Andrew's git / gitweb.git / commit.c
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commit.con commit git-push: avoid falling back on pushing "matching" refs. (9e9b267)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4
   5int save_commit_buffer = 1;
   6
   7struct sort_node
   8{
   9        /*
  10         * the number of children of the associated commit
  11         * that also occur in the list being sorted.
  12         */
  13        unsigned int indegree;
  14
  15        /*
  16         * reference to original list item that we will re-use
  17         * on output.
  18         */
  19        struct commit_list * list_item;
  20
  21};
  22
  23const char *commit_type = "commit";
  24
  25enum cmit_fmt get_commit_format(const char *arg)
  26{
  27        if (!*arg)
  28                return CMIT_FMT_DEFAULT;
  29        if (!strcmp(arg, "=raw"))
  30                return CMIT_FMT_RAW;
  31        if (!strcmp(arg, "=medium"))
  32                return CMIT_FMT_MEDIUM;
  33        if (!strcmp(arg, "=short"))
  34                return CMIT_FMT_SHORT;
  35        if (!strcmp(arg, "=full"))
  36                return CMIT_FMT_FULL;
  37        if (!strcmp(arg, "=fuller"))
  38                return CMIT_FMT_FULLER;
  39        if (!strcmp(arg, "=oneline"))
  40                return CMIT_FMT_ONELINE;
  41        die("invalid --pretty format");
  42}
  43
  44static struct commit *check_commit(struct object *obj,
  45                                   const unsigned char *sha1,
  46                                   int quiet)
  47{
  48        if (obj->type != commit_type) {
  49                if (!quiet)
  50                        error("Object %s is a %s, not a commit",
  51                              sha1_to_hex(sha1), obj->type);
  52                return NULL;
  53        }
  54        return (struct commit *) obj;
  55}
  56
  57struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  58                                              int quiet)
  59{
  60        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  61
  62        if (!obj)
  63                return NULL;
  64        return check_commit(obj, sha1, quiet);
  65}
  66
  67struct commit *lookup_commit_reference(const unsigned char *sha1)
  68{
  69        return lookup_commit_reference_gently(sha1, 0);
  70}
  71
  72struct commit *lookup_commit(const unsigned char *sha1)
  73{
  74        struct object *obj = lookup_object(sha1);
  75        if (!obj) {
  76                struct commit *ret = xmalloc(sizeof(struct commit));
  77                memset(ret, 0, sizeof(struct commit));
  78                created_object(sha1, &ret->object);
  79                ret->object.type = commit_type;
  80                return ret;
  81        }
  82        if (!obj->type)
  83                obj->type = commit_type;
  84        return check_commit(obj, sha1, 0);
  85}
  86
  87static unsigned long parse_commit_date(const char *buf)
  88{
  89        unsigned long date;
  90
  91        if (memcmp(buf, "author", 6))
  92                return 0;
  93        while (*buf++ != '\n')
  94                /* nada */;
  95        if (memcmp(buf, "committer", 9))
  96                return 0;
  97        while (*buf++ != '>')
  98                /* nada */;
  99        date = strtoul(buf, NULL, 10);
 100        if (date == ULONG_MAX)
 101                date = 0;
 102        return date;
 103}
 104
 105static struct commit_graft {
 106        unsigned char sha1[20];
 107        int nr_parent;
 108        unsigned char parent[0][20]; /* more */
 109} **commit_graft;
 110static int commit_graft_alloc, commit_graft_nr;
 111
 112static int commit_graft_pos(const unsigned char *sha1)
 113{
 114        int lo, hi;
 115        lo = 0;
 116        hi = commit_graft_nr;
 117        while (lo < hi) {
 118                int mi = (lo + hi) / 2;
 119                struct commit_graft *graft = commit_graft[mi];
 120                int cmp = memcmp(sha1, graft->sha1, 20);
 121                if (!cmp)
 122                        return mi;
 123                if (cmp < 0)
 124                        hi = mi;
 125                else
 126                        lo = mi + 1;
 127        }
 128        return -lo - 1;
 129}
 130
 131static void prepare_commit_graft(void)
 132{
 133        char *graft_file = get_graft_file();
 134        FILE *fp = fopen(graft_file, "r");
