Andrew's git / gitweb.git / commit.c
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commit.con commit [PATCH] Fix local pull that uses packs. (d920032)
   1#include <ctype.h>
   2#include "tag.h"
   3#include "commit.h"
   4#include "cache.h"
   5
   6struct sort_node
   7{
   8        /*
   9         * the number of children of the associated commit
  10         * that also occur in the list being sorted.
  11         */
  12        unsigned int indegree;
  13
  14        /*
  15         * reference to original list item that we will re-use
  16         * on output.
  17         */
  18        struct commit_list * list_item;
  19
  20};
  21
  22const char *commit_type = "commit";
  23
  24enum cmit_fmt get_commit_format(const char *arg)
  25{
  26        if (!*arg)
  27                return CMIT_FMT_DEFAULT;
  28        if (!strcmp(arg, "=raw"))
  29                return CMIT_FMT_RAW;
  30        if (!strcmp(arg, "=medium"))
  31                return CMIT_FMT_MEDIUM;
  32        if (!strcmp(arg, "=short"))
  33                return CMIT_FMT_SHORT;
  34        if (!strcmp(arg, "=full"))
  35                return CMIT_FMT_FULL;
  36        if (!strcmp(arg, "=oneline"))
  37                return CMIT_FMT_ONELINE;
  38        die("invalid --pretty format");
  39}
  40
  41static struct commit *check_commit(struct object *obj, const unsigned char *sha1)
  42{
  43        if (obj->type != commit_type) {
  44                error("Object %s is a %s, not a commit", 
  45                      sha1_to_hex(sha1), obj->type);
  46                return NULL;
  47        }
  48        return (struct commit *) obj;
  49}
  50
  51struct commit *lookup_commit_reference(const unsigned char *sha1)
  52{
  53        struct object *obj = deref_tag(parse_object(sha1));
  54
  55        if (!obj)
  56                return NULL;
  57        return check_commit(obj, sha1);
  58}
  59
  60struct commit *lookup_commit(const unsigned char *sha1)
  61{
  62        struct object *obj = lookup_object(sha1);
  63        if (!obj) {
  64                struct commit *ret = xmalloc(sizeof(struct commit));
  65                memset(ret, 0, sizeof(struct commit));
  66                created_object(sha1, &ret->object);
  67                ret->object.type = commit_type;
  68                return ret;
  69        }
  70        if (!obj->type)
  71                obj->type = commit_type;
  72        return check_commit(obj, sha1);
  73}
  74
  75static unsigned long parse_commit_date(const char *buf)
  76{
  77        unsigned long date;
  78
  79        if (memcmp(buf, "author", 6))
  80                return 0;
  81        while (*buf++ != '\n')
  82                /* nada */;
  83        if (memcmp(buf, "committer", 9))
  84                return 0;
  85        while (*buf++ != '>')
  86                /* nada */;
  87        date = strtoul(buf, NULL, 10);
  88        if (date == ULONG_MAX)
  89                date = 0;
  90        return date;
  91}
  92
  93static struct commit_graft {
  94        unsigned char sha1[20];
  95        int nr_parent;
  96        unsigned char parent[0][20]; /* more */
  97} **commit_graft;
  98static int commit_graft_alloc, commit_graft_nr;
  99
 100static int commit_graft_pos(const unsigned char *sha1)
 101{
 102        int lo, hi;
 103        lo = 0;
 104        hi = commit_graft_nr;
 105        while (lo < hi) {
 106                int mi = (lo + hi) / 2;
 107                struct commit_graft *graft = commit_graft[mi];
 108                int cmp = memcmp(sha1, graft->sha1, 20);
 109                if (!cmp)
 110                        return mi;
 111                if (cmp < 0)
 112                        hi = mi;
 113                else
 114                        lo = mi + 1;
 115        }
 116        return -lo - 1;
 117}
 118
 119static void prepare_commit_graft(void)
 120{
 121        char *graft_file = get_graft_file();
 122        FILE *fp = fopen(graft_file, "r");
 123        char buf[1024];
 124        if (!fp) {
 125                commit_graft = (struct commit_graft **) "hack";
 126                return;
 127        }
 128        while (fgets(buf, sizeof(buf), fp)) {
 129                /* The format is just "Commit Parent1 Parent2 ...\n" */
 130                int len = strlen(buf);
 131                int i;
 132                struct commit_graft *graft = NULL;
 133
 134                if (buf[len-1] == '\n')
 135                        buf[--len] = 0;
 136                if (buf[0] == '#')
 137                        continue;
 138                if ((len + 1) % 41) {
 139                bad_graft_data:
 140                        error("bad graft data: %s", buf);
 141                        free(graft);
 142                        continue;
