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/time.h>
18 #include <sys/queue.h>
19 
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sha1.h>
24 #include <zlib.h>
25 
26 #include "got_error.h"
27 #include "got_object.h"
28 
29 #include "got_lib_delta.h"
30 #include "got_lib_inflate.h"
31 #include "got_lib_object.h"
32 #include "got_lib_object_idset.h"
33 #include "got_lib_object_cache.h"
34 
35 #define GOT_OBJECT_CACHE_SIZE_OBJ	256
36 #define GOT_OBJECT_CACHE_SIZE_TREE	256
37 #define GOT_OBJECT_CACHE_SIZE_COMMIT	64
38 #define GOT_OBJECT_CACHE_SIZE_TAG	32
39 
40 const struct got_error *
41 got_object_cache_init(struct got_object_cache *cache,
42     enum got_object_cache_type type)
43 {
44 	memset(cache, 0, sizeof(*cache));
45 
46 	cache->idset = got_object_idset_alloc();
47 	if (cache->idset == NULL)
48 		return got_error_from_errno();
49 
50 	cache->type = type;
51 	switch (type) {
52 	case GOT_OBJECT_CACHE_TYPE_OBJ:
53 		cache->size = GOT_OBJECT_CACHE_SIZE_OBJ;
54 		break;
55 	case GOT_OBJECT_CACHE_TYPE_TREE:
56 		cache->size = GOT_OBJECT_CACHE_SIZE_TREE;
57 		break;
58 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
59 		cache->size = GOT_OBJECT_CACHE_SIZE_COMMIT;
60 		break;
61 	case GOT_OBJECT_CACHE_TYPE_TAG:
62 		cache->size = GOT_OBJECT_CACHE_SIZE_TAG;
63 		break;
64 	}
65 	return NULL;
66 }
67 
68 const struct got_error *
69 got_object_cache_add(struct got_object_cache *cache, struct got_object_id *id, void *item)
70 {
71 	const struct got_error *err = NULL;
72 	struct got_object_cache_entry *ce;
73 	int nelem;
74 
75 	nelem = got_object_idset_num_elements(cache->idset);
76 	if (nelem >= cache->size) {
77 		err = got_object_idset_remove((void **)&ce,
78 		    cache->idset, NULL);
79 		if (err)
80 			return err;
81 		switch (cache->type) {
82 		case GOT_OBJECT_CACHE_TYPE_OBJ:
83 			got_object_close(ce->data.obj);
84 			break;
85 		case GOT_OBJECT_CACHE_TYPE_TREE:
86 			got_object_tree_close(ce->data.tree);
87 			break;
88 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
89 			got_object_commit_close(ce->data.commit);
90 			break;
91 		case GOT_OBJECT_CACHE_TYPE_TAG:
92 			got_object_tag_close(ce->data.tag);
93 			break;
94 		}
95 		free(ce);
96 		cache->cache_evict++;
97 	}
98 
99 	ce = malloc(sizeof(*ce));
100 	if (ce == NULL)
101 		return got_error_from_errno();
102 	memcpy(&ce->id, id, sizeof(ce->id));
103 	switch (cache->type) {
104 	case GOT_OBJECT_CACHE_TYPE_OBJ:
105 		ce->data.obj = (struct got_object *)item;
106 		break;
107 	case GOT_OBJECT_CACHE_TYPE_TREE:
108 		ce->data.tree = (struct got_tree_object *)item;
109 		break;
110 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
111 		ce->data.commit = (struct got_commit_object *)item;
112 		break;
113 	case GOT_OBJECT_CACHE_TYPE_TAG:
114 		ce->data.tag = (struct got_tag_object *)item;
115 		break;
116 	}
117 
118 	err = got_object_idset_add(cache->idset, id, ce);
119 	if (err) {
120 		if (err->code == GOT_ERR_OBJ_EXISTS) {
121 			free(ce);
122 			err = NULL;
123 		}
124 	}
125 	return err;
126 }
127 
128 void *
129 got_object_cache_get(struct got_object_cache *cache, struct got_object_id *id)