 135        char buf[1024];
 136        if (!fp) {
 137                commit_graft = (struct commit_graft **) "hack";
 138                return;
 139        }
 140        while (fgets(buf, sizeof(buf), fp)) {
 141                /* The format is just "Commit Parent1 Parent2 ...\n" */
 142                int len = strlen(buf);
 143                int i;
 144                struct commit_graft *graft = NULL;
 145
 146                if (buf[len-1] == '\n')
 147                        buf[--len] = 0;
 148                if (buf[0] == '#')
 149                        continue;
 150                if ((len + 1) % 41) {
 151                bad_graft_data:
 152                        error("bad graft data: %s", buf);
 153                        free(graft);
 154                        continue;
 155                }
 156                i = (len + 1) / 41 - 1;
 157                graft = xmalloc(sizeof(*graft) + 20 * i);
 158                graft->nr_parent = i;
 159                if (get_sha1_hex(buf, graft->sha1))
 160                        goto bad_graft_data;
 161                for (i = 40; i < len; i += 41) {
 162                        if (buf[i] != ' ')
 163                                goto bad_graft_data;
 164                        if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 165                                goto bad_graft_data;
 166                }
 167                i = commit_graft_pos(graft->sha1);
 168                if (0 <= i) {
 169                        error("duplicate graft data: %s", buf);
 170                        free(graft);
 171                        continue;
 172                }
 173                i = -i - 1;
 174                if (commit_graft_alloc <= ++commit_graft_nr) {
 175                        commit_graft_alloc = alloc_nr(commit_graft_alloc);
 176                        commit_graft = xrealloc(commit_graft,
 177                                                sizeof(*commit_graft) *
 178                                                commit_graft_alloc);
 179                }
 180                if (i < commit_graft_nr)
 181                        memmove(commit_graft + i + 1,
 182                                commit_graft + i,
 183                                (commit_graft_nr - i - 1) *
 184                                sizeof(*commit_graft));
 185                commit_graft[i] = graft;
 186        }
 187        fclose(fp);
 188}
 189
 190static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 191{
 192        int pos;
 193        if (!commit_graft)
 194                prepare_commit_graft();
 195        pos = commit_graft_pos(sha1);
 196        if (pos < 0)
 197                return NULL;
 198        return commit_graft[pos];
 199}
 200
 201int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 202{
 203        char *bufptr = buffer;
 204        unsigned char parent[20];
 205        struct commit_list **pptr;
 206        struct commit_graft *graft;
 207        unsigned n_refs = 0;
 208
 209        if (item->object.parsed)
 210                return 0;
 211        item->object.parsed = 1;
 212        if (memcmp(bufptr, "tree ", 5))
 213                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 214        if (get_sha1_hex(bufptr + 5, parent) < 0)
 215                return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 216        item->tree = lookup_tree(parent);
 217        if (item->tree)
 218                n_refs++;
 219        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 220        pptr = &item->parents;
 221
 222        graft = lookup_commit_graft(item->object.sha1);
 223        while (!memcmp(bufptr, "parent ", 7)) {
 224                struct commit *new_parent;
 225
 226                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 227                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 228                bufptr += 48;
 229                if (graft)
 230                        continue;
 231                new_parent = lookup_commit(parent);
 232                if (new_parent) {
 233                        pptr = &commit_list_insert(new_parent, pptr)->next;
 234                        n_refs++;
 235                }
 236        }
 237        if (graft) {
 238                int i;
 239                struct commit *new_parent;
 240                for (i = 0; i < graft->nr_parent; i++) {
