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![Nguyễn Thái Ngọc Duy](/assets/img/avatar_default.png)
Traditionally, all the callers of check_sha1_signature() first called read_sha1_file() to prepare the whole object data in core, and called this function. The function is used to revalidate what we read from the object database actually matches the object name we used to ask for the data from the object database. Update the API to allow callers to pass NULL as the object data, and have the function read and hash the object data using streaming API to recompute the object name, without having to hold everything in core at the same time. This is most useful in parse_object() that parses a blob object, because this caller does not have to keep the actual blob data around in memory after a "struct blob" is returned. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
289 lines
6.2 KiB
C
289 lines
6.2 KiB
C
#include "cache.h"
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#include "object.h"
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#include "blob.h"
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#include "tree.h"
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#include "commit.h"
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#include "tag.h"
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static struct object **obj_hash;
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static int nr_objs, obj_hash_size;
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unsigned int get_max_object_index(void)
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{
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return obj_hash_size;
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}
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struct object *get_indexed_object(unsigned int idx)
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{
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return obj_hash[idx];
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}
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static const char *object_type_strings[] = {
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NULL, /* OBJ_NONE = 0 */
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"commit", /* OBJ_COMMIT = 1 */
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"tree", /* OBJ_TREE = 2 */
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"blob", /* OBJ_BLOB = 3 */
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"tag", /* OBJ_TAG = 4 */
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};
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const char *typename(unsigned int type)
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{
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if (type >= ARRAY_SIZE(object_type_strings))
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return NULL;
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return object_type_strings[type];
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}
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int type_from_string(const char *str)
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{
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int i;
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for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
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if (!strcmp(str, object_type_strings[i]))
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return i;
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die("invalid object type \"%s\"", str);
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}
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static unsigned int hash_obj(struct object *obj, unsigned int n)
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{
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unsigned int hash;
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memcpy(&hash, obj->sha1, sizeof(unsigned int));
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return hash % n;
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}
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static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
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{
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unsigned int j = hash_obj(obj, size);
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while (hash[j]) {
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j++;
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if (j >= size)
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j = 0;
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}
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hash[j] = obj;
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}
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static unsigned int hashtable_index(const unsigned char *sha1)
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{
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unsigned int i;
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memcpy(&i, sha1, sizeof(unsigned int));
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return i % obj_hash_size;
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}
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struct object *lookup_object(const unsigned char *sha1)
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{
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unsigned int i;
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struct object *obj;
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if (!obj_hash)
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return NULL;
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i = hashtable_index(sha1);
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while ((obj = obj_hash[i]) != NULL) {
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if (!hashcmp(sha1, obj->sha1))
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break;
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i++;
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if (i == obj_hash_size)
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i = 0;
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}
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return obj;
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}
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static void grow_object_hash(void)
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{
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int i;
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int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
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struct object **new_hash;
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new_hash = xcalloc(new_hash_size, sizeof(struct object *));
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for (i = 0; i < obj_hash_size; i++) {
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struct object *obj = obj_hash[i];
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if (!obj)
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continue;
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insert_obj_hash(obj, new_hash, new_hash_size);
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}
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free(obj_hash);
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obj_hash = new_hash;
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obj_hash_size = new_hash_size;
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}
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void *create_object(const unsigned char *sha1, int type, void *o)
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{
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struct object *obj = o;
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obj->parsed = 0;
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obj->used = 0;
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obj->type = type;
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obj->flags = 0;
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hashcpy(obj->sha1, sha1);
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if (obj_hash_size - 1 <= nr_objs * 2)
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grow_object_hash();
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insert_obj_hash(obj, obj_hash, obj_hash_size);
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nr_objs++;
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return obj;
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}
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struct object *lookup_unknown_object(const unsigned char *sha1)
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{
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struct object *obj = lookup_object(sha1);
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if (!obj)
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obj = create_object(sha1, OBJ_NONE, alloc_object_node());
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return obj;
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}
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struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
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{
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struct object *obj;
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int eaten = 0;
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obj = NULL;
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if (type == OBJ_BLOB) {
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struct blob *blob = lookup_blob(sha1);
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if (blob) {
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if (parse_blob_buffer(blob, buffer, size))
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return NULL;
