Andrew's git - gitweb.git/blob

   1#include <stdlib.h>
   2#include "cache.h"
   3#include "commit.h"
   4#include "refs.h"
   5
   6static const char show_branch_usage[] =
   7"git-show-branch [--all] [--heads] [--tags] [--more=count] [<refs>...]";
   8
   9#define UNINTERESTING   01
  10
  11#define REV_SHIFT        2
  12#define MAX_REVS        29 /* should not exceed bits_per_int - REV_SHIFT */
  13
  14static struct commit *interesting(struct commit_list *list)
  15{
  16        while (list) {
  17                struct commit *commit = list->item;
  18                list = list->next;
  19                if (commit->object.flags & UNINTERESTING)
  20                        continue;
  21                return commit;
  22        }
  23        return NULL;
  24}
  25
  26static struct commit *pop_one_commit(struct commit_list **list_p)
  27{
  28        struct commit *commit;
  29        struct commit_list *list;
  30        list = *list_p;
  31        commit = list->item;
  32        *list_p = list->next;
  33        free(list);
  34        return commit;
  35}
  36
  37struct commit_name {
  38        int head_rev;   /* which head's ancestor? */
  39        int generation; /* how many parents away from head_rev */
  40};
  41
  42/* Name the commit as nth generation ancestor of head_rev;
  43 * we count only the first-parent relationship for naming purposes.
  44 */
  45static void name_commit(struct commit *commit, int head_rev, int nth)
  46{
  47        struct commit_name *name;
  48        if (!commit->object.util)
  49                commit->object.util = xmalloc(sizeof(struct commit_name));
  50        name = commit->object.util;
  51        name->head_rev = head_rev;
  52        name->generation = nth;
  53}
  54
  55/* Parent is the first parent of the commit.  We may name it
  56 * as (n+1)th generation ancestor of the same head_rev as
  57 * commit is nth generation ancestore of, if that generation
  58 * number is better than the name it already has.
  59 */
  60static void name_parent(struct commit *commit, struct commit *parent)
  61{
  62        struct commit_name *commit_name = commit->object.util;
  63        struct commit_name *parent_name = parent->object.util;
  64        if (!commit_name)
  65                return;
  66        if (!parent_name ||
  67            commit_name->generation + 1 < parent_name->generation)
  68                name_commit(parent, commit_name->head_rev,
  69                            commit_name->generation + 1);
  70}
  71
  72static int mark_seen(struct commit *commit, struct commit_list **seen_p)
  73{
  74        if (!commit->object.flags) {
  75                insert_by_date(commit, seen_p);
  76                return 1;
  77        }
  78        return 0;
  79}
  80
  81static void join_revs(struct commit_list **list_p,
  82                      struct commit_list **seen_p,
  83                      int num_rev, int extra)
  84{
  85        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
  86        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
  87
  88        while (*list_p) {
  89                struct commit_list *parents;
  90                struct commit *commit = pop_one_commit(list_p);
  91                int flags = commit->object.flags & all_mask;
  92                int nth_parent = 0;
  93                int still_interesting = !!interesting(*list_p);
  94
  95                if (!still_interesting && extra < 0)
  96                        break;
  97
  98                mark_seen(commit, seen_p);
  99                if ((flags & all_revs) == all_revs)
 100                        flags |= UNINTERESTING;
 101                parents = commit->parents;
 102
 103                while (parents) {
 104                        struct commit *p = parents->item;
 105                        int this_flag = p->object.flags;
 106                        parents = parents->next;
 107                        nth_parent++;
 108                        if (nth_parent == 1)
 109                                name_parent(commit, p);
 110
 111                        if ((this_flag & flags) == flags)
 112                                continue;
 113                        parse_commit(p);
 114                        if (mark_seen(p, seen_p) && !still_interesting)
 115                                extra--;
 116                        p->object.flags |= flags;
 117                        insert_by_date(p, list_p);
 118                }
 119        }
 120}
 121
