patch-ids.c

   1 #include "cache.h"
   2 #include "diff.h"
   3 #include "commit.h"
   4 #include "sha1-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)
  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);
  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 "cmp" 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_cmp(const void *cmpfn_data,
  39                         const void *entry,
  40                         const void *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 = (void *)entry;
  46         struct patch_id *b = (void *)entry_or_key;
  47
  48         if (is_null_oid(&a->patch_id) &&
  49             commit_patch_id(a->commit, opt, &a->patch_id, 0))
  50                 return error("Could not get patch ID for %s",
  51                         oid_to_hex(&a->commit->object.oid));
  52         if (is_null_oid(&b->patch_id) &&
  53             commit_patch_id(b->commit, opt, &b->patch_id, 0))
  54                 return error("Could not get patch ID for %s",
  55                         oid_to_hex(&b->commit->object.oid));
  56         return oidcmp(&a->patch_id, &b->patch_id);
  57 }
  58
  59 int init_patch_ids(struct patch_ids *ids)
  60 {
  61         memset(ids, 0, sizeof(*ids));
  62         diff_setup(&ids->diffopts);
  63         ids->diffopts.detect_rename = 0;
  64         ids->diffopts.flags.recursive = 1;
  65         diff_setup_done(&ids->diffopts);
  66         hashmap_init(&ids->patches, patch_id_cmp, &ids->diffopts, 256);
  67         return 0;
  68 }
  69
  70 int free_patch_ids(struct patch_ids *ids)
  71 {
  72         hashmap_free(&ids->patches, 1);
  73         return 0;
  74 }
  75
  76 static int init_patch_id_entry(struct patch_id *patch,
  77                                struct commit *commit,
  78                                struct patch_ids *ids)
  79 {
  80         struct object_id header_only_patch_id;
  81
  82         patch->commit = commit;
  83         if (commit_patch_id(commit, &ids->diffopts, &header_only_patch_id, 1))
  84                 return -1;
  85
  86         hashmap_entry_init(patch, sha1hash(header_only_patch_id.hash));
  87         return 0;
  88 }
  89
  90 struct patch_id *has_commit_patch_id(struct commit *commit,
  91                                      struct patch_ids *ids)
  92 {
  93         struct patch_id patch;
  94
  95         if (!patch_id_defined(commit))
  96                 return NULL;
  97
  98         memset(&patch, 0, sizeof(patch));
  99         if (init_patch_id_entry(&patch, commit, ids))
 100                 return NULL;
 101
 102         return hashmap_get(&ids->patches, &patch, NULL);
 103 }
 104
 105 struct patch_id *add_commit_patch_id(struct commit *commit,
 106                                      struct patch_ids *ids)
 107 {
 108         struct patch_id *key;
 109
 110         if (!patch_id_defined(commit))
 111                 return NULL;
 112
 113         key = xcalloc(1, sizeof(*key));
 114         if (init_patch_id_entry(key, commit, ids)) {
 115                 free(key);
 116                 return NULL;
 117         }
 118
 119         hashmap_add(&ids->patches, key);
 120         return key;
 121 }