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 int commit_patch_id(struct commit *commit, struct diff_options *options,
   8                     unsigned char *sha1, int diff_header_only)
   9 {
  10         if (commit->parents)
  11                 diff_tree_sha1(commit->parents->item->object.oid.hash,
  12                                commit->object.oid.hash, "", options);
  13         else
  14                 diff_root_tree_sha1(commit->object.oid.hash, "", options);
  15         diffcore_std(options);
  16         return diff_flush_patch_id(options, sha1, diff_header_only);
  17 }
  18
  19 /*
  20  * When we cannot load the full patch-id for both commits for whatever
  21  * reason, the function returns -1 (i.e. return error(...)). Despite
  22  * the "cmp" in the name of this function, the caller only cares about
  23  * the return value being zero (a and b are equivalent) or non-zero (a
  24  * and b are different), and returning non-zero would keep both in the
  25  * result, even if they actually were equivalent, in order to err on
  26  * the side of safety.  The actual value being negative does not have
  27  * any significance; only that it is non-zero matters.
  28  */
  29 static int patch_id_cmp(struct patch_id *a,
  30                         struct patch_id *b,
  31                         struct diff_options *opt)
  32 {
  33         if (is_null_sha1(a->patch_id) &&
  34             commit_patch_id(a->commit, opt, a->patch_id, 0))
  35                 return error("Could not get patch ID for %s",
  36                         oid_to_hex(&a->commit->object.oid));
  37         if (is_null_sha1(b->patch_id) &&
  38             commit_patch_id(b->commit, opt, b->patch_id, 0))
  39                 return error("Could not get patch ID for %s",
  40                         oid_to_hex(&b->commit->object.oid));
  41         return hashcmp(a->patch_id, b->patch_id);
  42 }
  43
  44 int init_patch_ids(struct patch_ids *ids)
  45 {
  46         memset(ids, 0, sizeof(*ids));
  47         diff_setup(&ids->diffopts);
  48         DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
  49         diff_setup_done(&ids->diffopts);
  50         hashmap_init(&ids->patches, (hashmap_cmp_fn)patch_id_cmp, 256);
  51         return 0;
  52 }
  53
  54 int free_patch_ids(struct patch_ids *ids)
  55 {
  56         hashmap_free(&ids->patches, 1);
  57         return 0;
  58 }
  59
  60 static int init_patch_id_entry(struct patch_id *patch,
  61                                struct commit *commit,
  62                                struct patch_ids *ids)
  63 {
  64         unsigned char header_only_patch_id[GIT_SHA1_RAWSZ];
  65
  66         patch->commit = commit;
  67         if (commit_patch_id(commit, &ids->diffopts, header_only_patch_id, 1))
  68                 return -1;
  69
  70         hashmap_entry_init(patch, sha1hash(header_only_patch_id));
  71         return 0;
  72 }
  73
  74 struct patch_id *has_commit_patch_id(struct commit *commit,
  75                                      struct patch_ids *ids)
  76 {
  77         struct patch_id patch;
  78
  79         memset(&patch, 0, sizeof(patch));
  80         if (init_patch_id_entry(&patch, commit, ids))
  81                 return NULL;
  82
  83         return hashmap_get(&ids->patches, &patch, &ids->diffopts);
  84 }
  85
  86 struct patch_id *add_commit_patch_id(struct commit *commit,
  87                                      struct patch_ids *ids)
  88 {
  89         struct patch_id *key = xcalloc(1, sizeof(*key));
  90
  91         if (init_patch_id_entry(key, commit, ids)) {
  92                 free(key);
  93                 return NULL;
  94         }
  95
  96         hashmap_add(&ids->patches, key);
  97         return key;
  98 }