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 <string.h>
23 #include <sha1.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 #define GOT_OBJECT_CACHE_SIZE_OBJ	256
36 #define GOT_OBJECT_CACHE_SIZE_TREE	256
37 #define GOT_OBJECT_CACHE_SIZE_COMMIT	64
38 
39 const struct got_error *
40 got_object_cache_init(struct got_object_cache *cache,
41     enum got_object_cache_type type)
42 {
43 	memset(cache, 0, sizeof(*cache));
44 
45 	cache->idset = got_object_idset_alloc();
46 	if (cache->idset == NULL)
47 		return got_error_from_errno();
48 
49 	cache->type = type;
50 	switch (type) {
51 	case GOT_OBJECT_CACHE_TYPE_OBJ:
52 		cache->size = GOT_OBJECT_CACHE_SIZE_OBJ;
53 		break;
54 	case GOT_OBJECT_CACHE_TYPE_TREE:
55 		cache->size = GOT_OBJECT_CACHE_SIZE_TREE;
56 		break;
57 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
58 		cache->size = GOT_OBJECT_CACHE_SIZE_COMMIT;
59 		break;
60 	}
61 	return NULL;
62 }
63 
64 const struct got_error *
65 got_object_cache_add(struct got_object_cache *cache, struct got_object_id *id, void *item)
66 {
67 	const struct got_error *err = NULL;
68 	struct got_object_cache_entry *ce;
69 	int nelem;
70 
71 	nelem = got_object_idset_num_elements(cache->idset);
72 	if (nelem >= cache->size) {
73 		err = got_object_idset_remove((void **)&ce,
74 		    cache->idset, NULL);
75 		if (err)
76 			return err;
77 		switch (cache->type) {
78 		case GOT_OBJECT_CACHE_TYPE_OBJ:
79 			got_object_close(ce->data.obj);
80 			break;
81 		case GOT_OBJECT_CACHE_TYPE_TREE:
82 			got_object_tree_close(ce->data.tree);
83 			break;
84 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
85 			got_object_commit_close(ce->data.commit);
86 			break;
87 		}
88 		free(ce);
89 		cache->cache_evict++;
90 	}
91 
92 	ce = malloc(sizeof(*ce));
93 	if (ce == NULL)
94 		return got_error_from_errno();
95 	memcpy(&ce->id, id, sizeof(ce->id));
96 	switch (cache->type) {
97 	case GOT_OBJECT_CACHE_TYPE_OBJ:
98 		ce->data.obj = (struct got_object *)item;
99 		break;
100 	case GOT_OBJECT_CACHE_TYPE_TREE:
101 		ce->data.tree = (struct got_tree_object *)item;
102 		break;
103 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
104 		ce->data.commit = (struct got_commit_object *)item;
105 		break;
106 	}
107 
108 	err = got_object_idset_add(cache->idset, id, ce);
109 	if (err) {
110 		if (err->code == GOT_ERR_OBJ_EXISTS) {
111 			free(ce);
112 			err = NULL;
113 		}
114 	}
115 	return err;
116 }
117 
118 void *
119 got_object_cache_get(struct got_object_cache *cache, struct got_object_id *id)
120 {
121 	struct got_object_cache_entry *ce;
122 
123 	cache->cache_searches++;
124 	ce = got_object_idset_get(cache->idset, id);
125 	if (ce) {
126 		cache->cache_hit++;
127 		switch (cache->type) {
128 		case GOT_OBJECT_CACHE_TYPE_OBJ:
129 			return ce->data.obj;
130 		case GOT_OBJECT_CACHE_TYPE_TREE:
131 			return ce->data.tree;
132 		case GOT_OBJECT_CACHE_TYPE_COMMIT:
133 			return ce->data.commit;
134 		}
135 	}
136 
137 	cache->cache_miss++;
138 	return NULL;
139 }
140 
141 #ifdef GOT_OBJ_CACHE_DEBUG
142 static void
143 print_cache_stats(struct got_object_cache *cache, const char *name)
144 {
145 	fprintf(stderr, "%s: %s cache: %d elements, %d searches, %d hits, "
146 	    "%d missed, %d evicted\n", getprogname(), name,
147 	    got_object_idset_num_elements(cache->idset),
148 	    cache->cache_searches, cache->cache_hit,
149 	    cache->cache_miss, cache->cache_evict);
150 }
151 
152 const struct got_error *
153 check_refcount(struct got_object_id *id, void *data, void *arg)
154 {
155 	struct got_object_cache *cache = arg;
156 	struct got_object_cache_entry *ce = data;
157 	struct got_object *obj;
158 	struct got_tree_object *tree;
159 	struct got_commit_object *commit;
160 	char *id_str;
161 
162 	if (got_object_id_str(&id_str, id) != NULL)
163 		return NULL;
164 
165 	switch (cache->type) {
166 	case GOT_OBJECT_CACHE_TYPE_OBJ:
167 		obj = ce->data.obj;
168 		if (obj->refcnt == 1)
169 			break;
170 		fprintf(stderr, "object %s has %d unclaimed references\n",
171 		    id_str, obj->refcnt - 1);
172 		break;
173 	case GOT_OBJECT_CACHE_TYPE_TREE:
174 		tree = ce->data.tree;
175 		if (tree->refcnt == 1)
176 			break;
177 		fprintf(stderr, "tree %s has %d unclaimed references\n",
178 		    id_str, tree->refcnt - 1);
179 		break;
180 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
181 		commit = ce->data.commit;
182 		if (commit->refcnt == 1)
183 			break;
184 		fprintf(stderr, "commit %s has %d unclaimed references\n",
185 		    id_str, commit->refcnt - 1);
186 		break;
187 	}
188 	free(id_str);
189 	return NULL;
190 }
191 #endif
192 
193 void
194 got_object_cache_close(struct got_object_cache *cache)
195 {
196 #ifdef GOT_OBJ_CACHE_DEBUG
197 	switch (cache->type) {
198 	case GOT_OBJECT_CACHE_TYPE_OBJ:
199 		print_cache_stats(cache, "object");
200 		break;
201 	case GOT_OBJECT_CACHE_TYPE_TREE:
202 		print_cache_stats(cache, "tree");
203 		break;
204 	case GOT_OBJECT_CACHE_TYPE_COMMIT:
205 		print_cache_stats(cache, "commit");
206 		break;
207 	}
208 
209 	got_object_idset_for_each(cache->idset, check_refcount, cache);
210 #endif
211 
212 	if (cache->idset) {
213 		got_object_idset_free(cache->idset);
214 		cache->idset = NULL;
215 	}
216 	cache->size = 0;
217 }