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 
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <stdint.h>
22 #include <string.h>
23 #include <limits.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 /*
36  * XXX This should be reworked to track cache size and usage in bytes,
37  * rather than tracking N elements capped to a maximum element size.
38  */
39 #define GOT_OBJECT_CACHE_SIZE_OBJ	256
40 #define GOT_OBJECT_CACHE_SIZE_TREE	256
41 #define GOT_OBJECT_CACHE_SIZE_COMMIT	64
42 #define GOT_OBJECT_CACHE_SIZE_TAG	2048
43 #define GOT_OBJECT_CACHE_MAX_ELEM_SIZE	1048576	/* 1 MB */
44 
45 const struct got_error *
46 got_object_cache_init(struct got_object_cache *cache,
47     enum got_object_cache_type type)
48 {
49 	memset(cache, 0, sizeof(*cache));
50 
51 	cache->idset = got_object_idset_alloc();
52 	if (cache->idset == NULL)
53 		return got_error_from_errno("got_object_idset_alloc");
54 
55 	cache->type = type;
56 	switch (type) {
57 	case GOT_OBJECT_CACHE_TYPE_OBJ:
58 		cache->size = GOT_OBJECT_CACHE_SIZE_OBJ;
59 		break;
60 	case GOT_OBJECT_CACHE_TYPE_TREE:
61 		cache->size = GOT_OBJECT_CACHE_SIZE_TREE;
62 		break;
63 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
64 		cache->size = GOT_OBJECT_CACHE_SIZE_COMMIT;
65 		break;
66 	case GOT_OBJECT_CACHE_TYPE_TAG:
67 		cache->size = GOT_OBJECT_CACHE_SIZE_TAG;
68 		break;
69 	}
70 	return NULL;
71 }
72 
73 size_t
74 get_size_obj(struct got_object *obj)
75 {
76 	size_t size = sizeof(*obj);
77 	struct got_delta *delta;
78 
79 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
80 		return size;
81 
82 	STAILQ_FOREACH(delta, &obj->deltas.entries, entry) {
83 		if (SIZE_MAX - sizeof(*delta) < size)
84 			return SIZE_MAX;
85 		size += sizeof(*delta);
86 	}
87 
88 	return size;
89 }
90 
91 size_t
92 get_size_tree(struct got_tree_object *tree)
93 {
94 	size_t size = sizeof(*tree);
95 
96 	size += sizeof(struct got_tree_entry) * tree->nentries;
97 	return size;
98 }
99 
100 size_t
101 get_size_commit(struct got_commit_object *commit)
102 {
103 	size_t size = sizeof(*commit);
104 	struct got_object_qid *qid;
105 
106 	size += sizeof(*commit->tree_id);
107 	size += strlen(commit->author);
108 	size += strlen(commit->committer);
109 	size += strlen(commit->logmsg);
110 
111 	STAILQ_FOREACH(qid, &commit->parent_ids, entry)
112 		size += sizeof(*qid) + sizeof(*qid->id);
113 
114 	return size;
115 }
116 
117 size_t
118 get_size_tag(struct got_tag_object *tag)
119 {
120 	size_t size = sizeof(*tag);
121 
122 	size += strlen(tag->tag);
123 	size += strlen(tag->tagger);
124 	size += strlen(tag->tagmsg);
125 
126 	return size;
127 }
128 
129 const struct got_error *
130 got_object_cache_add(struct got_object_cache *cache, struct got_object_id *id, void *item)
131 {
132 	const struct got_error *err = NULL;
133 	struct got_object_cache_entry *ce;
134 	int nelem;
135 	size_t size;
136 
137 	switch (cache->type) {
138 	case GOT_OBJECT_CACHE_TYPE_OBJ:
139 		size = get_size_obj((struct got_object *)item);
140 		break;
141 	case GOT_OBJECT_CACHE_TYPE_TREE:
142 		size = get_size_tree((struct got_tree_object *)item);
143 		break;
144 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
145 		size = get_size_commit((struct got_commit_object *)item);
146 		break;
147 	case GOT_OBJECT_CACHE_TYPE_TAG:
148 		size = get_size_tag((struct got_tag_object *)item);
149 		break;
150 	default:
151 		return got_error(GOT_ERR_OBJ_TYPE);
152 	}
153 
154 	if (size > GOT_OBJECT_CACHE_MAX_ELEM_SIZE) {
155 #ifdef GOT_OBJ_CACHE_DEBUG
156 		char *id_str;
157 		if (got_object_id_str(&id_str, id) != NULL)
158 			return got_error_from_errno("got_object_id_str");
159 		fprintf(stderr, "%s: not caching ", getprogname());
160 		switch (cache->type) {
161 		case GOT_OBJECT_CACHE_TYPE_OBJ:
162 			fprintf(stderr, "object");
163 			break;
164 		case GOT_OBJECT_CACHE_TYPE_TREE:
165 			fprintf(stderr, "tree");
166 			break;
167 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
168 			fprintf(stderr, "commit");
169 			break;
170 		case GOT_OBJECT_CACHE_TYPE_TAG:
171 			fprintf(stderr, "tag");
172 			break;
173 		}
174 		fprintf(stderr, " %s (%zd bytes; %zd MB)\n", id_str, size,
175 		    size/1024/1024);
176 		free(id_str);
177 #endif
178 		cache->cache_toolarge++;
179 		return got_error(GOT_ERR_OBJ_TOO_LARGE);
180 	}
181 
182 	nelem = got_object_idset_num_elements(cache->idset);
183 	if (nelem >= cache->size) {
184 		err = got_object_idset_remove((void **)&ce,
185 		    cache->idset, NULL);
186 		if (err)
187 			return err;