 143                }
 144                i = (len + 1) / 41 - 1;
 145                graft = xmalloc(sizeof(*graft) + 20 * i);
 146                graft->nr_parent = i;
 147                if (get_sha1_hex(buf, graft->sha1))
 148                        goto bad_graft_data;
 149                for (i = 40; i < len; i += 41) {
 150                        if (buf[i] != ' ')
 151                                goto bad_graft_data;
 152                        if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 153                                goto bad_graft_data;
 154                }
 155                i = commit_graft_pos(graft->sha1);
 156                if (0 <= i) {
 157                        error("duplicate graft data: %s", buf);
 158                        free(graft);
 159                        continue;
 160                }
 161                i = -i - 1;
 162                if (commit_graft_alloc <= ++commit_graft_nr) {
 163                        commit_graft_alloc = alloc_nr(commit_graft_alloc);
 164                        commit_graft = xrealloc(commit_graft,
 165                                                sizeof(*commit_graft) *
 166                                                commit_graft_alloc);
 167                }
 168                if (i < commit_graft_nr)
 169                        memmove(commit_graft + i + 1,
 170                                commit_graft + i,
 171                                (commit_graft_nr - i - 1) *
 172                                sizeof(*commit_graft));
 173                commit_graft[i] = graft;
 174        }
 175        fclose(fp);
 176}
 177
 178static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 179{
 180        int pos;
 181        if (!commit_graft)
 182                prepare_commit_graft();
 183        pos = commit_graft_pos(sha1);
 184        if (pos < 0)
 185                return NULL;
 186        return commit_graft[pos];
 187}
 188
 189int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 190{
 191        char *bufptr = buffer;
 192        unsigned char parent[20];
 193        struct commit_list **pptr;
 194        struct commit_graft *graft;
 195
 196        if (item->object.parsed)
 197                return 0;
 198        item->object.parsed = 1;
 199        if (memcmp(bufptr, "tree ", 5))
 200                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 201        if (get_sha1_hex(bufptr + 5, parent) < 0)
 202                return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 203        item->tree = lookup_tree(parent);
 204        if (item->tree)
 205                add_ref(&item->object, &item->tree->object);
 206        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 207        pptr = &item->parents;
 208
 209        graft = lookup_commit_graft(item->object.sha1);
 210        while (!memcmp(bufptr, "parent ", 7)) {
 211                struct commit *new_parent;
 212
 213                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 214                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 215                bufptr += 48;
 216                if (graft)
 217                        continue;
 218                new_parent = lookup_commit(parent);
 219                if (new_parent) {
 220                        pptr = &commit_list_insert(new_parent, pptr)->next;
 221                        add_ref(&item->object, &new_parent->object);
 222                }
 223        }
 224        if (graft) {
 225                int i;
 226                struct commit *new_parent;
 227                for (i = 0; i < graft->nr_parent; i++) {
 228                        new_parent = lookup_commit(graft->parent[i]);
 229                        if (!new_parent)
 230                                continue;
 231                        pptr = &commit_list_insert(new_parent, pptr)->next;
 232                        add_ref(&item->object, &new_parent->object);
 233                }
 234        }
 235        item->date = parse_commit_date(bufptr);
 236        return 0;
 237}
 238
 239int parse_commit(struct commit *item)
 240{
 241        char type[20];
 242        void *buffer;
 243        unsigned long size;
 244        int ret;
 245
 246        if (item->object.parsed)
 247                return 0;
 248        buffer = read_sha1_file(item->object.sha1, type, &size);
 249        if (!buffer)
 250                return error("Could not read %s",
 251                             sha1_to_hex(item->object.sha1));
 252        if (strcmp(type, commit_type)) {
 253                free(buffer);
 254                return error("Object %s not a commit",
 255                             sha1_to_hex(item->object.sha1));
 256        }
 257        ret = parse_commit_buffer(item, buffer, size);
