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 <sha1.h>
27 #include <zlib.h>
28 
29 #include "got_error.h"
30 #include "got_object.h"
31 
32 #include "got_lib_delta.h"
33 #include "got_lib_inflate.h"
34 #include "got_lib_object.h"
35 #include "got_lib_object_idset.h"
36 #include "got_lib_object_cache.h"
37 
38 /*
39  * XXX This should be reworked to track cache size and usage in bytes,
40  * rather than tracking N elements capped to a maximum element size.
41  */
42 #define GOT_OBJECT_CACHE_SIZE_OBJ	256
43 #define GOT_OBJECT_CACHE_SIZE_TREE	256
44 #define GOT_OBJECT_CACHE_SIZE_COMMIT	64
45 #define GOT_OBJECT_CACHE_SIZE_TAG	2048
46 #define GOT_OBJECT_CACHE_SIZE_RAW	64
47 #define GOT_OBJECT_CACHE_MAX_ELEM_SIZE	1048576	/* 1 MB */
48 
49 const struct got_error *
50 got_object_cache_init(struct got_object_cache *cache,
51     enum got_object_cache_type type)
52 {
53 	struct rlimit rl;
54 
55 	memset(cache, 0, sizeof(*cache));
56 
57 	cache->idset = got_object_idset_alloc();
58 	if (cache->idset == NULL)
59 		return got_error_from_errno("got_object_idset_alloc");
60 
61 	cache->type = type;
62 	switch (type) {
63 	case GOT_OBJECT_CACHE_TYPE_OBJ:
64 		cache->size = GOT_OBJECT_CACHE_SIZE_OBJ;
65 		break;
66 	case GOT_OBJECT_CACHE_TYPE_TREE:
67 		cache->size = GOT_OBJECT_CACHE_SIZE_TREE;
68 		break;
69 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
70 		cache->size = GOT_OBJECT_CACHE_SIZE_COMMIT;
71 		break;
72 	case GOT_OBJECT_CACHE_TYPE_TAG:
73 		cache->size = GOT_OBJECT_CACHE_SIZE_TAG;
74 		break;
75 	case GOT_OBJECT_CACHE_TYPE_RAW:
76 		if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
77 			return got_error_from_errno("getrlimit");
78 		cache->size = GOT_OBJECT_CACHE_SIZE_RAW;
79 		if (cache->size > rl.rlim_cur / 16)
80 			cache->size = rl.rlim_cur / 16;
81 		break;
82 	}
83 	return NULL;
84 }
85 
86 static size_t
87 get_size_obj(struct got_object *obj)
88 {
89 	size_t size = sizeof(*obj);
90 	struct got_delta *delta;
91 
92 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
93 		return size;
94 
95 	STAILQ_FOREACH(delta, &obj->deltas.entries, entry) {
96 		if (SIZE_MAX - sizeof(*delta) < size)
97 			return SIZE_MAX;
98 		size += sizeof(*delta);
99 	}
100 
101 	return size;
102 }
103 
104 static size_t
105 get_size_tree(struct got_tree_object *tree)
106 {
107 	size_t size = sizeof(*tree);
108 
109 	size += sizeof(struct got_tree_entry) * tree->nentries;
110 	return size;
111 }
112 
113 static size_t
114 get_size_commit(struct got_commit_object *commit)
115 {
116 	size_t size = sizeof(*commit);
117 	struct got_object_qid *qid;
118 
119 	size += sizeof(*commit->tree_id);
120 	size += strlen(commit->author);
121 	size += strlen(commit->committer);
122 	size += strlen(commit->logmsg);
123 
124 	STAILQ_FOREACH(qid, &commit->parent_ids, entry)
125 		size += sizeof(*qid) + sizeof(qid->id);
126 
127 	return size;
128 }
129 
130 static size_t
131 get_size_tag(struct got_tag_object *tag)
132 {
133 	size_t size = sizeof(*tag);
134 
135 	size += strlen(tag->tag);
136 	size += strlen(tag->tagger);
137 	size += strlen(tag->tagmsg);
138 
139 	return size;
140 }
141 
142 static size_t
143 get_size_raw(struct got_raw_object *raw)
144 {
145 	return sizeof(*raw);
146 }
147 
148 const struct got_error *
149 got_object_cache_add(struct got_object_cache *cache, struct got_object_id *id,
150     void *item)
151 {
152 	const struct got_error *err = NULL;
153 	struct got_object_cache_entry *ce;
154 	int nelem;
