patch-ids.c

   1 #include "cache.h"
   2 #include "diff.h"
   3 #include "commit.h"
   4 #include "hash-lookup.h"
   5 #include "patch-ids.h"
   6
   7 static int patch_id_defined(struct commit *commit)
   8 {
   9         /* must be 0 or 1 parents */
  10         return !commit->parents || !commit->parents->next;
  11 }
  12
  13 int commit_patch_id(struct commit *commit, struct diff_options *options,
  14                     struct object_id *oid, int diff_header_only, int stable)
  15 {
  16         if (!patch_id_defined(commit))
  17                 return -1;
  18
  19         if (commit->parents)
  20                 diff_tree_oid(&commit->parents->item->object.oid,
  21                               &commit->object.oid, "", options);
  22         else
  23                 diff_root_tree_oid(&commit->object.oid, "", options);
  24         diffcore_std(options);
  25         return diff_flush_patch_id(options, oid, diff_header_only, stable);
  26 }
  27
  28 /*
  29  * When we cannot load the full patch-id for both commits for whatever
  30  * reason, the function returns -1 (i.e. return error(...)). Despite
  31  * the "neq" in the name of this function, the caller only cares about
  32  * the return value being zero (a and b are equivalent) or non-zero (a
  33  * and b are different), and returning non-zero would keep both in the
  34  * result, even if they actually were equivalent, in order to err on
  35  * the side of safety.  The actual value being negative does not have
  36  * any significance; only that it is non-zero matters.
  37  */
  38 static int patch_id_neq(const void *cmpfn_data,
  39                         const struct hashmap_entry *eptr,
  40                         const struct hashmap_entry *entry_or_key,
  41                         const void *unused_keydata)
  42 {
  43         /* NEEDSWORK: const correctness? */
  44         struct diff_options *opt = (void *)cmpfn_data;
  45         struct patch_id *a, *b;
  46
  47         a = container_of(eptr, struct patch_id, ent);
  48         b = container_of(entry_or_key, struct patch_id, ent);
  49
  50         if (is_null_oid(&a->patch_id) &&
  51             commit_patch_id(a->commit, opt, &a->patch_id, 0, 0))
  52                 return error("Could not get patch ID for %s",
  53                         oid_to_hex(&a->commit->object.oid));
  54         if (is_null_oid(&b->patch_id) &&
  55             commit_patch_id(b->commit, opt, &b->patch_id, 0, 0))
  56                 return error("Could not get patch ID for %s",
  57                         oid_to_hex(&b->commit->object.oid));
  58         return !oideq(&a->patch_id, &b->patch_id);
  59 }
  60
  61 int init_patch_ids(struct repository *r, struct patch_ids *ids)
  62 {
  63         memset(ids, 0, sizeof(*ids));
  64         repo_diff_setup(r, &ids->diffopts);
  65         ids->diffopts.detect_rename = 0;
  66         ids->diffopts.flags.recursive = 1;
  67         diff_setup_done(&ids->diffopts);
  68         hashmap_init(&ids->patches, patch_id_neq, &ids->diffopts, 256);
  69         return 0;
  70 }
  71
  72 int free_patch_ids(struct patch_ids *ids)
  73 {
  74         hashmap_clear_and_free(&ids->patches, struct patch_id, ent);
  75         return 0;
  76 }
  77
  78 static int init_patch_id_entry(struct patch_id *patch,
  79                                struct commit *commit,
  80                                struct patch_ids *ids)
  81 {
  82         struct object_id header_only_patch_id;
  83
  84         patch->commit = commit;
  85         if (commit_patch_id(commit, &ids->diffopts, &header_only_patch_id, 1, 0))
  86                 return -1;
  87
  88         hashmap_entry_init(&patch->ent, oidhash(&header_only_patch_id));
  89         return 0;
  90 }
  91
  92 struct patch_id *has_commit_patch_id(struct commit *commit,
  93                                      struct patch_ids *ids)
  94 {
  95         struct patch_id patch;
  96
  97         if (!patch_id_defined(commit))
  98                 return NULL;
  99
 100         memset(&patch, 0, sizeof(patch));
 101         if (init_patch_id_entry(&patch, commit, ids))
 102                 return NULL;
 103
 104         return hashmap_get_entry(&ids->patches, &patch, ent, NULL);
 105 }
 106
 107 struct patch_id *add_commit_patch_id(struct commit *commit,
 108                                      struct patch_ids *ids)
 109 {
 110         struct patch_id *key;
 111
 112         if (!patch_id_defined(commit))
 113                 return NULL;
 114
 115         key = xcalloc(1, sizeof(*key));
 116         if (init_patch_id_entry(key, commit, ids)) {
 117                 free(key);
 118                 return NULL;
 119         }
 120
 121         hashmap_add(&ids->patches, &key->ent);
 122         return key;
 123 }