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 <sha1.h>
25 #include <zlib.h>
26 
27 #include "got_error.h"
28 #include "got_object.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 #include "got_lib_object_cache.h"
35 
36 /*
37  * XXX This should be reworked to track cache size and usage in bytes,
38  * rather than tracking N elements capped to a maximum element size.
39  */
40 #define GOT_OBJECT_CACHE_SIZE_OBJ	256
41 #define GOT_OBJECT_CACHE_SIZE_TREE	256
42 #define GOT_OBJECT_CACHE_SIZE_COMMIT	64
43 #define GOT_OBJECT_CACHE_SIZE_TAG	2048
44 #define GOT_OBJECT_CACHE_MAX_ELEM_SIZE	1048576	/* 1 MB */
45 
46 const struct got_error *
47 got_object_cache_init(struct got_object_cache *cache,
48     enum got_object_cache_type type)
49 {
50 	memset(cache, 0, sizeof(*cache));
51 
52 	cache->idset = got_object_idset_alloc();
53 	if (cache->idset == NULL)
54 		return got_error_from_errno("got_object_idset_alloc");
55 
56 	cache->type = type;
57 	switch (type) {
58 	case GOT_OBJECT_CACHE_TYPE_OBJ:
59 		cache->size = GOT_OBJECT_CACHE_SIZE_OBJ;
60 		break;
61 	case GOT_OBJECT_CACHE_TYPE_TREE:
62 		cache->size = GOT_OBJECT_CACHE_SIZE_TREE;
63 		break;
64 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
65 		cache->size = GOT_OBJECT_CACHE_SIZE_COMMIT;
66 		break;
67 	case GOT_OBJECT_CACHE_TYPE_TAG:
68 		cache->size = GOT_OBJECT_CACHE_SIZE_TAG;
69 		break;
70 	}
71 	return NULL;
72 }
73 
74 size_t
75 get_size_obj(struct got_object *obj)
76 {
77 	size_t size = sizeof(*obj);
78 	struct got_delta *delta;
79 
80 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
81 		return size;
82 
83 	STAILQ_FOREACH(delta, &obj->deltas.entries, entry) {
84 		if (SIZE_MAX - sizeof(*delta) < size)
85 			return SIZE_MAX;
86 		size += sizeof(*delta);
87 	}
88 
89 	return size;
90 }
91 
92 size_t
93 get_size_tree(struct got_tree_object *tree)
94 {
95 	size_t size = sizeof(*tree);
96 
97 	size += sizeof(struct got_tree_entry) * tree->nentries;
98 	return size;
99 }
100 
101 size_t
102 get_size_commit(struct got_commit_object *commit)
103 {
104 	size_t size = sizeof(*commit);
105 	struct got_object_qid *qid;
106 
107 	size += sizeof(*commit->tree_id);
108 	size += strlen(commit->author);
109 	size += strlen(commit->committer);
110 	size += strlen(commit->logmsg);
111 
112 	STAILQ_FOREACH(qid, &commit->parent_ids, entry)
113 		size += sizeof(*qid) + sizeof(*qid->id);
114 
115 	return size;
116 }
117 
118 size_t
119 get_size_tag(struct got_tag_object *tag)
120 {
121 	size_t size = sizeof(*tag);
122 
123 	size += strlen(tag->tag);
124 	size += strlen(tag->tagger);
125 	size += strlen(tag->tagmsg);
126 
127 	return size;
128 }
129 
130 const struct got_error *
131 got_object_cache_add(struct got_object_cache *cache, struct got_object_id *id, void *item)
132 {
133 	const struct got_error *err = NULL;
134 	struct got_object_cache_entry *ce;
135 	int nelem;
136 	size_t size;
137 
138 	switch (cache->type) {
139 	case GOT_OBJECT_CACHE_TYPE_OBJ:
140 		size = get_size_obj((struct got_object *)item);
141 		break;
142 	case GOT_OBJECT_CACHE_TYPE_TREE:
143 		size = get_size_tree((struct got_tree_object *)item);
144 		break;
145 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
146 		size = get_size_commit((struct got_commit_object *)item);
147 		break;
148 	case GOT_OBJECT_CACHE_TYPE_TAG:
149 		size = get_size_tag((struct got_tag_object *)item);
150 		break;
151 	default:
152 		return got_error(GOT_ERR_OBJ_TYPE);
153 	}
154 
155 	if (size > GOT_OBJECT_CACHE_MAX_ELEM_SIZE) {
156 #ifdef GOT_OBJ_CACHE_DEBUG
157 		char *id_str;
158 		if (got_object_id_str(&id_str, id) != NULL)
159 			return got_error_from_errno("got_object_id_str");
160 		fprintf(stderr, "%s: not caching ", getprogname());
161 		switch (cache->type) {
162 		case GOT_OBJECT_CACHE_TYPE_OBJ:
163 			fprintf(stderr, "object");
164 			break;
165 		case GOT_OBJECT_CACHE_TYPE_TREE:
166 			fprintf(stderr, "tree");
167 			break;
168 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
169 			fprintf(stderr, "commit");
170 			break;
171 		case GOT_OBJECT_CACHE_TYPE_TAG:
172 			fprintf(stderr, "tag");
173 			break;
174 		}
175 		fprintf(stderr, " %s (%zd bytes; %zd MB)\n", id_str, size,
176 		    size/1024/1024);
177 		free(id_str);
178 #endif
179 		cache->cache_toolarge++;
180 		return got_error(GOT_ERR_OBJ_TOO_LARGE);
181 	}
182 
183 	nelem = got_object_idset_num_elements(cache->idset);
184 	if (nelem >= cache->size) {
185 		err = got_object_idset_remove((void **)&ce,
186 		    cache->idset, NULL);
187 		if (err)
