commit.c

   1 #include "commit.h"
   2 #include "cache.h"
   3 #include <string.h>
   4 #include <limits.h>
   5
   6 const char *commit_type = "commit";
   7
   8 struct commit *lookup_commit(unsigned char *sha1)
   9 {
  10         struct object *obj = lookup_object(sha1);
  11         if (!obj) {
  12                 struct commit *ret = malloc(sizeof(struct commit));
  13                 memset(ret, 0, sizeof(struct commit));
  14                 created_object(sha1, &ret->object);
  15                 return ret;
  16         }
  17         if (obj->parsed && obj->type != commit_type) {
  18                 error("Object %s is a %s, not a commit",
  19                       sha1_to_hex(sha1), obj->type);
  20                 return NULL;
  21         }
  22         return (struct commit *) obj;
  23 }
  24
  25 static unsigned long parse_commit_date(const char *buf)
  26 {
  27         unsigned long date;
  28
  29         if (memcmp(buf, "author", 6))
  30                 return 0;
  31         while (*buf++ != '\n')
  32                 /* nada */;
  33         if (memcmp(buf, "committer", 9))
  34                 return 0;
  35         while (*buf++ != '>')
  36                 /* nada */;
  37         date = strtoul(buf, NULL, 10);
  38         if (date == ULONG_MAX)
  39                 date = 0;
  40         return date;
  41 }
  42
  43 int parse_commit(struct commit *item)
  44 {
  45         char type[20];
  46         void * buffer, *bufptr;
  47         unsigned long size;
  48         unsigned char parent[20];
  49         if (item->object.parsed)
  50                 return 0;
  51         item->object.parsed = 1;
  52         buffer = bufptr = read_sha1_file(item->object.sha1, type, &size);
  53         if (!buffer)
  54                 return error("Could not read %s",
  55                              sha1_to_hex(item->object.sha1));
  56         if (strcmp(type, commit_type))
  57                 return error("Object %s not a commit",
  58                              sha1_to_hex(item->object.sha1));
  59         item->object.type = commit_type;
  60         get_sha1_hex(bufptr + 5, parent);
  61         item->tree = lookup_tree(parent);
  62         add_ref(&item->object, &item->tree->object);
  63         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
  64         while (!memcmp(bufptr, "parent ", 7) &&
  65                !get_sha1_hex(bufptr + 7, parent)) {
  66                 struct commit *new_parent = lookup_commit(parent);
  67                 commit_list_insert(new_parent, &item->parents);
  68                 add_ref(&item->object, &new_parent->object);
  69                 bufptr += 48;
  70         }
  71         item->date = parse_commit_date(bufptr);
  72         free(buffer);
  73         return 0;
  74 }
  75
  76 void commit_list_insert(struct commit *item, struct commit_list **list_p)
  77 {
  78         struct commit_list *new_list = malloc(sizeof(struct commit_list));
  79         new_list->item = item;
  80         new_list->next = *list_p;
  81         *list_p = new_list;
  82 }
  83
  84 void free_commit_list(struct commit_list *list)
  85 {
  86         while (list) {
  87                 struct commit_list *temp = list;
  88                 list = temp->next;
  89                 free(temp);
  90         }
  91 }
  92
  93 static void insert_by_date(struct commit_list **list, struct commit *item)
  94 {
  95         struct commit_list **pp = list;
  96         struct commit_list *p;
  97         while ((p = *pp) != NULL) {
  98                 if (p->item->date < item->date) {
  99                         break;
 100                 }
 101                 pp = &p->next;
 102         }
 103         commit_list_insert(item, pp);
 104 }
 105
 106
 107 void sort_by_date(struct commit_list **list)
 108 {
 109         struct commit_list *ret = NULL;
 110         while (*list) {
 111                 insert_by_date(&ret, (*list)->item);
 112                 *list = (*list)->next;
 113         }
 114         *list = ret;
 115 }
 116
 117 struct commit *pop_most_recent_commit(struct commit_list **list)
 118 {
 119         struct commit *ret = (*list)->item;
 120         struct commit_list *parents = ret->parents;
 121         struct commit_list *old = *list;
 122
 123         *list = (*list)->next;
 124         free(old);
 125
 126         while (parents) {
 127                 parse_commit(parents->item);
 128                 insert_by_date(list, parents->item);
 129                 parents = parents->next;
 130         }
 131         return ret;
 132 }