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 #include <sys/resource.h>
20 
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <stdint.h>
24 #include <string.h>
25 #include <limits.h>
26 #include <zlib.h>
27 
28 #include "got_error.h"
29 #include "got_object.h"
30 
31 #include "got_lib_delta.h"
32 #include "got_lib_inflate.h"
33 #include "got_lib_object.h"
34 #include "got_lib_object_idset.h"
35 #include "got_lib_object_cache.h"
36 
37 /*
38  * XXX This should be reworked to track cache size and usage in bytes,
39  * rather than tracking N elements capped to a maximum element size.
40  */
41 #define GOT_OBJECT_CACHE_SIZE_OBJ	256
42 #define GOT_OBJECT_CACHE_SIZE_TREE	256
43 #define GOT_OBJECT_CACHE_SIZE_COMMIT	64
44 #define GOT_OBJECT_CACHE_SIZE_TAG	2048
45 #define GOT_OBJECT_CACHE_SIZE_RAW	64
46 #define GOT_OBJECT_CACHE_MAX_ELEM_SIZE	1048576	/* 1 MB */
47 
48 const struct got_error *
49 got_object_cache_init(struct got_object_cache *cache,
50     enum got_object_cache_type type)
51 {
52 	struct rlimit rl;
53 
54 	memset(cache, 0, sizeof(*cache));
55 
56 	cache->idset = got_object_idset_alloc();
57 	if (cache->idset == NULL)
58 		return got_error_from_errno("got_object_idset_alloc");
59 
60 	cache->type = type;
61 	switch (type) {
62 	case GOT_OBJECT_CACHE_TYPE_OBJ:
63 		cache->size = GOT_OBJECT_CACHE_SIZE_OBJ;
64 		break;
65 	case GOT_OBJECT_CACHE_TYPE_TREE:
66 		cache->size = GOT_OBJECT_CACHE_SIZE_TREE;
67 		break;
68 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
69 		cache->size = GOT_OBJECT_CACHE_SIZE_COMMIT;
70 		break;
71 	case GOT_OBJECT_CACHE_TYPE_TAG:
72 		cache->size = GOT_OBJECT_CACHE_SIZE_TAG;
73 		break;
74 	case GOT_OBJECT_CACHE_TYPE_RAW:
75 		if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
76 			return got_error_from_errno("getrlimit");
77 		cache->size = GOT_OBJECT_CACHE_SIZE_RAW;
78 		if (cache->size > rl.rlim_cur / 16)
79 			cache->size = rl.rlim_cur / 16;
80 		break;
81 	}
82 	return NULL;
83 }
84 
85 static size_t
86 get_size_obj(struct got_object *obj)
87 {
88 	size_t size = sizeof(*obj);
89 	struct got_delta *delta;
90 
91 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
92 		return size;
93 
94 	STAILQ_FOREACH(delta, &obj->deltas.entries, entry) {
95 		if (SIZE_MAX - sizeof(*delta) < size)
96 			return SIZE_MAX;
97 		size += sizeof(*delta);
98 	}
99 
100 	return size;
101 }
102 
103 static size_t
104 get_size_tree(struct got_tree_object *tree)
105 {
106 	size_t size = sizeof(*tree);
107 
108 	size += sizeof(struct got_tree_entry) * tree->nentries;
109 	return size;
110 }
111 
112 static size_t
113 get_size_commit(struct got_commit_object *commit)
114 {
115 	size_t size = sizeof(*commit);
116 	struct got_object_qid *qid;
117 
118 	size += sizeof(*commit->tree_id);
119 	size += strlen(commit->author);
120 	size += strlen(commit->committer);
121 	size += strlen(commit->logmsg);
122 
123 	STAILQ_FOREACH(qid, &commit->parent_ids, entry)
124 		size += sizeof(*qid) + sizeof(qid->id);
125 
126 	return size;
127 }
128 
129 static size_t
130 get_size_tag(struct got_tag_object *tag)
131 {
132 	size_t size = sizeof(*tag);
133 
134 	size += strlen(tag->tag);
135 	size += strlen(tag->tagger);
136 	size += strlen(tag->tagmsg);
137 
138 	return size;
139 }
140 
141 static size_t
142 get_size_raw(struct got_raw_object *raw)
143 {
144 	return sizeof(*raw);
145 }
146 
147 const struct got_error *
148 got_object_cache_add(struct got_object_cache *cache, struct got_object_id *id,
149     void *item)
150 {
