refs.c

   1 /* Copyright (c) 2006-2012 Jonas Fonseca <fonseca@diku.dk>
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License as
   5  * published by the Free Software Foundation; either version 2 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include "tig.h"
  15 #include "io.h"
  16 #include "refs.h"
  17
  18 static struct ref **refs = NULL;
  19 static size_t refs_size = 0;
  20 static struct ref *refs_head = NULL;
  21
  22 static struct ref_list **ref_lists = NULL;
  23 static size_t ref_lists_size = 0;
  24
  25 DEFINE_ALLOCATOR(realloc_refs, struct ref *, 256)
  26 DEFINE_ALLOCATOR(realloc_refs_list, struct ref *, 8)
  27 DEFINE_ALLOCATOR(realloc_ref_lists, struct ref_list *, 8)
  28
  29 static int
  30 compare_refs(const void *ref1_, const void *ref2_)
  31 {
  32         const struct ref *ref1 = *(const struct ref **)ref1_;
  33         const struct ref *ref2 = *(const struct ref **)ref2_;
  34
  35         if (ref1->tag != ref2->tag)
  36                 return ref2->tag - ref1->tag;
  37         if (ref1->ltag != ref2->ltag)
  38                 return ref2->ltag - ref1->ltag;
  39         if (ref1->head != ref2->head)
  40                 return ref2->head - ref1->head;
  41         if (ref1->tracked != ref2->tracked)
  42                 return ref2->tracked - ref1->tracked;
  43         if (ref1->replace != ref2->replace)
  44                 return ref2->replace - ref1->replace;
  45         /* Order remotes last. */
  46         if (ref1->remote != ref2->remote)
  47                 return ref1->remote - ref2->remote;
  48         return strcmp(ref1->name, ref2->name);
  49 }
  50
  51 void
  52 foreach_ref(bool (*visitor)(void *data, const struct ref *ref), void *data)
  53 {
  54         size_t i;
  55
  56         for (i = 0; i < refs_size; i++)
  57                 if (!visitor(data, refs[i]))
  58                         break;
  59 }
  60
  61 struct ref *
  62 get_ref_head()
  63 {
  64         return refs_head;
  65 }
  66
  67 struct ref_list *
  68 get_ref_list(const char *id)
  69 {
  70         struct ref_list *list;
  71         size_t i;
  72
  73         for (i = 0; i < ref_lists_size; i++)
  74                 if (!strcmp(id, ref_lists[i]->id))
  75                         return ref_lists[i];
  76
  77         if (!realloc_ref_lists(&ref_lists, ref_lists_size, 1))
  78                 return NULL;
  79         list = calloc(1, sizeof(*list));
  80         if (!list)
  81                 return NULL;
  82
  83         for (i = 0; i < refs_size; i++) {
  84                 if (!strcmp(id, refs[i]->id) &&
  85                     realloc_refs_list(&list->refs, list->size, 1))
  86                         list->refs[list->size++] = refs[i];
  87         }
  88
  89         if (!list->refs) {
  90                 free(list);
  91                 return NULL;
  92         }
  93
  94         qsort(list->refs, list->size, sizeof(*list->refs), compare_refs);
  95         ref_lists[ref_lists_size++] = list;
  96         return list;
  97 }
  98
  99 struct ref_opt {
 100         const char *remote;
 101         const char *head;
 102 };
 103
 104 static int
 105 read_ref(char *id, size_t idlen, char *name, size_t namelen, void *data)
 106 {
 107         struct ref_opt *opt = data;
 108         struct ref *ref = NULL;
 109         bool tag = FALSE;
 110         bool ltag = FALSE;
 111         bool remote = FALSE;
 112         bool replace = FALSE;
 113         bool tracked = FALSE;
 114         bool head = FALSE;
 115         int pos;
 116
 117         if (!prefixcmp(name, "refs/tags/")) {
 118                 if (!suffixcmp(name, namelen, "^{}")) {
 119                         namelen -= 3;
 120                         name[namelen] = 0;
 121                 } else {
 122                         ltag = TRUE;
 123                 }
 124
 125                 tag = TRUE;
 126                 namelen -= STRING_SIZE("refs/tags/");
 127                 name    += STRING_SIZE("refs/tags/");
 128
 129         } else if (!prefixcmp(name, "refs/remotes/")) {
 130                 remote = TRUE;
 131                 namelen -= STRING_SIZE("refs/remotes/");
 132                 name    += STRING_SIZE("refs/remotes/");
