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