 241                        new_parent = lookup_commit(graft->parent[i]);
 242                        if (!new_parent)
 243                                continue;
 244                        pptr = &commit_list_insert(new_parent, pptr)->next;
 245                        n_refs++;
 246                }
 247        }
 248        item->date = parse_commit_date(bufptr);
 249
 250        if (track_object_refs) {
 251                unsigned i = 0;
 252                struct commit_list *p;
 253                struct object_refs *refs = alloc_object_refs(n_refs);
 254                if (item->tree)
 255                        refs->ref[i++] = &item->tree->object;
 256                for (p = item->parents; p; p = p->next)
 257                        refs->ref[i++] = &p->item->object;
 258                set_object_refs(&item->object, refs);
 259        }
 260
 261        return 0;
 262}
 263
 264int parse_commit(struct commit *item)
 265{
 266        char type[20];
 267        void *buffer;
 268        unsigned long size;
 269        int ret;
 270
 271        if (item->object.parsed)
 272                return 0;
 273        buffer = read_sha1_file(item->object.sha1, type, &size);
 274        if (!buffer)
 275                return error("Could not read %s",
 276                             sha1_to_hex(item->object.sha1));
 277        if (strcmp(type, commit_type)) {
 278                free(buffer);
 279                return error("Object %s not a commit",
 280                             sha1_to_hex(item->object.sha1));
 281        }
 282        ret = parse_commit_buffer(item, buffer, size);
 283        if (save_commit_buffer && !ret) {
 284                item->buffer = buffer;
 285                return 0;
 286        }
 287        free(buffer);
 288        return ret;
 289}
 290
 291struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 292{
 293        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 294        new_list->item = item;
 295        new_list->next = *list_p;
 296        *list_p = new_list;
 297        return new_list;
 298}
 299
 300void free_commit_list(struct commit_list *list)
 301{
 302        while (list) {
 303                struct commit_list *temp = list;
 304                list = temp->next;
 305                free(temp);
 306        }
 307}
 308
 309struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 310{
 311        struct commit_list **pp = list;
 312        struct commit_list *p;
 313        while ((p = *pp) != NULL) {
 314                if (p->item->date < item->date) {
 315                        break;
 316                }
 317                pp = &p->next;
 318        }
 319        return commit_list_insert(item, pp);
 320}
 321
 322        
 323void sort_by_date(struct commit_list **list)
 324{
 325        struct commit_list *ret = NULL;
 326        while (*list) {
 327                insert_by_date((*list)->item, &ret);
 328                *list = (*list)->next;
 329        }
 330        *list = ret;
 331}
 332
 333struct commit *pop_most_recent_commit(struct commit_list **list,
 334                                      unsigned int mark)
 335{
 336        struct commit *ret = (*list)->item;
 337        struct commit_list *parents = ret->parents;
 338        struct commit_list *old = *list;
 339
 340        *list = (*list)->next;
 341        free(old);
 342
 343        while (parents) {
 344                struct commit *commit = parents->item;
 345                parse_commit(commit);
 346                if (!(commit->object.flags & mark)) {
 347                        commit->object.flags |= mark;
 348                        insert_by_date(commit, list);
 349                }
 350                parents = parents->next;
 351        }
 352        return ret;
 353}
 354
 355void clear_commit_marks(struct commit *commit, unsigned int mark)
 356{
 357        struct commit_list *parents;
 358
 359        parents = commit->parents;
 360        commit->object.flags &= ~mark;
 361        while (parents) {
 362                if (parents->item && parents->item->object.parsed)
 363                        clear_commit_marks(parents->item, mark);
 364                parents = parents->next;
 365        }
 366}
 367
 368/*
 369 * Generic support for pretty-printing the header
 370 */
 371static int get_one_line(const char *msg, unsigned long len)
 372{