188 			return err;
189 		switch (cache->type) {
190 		case GOT_OBJECT_CACHE_TYPE_OBJ:
191 			got_object_close(ce->data.obj);
192 			break;
193 		case GOT_OBJECT_CACHE_TYPE_TREE:
194 			got_object_tree_close(ce->data.tree);
195 			break;
196 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
197 			got_object_commit_close(ce->data.commit);
198 			break;
199 		case GOT_OBJECT_CACHE_TYPE_TAG:
200 			got_object_tag_close(ce->data.tag);
201 			break;
202 		}
203 		free(ce);
204 		cache->cache_evict++;
205 	}
206 
207 	ce = malloc(sizeof(*ce));
208 	if (ce == NULL)
209 		return got_error_from_errno("malloc");
210 	memcpy(&ce->id, id, sizeof(ce->id));
211 	switch (cache->type) {
212 	case GOT_OBJECT_CACHE_TYPE_OBJ:
213 		ce->data.obj = (struct got_object *)item;
214 		break;
215 	case GOT_OBJECT_CACHE_TYPE_TREE:
216 		ce->data.tree = (struct got_tree_object *)item;
217 		break;
218 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
219 		ce->data.commit = (struct got_commit_object *)item;
220 		break;
221 	case GOT_OBJECT_CACHE_TYPE_TAG:
222 		ce->data.tag = (struct got_tag_object *)item;
223 		break;
224 	}
225 
226 	err = got_object_idset_add(cache->idset, id, ce);
227 	if (err)
228 		free(ce);
229 	return err;
230 }
231 
232 void *
233 got_object_cache_get(struct got_object_cache *cache, struct got_object_id *id)
234 {
235 	struct got_object_cache_entry *ce;
236 
237 	cache->cache_searches++;
238 	ce = got_object_idset_get(cache->idset, id);
239 	if (ce) {
240 		cache->cache_hit++;
241 		switch (cache->type) {
242 		case GOT_OBJECT_CACHE_TYPE_OBJ:
243 			return ce->data.obj;
244 		case GOT_OBJECT_CACHE_TYPE_TREE:
245 			return ce->data.tree;
246 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
247 			return ce->data.commit;
248 		case GOT_OBJECT_CACHE_TYPE_TAG:
249 			return ce->data.tag;
250 		}
251 	}
252 
253 	cache->cache_miss++;
254 	return NULL;
255 }
256 
257 #ifdef GOT_OBJ_CACHE_DEBUG
258 static void
259 print_cache_stats(struct got_object_cache *cache, const char *name)
260 {
261 	fprintf(stderr, "%s: %s cache: %d elements, %d searches, %d hits, "
262 	    "%d missed, %d evicted, %d too large\n", getprogname(), name,
263 	    got_object_idset_num_elements(cache->idset),
264 	    cache->cache_searches, cache->cache_hit,
265 	    cache->cache_miss, cache->cache_evict, cache->cache_toolarge);
266 }
267 
268 const struct got_error *
269 check_refcount(struct got_object_id *id, void *data, void *arg)
270 {
271 	struct got_object_cache *cache = arg;
272 	struct got_object_cache_entry *ce = data;
273 	struct got_object *obj;
274 	struct got_tree_object *tree;
275 	struct got_commit_object *commit;
276 	struct got_tag_object *tag;
277 	char *id_str;
278 
279 	if (got_object_id_str(&id_str, id) != NULL)
280 		return NULL;
281 
282 	switch (cache->type) {
283 	case GOT_OBJECT_CACHE_TYPE_OBJ:
284 		obj = ce->data.obj;
285 		if (obj->refcnt == 1)
286 			break;
287 		fprintf(stderr, "object %s has %d unclaimed references\n",
288 		    id_str, obj->refcnt - 1);
289 		break;
290 	case GOT_OBJECT_CACHE_TYPE_TREE:
291 		tree = ce->data.tree;
292 		if (tree->refcnt == 1)
293 			break;
294 		fprintf(stderr, "tree %s has %d unclaimed references\n",
295 		    id_str, tree->refcnt - 1);
296 		break;
297 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
298 		commit = ce->data.commit;
299 		if (commit->refcnt == 1)
300 			break;
301 		fprintf(stderr, "commit %s has %d unclaimed references\n",
302 		    id_str, commit->refcnt - 1);
303 		break;
304 	case GOT_OBJECT_CACHE_TYPE_TAG:
305 		tag = ce->data.tag;
306 		if (tag->refcnt == 1)
307 			break;
308 		fprintf(stderr, "tag %s has %d unclaimed references\n",
309 		    id_str, tag->refcnt - 1);
310 		break;
311 	}
312 	free(id_str);
313 	return NULL;
314 }
315 #endif
316 
317 void
318 got_object_cache_close(struct got_object_cache *cache)
319 {
320 #ifdef GOT_OBJ_CACHE_DEBUG
321 	switch (cache->type) {
322 	case GOT_OBJECT_CACHE_TYPE_OBJ:
323 		print_cache_stats(cache, "object");
324 		break;
325 	case GOT_OBJECT_CACHE_TYPE_TREE:
326 		print_cache_stats(cache, "tree");
327 		break;
328 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
329 		print_cache_stats(cache, "commit");
330 		break;
331 	case GOT_OBJECT_CACHE_TYPE_TAG:
332 		print_cache_stats(cache, "tag");
333 		break;
334 	}
335 
336 	got_object_idset_for_each(cache->idset, check_refcount, cache);
337 #endif
338 
339 	if (cache->idset) {
340 		got_object_idset_free(cache->idset);
341 		cache->idset = NULL;
342 	}
343 	cache->size = 0;
344 }