1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 
19 #include <stdlib.h>
20 #include <string.h>
21 #include <sha1.h>
22 #include <stdio.h>
23 #include <zlib.h>
24 #include <limits.h>
25 #include <time.h>
26 
27 #include "got_object.h"
28 #include "got_error.h"
29 
30 #include "got_lib_delta.h"
31 #include "got_lib_inflate.h"
32 #include "got_lib_object.h"
33 #include "got_lib_object_idset.h"
34 
35 #ifndef nitems
36 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
37 #endif
38 
39 struct got_object_idset_element {
40 	TAILQ_ENTRY(got_object_idset_element) entry;
41 	struct got_object_id id;
42 	void *data;	/* API user data */
43 };
44 
45 struct got_object_idset {
46 	/*
47 	 * A set is implemented as a collection of 256 lists.
48 	 * The value of the first byte of an object ID determines
49 	 * which of these lists an object ID is stored in.
50 	 */
51 	TAILQ_HEAD(, got_object_idset_element) entries[0xff + 1];
52 	int nelem[0xff + 1];
53 	int totelem;
54 #define GOT_OBJECT_IDSET_MAX_ELEM INT_MAX
55 };
56 
57 struct got_object_idset *
58 got_object_idset_alloc(void)
59 {
60 	struct got_object_idset *set;
61 	int i;
62 
63 	set = calloc(1, sizeof(*set));
64 	if (set == NULL)
65 		return NULL;
66 
67 	for (i = 0; i < nitems(set->entries); i++)
68 		TAILQ_INIT(&set->entries[i]);
69 
70 	return set;
71 }
72 
73 void
74 got_object_idset_free(struct got_object_idset *set)
75 {
76 	struct got_object_idset_element *entry;
77 	int i;
78 
79 	for (i = 0; i < nitems(set->entries); i++) {
80 		while (!TAILQ_EMPTY(&set->entries[i])) {
81 			entry = TAILQ_FIRST(&set->entries[i]);
82 			TAILQ_REMOVE(&set->entries[i], entry, entry);
83 			/* User data should be freed by caller. */
84 			free(entry);
85 		}
86 	}
87 	free(set);
88 }
89 
90 const struct got_error *
91 got_object_idset_add(struct got_object_idset *set, struct got_object_id *id,
92     void *data)
93 {
94 	struct got_object_idset_element *new;
95 	uint8_t i = id->sha1[0];
96 
97 	if (set->totelem >= GOT_OBJECT_IDSET_MAX_ELEM)
98 		return got_error(GOT_ERR_NO_SPACE);
99 
100 	new = malloc(sizeof(*new));
101 	if (new == NULL)
102 		return got_error_from_errno();
103 
104 	memcpy(&new->id, id, sizeof(new->id));
105 	new->data = data;
106 
107 	TAILQ_INSERT_HEAD(&set->entries[i], new, entry);
108 	set->nelem[i]++;
109 	set->totelem++;
110 	return NULL;
111 }
112 
113 void *
114 got_object_idset_get(struct got_object_idset *set, struct got_object_id *id)
115 {
116 	struct got_object_idset_element *entry;
117 	uint8_t i = id->sha1[0];
118 
119 	TAILQ_FOREACH(entry, &set->entries[i], entry) {
120 		if (got_object_id_cmp(&entry->id, id) == 0)
121 			return entry->data;
122 	}
123 
124 	return NULL;
125 }
126 
127 const struct got_error *
128 got_object_idset_remove(void **data, struct got_object_idset *set,
129     struct got_object_id *id)
130 {
131 	struct got_object_idset_element *entry, *tmp;
132 	uint8_t i = id->sha1[0];
133 
134 	if (data)
135 		*data = NULL;
136 
137 	if (set->nelem[i] == 0)
138 		return got_error(GOT_ERR_NO_OBJ);
139 
140 	TAILQ_FOREACH_SAFE(entry, &set->entries[i], entry, tmp) {
141 		if (got_object_id_cmp(&entry->id, id) == 0) {
142 			TAILQ_REMOVE(&set->entries[i], entry, entry);
143 			if (data)
144 				*data = entry->data;
145 			free(entry);
146 			set->nelem[i]--;
147 			set->totelem--;
148 			return NULL;
149 		}
150 	}
151 
152 	return got_error(GOT_ERR_NO_OBJ);
153 }
154 
155 int
156 got_object_idset_contains(struct got_object_idset *set,
157     struct got_object_id *id)
158 {
159 	struct got_object_idset_element *entry;
160 	uint8_t i = id->sha1[0];
161 
162 	TAILQ_FOREACH(entry, &set->entries[i], entry) {
163 		if (got_object_id_cmp(&entry->id, id) == 0)
164 			return 1;
165 	}
166 
167 	return 0;
168 }
169 
170 void got_object_idset_for_each(struct got_object_idset *set,
171     void (*cb)(struct got_object_id *, void *, void *), void *arg)
172 {
173 	struct got_object_idset_element *entry;
174 	int i;
175 
176 	for (i = 0; i < nitems(set->entries); i++) {
177 		TAILQ_FOREACH(entry, &set->entries[i], entry)
178 			cb(&entry->id, entry->data, arg);
179 	}
180 }
181 
182 int
183 got_object_idset_num_elements(struct got_object_idset *set)
184 {
185 	return set->totelem;
186 }