Andrew's git / gitweb.git / commit.c
?
commit.con commit Yank writing-back support from gitfakemmap. (f48000f)
   1#include <ctype.h>
   2#include "tag.h"
   3#include "commit.h"
   4#include "cache.h"
   5
   6int save_commit_buffer = 1;
   7
   8struct sort_node
   9{
  10        /*
  11         * the number of children of the associated commit
  12         * that also occur in the list being sorted.
  13         */
  14        unsigned int indegree;
  15
  16        /*
  17         * reference to original list item that we will re-use
  18         * on output.
  19         */
  20        struct commit_list * list_item;
  21
  22};
  23
  24const char *commit_type = "commit";
  25
  26enum cmit_fmt get_commit_format(const char *arg)
  27{
  28        if (!*arg)
  29                return CMIT_FMT_DEFAULT;
  30        if (!strcmp(arg, "=raw"))
  31                return CMIT_FMT_RAW;
  32        if (!strcmp(arg, "=medium"))
  33                return CMIT_FMT_MEDIUM;
  34        if (!strcmp(arg, "=short"))
  35                return CMIT_FMT_SHORT;
  36        if (!strcmp(arg, "=full"))
  37                return CMIT_FMT_FULL;
  38        if (!strcmp(arg, "=oneline"))
  39                return CMIT_FMT_ONELINE;
  40        die("invalid --pretty format");
  41}
  42
  43static struct commit *check_commit(struct object *obj,
  44                                   const unsigned char *sha1,
  45                                   int quiet)
  46{
  47        if (obj->type != commit_type) {
  48                if (!quiet)
  49                        error("Object %s is a %s, not a commit",
  50                              sha1_to_hex(sha1), obj->type);
  51                return NULL;
  52        }
  53        return (struct commit *) obj;
  54}
  55
  56struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  57                                              int quiet)
  58{
  59        struct object *obj = deref_tag(parse_object(sha1));
  60
  61        if (!obj)
  62                return NULL;
  63        return check_commit(obj, sha1, quiet);
  64}
  65
  66struct commit *lookup_commit_reference(const unsigned char *sha1)
  67{
  68        return lookup_commit_reference_gently(sha1, 0);
  69}
  70
  71struct commit *lookup_commit(const unsigned char *sha1)
  72{
  73        struct object *obj = lookup_object(sha1);
  74        if (!obj) {
  75                struct commit *ret = xmalloc(sizeof(struct commit));
  76                memset(ret, 0, sizeof(struct commit));
  77                created_object(sha1, &ret->object);
  78                ret->object.type = commit_type;
  79                return ret;
  80        }
  81        if (!obj->type)
  82                obj->type = commit_type;
  83        return check_commit(obj, sha1, 0);
  84}
  85
  86static unsigned long parse_commit_date(const char *buf)
  87{
  88        unsigned long date;
  89
  90        if (memcmp(buf, "author", 6))
  91                return 0;
  92        while (*buf++ != '\n')
  93                /* nada */;
  94        if (memcmp(buf, "committer", 9))
  95                return 0;
  96        while (*buf++ != '>')
  97                /* nada */;
  98        date = strtoul(buf, NULL, 10);
  99        if (date == ULONG_MAX)
 100                date = 0;
 101        return date;
 102}
 103
 104static struct commit_graft {
 105        unsigned char sha1[20];
 106        int nr_parent;
 107        unsigned char parent[0][20]; /* more */
 108} **commit_graft;
 109static int commit_graft_alloc, commit_graft_nr;
 110
 111static int commit_graft_pos(const unsigned char *sha1)
 112{
 113        int lo, hi;
 114        lo = 0;
 115        hi = commit_graft_nr;
 116        while (lo < hi) {
 117                int mi = (lo + hi) / 2;
 118                struct commit_graft *graft = commit_graft[mi];
 119                int cmp = memcmp(sha1, graft->sha1, 20);
 120                if (!cmp)
 121                        return mi;
 122                if (cmp < 0)
 123                        hi = mi;
 124                else
 125                        lo = mi + 1;
 126        }
 127        return -lo - 1;
 128}
 129
 130static void prepare_commit_graft(void)
 131{
 132        char *graft_file = get_graft_file();
 133        FILE *fp = fopen(graft_file, "r");
 134        char buf[1024];
 135        if (!fp) {
 136                commit_graft = (struct commit_graft **) "hack";
 137                return;
 138        }
 139        while (fgets(buf, sizeof(buf), fp)) {
 140                /* The format is just "Commit Parent1 Parent2 ...\n" */
 141                int len = strlen(buf);
 142                int i;
 143                struct commit_graft *graft = NULL;
 144
 145                if (buf[len-1] == '\n')
 146                        buf[--len] = 0;
 147                if (buf[0] == '#')
 148                        continue;
