t/lib-diff-alternative: abstract away SHA-1-specific constants
[gitweb.git] / commit-graph.c
index ea29c5c2d86ae69f7ea0a5ac1a5fb4dfafec9660..3fc1e0da2768d3f209da08b6b4c71df133a3ec88 100644 (file)
@@ -9,6 +9,7 @@
 #include "revision.h"
 #include "sha1-lookup.h"
 #include "commit-graph.h"
+#include "object-store.h"
 
 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
@@ -38,7 +39,6 @@
 #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 +179,147 @@ 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(the_repository);
+       for (alt = the_repository->objects->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)
@@ -411,7 +552,12 @@ static void close_reachable(struct packed_oid_list *oids)
        }
 }
 
-void write_commit_graph(const char *obj_dir)
+void write_commit_graph(const char *obj_dir,
+                       const char **pack_indexes,
+                       int nr_packs,
+                       const char **commit_hex,
+                       int nr_commits,
+                       int append)
 {
        struct packed_oid_list oids;
        struct packed_commit_list commits;
@@ -429,11 +575,66 @@ void write_commit_graph(const char *obj_dir)
        oids.nr = 0;
        oids.alloc = approximate_object_count() / 4;
 
+       if (append) {
+               prepare_commit_graph_one(obj_dir);
+               if (commit_graph)
+                       oids.alloc += commit_graph->num_commits;
+       }
+
        if (oids.alloc < 1024)
                oids.alloc = 1024;
        ALLOC_ARRAY(oids.list, oids.alloc);
 
-       for_each_packed_object(add_packed_commits, &oids, 0);
+       if (append && commit_graph) {
+               for (i = 0; i < commit_graph->num_commits; i++) {
+                       const unsigned char *hash = commit_graph->chunk_oid_lookup +
+                               commit_graph->hash_len * i;
+                       hashcpy(oids.list[oids.nr++].hash, hash);
+               }
+       }
+
+       if (pack_indexes) {
+               struct strbuf packname = STRBUF_INIT;
+               int dirlen;
+               strbuf_addf(&packname, "%s/pack/", obj_dir);
+               dirlen = packname.len;
+               for (i = 0; i < nr_packs; i++) {
+                       struct packed_git *p;
+                       strbuf_setlen(&packname, dirlen);
+                       strbuf_addstr(&packname, pack_indexes[i]);
+                       p = add_packed_git(packname.buf, packname.len, 1);
+                       if (!p)
+                               die("error adding pack %s", packname.buf);
+                       if (open_pack_index(p))
+                               die("error opening index for %s", packname.buf);
+                       for_each_object_in_pack(p, add_packed_commits, &oids);
+                       close_pack(p);
+               }
+               strbuf_release(&packname);
+       }
+
+       if (commit_hex) {
+               for (i = 0; i < nr_commits; i++) {
+                       const char *end;
+                       struct object_id oid;
+                       struct commit *result;
+
+                       if (commit_hex[i] && parse_oid_hex(commit_hex[i], &oid, &end))
+                               continue;
+
+                       result = lookup_commit_reference_gently(&oid, 1);
+
+                       if (result) {
+                               ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
+                               oidcpy(&oids.list[oids.nr], &(result->object.oid));
+                               oids.nr++;
+                       }
+               }
+       }
+
+       if (!pack_indexes && !commit_hex)
+               for_each_packed_object(add_packed_commits, &oids, 0);
+
        close_reachable(&oids);
 
        QSORT(oids.list, oids.nr, commit_compare);
@@ -530,6 +731,7 @@ 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);