 133                 tracked  = !strcmp(opt->remote, name);
 134
 135         } else if (!prefixcmp(name, "refs/replace/")) {
 136                 replace = TRUE;
 137                 id      = name + strlen("refs/replace/");
 138                 idlen   = namelen - strlen("refs/replace/");
 139                 name    = "replaced";
 140                 namelen = strlen(name);
 141
 142         } else if (!prefixcmp(name, "refs/heads/")) {
 143                 namelen -= STRING_SIZE("refs/heads/");
 144                 name    += STRING_SIZE("refs/heads/");
 145                 head     = strlen(opt->head) == namelen
 146                            && !strncmp(opt->head, name, namelen);
 147
 148         } else if (!strcmp(name, "HEAD")) {
 149                 /* Handle the case of HEAD not being a symbolic ref,
 150                  * i.e. during a rebase. */
 151                 if (*opt->head)
 152                         return OK;
 153                 head = TRUE;
 154         }
 155
 156         /* If we are reloading or it's an annotated tag, replace the
 157          * previous SHA1 with the resolved commit id; relies on the fact
 158          * git-ls-remote lists the commit id of an annotated tag right
 159          * before the commit id it points to. */
 160         for (pos = 0; pos < refs_size; pos++) {
 161                 int cmp = replace ? strcmp(id, refs[pos]->id) : strcmp(name, refs[pos]->name);
 162
 163                 if (!cmp) {
 164                         ref = refs[pos];
 165                         break;
 166                 }
 167         }
 168
 169         if (!ref) {
 170                 if (!realloc_refs(&refs, refs_size, 1))
 171                         return ERR;
 172                 ref = calloc(1, sizeof(*ref) + namelen);
 173                 if (!ref)
 174                         return ERR;
 175                 refs[refs_size++] = ref;
 176                 strncpy(ref->name, name, namelen);
 177         }
 178
 179         ref->head = head;
 180         ref->tag = tag;
 181         ref->ltag = ltag;
 182         ref->remote = remote;
 183         ref->replace = replace;
 184         ref->tracked = tracked;
 185         string_ncopy_do(ref->id, SIZEOF_REV, id, idlen);
 186
 187         if (head)
 188                 refs_head = ref;
 189         return OK;
 190 }
 191
 192 int
 193 reload_refs(const char *git_dir, const char *remote_name, char *head, size_t headlen)
 194 {
 195         const char *head_argv[] = {
 196                 "git", "symbolic-ref", "HEAD", NULL
 197         };
 198         const char *ls_remote_argv[SIZEOF_ARG] = {
 199                 "git", "ls-remote", git_dir, NULL
 200         };
 201         static bool init = FALSE;
 202         struct ref_opt opt = { remote_name, head };
 203         size_t i;
 204
 205         if (!init) {
 206                 if (!argv_from_env(ls_remote_argv, "TIG_LS_REMOTE"))
 207                         return ERR;
 208                 init = TRUE;
 209         }
 210
 211         if (!*git_dir)
 212                 return OK;
 213
 214         if (io_run_buf(head_argv, head, headlen) &&
 215             !prefixcmp(head, "refs/heads/")) {
 216                 char *offset = head + STRING_SIZE("refs/heads/");
 217
 218                 memmove(head, offset, strlen(offset) + 1);
 219         }
 220
 221         refs_head = NULL;
 222         for (i = 0; i < refs_size; i++)
 223                 refs[i]->id[0] = 0;
 224
 225         if (io_run_load(ls_remote_argv, "\t", read_ref, &opt) == ERR)
 226                 return ERR;
 227
 228         /* Update the ref lists to reflect changes. */
 229         for (i = 0; i < ref_lists_size; i++) {
 230                 struct ref_list *list = ref_lists[i];
 231                 size_t old, new;
 232
 233                 for (old = new = 0; old < list->size; old++)
 234                         if (!strcmp(list->id, list->refs[old]->id))
 235                                 list->refs[new++] = list->refs[old];
 236                 list->size = new;
 237         }
 238
 239         qsort(refs, refs_size, sizeof(*refs), compare_refs);
 240
 241         return OK;
 242 }