151 	const struct got_error *err = NULL;
152 	struct got_object_cache_entry *ce;
153 	int nelem;
154 	size_t size;
155 
156 	switch (cache->type) {
157 	case GOT_OBJECT_CACHE_TYPE_OBJ:
158 		size = get_size_obj((struct got_object *)item);
159 		break;
160 	case GOT_OBJECT_CACHE_TYPE_TREE:
161 		size = get_size_tree((struct got_tree_object *)item);
162 		break;
163 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
164 		size = get_size_commit((struct got_commit_object *)item);
165 		break;
166 	case GOT_OBJECT_CACHE_TYPE_TAG:
167 		size = get_size_tag((struct got_tag_object *)item);
168 		break;
169 	case GOT_OBJECT_CACHE_TYPE_RAW:
170 		size = get_size_raw((struct got_raw_object *)item);
171 		break;
172 	default:
173 		return got_error(GOT_ERR_OBJ_TYPE);
174 	}
175 
176 	if (size > GOT_OBJECT_CACHE_MAX_ELEM_SIZE) {
177 #ifdef GOT_OBJ_CACHE_DEBUG
178 		char *id_str;
179 		if (got_object_id_str(&id_str, id) != NULL)
180 			return got_error_from_errno("got_object_id_str");
181 		fprintf(stderr, "%s: not caching ", getprogname());
182 		switch (cache->type) {
183 		case GOT_OBJECT_CACHE_TYPE_OBJ:
184 			fprintf(stderr, "object");
185 			break;
186 		case GOT_OBJECT_CACHE_TYPE_TREE:
187 			fprintf(stderr, "tree");
188 			break;
189 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
190 			fprintf(stderr, "commit");
191 			break;
192 		case GOT_OBJECT_CACHE_TYPE_TAG:
193 			fprintf(stderr, "tag");
194 			break;
195 		case GOT_OBJECT_CACHE_TYPE_RAW:
196 			fprintf(stderr, "raw");
197 			break;
198 		}
199 		fprintf(stderr, " %s (%zd bytes; %zd MB)\n", id_str, size,
200 		    size/1024/1024);
201 		free(id_str);
202 #endif
203 		cache->cache_toolarge++;
204 		return got_error(GOT_ERR_OBJ_TOO_LARGE);
205 	}
206 
207 	nelem = got_object_idset_num_elements(cache->idset);
208 	if (nelem >= cache->size) {
209 		err = got_object_idset_remove((void **)&ce,
210 		    cache->idset, NULL);
211 		if (err)
212 			return err;
213 		switch (cache->type) {
214 		case GOT_OBJECT_CACHE_TYPE_OBJ:
215 			got_object_close(ce->data.obj);
216 			break;
217 		case GOT_OBJECT_CACHE_TYPE_TREE:
218 			got_object_tree_close(ce->data.tree);
219 			break;
220 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
221 			got_object_commit_close(ce->data.commit);
222 			break;
223 		case GOT_OBJECT_CACHE_TYPE_TAG:
224 			got_object_tag_close(ce->data.tag);
225 			break;
226 		case GOT_OBJECT_CACHE_TYPE_RAW:
227 			got_object_raw_close(ce->data.raw);
228 			break;
229 		}
230 		free(ce);
231 		cache->cache_evict++;
232 	}
233 
234 	ce = malloc(sizeof(*ce));
235 	if (ce == NULL)
236 		return got_error_from_errno("malloc");
237 	memcpy(&ce->id, id, sizeof(ce->id));
238 	switch (cache->type) {
239 	case GOT_OBJECT_CACHE_TYPE_OBJ:
240 		ce->data.obj = (struct got_object *)item;
241 		break;
242 	case GOT_OBJECT_CACHE_TYPE_TREE:
243 		ce->data.tree = (struct got_tree_object *)item;
244 		break;
245 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
246 		ce->data.commit = (struct got_commit_object *)item;
247 		break;
248 	case GOT_OBJECT_CACHE_TYPE_TAG:
249 		ce->data.tag = (struct got_tag_object *)item;
250 		break;
251 	case GOT_OBJECT_CACHE_TYPE_RAW:
252 		ce->data.raw = (struct got_raw_object *)item;
253 		break;
254 	}
255 
256 	err = got_object_idset_add(cache->idset, id, ce);
257 	if (err)
258 		free(ce);
259 	return err;
260 }
261 
262 void *
263 got_object_cache_get(struct got_object_cache *cache, struct got_object_id *id)
264 {
265 	struct got_object_cache_entry *ce;
266 
267 	cache->cache_searches++;
