graph is %s != %s",
+                                    oid_to_hex(&cur_oid),
+                                    oid_to_hex(get_commit_tree_oid(graph_commit)),
+                                    oid_to_hex(get_commit_tree_oid(odb_commit)));
+
+               graph_parents = graph_commit->parents;
+               odb_parents = odb_commit->parents;
+
+               while (graph_parents) {
+                       if (odb_parents == NULL) {
+                               graph_report("commit-graph parent list for commit %s is too long",
+                                            oid_to_hex(&cur_oid));
+                               break;
+                       }
+
+                       if (oidcmp(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
+                               graph_report("commit-graph parent for %s is %s != %s",
+                                            oid_to_hex(&cur_oid),
+                                            oid_to_hex(&graph_parents->item->object.oid),
+                                            oid_to_hex(&odb_parents->item->object.oid));
+
+                       if (graph_parents->item->generation > max_generation)
+                               max_generation = graph_parents->item->generation;
+
+                       graph_parents = graph_parents->next;
+                       odb_parents = odb_parents->next;
+               }
+
+               if (odb_parents != NULL)
+                       graph_report("commit-graph parent list for commit %s terminates early",
+                                    oid_to_hex(&cur_oid));
+
+               if (!graph_commit->generation) {
+                       if (generation_zero == GENERATION_NUMBER_EXISTS)
+                               graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
+                                            oid_to_hex(&cur_oid));
+                       generation_zero = GENERATION_ZERO_EXISTS;
+               } else if (generation_zero == GENERATION_ZERO_EXISTS)
+                       graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
+                                    oid_to_hex(&cur_oid));
+
+               if (generation_zero == GENERATION_ZERO_EXISTS)
+                       continue;
+
+               /*
+                * If one of our parents has generation GENERATION_NUMBER_MAX, then
+                * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
+                * extra logic in the following condition.
+                */
+               if (max_generation == GENERATION_NUMBER_MAX)
+                       max_generation--;
+
+               if (graph_commit->generation != max_generation + 1)
+                       graph_report("commit-graph generation for commit %s is %u != %u",
+                                    oid_to_hex(&cur_oid),
+                                    graph_commit->generation,
+                                    max_generation + 1);
+       }
+
+       return verify_commit_graph_error;
+}