Andrew's git / gitweb.git / commit.c
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commit.con commit Merge with gitk. (80bd6f3)
   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        die("invalid --pretty format");
  37}
  38
  39static struct commit *check_commit(struct object *obj, const unsigned char *sha1)
  40{
  41        if (obj->type != commit_type) {
  42                error("Object %s is a %s, not a commit", 
  43                      sha1_to_hex(sha1), obj->type);
  44                return NULL;
  45        }
  46        return (struct commit *) obj;
  47}
  48
  49struct commit *lookup_commit_reference(const unsigned char *sha1)
  50{
  51        struct object *obj = parse_object(sha1);
  52
  53        if (!obj)
  54                return NULL;
  55        while (obj->type == tag_type)
  56                obj = parse_object(((struct tag *)obj)->tagged->sha1);
  57
  58        return check_commit(obj, sha1);
  59}
  60
  61struct commit *lookup_commit(const unsigned char *sha1)
  62{
  63        struct object *obj = lookup_object(sha1);
  64        if (!obj) {
  65                struct commit *ret = xmalloc(sizeof(struct commit));
  66                memset(ret, 0, sizeof(struct commit));
  67                created_object(sha1, &ret->object);
  68                ret->object.type = commit_type;
  69                return ret;
  70        }
  71        if (!obj->type)
  72                obj->type = commit_type;
  73        return check_commit(obj, sha1);
  74}
  75
  76static unsigned long parse_commit_date(const char *buf)
  77{
  78        unsigned long date;
  79
  80        if (memcmp(buf, "author", 6))
  81                return 0;
  82        while (*buf++ != '\n')
  83                /* nada */;
  84        if (memcmp(buf, "committer", 9))
  85                return 0;
  86        while (*buf++ != '>')
  87                /* nada */;
  88        date = strtoul(buf, NULL, 10);
  89        if (date == ULONG_MAX)
  90                date = 0;
  91        return date;
  92}
  93
  94int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
  95{
  96        char *bufptr = buffer;
  97        unsigned char parent[20];
  98        struct commit_list **pptr;
  99
 100        if (item->object.parsed)
 101                return 0;
 102        item->object.parsed = 1;
 103        if (memcmp(bufptr, "tree ", 5))
 104                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 105        if (get_sha1_hex(bufptr + 5, parent) < 0)
 106                return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 107        item->tree = lookup_tree(parent);
 108        if (item->tree)
 109                add_ref(&item->object, &item->tree->object);
 110        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 111        pptr = &item->parents;
 112        while (!memcmp(bufptr, "parent ", 7)) {
 113                struct commit *new_parent;
 114
 115                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 116                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 117                new_parent = lookup_commit(parent);
 118                if (new_parent) {
 119                        pptr = &commit_list_insert(new_parent, pptr)->next;
 120                        add_ref(&item->object, &new_parent->object);
 121                }
 122                bufptr += 48;
 123        }
 124        item->date = parse_commit_date(bufptr);
 125        return 0;
 126}
 127
 128int parse_commit(struct commit *item)
 129{
 130        char type[20];
 131        void *buffer;
 132        unsigned long size;
 133        int ret;
 134
 135        if (item->object.parsed)
 136                return 0;
 137        buffer = read_sha1_file(item->object.sha1, type, &size);
 138        if (!buffer)
 139                return error("Could not read %s",
 140                             sha1_to_hex(item->object.sha1));
 141        if (strcmp(type, commit_type)) {
 142                free(buffer);
 143                return error("Object %s not a commit",
 144                             sha1_to_hex(item->object.sha1));
 145        }
 146        ret = parse_commit_buffer(item, buffer, size);
 147        if (!ret) {
 148                item->buffer = buffer;
 149                return 0;
 150        }
 151        free(buffer);
 152        return ret;
 153}
 154