 149                if ((len + 1) % 41) {
 150                bad_graft_data:
 151                        error("bad graft data: %s", buf);
 152                        free(graft);
 153                        continue;
 154                }
 155                i = (len + 1) / 41 - 1;
 156                graft = xmalloc(sizeof(*graft) + 20 * i);
 157                graft->nr_parent = i;
 158                if (get_sha1_hex(buf, graft->sha1))
 159                        goto bad_graft_data;
 160                for (i = 40; i < len; i += 41) {
 161                        if (buf[i] != ' ')
 162                                goto bad_graft_data;
 163                        if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 164                                goto bad_graft_data;
 165                }
 166                i = commit_graft_pos(graft->sha1);
 167                if (0 <= i) {
 168                        error("duplicate graft data: %s", buf);
 169                        free(graft);
 170                        continue;
 171                }
 172                i = -i - 1;
 173                if (commit_graft_alloc <= ++commit_graft_nr) {
 174                        commit_graft_alloc = alloc_nr(commit_graft_alloc);
 175                        commit_graft = xrealloc(commit_graft,
 176                                                sizeof(*commit_graft) *
 177                                                commit_graft_alloc);
 178                }
 179                if (i < commit_graft_nr)
 180                        memmove(commit_graft + i + 1,
 181                                commit_graft + i,
 182                                (commit_graft_nr - i - 1) *
 183                                sizeof(*commit_graft));
 184                commit_graft[i] = graft;
 185        }
 186        fclose(fp);
 187}
 188
 189static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 190{
 191        int pos;
 192        if (!commit_graft)
 193                prepare_commit_graft();
 194        pos = commit_graft_pos(sha1);
 195        if (pos < 0)
 196                return NULL;
 197        return commit_graft[pos];
 198}
 199
 200int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 201{
 202        char *bufptr = buffer;
 203        unsigned char parent[20];
 204        struct commit_list **pptr;
 205        struct commit_graft *graft;
 206
 207        if (item->object.parsed)
 208                return 0;
 209        item->object.parsed = 1;
 210        if (memcmp(bufptr, "tree ", 5))
 211                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 212        if (get_sha1_hex(bufptr + 5, parent) < 0)
 213                return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 214        item->tree = lookup_tree(parent);
 215        if (item->tree)
 216                add_ref(&item->object, &item->tree->object);
 217        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 218        pptr = &item->parents;
 219
 220        graft = lookup_commit_graft(item->object.sha1);
 221        while (!memcmp(bufptr, "parent ", 7)) {
 222                struct commit *new_parent;
 223
 224                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 225                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 226                bufptr += 48;
 227                if (graft)
 228                        continue;
 229                new_parent = lookup_commit(parent);
 230                if (new_parent) {
 231                        pptr = &commit_list_insert(new_parent, pptr)->next;
 232                        add_ref(&item->object, &new_parent->object);
 233                }
 234        }
 235        if (graft) {
 236                int i;
 237                struct commit *new_parent;
 238                for (i = 0; i < graft->nr_parent; i++) {
 239                        new_parent = lookup_commit(graft->parent[i]);
 240                        if (!new_parent)
 241                                continue;
 242                        pptr = &commit_list_insert(new_parent, pptr)->next;
 243                        add_ref(&item->object, &new_parent->object);
 244                }
 245        }
 246        item->date = parse_commit_date(bufptr);
 247        return 0;
 248}
 249
 250int parse_commit(struct commit *item)
 251{
 252        char type[20];
 253        void *buffer;
 254        unsigned long size;
 255        int ret;
 256
 257        if (item->object.parsed)
 258                return 0;
 259        buffer = read_sha1_file(item->object.sha1, type, &size);
 260        if (!buffer)
 261                return error("Could not read %s",
 262                             sha1_to_hex(item->object.sha1));
 263        if (strcmp(type, commit_type)) {
 264                free(buffer);
 265                return error("Object %s not a commit",
