aboutsummaryrefslogtreecommitdiff
path: root/object.c
blob: fdcfff7c86057bf8e5a7285518f186c67a1715bb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
#include "cache.h"
#include "object.h"
#include "blob.h"
#include "tree.h"
#include "commit.h"
#include "tag.h"

static struct object **obj_hash;
static int nr_objs, obj_hash_size;

unsigned int get_max_object_index(void)
{
	return obj_hash_size;
}

struct object *get_indexed_object(unsigned int idx)
{
	return obj_hash[idx];
}

const char *type_names[] = {
	"none", "commit", "tree", "blob", "tag",
	"bad type 5", "bad type 6", "delta", "bad",
};

static unsigned int hash_obj(struct object *obj, unsigned int n)
{
	unsigned int hash = *(unsigned int *)obj->sha1;
	return hash % n;
}

static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
{
	int j = hash_obj(obj, size);

	while (hash[j]) {
		j++;
		if (j >= size)
			j = 0;
	}
	hash[j] = obj;
}

static int hashtable_index(const unsigned char *sha1)
{
	unsigned int i;
	memcpy(&i, sha1, sizeof(unsigned int));
	return (int)(i % obj_hash_size);
}

struct object *lookup_object(const unsigned char *sha1)
{
	int i;
	struct object *obj;

	if (!obj_hash)
		return NULL;

	i = hashtable_index(sha1);
	while ((obj = obj_hash[i]) != NULL) {
		if (!hashcmp(sha1, obj->sha1))
			break;
		i++;
		if (i == obj_hash_size)
			i = 0;
	}
	return obj;
}

static void grow_object_hash(void)
{
	int i;
	int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
	struct object **new_hash;

	new_hash = calloc(new_hash_size, sizeof(struct object *));
	for (i = 0; i < obj_hash_size; i++) {
		struct object *obj = obj_hash[i];
		if (!obj)
			continue;
		insert_obj_hash(obj, new_hash, new_hash_size);
	}
	free(obj_hash);
	obj_hash = new_hash;
	obj_hash_size = new_hash_size;
}

void created_object(const unsigned char *sha1, struct object *obj)
{
	obj->parsed = 0;
	obj->used = 0;
	obj->type = OBJ_NONE;
	obj->flags = 0;
	memcpy(obj->sha1, sha1, 20);

	if (obj_hash_size - 1 <= nr_objs * 2)
		grow_object_hash();

	insert_obj_hash(obj, obj_hash, obj_hash_size);
	nr_objs++;
}

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 = OBJ_NONE;
		return &ret->object;
	}
	return obj;
}

struct object *parse_object(const unsigned char *sha1)
{
	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));
		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 {
			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;
}

void add_object_array(struct object *obj, const char *name, struct object_array *array)
{
	unsigned nr = array->nr;
	unsigned alloc = array->alloc;
	struct object_array_entry *objects = array->objects;

	if (nr >= alloc) {
		alloc = (alloc + 32) * 2;
		objects = xrealloc(objects, alloc * sizeof(*objects));
		array->alloc = alloc;
		array->objects = objects;
	}
	objects[nr].item = obj;
	objects[nr].name = name;
	array->nr = ++nr;
}