 155struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 156{
 157        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 158        new_list->item = item;
 159        new_list->next = *list_p;
 160        *list_p = new_list;
 161        return new_list;
 162}
 163
 164void free_commit_list(struct commit_list *list)
 165{
 166        while (list) {
 167                struct commit_list *temp = list;
 168                list = temp->next;
 169                free(temp);
 170        }
 171}
 172
 173struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 174{
 175        struct commit_list **pp = list;
 176        struct commit_list *p;
 177        while ((p = *pp) != NULL) {
 178                if (p->item->date < item->date) {
 179                        break;
 180                }
 181                pp = &p->next;
 182        }
 183        return commit_list_insert(item, pp);
 184}
 185
 186        
 187void sort_by_date(struct commit_list **list)
 188{
 189        struct commit_list *ret = NULL;
 190        while (*list) {
 191                insert_by_date((*list)->item, &ret);
 192                *list = (*list)->next;
 193        }
 194        *list = ret;
 195}
 196
 197struct commit *pop_most_recent_commit(struct commit_list **list,
 198                                      unsigned int mark)
 199{
 200        struct commit *ret = (*list)->item;
 201        struct commit_list *parents = ret->parents;
 202        struct commit_list *old = *list;
 203
 204        *list = (*list)->next;
 205        free(old);
 206
 207        while (parents) {
 208                struct commit *commit = parents->item;
 209                parse_commit(commit);
 210                if (!(commit->object.flags & mark)) {
 211                        commit->object.flags |= mark;
 212                        insert_by_date(commit, list);
 213                }
 214                parents = parents->next;
 215        }
 216        return ret;
 217}
 218
 219/*
 220 * Generic support for pretty-printing the header
 221 */
 222static int get_one_line(const char *msg, unsigned long len)
 223{
 224        int ret = 0;
 225
 226        while (len--) {
 227                char c = *msg++;
 228                ret++;
 229                if (c == '\n')
 230                        break;
 231                if (!c)
 232                        return 0;
 233        }
 234        return ret;
 235}
 236
 237static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 238{
 239        char *date;
 240        unsigned int namelen;
 241        unsigned long time;
 242        int tz, ret;
 243
 244        date = strchr(line, '>');
 245        if (!date)
 246                return 0;
 247        namelen = ++date - line;
 248        time = strtoul(date, &date, 10);
 249        tz = strtol(date, NULL, 10);
 250
 251        ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
 252        if (fmt == CMIT_FMT_MEDIUM)
 253                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 254        return ret;
 255}
 256
 257static int is_empty_line(const char *line, int len)
 258{
 259        while (len && isspace(line[len-1]))
 260                len--;
 261        return !len;
 262}
 263
 264static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 265{
 266        int offset = 0;
 267        switch (parents) {
 268        case 1:
 269                break;
 270        case 2:
 271                /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 272                offset = sprintf(buf, "Merge: %.40s\n", line-41);
 273                /* Fallthrough */
 274        default:
 275                /* Replace the previous '\n' with a space */
 276                buf[offset-1] = ' ';
 277                offset += sprintf(buf + offset, "%.40s\n", line+7);
 278        }
 279        return offset;
 280}
 281
 282unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 283{
 284        int hdr = 1, body = 0;
 285        unsigned long offset = 0;
 286        int parents = 0;
 287
 288        for (;;) {
 289                const char *line = msg;
 290                int linelen = get_one_line(msg, len);
 291
 292                if (!linelen)
 293                        break;
 294
 295                /*
 296                 * We want some slop for indentation and a possible
 297                 * final "...". Thus the "+ 20".