 266                             sha1_to_hex(item->object.sha1));
 267        }
 268        ret = parse_commit_buffer(item, buffer, size);
 269        if (save_commit_buffer && !ret) {
 270                item->buffer = buffer;
 271                return 0;
 272        }
 273        free(buffer);
 274        return ret;
 275}
 276
 277struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 278{
 279        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 280        new_list->item = item;
 281        new_list->next = *list_p;
 282        *list_p = new_list;
 283        return new_list;
 284}
 285
 286void free_commit_list(struct commit_list *list)
 287{
 288        while (list) {
 289                struct commit_list *temp = list;
 290                list = temp->next;
 291                free(temp);
 292        }
 293}
 294
 295struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 296{
 297        struct commit_list **pp = list;
 298        struct commit_list *p;
 299        while ((p = *pp) != NULL) {
 300                if (p->item->date < item->date) {
 301                        break;
 302                }
 303                pp = &p->next;
 304        }
 305        return commit_list_insert(item, pp);
 306}
 307
 308        
 309void sort_by_date(struct commit_list **list)
 310{
 311        struct commit_list *ret = NULL;
 312        while (*list) {
 313                insert_by_date((*list)->item, &ret);
 314                *list = (*list)->next;
 315        }
 316        *list = ret;
 317}
 318
 319struct commit *pop_most_recent_commit(struct commit_list **list,
 320                                      unsigned int mark)
 321{
 322        struct commit *ret = (*list)->item;
 323        struct commit_list *parents = ret->parents;
 324        struct commit_list *old = *list;
 325
 326        *list = (*list)->next;
 327        free(old);
 328
 329        while (parents) {
 330                struct commit *commit = parents->item;
 331                parse_commit(commit);
 332                if (!(commit->object.flags & mark)) {
 333                        commit->object.flags |= mark;
 334                        insert_by_date(commit, list);
 335                }
 336                parents = parents->next;
 337        }
 338        return ret;
 339}
 340
 341/*
 342 * Generic support for pretty-printing the header
 343 */
 344static int get_one_line(const char *msg, unsigned long len)
 345{
 346        int ret = 0;
 347
 348        while (len--) {
 349                char c = *msg++;
 350                ret++;
 351                if (c == '\n')
 352                        break;
 353                if (!c)
 354                        return 0;
 355        }
 356        return ret;
 357}
 358
 359static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 360{
 361        char *date;
 362        int namelen;
 363        unsigned long time;
 364        int tz, ret;
 365
 366        if (fmt == CMIT_FMT_ONELINE)
 367                return 0;
 368        date = strchr(line, '>');
 369        if (!date)
 370                return 0;
 371        namelen = ++date - line;
 372        time = strtoul(date, &date, 10);
 373        tz = strtol(date, NULL, 10);
 374
 375        ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
 376        if (fmt == CMIT_FMT_MEDIUM)
 377                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 378        return ret;
 379}
 380
 381static int is_empty_line(const char *line, int len)
 382{
 383        while (len && isspace(line[len-1]))
 384                len--;
 385        return !len;
 386}
 387
 388static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 389{
 390        int offset = 0;
 391
 392        if (fmt == CMIT_FMT_ONELINE)
 393                return offset;
 394        switch (parents) {
 395        case 1:
 396                break;
 397        case 2:
 398                /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 399                offset = sprintf(buf, "Merge: %.40s\n", line-41);
 400                /* Fallthrough */
 401        default:
 402                /* Replace the previous '\n' with a space */
 403                buf[offset-1] = ' ';
 404                offset += sprintf(buf + offset, "%.40s\n", line+7);
 405        }
 406        return offset;
 407}
 408
 409unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 410{
 411        int hdr = 1, body = 0;
 412        unsigned long offset = 0;
 413        int parents = 0;
 414        int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 415
 416        for (;;) {
 417                const char *line = msg;
 418                int linelen = get_one_line(msg, len);
 419
 420                if (!linelen)
 421                        break;
 422
 423                /*
 424                 * We want some slop for indentation and a possible
 425                 * final "...". Thus the "+ 20".
