git-tar-tree: no more void pointer arithmetic
[git.git] / object.c
index c1f2291..0f70890 100644 (file)
--- a/object.c
+++ b/object.c
@@ -1,38 +1,46 @@
+#include "cache.h"
 #include "object.h"
 #include "blob.h"
 #include "tree.h"
 #include "commit.h"
-#include "cache.h"
 #include "tag.h"
-#include <stdlib.h>
-#include <string.h>
 
 struct object **objs;
-int nr_objs;
-static int obj_allocs;
+static int nr_objs;
+int obj_allocs;
+
+const char *type_names[] = {
+       "none", "blob", "tree", "commit", "bad"
+};
+
+int track_object_refs = 0;
 
-static int find_object(unsigned char *sha1)
+static int hashtable_index(const unsigned char *sha1)
 {
-       int first = 0, last = nr_objs;
-
-        while (first < last) {
-                int next = (first + last) / 2;
-                struct object *obj = objs[next];
-                int cmp;
-
-                cmp = memcmp(sha1, obj->sha1, 20);
-                if (!cmp)
-                        return next;
-                if (cmp < 0) {
-                        last = next;
-                        continue;
-                }
-                first = next+1;
-        }
-        return -first-1;
+       unsigned int i;
+       memcpy(&i, sha1, sizeof(unsigned int));
+       return (int)(i % obj_allocs);
 }
 
-struct object *lookup_object(unsigned char *sha1)
+static int find_object(const unsigned char *sha1)
+{
+       int i;
+
+       if (!objs)
+               return -1;
+
+       i = hashtable_index(sha1);
+       while (objs[i]) {
+               if (memcmp(sha1, objs[i]->sha1, 20) == 0)
+                       return i;
+               i++;
+               if (i == obj_allocs)
+                       i = 0;
+       }
+       return -1 - i;
+}
+
+struct object *lookup_object(const unsigned char *sha1)
 {
        int pos = find_object(sha1);
        if (pos >= 0)
@@ -40,98 +48,225 @@ struct object *lookup_object(unsigned char *sha1)
        return NULL;
 }
 
-void created_object(unsigned char *sha1, struct object *obj)
+void created_object(const unsigned char *sha1, struct object *obj)
 {
-       int pos = find_object(sha1);
+       int pos;
 
        obj->parsed = 0;
        memcpy(obj->sha1, sha1, 20);
-       obj->type = NULL;
+       obj->type = TYPE_NONE;
        obj->refs = NULL;
        obj->used = 0;
 
-       if (pos >= 0)
-               die("Inserting %s twice\n", sha1_to_hex(sha1));
-       pos = -pos-1;
-
-       if (obj_allocs == nr_objs) {
-               obj_allocs = alloc_nr(obj_allocs);
+       if (obj_allocs - 1 <= nr_objs * 2) {
+               int i, count = obj_allocs;
+               obj_allocs = (obj_allocs < 32 ? 32 : 2 * obj_allocs);
                objs = xrealloc(objs, obj_allocs * sizeof(struct object *));
+               memset(objs + count, 0, (obj_allocs - count)
+                               * sizeof(struct object *));
+               for (i = 0; i < obj_allocs; i++)
+                       if (objs[i]) {
+                               int j = find_object(objs[i]->sha1);
+                               if (j != i) {
+                                       j = -1 - j;
+                                       objs[j] = objs[i];
+                                       objs[i] = NULL;
+                               }
+                       }
        }
 
-       /* Insert it into the right place */
-       memmove(objs + pos + 1, objs + pos, (nr_objs - pos) * 
-               sizeof(struct object *));
+       pos = find_object(sha1);
+       if (pos >= 0)
+               die("Inserting %s twice\n", sha1_to_hex(sha1));
+       pos = -pos-1;
 
        objs[pos] = obj;
        nr_objs++;
 }
 
-void add_ref(struct object *refer, struct object *target)
+struct object_refs *alloc_object_refs(unsigned count)
+{
+       struct object_refs *refs;
+       size_t size = sizeof(*refs) + count*sizeof(struct object *);
+
+       refs = xcalloc(1, size);
+       refs->count = count;
+       return refs;
+}
+
+static int compare_object_pointers(const void *a, const void *b)
 {
-       struct object_list **pp = &refer->refs;
-       struct object_list *p;
-       
-       while ((p = *pp) != NULL) {
-               if (p->item == target)
-                       return;
-               pp = &p->next;
+       const struct object * const *pa = a;
+       const struct object * const *pb = b;
+       if (*pa == *pb)
+               return 0;
+       else if (*pa < *pb)
+               return -1;
+       else
+               return 1;
+}
+
+void set_object_refs(struct object *obj, struct object_refs *refs)
+{
+       unsigned int i, j;
+
+       /* Do not install empty list of references */
+       if (refs->count < 1) {
+               free(refs);
+               return;
        }
 
