p5551: add a script to test fetch pack-dir rescans
[gitweb.git] / patch-ids.c
index a4d00166646d3dc354f3c06e9e75ce7dc3724f6a..b4166b0f384691ada862ff0b1e37387b018587b1 100644 (file)
 #include "sha1-lookup.h"
 #include "patch-ids.h"
 
+static int patch_id_defined(struct commit *commit)
+{
+       /* must be 0 or 1 parents */
+       return !commit->parents || !commit->parents->next;
+}
+
 int commit_patch_id(struct commit *commit, struct diff_options *options,
-                   unsigned char *sha1)
+                   struct object_id *oid, int diff_header_only)
 {
+       if (!patch_id_defined(commit))
+               return -1;
+
        if (commit->parents)
-               diff_tree_sha1(commit->parents->item->object.oid.hash,
-                              commit->object.oid.hash, "", options);
+               diff_tree_oid(&commit->parents->item->object.oid,
+                             &commit->object.oid, "", options);
        else
-               diff_root_tree_sha1(commit->object.oid.hash, "", options);
+               diff_root_tree_oid(&commit->object.oid, "", options);
        diffcore_std(options);
-       return diff_flush_patch_id(options, sha1);
-}
-
-static const unsigned char *patch_id_access(size_t index, void *table)
-{
-       struct patch_id **id_table = table;
-       return id_table[index]->patch_id;
+       return diff_flush_patch_id(options, oid, diff_header_only);
 }
 
-static int patch_pos(struct patch_id **table, int nr, const unsigned char *id)
+/*
+ * When we cannot load the full patch-id for both commits for whatever
+ * reason, the function returns -1 (i.e. return error(...)). Despite
+ * the "cmp" in the name of this function, the caller only cares about
+ * the return value being zero (a and b are equivalent) or non-zero (a
+ * and b are different), and returning non-zero would keep both in the
+ * result, even if they actually were equivalent, in order to err on
+ * the side of safety.  The actual value being negative does not have
+ * any significance; only that it is non-zero matters.
+ */
+static int patch_id_cmp(struct diff_options *opt,
+                       struct patch_id *a,
+                       struct patch_id *b,
+                       const void *unused_keydata)
 {
-       return sha1_pos(id, table, nr, patch_id_access);
+       if (is_null_oid(&a->patch_id) &&
+           commit_patch_id(a->commit, opt, &a->patch_id, 0))
+               return error("Could not get patch ID for %s",
+                       oid_to_hex(&a->commit->object.oid));
+       if (is_null_oid(&b->patch_id) &&
+           commit_patch_id(b->commit, opt, &b->patch_id, 0))
+               return error("Could not get patch ID for %s",
+                       oid_to_hex(&b->commit->object.oid));
+       return oidcmp(&a->patch_id, &b->patch_id);
 }
 
-#define BUCKET_SIZE 190 /* 190 * 21 = 3990, with slop close enough to 4K */
-struct patch_id_bucket {
-       struct patch_id_bucket *next;
-       int nr;
-       struct patch_id bucket[BUCKET_SIZE];
-};
-
 int init_patch_ids(struct patch_ids *ids)
 {
        memset(ids, 0, sizeof(*ids));
        diff_setup(&ids->diffopts);
+       ids->diffopts.detect_rename = 0;
        DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
        diff_setup_done(&ids->diffopts);
+       hashmap_init(&ids->patches, (hashmap_cmp_fn)patch_id_cmp,
+                    &ids->diffopts, 256);
        return 0;
 }
 
 int free_patch_ids(struct patch_ids *ids)
 {
-       struct patch_id_bucket *next, *patches;
-
-       free(ids->table);
-       for (patches = ids->patches; patches; patches = next) {
-               next = patches->next;
-               free(patches);
-       }
+       hashmap_free(&ids->patches, 1);
        return 0;
 }
 
-static struct patch_id *add_commit(struct commit *commit,
-                                  struct patch_ids *ids,
-                                  int no_add)
+static int init_patch_id_entry(struct patch_id *patch,
+                              struct commit *commit,
+                              struct patch_ids *ids)
 {
-       struct patch_id_bucket *bucket;
-       struct patch_id *ent;
-       unsigned char sha1[20];
-       int pos;
-
-       if (commit_patch_id(commit, &ids->diffopts, sha1))
-               return NULL;
-       pos = patch_pos(ids->table, ids->nr, sha1);
-       if (0 <= pos)
-               return ids->table[pos];
-       if (no_add)
-               return NULL;
+       struct object_id header_only_patch_id;
 
-       pos = -1 - pos;
+       patch->commit = commit;
+       if (commit_patch_id(commit, &ids->diffopts, &header_only_patch_id, 1))
+               return -1;
 
-       bucket = ids->patches;
-       if (!bucket || (BUCKET_SIZE <= bucket->nr)) {
-               bucket = xcalloc(1, sizeof(*bucket));
-               bucket->next = ids->patches;
-               ids->patches = bucket;
-       }
-       ent = &bucket->bucket[bucket->nr++];
-       hashcpy(ent->patch_id, sha1);
-
-       ALLOC_GROW(ids->table, ids->nr + 1, ids->alloc);
-       if (pos < ids->nr)
-               memmove(ids->table + pos + 1, ids->table + pos,
-                       sizeof(ent) * (ids->nr - pos));
-       ids->nr++;
-       ids->table[pos] = ent;
-       return ids->table[pos];
+       hashmap_entry_init(patch, sha1hash(header_only_patch_id.hash));
+       return 0;
 }
 
 struct patch_id *has_commit_patch_id(struct commit *commit,
                                     struct patch_ids *ids)
 {
-       return add_commit(commit, ids, 1);
+       struct patch_id patch;
+
+       if (!patch_id_defined(commit))
+               return NULL;
+
+       memset(&patch, 0, sizeof(patch));
+       if (init_patch_id_entry(&patch, commit, ids))
+               return NULL;
+
+       return hashmap_get(&ids->patches, &patch, NULL);
 }
 
 struct patch_id *add_commit_patch_id(struct commit *commit,
                                     struct patch_ids *ids)
 {
-       return add_commit(commit, ids, 0);
+       struct patch_id *key;
+
+       if (!patch_id_defined(commit))
+               return NULL;
+
+       key = xcalloc(1, sizeof(*key));
+       if (init_patch_id_entry(key, commit, ids)) {
+               free(key);
+               return NULL;
+       }
+
+       hashmap_add(&ids->patches, key);
+       return key;
 }