155 	size_t size;
156 
157 	switch (cache->type) {
158 	case GOT_OBJECT_CACHE_TYPE_OBJ:
159 		size = get_size_obj((struct got_object *)item);
160 		break;
161 	case GOT_OBJECT_CACHE_TYPE_TREE:
162 		size = get_size_tree((struct got_tree_object *)item);
163 		break;
164 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
165 		size = get_size_commit((struct got_commit_object *)item);
166 		break;
167 	case GOT_OBJECT_CACHE_TYPE_TAG:
168 		size = get_size_tag((struct got_tag_object *)item);
169 		break;
170 	case GOT_OBJECT_CACHE_TYPE_RAW:
171 		size = get_size_raw((struct got_raw_object *)item);
172 		break;
173 	default:
174 		return got_error(GOT_ERR_OBJ_TYPE);
175 	}
176 
177 	if (size > GOT_OBJECT_CACHE_MAX_ELEM_SIZE) {
178 #ifdef GOT_OBJ_CACHE_DEBUG
179 		char *id_str;
180 		if (got_object_id_str(&id_str, id) != NULL)
181 			return got_error_from_errno("got_object_id_str");
182 		fprintf(stderr, "%s: not caching ", getprogname());
183 		switch (cache->type) {
184 		case GOT_OBJECT_CACHE_TYPE_OBJ:
185 			fprintf(stderr, "object");
186 			break;
187 		case GOT_OBJECT_CACHE_TYPE_TREE:
188 			fprintf(stderr, "tree");
189 			break;
190 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
191 			fprintf(stderr, "commit");
192 			break;
193 		case GOT_OBJECT_CACHE_TYPE_TAG:
194 			fprintf(stderr, "tag");
195 			break;
196 		case GOT_OBJECT_CACHE_TYPE_RAW:
197 			fprintf(stderr, "raw");
198 			break;
199 		}
200 		fprintf(stderr, " %s (%zd bytes; %zd MB)\n", id_str, size,
201 		    size/1024/1024);
202 		free(id_str);
203 #endif
204 		cache->cache_toolarge++;
205 		return got_error(GOT_ERR_OBJ_TOO_LARGE);
206 	}
207 
208 	nelem = got_object_idset_num_elements(cache->idset);
209 	if (nelem >= cache->size) {
210 		err = got_object_idset_remove((void **)&ce,
211 		    cache->idset, NULL);
212 		if (err)
213 			return err;
214 		switch (cache->type) {
215 		case GOT_OBJECT_CACHE_TYPE_OBJ:
216 			got_object_close(ce->data.obj);
217 			break;
218 		case GOT_OBJECT_CACHE_TYPE_TREE:
219 			got_object_tree_close(ce->data.tree);
220 			break;
221 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
222 			got_object_commit_close(ce->data.commit);
223 			break;
224 		case GOT_OBJECT_CACHE_TYPE_TAG:
225 			got_object_tag_close(ce->data.tag);
226 			break;
227 		case GOT_OBJECT_CACHE_TYPE_RAW:
228 			got_object_raw_close(ce->data.raw);
229 			break;
230 		}
231 		free(ce);
232 		cache->cache_evict++;
233 	}
234 
235 	ce = malloc(sizeof(*ce));
236 	if (ce == NULL)
237 		return got_error_from_errno("malloc");
238 	memcpy(&ce->id, id, sizeof(ce->id));
239 	switch (cache->type) {
240 	case GOT_OBJECT_CACHE_TYPE_OBJ:
241 		ce->data.obj = (struct got_object *)item;
242 		break;
243 	case GOT_OBJECT_CACHE_TYPE_TREE:
244 		ce->data.tree = (struct got_tree_object *)item;
245 		break;
246 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
247 		ce->data.commit = (struct got_commit_object *)item;
248 		break;
249 	case GOT_OBJECT_CACHE_TYPE_TAG:
250 		ce->data.tag = (struct got_tag_object *)item;
251 		break;
252 	case GOT_OBJECT_CACHE_TYPE_RAW:
253 		ce->data.raw = (struct got_raw_object *)item;
254 		break;
255 	}
256 
257 	err = got_object_idset_add(cache->idset, id, ce);
258 	if (err)
259 		free(ce);
260 	return err;
261 }
262 
263 void *
264 got_object_cache_get(struct got_object_cache *cache, struct got_object_id *id)
265 {
266 	struct got_object_cache_entry *ce;
267 
268 	cache->cache_searches++;
269 	ce = got_object_idset_get(cache->idset, id);
