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                     unsigned char *sha1, int diff_header_only)
  15 {
  16         if (!patch_id_defined(commit))
  17                 return -1;
  18
  19         if (commit->parents)
  20                 diff_tree_sha1(commit->parents->item->object.oid.hash,
  21                                commit->object.oid.hash, "", options);
  22         else
  23                 diff_root_tree_sha1(commit->object.oid.hash, "", options);
  24         diffcore_std(options);
  25         return diff_flush_patch_id(options, sha1, 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(struct patch_id *a,
  39                         struct patch_id *b,
  40                         struct diff_options *opt)
  41 {
  42         if (is_null_sha1(a->patch_id) &&
  43             commit_patch_id(a->commit, opt, a->patch_id, 0))
  44                 return error("Could not get patch ID for %s",
  45                         oid_to_hex(&a->commit->object.oid));
  46         if (is_null_sha1(b->patch_id) &&
  47             commit_patch_id(b->commit, opt, b->patch_id, 0))
  48                 return error("Could not get patch ID for %s",
  49                         oid_to_hex(&b->commit->object.oid));
  50         return hashcmp(a->patch_id, b->patch_id);
  51 }
  52
  53 int init_patch_ids(struct patch_ids *ids)
  54 {
  55         memset(ids, 0, sizeof(*ids));
  56         diff_setup(&ids->diffopts);
  57         ids->diffopts.detect_rename = 0;
  58         DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
  59         diff_setup_done(&ids->diffopts);
  60         hashmap_init(&ids->patches, (hashmap_cmp_fn)patch_id_cmp, 256);
  61         return 0;
  62 }
  63
  64 int free_patch_ids(struct patch_ids *ids)
  65 {
  66         hashmap_free(&ids->patches, 1);
  67         return 0;
  68 }
  69
  70 static int init_patch_id_entry(struct patch_id *patch,
  71                                struct commit *commit,
  72                                struct patch_ids *ids)
  73 {
  74         unsigned char header_only_patch_id[GIT_MAX_RAWSZ];
  75
  76         patch->commit = commit;
  77         if (commit_patch_id(commit, &ids->diffopts, header_only_patch_id, 1))
  78                 return -1;
  79
  80         hashmap_entry_init(patch, sha1hash(header_only_patch_id));
  81         return 0;
  82 }
  83
  84 struct patch_id *has_commit_patch_id(struct commit *commit,
  85                                      struct patch_ids *ids)
  86 {
  87         struct patch_id patch;
  88
  89         if (!patch_id_defined(commit))
  90                 return NULL;
  91
  92         memset(&patch, 0, sizeof(patch));
  93         if (init_patch_id_entry(&patch, commit, ids))
  94                 return NULL;
  95
  96         return hashmap_get(&ids->patches, &patch, &ids->diffopts);
  97 }
  98
  99 struct patch_id *add_commit_patch_id(struct commit *commit,
 100                                      struct patch_ids *ids)
 101 {
 102         struct patch_id *key = xcalloc(1, sizeof(*key));
 103
 104         if (!patch_id_defined(commit))
 105                 return NULL;
 106
 107         if (init_patch_id_entry(key, commit, ids)) {
 108                 free(key);
 109                 return NULL;
 110         }
 111
 112         hashmap_add(&ids->patches, key);
 113         return key;
 114 }