lib/keyword.c

   1 /*
   2  * Copyright (c) 2023 Mark Jamsek <mark@jamsek.dev>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include "got_compat.h"
  18
  19 #include <sys/queue.h>
  20
  21 #include <ctype.h>
  22 #include <limits.h>
  23 #include <stddef.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include "got_reference.h"
  29 #include "got_error.h"
  30 #include "got_object.h"
  31 #include "got_repository.h"
  32 #include "got_cancel.h"
  33 #include "got_worktree.h"
  34 #include "got_commit_graph.h"
  35 #include "got_keyword.h"
  36
  37 struct keyword_mod {
  38         char            *kw;
  39         uint64_t         n;
  40         uint8_t          sym;
  41         uint8_t          iskeyword;
  42         uint8_t          ismodified;
  43 };
  44
  45 #define GOT_KEYWORD_DESCENDANT  '+'
  46 #define GOT_KEYWORD_ANCESTOR    '-'
  47
  48 static const struct got_error *
  49 parse_keyword(struct keyword_mod *kwm, const char *keyword)
  50 {
  51         const char      *kw;
  52         char            *p;
  53
  54         if (keyword == NULL)
  55                 return NULL;
  56
  57         /* check if it is a (modified) keyword or modified reference */
  58         if (*keyword == ':') {
  59                 kwm->iskeyword = 1;
  60                 kw = keyword + 1;
  61         } else
  62                 kw = keyword;
  63
  64         kwm->kw = strdup(kw);
  65         if (kwm->kw == NULL)
  66                 return got_error_from_errno("strdup");
  67
  68         p = strchr(kwm->kw, ':');
  69
  70         if (p != NULL) {
  71                 *p = '\0';
  72                 ++p;
  73                 if (*p != GOT_KEYWORD_DESCENDANT && *p != GOT_KEYWORD_ANCESTOR)
  74                         return got_error_fmt(GOT_ERR_BAD_KEYWORD,
  75                             "'%s'", keyword);
  76
  77                 kwm->ismodified = 1;
  78                 kwm->sym = *p;
  79                 ++p;
  80
  81                 if (*p) {
  82                         const char      *errstr;
  83                         long long        n;
  84
  85                         n = strtonum(p, 0, LLONG_MAX, &errstr);
  86                         if (errstr != NULL)
  87                                 return got_error_fmt(GOT_ERR_BAD_KEYWORD,
  88                                     "'%s'", keyword);
  89
  90                         kwm->n = n;
  91                 } else
  92                         kwm->n = 1;     /* :(+/-) == :(+/-)1 */
  93         }
  94
  95         return NULL;
  96 }
  97
  98 const struct got_error *
  99 got_keyword_to_idstr(char **ret, const char *keyword,
 100     struct got_repository *repo, struct got_worktree *wt)
 101 {
 102         const struct got_error          *err = NULL;
 103         struct got_commit_graph         *graph = NULL;
 104         struct got_object_id            *head_id = NULL, *kwid = NULL;
 105         struct got_object_id             iter_id;
 106         struct got_reflist_head          refs;
 107         struct got_object_id_queue       commits;
 108         struct got_object_qid           *qid;
 109         struct keyword_mod               kwm;
 110         const char                      *kw = NULL;
 111         char                            *kwid_str = NULL;
 112         uint64_t                         n = 0;
 113
 114         *ret = NULL;
 115         TAILQ_INIT(&refs);
 116         STAILQ_INIT(&commits);
 117         memset(&kwm, 0, sizeof(kwm));
 118
 119         err = parse_keyword(&kwm, keyword);
 120         if (err != NULL)
 121                 goto done;
 122
 123         kw = kwm.kw;
 124
 125         if (kwm.iskeyword) {
 126                 if (strcmp(kw, GOT_KEYWORD_BASE) == 0) {
 127                         if (wt == NULL) {
 128                                 err = got_error_msg(GOT_ERR_NOT_WORKTREE,
 129                                     "'-c :base' requires work tree");
 130                                 goto done;
 131                         }
 132
 133                         err = got_object_id_str(&kwid_str,
 134                             got_worktree_get_base_commit_id(wt));
 135                         if (err != NULL)
 136                                 goto done;
 137                 } else if (strcmp(kw, GOT_KEYWORD_HEAD) == 0) {
 138                         struct got_reference *head_ref;
 139
 140                         err = got_ref_open(&head_ref, repo, wt != NULL ?