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obj = &blob->object;
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}
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} else if (type == OBJ_TREE) {
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struct tree *tree = lookup_tree(sha1);
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if (tree) {
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obj = &tree->object;
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if (!tree->buffer)
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tree->object.parsed = 0;
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if (!tree->object.parsed) {
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if (parse_tree_buffer(tree, buffer, size))
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return NULL;
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eaten = 1;
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}
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}
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} else if (type == OBJ_COMMIT) {
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struct commit *commit = lookup_commit(sha1);
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if (commit) {
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if (parse_commit_buffer(commit, buffer, size))
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return NULL;
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if (!commit->buffer) {
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commit->buffer = buffer;
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eaten = 1;
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}
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obj = &commit->object;
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}
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} else if (type == OBJ_TAG) {
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struct tag *tag = lookup_tag(sha1);
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if (tag) {
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if (parse_tag_buffer(tag, buffer, size))
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return NULL;
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obj = &tag->object;
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}
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} else {
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warning("object %s has unknown type id %d\n", sha1_to_hex(sha1), type);
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obj = NULL;
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}
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if (obj && obj->type == OBJ_NONE)
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obj->type = type;
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*eaten_p = eaten;
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return obj;
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}
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struct object *parse_object(const unsigned char *sha1)
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{
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unsigned long size;
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enum object_type type;
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int eaten;
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const unsigned char *repl = lookup_replace_object(sha1);
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void *buffer;
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struct object *obj;
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obj = lookup_object(sha1);
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if (obj && obj->parsed)
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return obj;
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if ((obj && obj->type == OBJ_BLOB) ||
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(!obj && has_sha1_file(sha1) &&
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sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
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if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
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error("sha1 mismatch %s\n", sha1_to_hex(repl));
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return NULL;
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}
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parse_blob_buffer(lookup_blob(sha1), NULL, 0);
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return lookup_object(sha1);
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}
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buffer = read_sha1_file(sha1, &type, &size);
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if (buffer) {
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if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
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free(buffer);
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error("sha1 mismatch %s\n", sha1_to_hex(repl));
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return NULL;
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}
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obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
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if (!eaten)
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free(buffer);
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return obj;
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}
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return NULL;
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}
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struct object_list *object_list_insert(struct object *item,
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struct object_list **list_p)
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{
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struct object_list *new_list = xmalloc(sizeof(struct object_list));
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new_list->item = item;
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new_list->next = *list_p;
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*list_p = new_list;
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return new_list;
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}
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int object_list_contains(struct object_list *list, struct object *obj)
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{
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while (list) {
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if (list->item == obj)
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return 1;
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list = list->next;
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}
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return 0;
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}
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void add_object_array(struct object *obj, const char *name, struct object_array *array)
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{
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add_object_array_with_mode(obj, name, array, S_IFINVALID);
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}
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void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
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{
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unsigned nr = array->nr;
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unsigned alloc = array->alloc;
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struct object_array_entry *objects = array->objects;
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if (nr >= alloc) {
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alloc = (alloc + 32) * 2;
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objects = xrealloc(objects, alloc * sizeof(*objects));
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array->alloc = alloc;
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array->objects = objects;
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}
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objects[nr].item = obj;
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objects[nr].name = name;
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objects[nr].mode = mode;
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array->nr = ++nr;
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}
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void object_array_remove_duplicates(struct object_array *array)
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{
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unsigned int ref, src, dst;
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struct object_array_entry *objects = array->objects;
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for (ref = 0; ref + 1 < array->nr; ref++) {
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for (src = ref + 1, dst = src;
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src < array->nr;
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src++) {
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if (!strcmp(objects[ref].name, objects[src].name))
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continue;
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if (src != dst)
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objects[dst] = objects[src];
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dst++;
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}
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array->nr = dst;
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}
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}
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