 258        if (!ret) {
 259                item->buffer = buffer;
 260                return 0;
 261        }
 262        free(buffer);
 263        return ret;
 264}
 265
 266struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 267{
 268        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 269        new_list->item = item;
 270        new_list->next = *list_p;
 271        *list_p = new_list;
 272        return new_list;
 273}
 274
 275void free_commit_list(struct commit_list *list)
 276{
 277        while (list) {
 278                struct commit_list *temp = list;
 279                list = temp->next;
 280                free(temp);
 281        }
 282}
 283
 284struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 285{
 286        struct commit_list **pp = list;
 287        struct commit_list *p;
 288        while ((p = *pp) != NULL) {
 289                if (p->item->date < item->date) {
 290                        break;
 291                }
 292                pp = &p->next;
 293        }
 294        return commit_list_insert(item, pp);
 295}
 296
 297        
 298void sort_by_date(struct commit_list **list)
 299{
 300        struct commit_list *ret = NULL;
 301        while (*list) {
 302                insert_by_date((*list)->item, &ret);
 303                *list = (*list)->next;
 304        }
 305        *list = ret;
 306}
 307
 308struct commit *pop_most_recent_commit(struct commit_list **list,
 309                                      unsigned int mark)
 310{
 311        struct commit *ret = (*list)->item;
 312        struct commit_list *parents = ret->parents;
 313        struct commit_list *old = *list;
 314
 315        *list = (*list)->next;
 316        free(old);
 317
 318        while (parents) {
 319                struct commit *commit = parents->item;
 320                parse_commit(commit);
 321                if (!(commit->object.flags & mark)) {
 322                        commit->object.flags |= mark;
 323                        insert_by_date(commit, list);
 324                }
 325                parents = parents->next;
 326        }
 327        return ret;
 328}
 329
 330/*
 331 * Generic support for pretty-printing the header
 332 */
 333static int get_one_line(const char *msg, unsigned long len)
 334{
 335        int ret = 0;
 336
 337        while (len--) {
 338                char c = *msg++;
 339                ret++;
 340                if (c == '\n')
 341                        break;
 342                if (!c)
 343                        return 0;
 344        }
 345        return ret;
 346}
 347
 348static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 349{
 350        char *date;
 351        unsigned int namelen;
 352        unsigned long time;
 353        int tz, ret;
 354
 355        if (fmt == CMIT_FMT_ONELINE)
 356                return 0;
 357        date = strchr(line, '>');
 358        if (!date)
 359                return 0;
 360        namelen = ++date - line;
 361        time = strtoul(date, &date, 10);
 362        tz = strtol(date, NULL, 10);
 363
 364        ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
 365        if (fmt == CMIT_FMT_MEDIUM)
 366                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 367        return ret;
 368}
 369
 370static int is_empty_line(const char *line, int len)
 371{
 372        while (len && isspace(line[len-1]))
 373                len--;
 374        return !len;
 375}
 376
 377static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 378{
 379        int offset = 0;
 380
 381        if (fmt == CMIT_FMT_ONELINE)
 382                return offset;
 383        switch (parents) {
 384        case 1:
 385                break;
 386        case 2:
 387                /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 388                offset = sprintf(buf, "Merge: %.40s\n", line-41);
 389                /* Fallthrough */
 390        default:
 391                /* Replace the previous '\n' with a space */
 392                buf[offset-1] = ' ';
 393                offset += sprintf(buf + offset, "%.40s\n", line+7);
 394        }
 395        return offset;
 396}
 397
 398unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 399{
 400        int hdr = 1, body = 0;
 401        unsigned long offset = 0;
 402        int parents = 0;
 403        int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 404
 405        for (;;) {
 406                const char *line = msg;
 407                int linelen = get_one_line(msg, len);
 408
 409                if (!linelen)
 410                        break;
 411
 412                /*
 413                 * We want some slop for indentation and a possible
 414                 * final "...". Thus the "+ 20".