188 		switch (cache->type) {
189 		case GOT_OBJECT_CACHE_TYPE_OBJ:
190 			got_object_close(ce->data.obj);
191 			break;
192 		case GOT_OBJECT_CACHE_TYPE_TREE:
193 			got_object_tree_close(ce->data.tree);
194 			break;
195 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
196 			got_object_commit_close(ce->data.commit);
197 			break;
198 		case GOT_OBJECT_CACHE_TYPE_TAG:
199 			got_object_tag_close(ce->data.tag);
200 			break;
201 		}
202 		free(ce);
203 		cache->cache_evict++;
204 	}
205 
206 	ce = malloc(sizeof(*ce));
207 	if (ce == NULL)
208 		return got_error_from_errno("malloc");
209 	memcpy(&ce->id, id, sizeof(ce->id));
210 	switch (cache->type) {
211 	case GOT_OBJECT_CACHE_TYPE_OBJ:
212 		ce->data.obj = (struct got_object *)item;
213 		break;
214 	case GOT_OBJECT_CACHE_TYPE_TREE:
215 		ce->data.tree = (struct got_tree_object *)item;
216 		break;
217 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
218 		ce->data.commit = (struct got_commit_object *)item;
219 		break;
220 	case GOT_OBJECT_CACHE_TYPE_TAG:
221 		ce->data.tag = (struct got_tag_object *)item;
222 		break;
223 	}
224 
225 	err = got_object_idset_add(cache->idset, id, ce);
226 	if (err)
227 		free(ce);
228 	return err;
229 }
230 
231 void *
232 got_object_cache_get(struct got_object_cache *cache, struct got_object_id *id)
233 {
234 	struct got_object_cache_entry *ce;
235 
236 	cache->cache_searches++;
237 	ce = got_object_idset_get(cache->idset, id);
238 	if (ce) {
239 		cache->cache_hit++;
240 		switch (cache->type) {
241 		case GOT_OBJECT_CACHE_TYPE_OBJ:
242 			return ce->data.obj;
243 		case GOT_OBJECT_CACHE_TYPE_TREE:
244 			return ce->data.tree;
245 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
246 			return ce->data.commit;
247 		case GOT_OBJECT_CACHE_TYPE_TAG:
248 			return ce->data.tag;
249 		}
250 	}
251 
252 	cache->cache_miss++;
253 	return NULL;
254 }
255 
256 #ifdef GOT_OBJ_CACHE_DEBUG
257 static void
258 print_cache_stats(struct got_object_cache *cache, const char *name)
259 {
260 	fprintf(stderr, "%s: %s cache: %d elements, %d searches, %d hits, "
261 	    "%d missed, %d evicted, %d too large\n", getprogname(), name,
262 	    got_object_idset_num_elements(cache->idset),
263 	    cache->cache_searches, cache->cache_hit,
264 	    cache->cache_miss, cache->cache_evict, cache->cache_toolarge);
265 }
266 
267 const struct got_error *
268 check_refcount(struct got_object_id *id, void *data, void *arg)
269 {
270 	struct got_object_cache *cache = arg;
271 	struct got_object_cache_entry *ce = data;
272 	struct got_object *obj;
273 	struct got_tree_object *tree;
274 	struct got_commit_object *commit;
275 	struct got_tag_object *tag;
276 	char *id_str;
277 
278 	if (got_object_id_str(&id_str, id) != NULL)
279 		return NULL;
280 
281 	switch (cache->type) {
282 	case GOT_OBJECT_CACHE_TYPE_OBJ:
283 		obj = ce->data.obj;
284 		if (obj->refcnt == 1)
285 			break;
286 		fprintf(stderr, "object %s has %d unclaimed references\n",
287 		    id_str, obj->refcnt - 1);
288 		break;
289 	case GOT_OBJECT_CACHE_TYPE_TREE:
290 		tree = ce->data.tree;
291 		if (tree->refcnt == 1)
292 			break;
293 		fprintf(stderr, "tree %s has %d unclaimed references\n",
294 		    id_str, tree->refcnt - 1);
295 		break;
296 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
297 		commit = ce->data.commit;
298 		if (commit->refcnt == 1)
299 			break;
300 		fprintf(stderr, "commit %s has %d unclaimed references\n",
301 		    id_str, commit->refcnt - 1);
302 		break;
303 	case GOT_OBJECT_CACHE_TYPE_TAG:
304 		tag = ce->data.tag;
305 		if (tag->refcnt == 1)
306 			break;
307 		fprintf(stderr, "tag %s has %d unclaimed references\n",
308 		    id_str, tag->refcnt - 1);
309 		break;
310 	}
311 	free(id_str);
312 	return NULL;
313 }
314 #endif
315 
316 void
317 got_object_cache_close(struct got_object_cache *cache)
318 {
319 #ifdef GOT_OBJ_CACHE_DEBUG
320 	switch (cache->type) {
321 	case GOT_OBJECT_CACHE_TYPE_OBJ:
322 		print_cache_stats(cache, "object");
323 		break;
324 	case GOT_OBJECT_CACHE_TYPE_TREE:
325 		print_cache_stats(cache, "tree");
326 		break;
327 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
328 		print_cache_stats(cache, "commit");
329 		break;
330 	case GOT_OBJECT_CACHE_TYPE_TAG:
331 		print_cache_stats(cache, "tag");
332 		break;
333 	}
334 
335 	got_object_idset_for_each(cache->idset, check_refcount, cache);
336 #endif
337 
338 	if (cache->idset) {
339 		got_object_idset_free(cache->idset);
340 		cache->idset = NULL;
341 	}
342 	cache->size = 0;
343 }