 122static void show_one_commit(struct commit *commit, char **head_name)
 123{
 124        char pretty[128], *cp;
 125        struct commit_name *name = commit->object.util;
 126        pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
 127                            pretty, sizeof(pretty));
 128        if (!strncmp(pretty, "[PATCH] ", 8))
 129                cp = pretty + 8;
 130        else
 131                cp = pretty;
 132        if (name && head_name) {
 133                printf("[%s", head_name[name->head_rev]);
 134                if (name->generation)
 135                        printf("~%d", name->generation);
 136                printf("] ");
 137        }
 138        puts(cp);
 139}
 140
 141static char *ref_name[MAX_REVS + 1];
 142static int ref_name_cnt;
 143
 144static int compare_ref_name(const void *a_, const void *b_)
 145{
 146        const char * const*a = a_, * const*b = b_;
 147        return strcmp(*a, *b);
 148}
 149
 150static void sort_ref_range(int bottom, int top)
 151{
 152        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 153              compare_ref_name);
 154}
 155
 156static int append_ref(const char *refname, const unsigned char *sha1)
 157{
 158        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 159        if (!commit)
 160                return 0;
 161        if (MAX_REVS < ref_name_cnt) {
 162                fprintf(stderr, "warning: ignoring %s; "
 163                        "cannot handle more than %d refs",
 164                        refname, MAX_REVS);
 165                return 0;
 166        }
 167        ref_name[ref_name_cnt++] = strdup(refname);
 168        ref_name[ref_name_cnt] = NULL;
 169        return 0;
 170}
 171
 172static int append_head_ref(const char *refname, const unsigned char *sha1)
 173{
 174        if (strncmp(refname, "refs/heads/", 11))
 175                return 0;
 176        return append_ref(refname + 11, sha1);
 177}
 178
 179static int append_tag_ref(const char *refname, const unsigned char *sha1)
 180{
 181        if (strncmp(refname, "refs/tags/", 10))
 182                return 0;
 183        return append_ref(refname + 5, sha1);
 184}
 185
 186static void snarf_refs(int head, int tag)
 187{
 188        if (head) {
 189                int orig_cnt = ref_name_cnt;
 190                for_each_ref(append_head_ref);
 191                sort_ref_range(orig_cnt, ref_name_cnt);
 192        }
 193        if (tag) {
 194                int orig_cnt = ref_name_cnt;
 195                for_each_ref(append_tag_ref);
 196                sort_ref_range(orig_cnt, ref_name_cnt);
 197        }
 198}
 199
 200static int rev_is_head(char *head_path, int headlen,
 201                       char *name,
 202                       unsigned char *head_sha1, unsigned char *sha1)
 203{
 204        int namelen;
 205        if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
 206                return 0;
 207        namelen = strlen(name);
 208        if ((headlen < namelen) ||
 209            memcmp(head_path + headlen - namelen, name, namelen))
 210                return 0;
 211        if (headlen == namelen ||
 212            head_path[headlen - namelen - 1] == '/')
 213                return 1;
 214        return 0;
 215}
 216
 217static int show_merge_base(struct commit_list *seen, int num_rev)
 218{
 219        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 220        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 221
 222        while (seen) {
 223                struct commit *commit = pop_one_commit(&seen);
 224                int flags = commit->object.flags & all_mask;
 225                if (!(flags & UNINTERESTING) &&
 226                    ((flags & all_revs) == all_revs)) {
 227                        puts(sha1_to_hex(commit->object.sha1));
 228                        return 0;
 229                }
 230        }
 231        return 1;
 232}
 233
 234int main(int ac, char **av)
 235{
 236        struct commit *rev[MAX_REVS], *commit;
 237        struct commit_list *list = NULL, *seen = NULL;
 238        int num_rev, i, extra = 0;
 239        int all_heads = 0, all_tags = 0;
 240        char head_path[128];
 241        int head_path_len;
 242        unsigned char head_sha1[20];
 243        int merge_base = 0;
 244        char **label;
 245
 246        while (1 < ac && av[1][0] == '-') {
 247                char *arg = av[1];
 248                if (!strcmp(arg, "--all"))
 249                        all_heads = all_tags = 1;
 250                else if (!strcmp(arg, "--heads"))