270 	if (ce) {
271 		cache->cache_hit++;
272 		switch (cache->type) {
273 		case GOT_OBJECT_CACHE_TYPE_OBJ:
274 			return ce->data.obj;
275 		case GOT_OBJECT_CACHE_TYPE_TREE:
276 			return ce->data.tree;
277 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
278 			return ce->data.commit;
279 		case GOT_OBJECT_CACHE_TYPE_TAG:
280 			return ce->data.tag;
281 		case GOT_OBJECT_CACHE_TYPE_RAW:
282 			return ce->data.raw;
283 		}
284 	}
285 
286 	cache->cache_miss++;
287 	return NULL;
288 }
289 
290 #ifdef GOT_OBJ_CACHE_DEBUG
291 static void
292 print_cache_stats(struct got_object_cache *cache, const char *name)
293 {
294 	fprintf(stderr, "%s: %s cache: %d elements, %d searches, %d hits, "
295 	    "%d missed, %d evicted, %d too large\n", getprogname(), name,
296 	    got_object_idset_num_elements(cache->idset),
297 	    cache->cache_searches, cache->cache_hit,
298 	    cache->cache_miss, cache->cache_evict, cache->cache_toolarge);
299 }
300 
301 const struct got_error *
302 check_refcount(struct got_object_id *id, void *data, void *arg)
303 {
304 	struct got_object_cache *cache = arg;
305 	struct got_object_cache_entry *ce = data;
306 	struct got_object *obj;
307 	struct got_tree_object *tree;
308 	struct got_commit_object *commit;
309 	struct got_tag_object *tag;
310 	struct got_raw_object *raw;
311 	char *id_str;
312 
313 	if (got_object_id_str(&id_str, id) != NULL)
314 		return NULL;
315 
316 	switch (cache->type) {
317 	case GOT_OBJECT_CACHE_TYPE_OBJ:
318 		obj = ce->data.obj;
319 		if (obj->refcnt == 1)
320 			break;
321 		fprintf(stderr, "object %s has %d unclaimed references\n",
322 		    id_str, obj->refcnt - 1);
323 		break;
324 	case GOT_OBJECT_CACHE_TYPE_TREE:
325 		tree = ce->data.tree;
326 		if (tree->refcnt == 1)
327 			break;
328 		fprintf(stderr, "tree %s has %d unclaimed references\n",
329 		    id_str, tree->refcnt - 1);
330 		break;
331 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
332 		commit = ce->data.commit;
333 		if (commit->refcnt == 1)
334 			break;
335 		fprintf(stderr, "commit %s has %d unclaimed references\n",
336 		    id_str, commit->refcnt - 1);
337 		break;
338 	case GOT_OBJECT_CACHE_TYPE_TAG:
339 		tag = ce->data.tag;
340 		if (tag->refcnt == 1)
341 			break;
342 		fprintf(stderr, "tag %s has %d unclaimed references\n",
343 		    id_str, tag->refcnt - 1);
344 		break;
345 	case GOT_OBJECT_CACHE_TYPE_RAW:
346 		raw = ce->data.raw;
347 		if (raw->refcnt == 1)
348 			break;
349 		fprintf(stderr, "raw %s has %d unclaimed references\n",
350 		    id_str, raw->refcnt - 1);
351 		break;
352 	}
353 	free(id_str);
354 	return NULL;
355 }
356 #endif
357 
358 void
359 got_object_cache_close(struct got_object_cache *cache)
360 {
361 #ifdef GOT_OBJ_CACHE_DEBUG
362 	switch (cache->type) {
363 	case GOT_OBJECT_CACHE_TYPE_OBJ:
364 		print_cache_stats(cache, "object");
365 		break;
366 	case GOT_OBJECT_CACHE_TYPE_TREE:
367 		print_cache_stats(cache, "tree");
368 		break;
369 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
370 		print_cache_stats(cache, "commit");
371 		break;
372 	case GOT_OBJECT_CACHE_TYPE_TAG:
373 		print_cache_stats(cache, "tag");
374 		break;
375 	case GOT_OBJECT_CACHE_TYPE_RAW:
376 		print_cache_stats(cache, "raw");
377 		break;
378 	}
379 
380 	got_object_idset_for_each(cache->idset, check_refcount, cache);
381 #endif
382 
383 	if (cache->idset) {
384 		got_object_idset_free(cache->idset);
385 		cache->idset = NULL;
386 	}
387 	cache->size = 0;
388 }