 426                 */
 427                if (offset + linelen + 20 > space) {
 428                        memcpy(buf + offset, "    ...\n", 8);
 429                        offset += 8;
 430                        break;
 431                }
 432
 433                msg += linelen;
 434                len -= linelen;
 435                if (hdr) {
 436                        if (linelen == 1) {
 437                                hdr = 0;
 438                                if (fmt != CMIT_FMT_ONELINE)
 439                                        buf[offset++] = '\n';
 440                                continue;
 441                        }
 442                        if (fmt == CMIT_FMT_RAW) {
 443                                memcpy(buf + offset, line, linelen);
 444                                offset += linelen;
 445                                continue;
 446                        }
 447                        if (!memcmp(line, "parent ", 7)) {
 448                                if (linelen != 48)
 449                                        die("bad parent line in commit");
 450                                offset += add_parent_info(fmt, buf + offset, line, ++parents);
 451                        }
 452                        if (!memcmp(line, "author ", 7))
 453                                offset += add_user_info("Author", fmt, buf + offset, line + 7);
 454                        if (fmt == CMIT_FMT_FULL) {
 455                                if (!memcmp(line, "committer ", 10))
 456                                        offset += add_user_info("Commit", fmt, buf + offset, line + 10);
 457                        }
 458                        continue;
 459                }
 460
 461                if (is_empty_line(line, linelen)) {
 462                        if (!body)
 463                                continue;
 464                        if (fmt == CMIT_FMT_SHORT)
 465                                break;
 466                } else {
 467                        body = 1;
 468                }
 469
 470                memset(buf + offset, ' ', indent);
 471                memcpy(buf + offset + indent, line, linelen);
 472                offset += linelen + indent;
 473                if (fmt == CMIT_FMT_ONELINE)
 474                        break;
 475        }
 476        if (fmt == CMIT_FMT_ONELINE) {
 477                /* We do not want the terminating newline */
 478                if (buf[offset - 1] == '\n')
 479                        offset--;
 480        }
 481        else {
 482                /* Make sure there is an EOLN */
 483                if (buf[offset - 1] != '\n')
 484                        buf[offset++] = '\n';
 485        }
 486        buf[offset] = '\0';
 487        return offset;
 488}
 489
 490struct commit *pop_commit(struct commit_list **stack)
 491{
 492        struct commit_list *top = *stack;
 493        struct commit *item = top ? top->item : NULL;
 494
 495        if (top) {
 496                *stack = top->next;
 497                free(top);
 498        }
 499        return item;
 500}
 501
 502int count_parents(struct commit * commit)
 503{
 504        int count = 0;
 505        struct commit_list * parents = commit->parents;
 506        for (count=0;parents; parents=parents->next,count++)
 507          ;
 508        return count;
 509}
 510
 511/*
 512 * Performs an in-place topological sort on the list supplied.
 513 */
 514void sort_in_topological_order(struct commit_list ** list)
 515{
 516        struct commit_list * next = *list;
 517        struct commit_list * work = NULL;
 518        struct commit_list ** pptr = list;
 519        struct sort_node * nodes;
 520        struct sort_node * next_nodes;
 521        int count = 0;
 522
 523        /* determine the size of the list */
 524        while (next) {
 525                next = next->next;
 526                count++;
 527        }
 528        /* allocate an array to help sort the list */
 529        nodes = xcalloc(count, sizeof(*nodes));
 530        /* link the list to the array */
 531        next_nodes = nodes;
 532        next=*list;
 533        while (next) {
 534                next_nodes->list_item = next;
 535                next->item->object.util = next_nodes;
 536                next_nodes++;
 537                next = next->next;
 538        }
 539        /* update the indegree */
 540        next=*list;
 541        while (next) {
 542                struct commit_list * parents = next->item->parents;
 543                while (parents) {
 544                        struct commit * parent=parents->item;
 545                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 546                        
 547                        if (pn)
 548                                pn->indegree++;
 549                        parents=parents->next;
 550                }
 551                next=next->next;
 552        }
 553        /* 
 554         * find the tips
 555         *
 556         * tips are nodes not reachable from any other node in the list 
 557         * 
 558         * the tips serve as a starting set for the work queue.
 559         */
 560        next=*list;
 561        while (next) {
 562                struct sort_node * node = (struct sort_node *)next->item->object.util;
 563
 564                if (node->indegree == 0) {
 565                        commit_list_insert(next->item, &work);
 566                }
 567                next=next->next;
 568        }
 569        /* process the list in topological order */
 570        while (work) {
 571                struct commit * work_item = pop_commit(&work);
 572                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 573                struct commit_list * parents = work_item->parents;
 574
 575                while (parents) {
 576                        struct commit * parent=parents->item;
 577                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 578                        
 579                        if (pn) {
 580                                /* 
 581                                 * parents are only enqueued for emission 
 582                                 * when all their children have been emitted thereby
 583                                 * guaranteeing topological order.
 584                                 */
 585                                pn->indegree--;
 586                                if (!pn->indegree) 
 587                                        commit_list_insert(parent, &work);
 588                        }
 589                        parents=parents->next;
 590                }
 591                /*
 592                 * work_item is a commit all of whose children
 593                 * have already been emitted. we can emit it now.
 594                 */
 595                *pptr = work_node->list_item;
 596                pptr = &(*pptr)->next;
 597                *pptr = NULL;
 598                work_item->object.util = NULL;
 599        }
 600        free(nodes);
 601}