commit.c

   1 #include "tag.h"
   2 #include "commit.h"
   3 #include "cache.h"
   4 #include <string.h>
   5 #include <limits.h>
   6
   7 const char *commit_type = "commit";
   8
   9 static struct commit *check_commit(struct object *obj, unsigned char *sha1)
  10 {
  11         if (obj->type != commit_type) {
  12                 error("Object %s is a %s, not a commit",
  13                       sha1_to_hex(sha1), obj->type);
  14                 return NULL;
  15         }
  16         return (struct commit *) obj;
  17 }
  18
  19 struct commit *lookup_commit_reference(unsigned char *sha1)
  20 {
  21         struct object *obj = parse_object(sha1);
  22
  23         if (!obj)
  24                 return NULL;
  25         if (obj->type == tag_type)
  26                 obj = ((struct tag *)obj)->tagged;
  27         return check_commit(obj, sha1);
  28 }
  29
  30 struct commit *lookup_commit(unsigned char *sha1)
  31 {
  32         struct object *obj = lookup_object(sha1);
  33         if (!obj) {
  34                 struct commit *ret = xmalloc(sizeof(struct commit));
  35                 memset(ret, 0, sizeof(struct commit));
  36                 created_object(sha1, &ret->object);
  37                 ret->object.type = commit_type;
  38                 return ret;
  39         }
  40         return check_commit(obj, sha1);
  41 }
  42
  43 static unsigned long parse_commit_date(const char *buf)
  44 {
  45         unsigned long date;
  46
  47         if (memcmp(buf, "author", 6))
  48                 return 0;
  49         while (*buf++ != '\n')
  50                 /* nada */;
  51         if (memcmp(buf, "committer", 9))
  52                 return 0;
  53         while (*buf++ != '>')
  54                 /* nada */;
  55         date = strtoul(buf, NULL, 10);
  56         if (date == ULONG_MAX)
  57                 date = 0;
  58         return date;
  59 }
  60
  61 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
  62 {
  63         void *bufptr = buffer;
  64         unsigned char parent[20];
  65
  66         if (item->object.parsed)
  67                 return 0;
  68         item->object.parsed = 1;
  69         get_sha1_hex(bufptr + 5, parent);
  70         item->tree = lookup_tree(parent);
  71         if (item->tree)
  72                 add_ref(&item->object, &item->tree->object);
  73         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
  74         while (!memcmp(bufptr, "parent ", 7) &&
  75                !get_sha1_hex(bufptr + 7, parent)) {
  76                 struct commit *new_parent = lookup_commit(parent);
  77                 if (new_parent) {
  78                         commit_list_insert(new_parent, &item->parents);
  79                         add_ref(&item->object, &new_parent->object);
  80                 }
  81                 bufptr += 48;
  82         }
  83         item->date = parse_commit_date(bufptr);
  84         return 0;
  85 }
  86
  87 int parse_commit(struct commit *item)
  88 {
  89         char type[20];
  90         void *buffer;
  91         unsigned long size;
  92         int ret;
  93
  94         if (item->object.parsed)
  95                 return 0;
  96         buffer = read_sha1_file(item->object.sha1, type, &size);
  97         if (!buffer)
  98                 return error("Could not read %s",
  99                              sha1_to_hex(item->object.sha1));
 100         if (strcmp(type, commit_type)) {
 101                 free(buffer);
 102                 return error("Object %s not a commit",
 103                              sha1_to_hex(item->object.sha1));
 104         }
 105         ret = parse_commit_buffer(item, buffer, size);
 106         free(buffer);
 107         return ret;
 108 }
 109
 110 void commit_list_insert(struct commit *item, struct commit_list **list_p)
 111 {
 112         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 113         new_list->item = item;
 114         new_list->next = *list_p;
 115         *list_p = new_list;
 116 }
 117
 118 void free_commit_list(struct commit_list *list)
 119 {
 120         while (list) {
 121                 struct commit_list *temp = list;
 122                 list = temp->next;
 123                 free(temp);
 124         }
 125 }
 126
 127 static void insert_by_date(struct commit_list **list, struct commit *item)
 128 {
 129         struct commit_list **pp = list;
 130         struct commit_list *p;
 131         while ((p = *pp) != NULL) {
 132                 if (p->item->date < item->date) {
 133                         break;
 134                 }
 135                 pp = &p->next;
 136         }
 137         commit_list_insert(item, pp);
 138 }
 139
 140
 141 void sort_by_date(struct commit_list **list)
 142 {
 143         struct commit_list *ret = NULL;
 144         while (*list) {
 145                 insert_by_date(&ret, (*list)->item);
 146                 *list = (*list)->next;
 147         }
 148         *list = ret;
 149 }
 150
 151 struct commit *pop_most_recent_commit(struct commit_list **list,
 152                                       unsigned int mark)
 153 {
 154         struct commit *ret = (*list)->item;
 155         struct commit_list *parents = ret->parents;
 156         struct commit_list *old = *list;
 157
 158         *list = (*list)->next;
 159         free(old);
 160
 161         while (parents) {
 162                 struct commit *commit = parents->item;
 163                 parse_commit(commit);
 164                 if (!(commit->object.flags & mark)) {
 165                         commit->object.flags |= mark;
 166                         insert_by_date(list, commit);
 167                 }
 168                 parents = parents->next;
 169         }
 170         return ret;
 171 }