 298                 */
 299                if (offset + linelen + 20 > space) {
 300                        memcpy(buf + offset, "    ...\n", 8);
 301                        offset += 8;
 302                        break;
 303                }
 304
 305                msg += linelen;
 306                len -= linelen;
 307                if (hdr) {
 308                        if (linelen == 1) {
 309                                hdr = 0;
 310                                buf[offset++] = '\n';
 311                                continue;
 312                        }
 313                        if (fmt == CMIT_FMT_RAW) {
 314                                memcpy(buf + offset, line, linelen);
 315                                offset += linelen;
 316                                continue;
 317                        }
 318                        if (!memcmp(line, "parent ", 7)) {
 319                                if (linelen != 48)
 320                                        die("bad parent line in commit");
 321                                offset += add_parent_info(fmt, buf + offset, line, ++parents);
 322                        }
 323                        if (!memcmp(line, "author ", 7))
 324                                offset += add_user_info("Author", fmt, buf + offset, line + 7);
 325                        if (fmt == CMIT_FMT_FULL) {
 326                                if (!memcmp(line, "committer ", 10))
 327                                        offset += add_user_info("Commit", fmt, buf + offset, line + 10);
 328                        }
 329                        continue;
 330                }
 331
 332                if (is_empty_line(line, linelen)) {
 333                        if (!body)
 334                                continue;
 335                        if (fmt == CMIT_FMT_SHORT)
 336                                break;
 337                } else {
 338                        body = 1;
 339                }
 340                memset(buf + offset, ' ', 4);
 341                memcpy(buf + offset + 4, line, linelen);
 342                offset += linelen + 4;
 343        }
 344        /* Make sure there is an EOLN */
 345        if (buf[offset - 1] != '\n')
 346                buf[offset++] = '\n';
 347        buf[offset] = '\0';
 348        return offset;
 349}
 350
 351struct commit *pop_commit(struct commit_list **stack)
 352{
 353        struct commit_list *top = *stack;
 354        struct commit *item = top ? top->item : NULL;
 355
 356        if (top) {
 357                *stack = top->next;
 358                free(top);
 359        }
 360        return item;
 361}
 362
 363int count_parents(struct commit * commit)
 364{
 365        int count = 0;
 366        struct commit_list * parents = commit->parents;
 367        for (count=0;parents; parents=parents->next,count++)
 368          ;
 369        return count;
 370}
 371
 372/*
 373 * Performs an in-place topological sort on the list supplied.
 374 */
 375void sort_in_topological_order(struct commit_list ** list)
 376{
 377        struct commit_list * next = *list;
 378        struct commit_list * work = NULL;
 379        struct commit_list ** pptr = list;
 380        struct sort_node * nodes;
 381        struct sort_node * next_nodes;
 382        int count = 0;
 383
 384        /* determine the size of the list */
 385        while (next) {
 386                next = next->next;
 387                count++;
 388        }
 389        /* allocate an array to help sort the list */
 390        nodes = xcalloc(count, sizeof(*nodes));
 391        /* link the list to the array */
 392        next_nodes = nodes;
 393        next=*list;
 394        while (next) {
 395                next_nodes->list_item = next;
 396                next->item->object.util = next_nodes;
 397                next_nodes++;
 398                next = next->next;
 399        }
 400        /* update the indegree */
 401        next=*list;
 402        while (next) {
 403                struct commit_list * parents = next->item->parents;
 404                while (parents) {
 405                        struct commit * parent=parents->item;
 406                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 407                        
 408                        if (pn)
 409                                pn->indegree++;
 410                        parents=parents->next;
 411                }
 412                next=next->next;
 413        }
 414        /* 
 415         * find the tips
 416         *
 417         * tips are nodes not reachable from any other node in the list 
 418         * 
 419         * the tips serve as a starting set for the work queue.
 420         */
 421        next=*list;
 422        while (next) {
 423                struct sort_node * node = (struct sort_node *)next->item->object.util;
 424
 425                if (node->indegree == 0) {
 426                        commit_list_insert(next->item, &work);
 427                }
 428                next=next->next;
 429        }
 430        /* process the list in topological order */
 431        while (work) {
 432                struct commit * work_item = pop_commit(&work);
 433                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 434                struct commit_list * parents = work_item->parents;
 435
 436                while (parents) {
 437                        struct commit * parent=parents->item;
 438                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 439                        
 440                        if (pn) {
 441                                /* 
 442                                 * parents are only enqueued for emission 
 443                                 * when all their children have been emitted thereby
 444                                 * guaranteeing topological order.
 445                                 */
 446                                pn->indegree--;
 447                                if (!pn->indegree) 
 448                                        commit_list_insert(parent, &work);
 449                        }
 450                        parents=parents->next;
 451                }
 452                /*
 453                 * work_item is a commit all of whose children
 454                 * have already been emitted. we can emit it now.
 455                 */
 456                *pptr = work_node->list_item;
 457                pptr = &(*pptr)->next;
 458                *pptr = NULL;
 459                work_item->object.util = NULL;
 460        }
 461        free(nodes);
 462}