268 	ce = got_object_idset_get(cache->idset, id);
269 	if (ce) {
270 		cache->cache_hit++;
271 		switch (cache->type) {
272 		case GOT_OBJECT_CACHE_TYPE_OBJ:
273 			return ce->data.obj;
274 		case GOT_OBJECT_CACHE_TYPE_TREE:
275 			return ce->data.tree;
276 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
277 			return ce->data.commit;
278 		case GOT_OBJECT_CACHE_TYPE_TAG:
279 			return ce->data.tag;
280 		case GOT_OBJECT_CACHE_TYPE_RAW:
281 			return ce->data.raw;
282 		}
283 	}
284 
285 	cache->cache_miss++;
286 	return NULL;
287 }
288 
289 #ifdef GOT_OBJ_CACHE_DEBUG
290 static void
291 print_cache_stats(struct got_object_cache *cache, const char *name)
292 {
293 	fprintf(stderr, "%s: %s cache: %d elements, %d searches, %d hits, "
294 	    "%d missed, %d evicted, %d too large\n", getprogname(), name,
295 	    got_object_idset_num_elements(cache->idset),
296 	    cache->cache_searches, cache->cache_hit,
297 	    cache->cache_miss, cache->cache_evict, cache->cache_toolarge);
298 }
299 
300 const struct got_error *
301 check_refcount(struct got_object_id *id, void *data, void *arg)
302 {
303 	struct got_object_cache *cache = arg;
304 	struct got_object_cache_entry *ce = data;
305 	struct got_object *obj;
306 	struct got_tree_object *tree;
307 	struct got_commit_object *commit;
308 	struct got_tag_object *tag;
309 	struct got_raw_object *raw;
310 	char *id_str;
311 
312 	if (got_object_id_str(&id_str, id) != NULL)
313 		return NULL;
314 
315 	switch (cache->type) {
316 	case GOT_OBJECT_CACHE_TYPE_OBJ:
317 		obj = ce->data.obj;
318 		if (obj->refcnt == 1)
319 			break;
320 		fprintf(stderr, "object %s has %d unclaimed references\n",
321 		    id_str, obj->refcnt - 1);
322 		break;
323 	case GOT_OBJECT_CACHE_TYPE_TREE:
324 		tree = ce->data.tree;
325 		if (tree->refcnt == 1)
326 			break;
327 		fprintf(stderr, "tree %s has %d unclaimed references\n",
328 		    id_str, tree->refcnt - 1);
329 		break;
330 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
331 		commit = ce->data.commit;
332 		if (commit->refcnt == 1)
333 			break;
334 		fprintf(stderr, "commit %s has %d unclaimed references\n",
335 		    id_str, commit->refcnt - 1);
336 		break;
337 	case GOT_OBJECT_CACHE_TYPE_TAG:
338 		tag = ce->data.tag;
339 		if (tag->refcnt == 1)
340 			break;
341 		fprintf(stderr, "tag %s has %d unclaimed references\n",
342 		    id_str, tag->refcnt - 1);
343 		break;
344 	case GOT_OBJECT_CACHE_TYPE_RAW:
345 		raw = ce->data.raw;
346 		if (raw->refcnt == 1)
347 			break;
348 		fprintf(stderr, "raw %s has %d unclaimed references\n",
349 		    id_str, raw->refcnt - 1);
350 		break;
351 	}
352 	free(id_str);
353 	return NULL;
354 }
355 #endif
356 
357 void
358 got_object_cache_close(struct got_object_cache *cache)
359 {
360 #ifdef GOT_OBJ_CACHE_DEBUG
361 	switch (cache->type) {
362 	case GOT_OBJECT_CACHE_TYPE_OBJ:
363 		print_cache_stats(cache, "object");
364 		break;
365 	case GOT_OBJECT_CACHE_TYPE_TREE:
366 		print_cache_stats(cache, "tree");
367 		break;
368 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
369 		print_cache_stats(cache, "commit");
370 		break;
371 	case GOT_OBJECT_CACHE_TYPE_TAG:
372 		print_cache_stats(cache, "tag");
373 		break;
374 	case GOT_OBJECT_CACHE_TYPE_RAW:
375 		print_cache_stats(cache, "raw");
376 		break;
377 	}
378 
379 	got_object_idset_for_each(cache->idset, check_refcount, cache);
380 #endif
381 
382 	if (cache->idset) {
383 		got_object_idset_free(cache->idset);
384 		cache->idset = NULL;
385 	}
386 	cache->size = 0;
387 }