 141                             got_worktree_get_head_ref_name(wt) :
 142                             GOT_REF_HEAD, 0);
 143                         if (err != NULL)
 144                                 goto done;
 145
 146                         kwid_str = got_ref_to_str(head_ref);
 147                         got_ref_close(head_ref);
 148                         if (kwid_str == NULL) {
 149                                 err = got_error_from_errno("got_ref_to_str");
 150                                 goto done;
 151                         }
 152                 } else {
 153                         err = got_error_fmt(GOT_ERR_BAD_KEYWORD, "'%s'", kw);
 154                         goto done;
 155                 }
 156         } else if (kwm.ismodified) {
 157                 /* reference:[(+|-)[N]] */
 158                 kwid_str = strdup(kw);
 159                 if (kwid_str == NULL) {
 160                         err = got_error_from_errno("strdup");
 161                         goto done;
 162                 }
 163         } else
 164                 goto done;
 165
 166         if (kwm.n == 0)
 167                 goto done;      /* unmodified keyword */
 168
 169         err = got_ref_list(&refs, repo, NULL, got_ref_cmp_by_name, NULL);
 170         if (err)
 171                 goto done;
 172
 173         err = got_repo_match_object_id(&kwid, NULL, kwid_str,
 174             GOT_OBJ_TYPE_COMMIT, &refs, repo);
 175         if (err != NULL)
 176                 goto done;
 177
 178         /*
 179          * If looking for a descendant, we need to iterate from
 180          * HEAD so grab its id now if it's not already in kwid.
 181          */
 182         if (kwm.sym == GOT_KEYWORD_DESCENDANT && kw != NULL &&
 183             strcmp(kw, GOT_KEYWORD_HEAD) != 0) {
 184                 struct got_reference *head_ref;
 185
 186                 err = got_ref_open(&head_ref, repo, wt != NULL ?
 187                     got_worktree_get_head_ref_name(wt) : GOT_REF_HEAD, 0);
 188                 if (err != NULL)
 189                         goto done;
 190                 err = got_ref_resolve(&head_id, repo, head_ref);
 191                 got_ref_close(head_ref);
 192                 if (err != NULL)
 193                         goto done;
 194         }
 195
 196         err = got_commit_graph_open(&graph, "/", 1);
 197         if (err)
 198                 goto done;
 199
 200         err = got_commit_graph_bfsort(graph,
 201             head_id != NULL ? head_id : kwid, repo, NULL, NULL);
 202         if (err)
 203                 goto done;
 204
 205         while (n <= kwm.n) {
 206                 err = got_commit_graph_iter_next(&iter_id, graph, repo,
 207                     NULL, NULL);
 208                 if (err) {
 209                         if (err->code == GOT_ERR_ITER_COMPLETED)
 210                                 err = NULL;
 211                         break;
 212                 }
 213
 214                 if (kwm.sym == GOT_KEYWORD_DESCENDANT) {
 215                         /*
 216                          * We want the Nth generation descendant of KEYWORD,
 217                          * so queue all commits from HEAD to KEYWORD then we
 218                          * can walk from KEYWORD to its Nth gen descendent.
 219                          */
 220                         err = got_object_qid_alloc(&qid, &iter_id);
 221                         if (err)
 222                                 goto done;
 223                         STAILQ_INSERT_HEAD(&commits, qid, entry);
 224
 225                         if (got_object_id_cmp(&iter_id, kwid) == 0)
 226                                 break;
 227                         continue;
 228                 }
 229                 ++n;
 230         }
 231
 232         if (kwm.sym == GOT_KEYWORD_DESCENDANT) {
 233                 n = 0;
 234
 235                 STAILQ_FOREACH(qid, &commits, entry) {
 236                         if (qid == STAILQ_LAST(&commits, got_object_qid, entry)
 237                             || n == kwm.n)
 238                                 break;
 239                         ++n;
 240                 }
 241
 242                 memcpy(&iter_id, &qid->id, sizeof(iter_id));
 243         }
 244
 245         free(kwid_str);
 246         err = got_object_id_str(&kwid_str, &iter_id);
 247
 248 done:
 249         free(kwid);
 250         free(kwm.kw);
 251         free(head_id);
 252         got_ref_list_free(&refs);
 253         got_object_id_queue_free(&commits);
 254         if (graph != NULL)
 255                 got_commit_graph_close(graph);
 256
 257         if (err != NULL) {
 258                 free(kwid_str);
 259                 return err;
 260         }
 261
 262         *ret = kwid_str;
 263         return NULL;
 264 }