-       target->used = 1;
-       p = xmalloc(sizeof(*p));
-       p->item = target;
-       p->next = NULL;
-       *pp = p;
+       /* Sort the list and filter out duplicates */
+       qsort(refs->ref, refs->count, sizeof(refs->ref[0]),
+             compare_object_pointers);
+       for (i = j = 1; i < refs->count; i++) {
+               if (refs->ref[i] != refs->ref[i - 1])
+                       refs->ref[j++] = refs->ref[i];
+       }
+       if (j < refs->count) {
+               /* Duplicates were found - reallocate list */
+               size_t size = sizeof(*refs) + j*sizeof(struct object *);
+               refs->count = j;
+               refs = xrealloc(refs, size);
+       }
+
+       for (i = 0; i < refs->count; i++)
+               refs->ref[i]->used = 1;
+       obj->refs = refs;
 }
 
 void mark_reachable(struct object *obj, unsigned int mask)
 {
-       struct object_list *p = obj->refs;
-
+       if (!track_object_refs)
+               die("cannot do reachability with object refs turned off");
        /* If we've been here already, don't bother */
        if (obj->flags & mask)
                return;
        obj->flags |= mask;
-       while (p) {
-               mark_reachable(p->item, mask);
-               p = p->next;
+       if (obj->refs) {
+               const struct object_refs *refs = obj->refs;
+               unsigned i;
+               for (i = 0; i < refs->count; i++)
+                       mark_reachable(refs->ref[i], mask);
+       }
+}
+
+struct object *lookup_object_type(const unsigned char *sha1, const char *type)
+{
+       if (!type) {
+               return lookup_unknown_object(sha1);
+       } else if (!strcmp(type, blob_type)) {
+               return &lookup_blob(sha1)->object;
+       } else if (!strcmp(type, tree_type)) {
+               return &lookup_tree(sha1)->object;
+       } else if (!strcmp(type, commit_type)) {
+               return &lookup_commit(sha1)->object;
+       } else if (!strcmp(type, tag_type)) {
+               return &lookup_tag(sha1)->object;
+       } else {
+               error("Unknown type %s", type);
+               return NULL;
+       }
+}
+
+union any_object {
+       struct object object;
+       struct commit commit;
+       struct tree tree;
+       struct blob blob;
+       struct tag tag;
+};
+
+struct object *lookup_unknown_object(const unsigned char *sha1)
+{
+       struct object *obj = lookup_object(sha1);
+       if (!obj) {
+               union any_object *ret = xcalloc(1, sizeof(*ret));
+               created_object(sha1, &ret->object);
+               ret->object.type = TYPE_NONE;
+               return &ret->object;
        }
+       return obj;
 }
 
-struct object *parse_object(unsigned char *sha1)
+struct object *parse_object(const unsigned char *sha1)
 {
-       unsigned long mapsize;
-       void *map = map_sha1_file(sha1, &mapsize);
-       if (map) {
-               char type[100];
-               unsigned long size;
-               void *buffer = unpack_sha1_file(map, mapsize, type, &size);
-               munmap(map, mapsize);
-               if (!buffer)
-                       return NULL;
+       unsigned long size;
+       char type[20];
+       void *buffer = read_sha1_file(sha1, type, &size);
+       if (buffer) {
+               struct object *obj;
                if (check_sha1_signature(sha1, buffer, size, type) < 0)
                        printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
-               free(buffer);
-               if (!strcmp(type, "blob")) {
-                       struct blob *ret = lookup_blob(sha1);
-                       parse_blob(ret);
-                       return &ret->object;
-               } else if (!strcmp(type, "tree")) {
-                       struct tree *ret = lookup_tree(sha1);
-                       parse_tree(ret);
-                       return &ret->object;
-               } else if (!strcmp(type, "commit")) {
-                       struct commit *ret = lookup_commit(sha1);
-                       parse_commit(ret);
-                       return &ret->object;
-               } else if (!strcmp(type, "tag")) {
-                       struct tag *ret = lookup_tag(sha1);
-                       parse_tag(ret);
-                       return &ret->object;
+               if (!strcmp(type, blob_type)) {
+                       struct blob *blob = lookup_blob(sha1);
+                       parse_blob_buffer(blob, buffer, size);
+                       obj = &blob->object;
+               } else if (!strcmp(type, tree_type)) {
+                       struct tree *tree = lookup_tree(sha1);
+                       obj = &tree->object;
+                       if (!tree->object.parsed) {
+                               parse_tree_buffer(tree, buffer, size);
+                               buffer = NULL;
+                       }
+               } else if (!strcmp(type, commit_type)) {
+                       struct commit *commit = lookup_commit(sha1);
+                       parse_commit_buffer(commit, buffer, size);
+                       if (!commit->buffer) {
+                               commit->buffer = buffer;
+                               buffer = NULL;
+                       }
+                       obj = &commit->object;
+               } else if (!strcmp(type, tag_type)) {
+                       struct tag *tag = lookup_tag(sha1);
+                       parse_tag_buffer(tag, buffer, size);
+                       obj = &tag->object;
                } else {
-                       return NULL;
+                       obj = NULL;
                }
+               free(buffer);
+               return obj;
        }
        return NULL;
 }
+
+struct object_list *object_list_insert(struct object *item,
+                                      struct object_list **list_p)
+{
+       struct object_list *new_list = xmalloc(sizeof(struct object_list));
+        new_list->item = item;
+        new_list->next = *list_p;
+        *list_p = new_list;
+        return new_list;
+}
+
+void object_list_append(struct object *item,
+                       struct object_list **list_p)
+{
+       while (*list_p) {
+               list_p = &((*list_p)->next);
+       }
+       *list_p = xmalloc(sizeof(struct object_list));
+       (*list_p)->next = NULL;
+       (*list_p)->item = item;
+}
+
+unsigned object_list_length(struct object_list *list)
+{
+       unsigned ret = 0;
+       while (list) {
+               list = list->next;
+               ret++;
+       }
+       return ret;
+}
+
+int object_list_contains(struct object_list *list, struct object *obj)
+{
+       while (list) {
+               if (list->item == obj)
+                       return 1;
+               list = list->next;
+       }
+       return 0;
+}