 415                 */
 416                if (offset + linelen + 20 > space) {
 417                        memcpy(buf + offset, "    ...\n", 8);
 418                        offset += 8;
 419                        break;
 420                }
 421
 422                msg += linelen;
 423                len -= linelen;
 424                if (hdr) {
 425                        if (linelen == 1) {
 426                                hdr = 0;
 427                                if (fmt != CMIT_FMT_ONELINE)
 428                                        buf[offset++] = '\n';
 429                                continue;
 430                        }
 431                        if (fmt == CMIT_FMT_RAW) {
 432                                memcpy(buf + offset, line, linelen);
 433                                offset += linelen;
 434                                continue;
 435                        }
 436                        if (!memcmp(line, "parent ", 7)) {
 437                                if (linelen != 48)
 438                                        die("bad parent line in commit");
 439                                offset += add_parent_info(fmt, buf + offset, line, ++parents);
 440                        }
 441                        if (!memcmp(line, "author ", 7))
 442                                offset += add_user_info("Author", fmt, buf + offset, line + 7);
 443                        if (fmt == CMIT_FMT_FULL) {
 444                                if (!memcmp(line, "committer ", 10))
 445                                        offset += add_user_info("Commit", fmt, buf + offset, line + 10);
 446                        }
 447                        continue;
 448                }
 449
 450                if (is_empty_line(line, linelen)) {
 451                        if (!body)
 452                                continue;
 453                        if (fmt == CMIT_FMT_SHORT)
 454                                break;
 455                } else {
 456                        body = 1;
 457                }
 458
 459                memset(buf + offset, ' ', indent);
 460                memcpy(buf + offset + indent, line, linelen);
 461                offset += linelen + indent;
 462                if (fmt == CMIT_FMT_ONELINE)
 463                        break;
 464        }
 465        if (fmt == CMIT_FMT_ONELINE) {
 466                /* We do not want the terminating newline */
 467                if (buf[offset - 1] == '\n')
 468                        offset--;
 469        }
 470        else {
 471                /* Make sure there is an EOLN */
 472                if (buf[offset - 1] != '\n')
 473                        buf[offset++] = '\n';
 474        }
 475        buf[offset] = '\0';
 476        return offset;
 477}
 478
 479struct commit *pop_commit(struct commit_list **stack)
 480{
 481        struct commit_list *top = *stack;
 482        struct commit *item = top ? top->item : NULL;
 483
 484        if (top) {
 485                *stack = top->next;
 486                free(top);
 487        }
 488        return item;
 489}
 490
 491int count_parents(struct commit * commit)
 492{
 493        int count = 0;
 494        struct commit_list * parents = commit->parents;
 495        for (count=0;parents; parents=parents->next,count++)
 496          ;
 497        return count;
 498}
 499
 500/*
 501 * Performs an in-place topological sort on the list supplied.
 502 */
 503void sort_in_topological_order(struct commit_list ** list)
 504{
 505        struct commit_list * next = *list;
 506        struct commit_list * work = NULL;
 507        struct commit_list ** pptr = list;
 508        struct sort_node * nodes;
 509        struct sort_node * next_nodes;
 510        int count = 0;
 511
 512        /* determine the size of the list */
 513        while (next) {
 514                next = next->next;
 515                count++;
 516        }
 517        /* allocate an array to help sort the list */
 518        nodes = xcalloc(count, sizeof(*nodes));
 519        /* link the list to the array */
 520        next_nodes = nodes;
 521        next=*list;
 522        while (next) {
 523                next_nodes->list_item = next;
 524                next->item->object.util = next_nodes;
 525                next_nodes++;
 526                next = next->next;
 527        }
 528        /* update the indegree */
 529        next=*list;
 530        while (next) {
 531                struct commit_list * parents = next->item->parents;
 532                while (parents) {
 533                        struct commit * parent=parents->item;
 534                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 535                        
 536                        if (pn)
 537                                pn->indegree++;
 538                        parents=parents->next;
 539                }
 540                next=next->next;
 541        }
 542        /* 
 543         * find the tips
 544         *
 545         * tips are nodes not reachable from any other node in the list 
 546         * 
 547         * the tips serve as a starting set for the work queue.
 548         */
 549        next=*list;
 550        while (next) {
 551                struct sort_node * node = (struct sort_node *)next->item->object.util;
 552
 553                if (node->indegree == 0) {
 554                        commit_list_insert(next->item, &work);
 555                }
 556                next=next->next;
 557        }
 558        /* process the list in topological order */
 559        while (work) {
 560                struct commit * work_item = pop_commit(&work);
 561                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 562                struct commit_list * parents = work_item->parents;
 563
 564                while (parents) {
 565                        struct commit * parent=parents->item;
 566                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 567                        
 568                        if (pn) {
 569                                /* 
 570                                 * parents are only enqueued for emission 
 571                                 * when all their children have been emitted thereby
 572                                 * guaranteeing topological order.
 573                                 */
 574                                pn->indegree--;
 575                                if (!pn->indegree) 
 576                                        commit_list_insert(parent, &work);
 577                        }
 578                        parents=parents->next;
 579                }
 580                /*
 581                 * work_item is a commit all of whose children
 582                 * have already been emitted. we can emit it now.
 583                 */
 584                *pptr = work_node->list_item;
 585                pptr = &(*pptr)->next;
 586                *pptr = NULL;
 587                work_item->object.util = NULL;
 588        }
 589        free(nodes);
 590}