130 {
131 	struct got_object_cache_entry *ce;
132 
133 	cache->cache_searches++;
134 	ce = got_object_idset_get(cache->idset, id);
135 	if (ce) {
136 		cache->cache_hit++;
137 		switch (cache->type) {
138 		case GOT_OBJECT_CACHE_TYPE_OBJ:
139 			return ce->data.obj;
140 		case GOT_OBJECT_CACHE_TYPE_TREE:
141 			return ce->data.tree;
142 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
143 			return ce->data.commit;
144 		case GOT_OBJECT_CACHE_TYPE_TAG:
145 			return ce->data.tag;
146 		}
147 	}
148 
149 	cache->cache_miss++;
150 	return NULL;
151 }
152 
153 #ifdef GOT_OBJ_CACHE_DEBUG
154 static void
155 print_cache_stats(struct got_object_cache *cache, const char *name)
156 {
157 	fprintf(stderr, "%s: %s cache: %d elements, %d searches, %d hits, "
158 	    "%d missed, %d evicted\n", getprogname(), name,
159 	    got_object_idset_num_elements(cache->idset),
160 	    cache->cache_searches, cache->cache_hit,
161 	    cache->cache_miss, cache->cache_evict);
162 }
163 
164 const struct got_error *
165 check_refcount(struct got_object_id *id, void *data, void *arg)
166 {
167 	struct got_object_cache *cache = arg;
168 	struct got_object_cache_entry *ce = data;
169 	struct got_object *obj;
170 	struct got_tree_object *tree;
171 	struct got_commit_object *commit;
172 	struct got_tag_object *tag;
173 	char *id_str;
174 
175 	if (got_object_id_str(&id_str, id) != NULL)
176 		return NULL;
177 
178 	switch (cache->type) {
179 	case GOT_OBJECT_CACHE_TYPE_OBJ:
180 		obj = ce->data.obj;
181 		if (obj->refcnt == 1)
182 			break;
183 		fprintf(stderr, "object %s has %d unclaimed references\n",
184 		    id_str, obj->refcnt - 1);
185 		break;
186 	case GOT_OBJECT_CACHE_TYPE_TREE:
187 		tree = ce->data.tree;
188 		if (tree->refcnt == 1)
189 			break;
190 		fprintf(stderr, "tree %s has %d unclaimed references\n",
191 		    id_str, tree->refcnt - 1);
192 		break;
193 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
194 		commit = ce->data.commit;
195 		if (commit->refcnt == 1)
196 			break;
197 		fprintf(stderr, "commit %s has %d unclaimed references\n",
198 		    id_str, commit->refcnt - 1);
199 		break;
200 	case GOT_OBJECT_CACHE_TYPE_TAG:
201 		tag = ce->data.tag;
202 		if (tag->refcnt == 1)
203 			break;
204 		fprintf(stderr, "tag %s has %d unclaimed references\n",
205 		    id_str, tag->refcnt - 1);
206 		break;
207 	}
208 	free(id_str);
209 	return NULL;
210 }
211 #endif
212 
213 void
214 got_object_cache_close(struct got_object_cache *cache)
215 {
216 #ifdef GOT_OBJ_CACHE_DEBUG
217 	switch (cache->type) {
218 	case GOT_OBJECT_CACHE_TYPE_OBJ:
219 		print_cache_stats(cache, "object");
220 		break;
221 	case GOT_OBJECT_CACHE_TYPE_TREE:
222 		print_cache_stats(cache, "tree");
223 		break;
224 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
225 		print_cache_stats(cache, "commit");
226 		break;
227 	}
228 
229 	got_object_idset_for_each(cache->idset, check_refcount, cache);
230 #endif
231 
232 	if (cache->idset) {
233 		got_object_idset_free(cache->idset);
234 		cache->idset = NULL;
235 	}
236 	cache->size = 0;
237 }