 373        int ret = 0;
 374
 375        while (len--) {
 376                char c = *msg++;
 377                ret++;
 378                if (c == '\n')
 379                        break;
 380                if (!c)
 381                        return 0;
 382        }
 383        return ret;
 384}
 385
 386static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 387{
 388        char *date;
 389        int namelen;
 390        unsigned long time;
 391        int tz, ret;
 392        const char *filler = "    ";
 393
 394        if (fmt == CMIT_FMT_ONELINE)
 395                return 0;
 396        date = strchr(line, '>');
 397        if (!date)
 398                return 0;
 399        namelen = ++date - line;
 400        time = strtoul(date, &date, 10);
 401        tz = strtol(date, NULL, 10);
 402
 403        ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 404                      (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 405                      filler, namelen, line);
 406        switch (fmt) {
 407        case CMIT_FMT_MEDIUM:
 408                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 409                break;
 410        case CMIT_FMT_FULLER:
 411                ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 412                break;
 413        default:
 414                /* notin' */
 415                break;
 416        }
 417        return ret;
 418}
 419
 420static int is_empty_line(const char *line, int len)
 421{
 422        while (len && isspace(line[len-1]))
 423                len--;
 424        return !len;
 425}
 426
 427static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 428{
 429        int offset = 0;
 430
 431        if (fmt == CMIT_FMT_ONELINE)
 432                return offset;
 433        switch (parents) {
 434        case 1:
 435                break;
 436        case 2:
 437                /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 438                offset = sprintf(buf, "Merge: %.40s\n", line-41);
 439                /* Fallthrough */
 440        default:
 441                /* Replace the previous '\n' with a space */
 442                buf[offset-1] = ' ';
 443                offset += sprintf(buf + offset, "%.40s\n", line+7);
 444        }
 445        return offset;
 446}
 447
 448unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 449{
 450        int hdr = 1, body = 0;
 451        unsigned long offset = 0;
 452        int parents = 0;
 453        int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 454
 455        for (;;) {
 456                const char *line = msg;
 457                int linelen = get_one_line(msg, len);
 458
 459                if (!linelen)
 460                        break;
 461
 462                /*
 463                 * We want some slop for indentation and a possible
 464                 * final "...". Thus the "+ 20".
 465                 */
 466                if (offset + linelen + 20 > space) {
 467                        memcpy(buf + offset, "    ...\n", 8);
 468                        offset += 8;
 469                        break;
 470                }
 471
 472                msg += linelen;
 473                len -= linelen;
 474                if (hdr) {
 475                        if (linelen == 1) {
 476                                hdr = 0;
 477                                if (fmt != CMIT_FMT_ONELINE)
 478                                        buf[offset++] = '\n';
 479                                continue;
 480                        }
 481                        if (fmt == CMIT_FMT_RAW) {
 482                                memcpy(buf + offset, line, linelen);
 483                                offset += linelen;
 484                                continue;
 485                        }
 486                        if (!memcmp(line, "parent ", 7)) {
 487                                if (linelen != 48)
 488                                        die("bad parent line in commit");
 489                                offset += add_parent_info(fmt, buf + offset, line, ++parents);
 490                        }
 491
 492                        /*
 493                         * MEDIUM == DEFAULT shows only author with dates.
 494                         * FULL shows both authors but not dates.
 495                         * FULLER shows both authors and dates.