 251                        all_heads = 1;
 252                else if (!strcmp(arg, "--tags"))
 253                        all_tags = 1;
 254                else if (!strcmp(arg, "--more"))
 255                        extra = 1;
 256                else if (!strncmp(arg, "--more=", 7)) {
 257                        extra = atoi(arg + 7);
 258                        if (extra < 0)
 259                                usage(show_branch_usage);
 260                }
 261                else if (!strcmp(arg, "--merge-base"))
 262                        merge_base = 1;
 263                else
 264                        usage(show_branch_usage);
 265                ac--; av++;
 266        }
 267        ac--; av++;
 268
 269        if (all_heads + all_tags)
 270                snarf_refs(all_heads, all_tags);
 271
 272        while (0 < ac) {
 273                unsigned char revkey[20];
 274                if (get_sha1(*av, revkey))
 275                        die("bad sha1 reference %s", *av);
 276                append_ref(*av, revkey);
 277                ac--; av++;
 278        }
 279
 280        /* If still no revs, then add heads */
 281        if (!ref_name_cnt)
 282                snarf_refs(1, 0);
 283
 284        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 285                unsigned char revkey[20];
 286
 287                if (MAX_REVS <= num_rev)
 288                        die("cannot handle more than %d revs.", MAX_REVS);
 289                if (get_sha1(ref_name[num_rev], revkey))
 290                        usage(show_branch_usage);
 291                commit = lookup_commit_reference(revkey);
 292                if (!commit)
 293                        die("cannot find commit %s (%s)",
 294                            ref_name[num_rev], revkey);
 295                parse_commit(commit);
 296                if (!commit->object.util)
 297                        name_commit(commit, num_rev, 0);
 298                mark_seen(commit, &seen);
 299
 300                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 301                 * and so on.  REV_SHIFT bits from bit 0 are used for
 302                 * internal bookkeeping.
 303                 */
 304                commit->object.flags |= 1u << (num_rev + REV_SHIFT);
 305                insert_by_date(commit, &list);
 306                rev[num_rev] = commit;
 307        }
 308        join_revs(&list, &seen, num_rev, extra);
 309
 310        head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
 311        if ((head_path_len < 0) || get_sha1("HEAD", head_sha1))
 312                head_path[0] = 0;
 313        else
 314                head_path[head_path_len] = 0;
 315
 316        if (merge_base)
 317                return show_merge_base(seen, num_rev);
 318
 319        /* Show list */
 320        if (1 < num_rev) {
 321                for (i = 0; i < num_rev; i++) {
 322                        int j;
 323                        int is_head = rev_is_head(head_path,
 324                                                  head_path_len,
 325                                                  ref_name[i],
 326                                                  head_sha1,
 327                                                  rev[i]->object.sha1);
 328                        for (j = 0; j < i; j++)
 329                                putchar(' ');
 330                        printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
 331                        show_one_commit(rev[i], NULL);
 332                }
 333                for (i = 0; i < num_rev; i++)
 334                        putchar('-');
 335                putchar('\n');
 336        }
 337
 338        label = ref_name;
 339        while (seen) {
 340                struct commit *commit = pop_one_commit(&seen);
 341                int this_flag = commit->object.flags;
 342                static char *obvious[] = { "" };
 343
 344                if ((this_flag & UNINTERESTING) && (--extra < 0))
 345                        break;
 346                if (1 < num_rev) {
 347                        for (i = 0; i < num_rev; i++)
 348                                putchar((this_flag & (1u << (i + REV_SHIFT)))
 349                                        ? '+' : ' ');
 350                        putchar(' ');
 351                }
 352                show_one_commit(commit, label);
 353                if (num_rev == 1)
 354                        label = obvious;
 355        }
 356        return 0;
 357}