 496                         */
 497                        if (!memcmp(line, "author ", 7))
 498                                offset += add_user_info("Author", fmt,
 499                                                        buf + offset,
 500                                                        line + 7);
 501                        if (!memcmp(line, "committer ", 10) &&
 502                            (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 503                                offset += add_user_info("Commit", fmt,
 504                                                        buf + offset,
 505                                                        line + 10);
 506                        continue;
 507                }
 508
 509                if (is_empty_line(line, linelen)) {
 510                        if (!body)
 511                                continue;
 512                        if (fmt == CMIT_FMT_SHORT)
 513                                break;
 514                } else {
 515                        body = 1;
 516                }
 517
 518                memset(buf + offset, ' ', indent);
 519                memcpy(buf + offset + indent, line, linelen);
 520                offset += linelen + indent;
 521                if (fmt == CMIT_FMT_ONELINE)
 522                        break;
 523        }
 524        if (fmt == CMIT_FMT_ONELINE) {
 525                /* We do not want the terminating newline */
 526                if (buf[offset - 1] == '\n')
 527                        offset--;
 528        }
 529        else {
 530                /* Make sure there is an EOLN */
 531                if (buf[offset - 1] != '\n')
 532                        buf[offset++] = '\n';
 533        }
 534        buf[offset] = '\0';
 535        return offset;
 536}
 537
 538struct commit *pop_commit(struct commit_list **stack)
 539{
 540        struct commit_list *top = *stack;
 541        struct commit *item = top ? top->item : NULL;
 542
 543        if (top) {
 544                *stack = top->next;
 545                free(top);
 546        }
 547        return item;
 548}
 549
 550int count_parents(struct commit * commit)
 551{
 552        int count = 0;
 553        struct commit_list * parents = commit->parents;
 554        for (count=0;parents; parents=parents->next,count++)
 555          ;
 556        return count;
 557}
 558
 559/*
 560 * Performs an in-place topological sort on the list supplied.
 561 */
 562void sort_in_topological_order(struct commit_list ** list)
 563{
 564        struct commit_list * next = *list;
 565        struct commit_list * work = NULL, **insert;
 566        struct commit_list ** pptr = list;
 567        struct sort_node * nodes;
 568        struct sort_node * next_nodes;
 569        int count = 0;
 570
 571        /* determine the size of the list */
 572        while (next) {
 573                next = next->next;
 574                count++;
 575        }
 576        
 577        if (!count)
 578                return;
 579        /* allocate an array to help sort the list */
 580        nodes = xcalloc(count, sizeof(*nodes));
 581        /* link the list to the array */
 582        next_nodes = nodes;
 583        next=*list;
 584        while (next) {
 585                next_nodes->list_item = next;
 586                next->item->object.util = next_nodes;
 587                next_nodes++;
 588                next = next->next;
 589        }
 590        /* update the indegree */
 591        next=*list;
 592        while (next) {
 593                struct commit_list * parents = next->item->parents;
 594                while (parents) {
 595                        struct commit * parent=parents->item;
 596                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 597                        
 598                        if (pn)
 599                                pn->indegree++;
 600                        parents=parents->next;
 601                }
 602                next=next->next;
 603        }
 604        /* 
 605         * find the tips
 606         *
 607         * tips are nodes not reachable from any other node in the list 
 608         * 
 609         * the tips serve as a starting set for the work queue.
 610         */
 611        next=*list;
 612        insert = &work;
 613        while (next) {
 614                struct sort_node * node = (struct sort_node *)next->item->object.util;
 615
 616                if (node->indegree == 0) {
 617                        insert = &commit_list_insert(next->item, insert)->next;
 618                }
 619                next=next->next;
 620        }
 621        /* process the list in topological order */
 622        while (work) {
 623                struct commit * work_item = pop_commit(&work);
 624                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 625                struct commit_list * parents = work_item->parents;
 626
 627                while (parents) {
 628                        struct commit * parent=parents->item;
 629                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 630                        
 631                        if (pn) {
 632                                /* 
 633                                 * parents are only enqueued for emission 
 634                                 * when all their children have been emitted thereby
 635                                 * guaranteeing topological order.
 636                                 */
 637                                pn->indegree--;
 638                                if (!pn->indegree) 
 639                                        commit_list_insert(parent, &work);
 640                        }
 641                        parents=parents->next;
 642                }
 643                /*
 644                 * work_item is a commit all of whose children
 645                 * have already been emitted. we can emit it now.
 646                 */
 647                *pptr = work_node->list_item;
 648                pptr = &(*pptr)->next;
 649                *pptr = NULL;
 650                work_item->object.util = NULL;
 651        }
 652        free(nodes);
 653}