Line data Source code
1 : /*
2 : Trivial Database: human-readable summary code
3 : Copyright (C) Rusty Russell 2010
4 :
5 : This library is free software; you can redistribute it and/or
6 : modify it under the terms of the GNU Lesser General Public
7 : License as published by the Free Software Foundation; either
8 : version 3 of the License, or (at your option) any later version.
9 :
10 : This library is distributed in the hope that it will be useful,
11 : but WITHOUT ANY WARRANTY; without even the implied warranty of
12 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 : Lesser General Public License for more details.
14 :
15 : You should have received a copy of the GNU Lesser General Public
16 : License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 : */
18 : #include "tdb_private.h"
19 :
20 : #define SUMMARY_FORMAT \
21 : "Size of file/data: %llu/%zu\n" \
22 : "Header offset/logical size: %zu/%zu\n" \
23 : "Number of records: %zu\n" \
24 : "Incompatible hash: %s\n" \
25 : "Active/supported feature flags: 0x%08x/0x%08x\n" \
26 : "Robust mutexes locking: %s\n" \
27 : "Smallest/average/largest keys: %zu/%zu/%zu\n" \
28 : "Smallest/average/largest data: %zu/%zu/%zu\n" \
29 : "Smallest/average/largest padding: %zu/%zu/%zu\n" \
30 : "Number of dead records: %zu\n" \
31 : "Smallest/average/largest dead records: %zu/%zu/%zu\n" \
32 : "Number of free records: %zu\n" \
33 : "Smallest/average/largest free records: %zu/%zu/%zu\n" \
34 : "Number of hash chains: %zu\n" \
35 : "Smallest/average/largest hash chains: %zu/%zu/%zu\n" \
36 : "Number of uncoalesced records: %zu\n" \
37 : "Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n" \
38 : "Percentage keys/data/padding/free/dead/rechdrs&tailers/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
39 :
40 : /* We don't use tally module, to keep upstream happy. */
41 : struct tally {
42 : size_t min, max, total;
43 : size_t num;
44 : };
45 :
46 42 : static void tally_init(struct tally *tally)
47 : {
48 42 : tally->total = 0;
49 42 : tally->num = 0;
50 42 : tally->min = tally->max = 0;
51 42 : }
52 :
53 9792 : static void tally_add(struct tally *tally, size_t len)
54 : {
55 9792 : if (tally->num == 0)
56 30 : tally->max = tally->min = len;
57 9762 : else if (len > tally->max)
58 22 : tally->max = len;
59 9740 : else if (len < tally->min)
60 36 : tally->min = len;
61 9792 : tally->num++;
62 9792 : tally->total += len;
63 9792 : }
64 :
65 42 : static size_t tally_mean(const struct tally *tally)
66 : {
67 42 : if (!tally->num)
68 12 : return 0;
69 30 : return tally->total / tally->num;
70 : }
71 :
72 786 : static size_t get_hash_length(struct tdb_context *tdb, unsigned int i)
73 : {
74 : tdb_off_t rec_ptr;
75 : struct tdb_chainwalk_ctx chainwalk;
76 786 : size_t count = 0;
77 :
78 786 : if (tdb_ofs_read(tdb, TDB_HASH_TOP(i), &rec_ptr) == -1)
79 0 : return 0;
80 :
81 786 : tdb_chainwalk_init(&chainwalk, rec_ptr);
82 :
83 : /* keep looking until we find the right record */
84 786 : while (rec_ptr) {
85 : struct tdb_record r;
86 : bool ok;
87 3000 : ++count;
88 3000 : if (tdb_rec_read(tdb, rec_ptr, &r) == -1)
89 0 : return 0;
90 3000 : rec_ptr = r.next;
91 3000 : ok = tdb_chainwalk_check(tdb, &chainwalk, rec_ptr);
92 3000 : if (!ok) {
93 0 : return SIZE_MAX;
94 : }
95 : }
96 786 : return count;
97 : }
98 :
99 6 : _PUBLIC_ char *tdb_summary(struct tdb_context *tdb)
100 : {
101 : off_t file_size;
102 : tdb_off_t off, rec_off;
103 : struct tally freet, keys, data, dead, extra, hashval, uncoal;
104 : struct tdb_record rec;
105 6 : char *ret = NULL;
106 : bool locked;
107 6 : size_t unc = 0;
108 : int len;
109 : struct tdb_record recovery;
110 :
111 : /* Read-only databases use no locking at all: it's best-effort.
112 : * We may have a write lock already, so skip that case too. */
113 6 : if (tdb->read_only || tdb->allrecord_lock.count != 0) {
114 0 : locked = false;
115 : } else {
116 6 : if (tdb_lockall_read(tdb) == -1)
117 0 : return NULL;
118 6 : locked = true;
119 : }
120 :
121 6 : if (tdb_recovery_area(tdb, tdb->methods, &rec_off, &recovery) != 0) {
122 0 : goto unlock;
123 : }
124 :
125 6 : tally_init(&freet);
126 6 : tally_init(&keys);
127 6 : tally_init(&data);
128 6 : tally_init(&dead);
129 6 : tally_init(&extra);
130 6 : tally_init(&hashval);
131 6 : tally_init(&uncoal);
132 :
133 3018 : for (off = TDB_DATA_START(tdb->hash_size);
134 3012 : off < tdb->map_size - 1;
135 3006 : off += sizeof(rec) + rec.rec_len) {
136 6012 : if (tdb->methods->tdb_read(tdb, off, &rec, sizeof(rec),
137 3006 : DOCONV()) == -1)
138 0 : goto unlock;
139 3006 : switch (rec.magic) {
140 3000 : case TDB_MAGIC:
141 3000 : tally_add(&keys, rec.key_len);
142 3000 : tally_add(&data, rec.data_len);
143 6000 : tally_add(&extra, rec.rec_len - (rec.key_len
144 3000 : + rec.data_len));
145 3000 : if (unc > 1)
146 0 : tally_add(&uncoal, unc - 1);
147 3000 : unc = 0;
148 3000 : break;
149 6 : case TDB_FREE_MAGIC:
150 6 : tally_add(&freet, rec.rec_len);
151 6 : unc++;
152 6 : break;
153 : /* If we crash after ftruncate, we can get zeroes or fill. */
154 0 : case TDB_RECOVERY_INVALID_MAGIC:
155 : case 0x42424242:
156 0 : unc++;
157 : /* If it's a valid recovery, we can trust rec_len. */
158 0 : if (off != rec_off) {
159 0 : rec.rec_len = tdb_dead_space(tdb, off)
160 0 : - sizeof(rec);
161 : }
162 :
163 : FALL_THROUGH;
164 : case TDB_DEAD_MAGIC:
165 0 : tally_add(&dead, rec.rec_len);
166 0 : break;
167 0 : default:
168 0 : TDB_LOG((tdb, TDB_DEBUG_ERROR,
169 : "Unexpected record magic 0x%x at offset %u\n",
170 : rec.magic, off));
171 0 : goto unlock;
172 : }
173 : }
174 6 : if (unc > 1)
175 0 : tally_add(&uncoal, unc - 1);
176 :
177 792 : for (off = 0; off < tdb->hash_size; off++)
178 786 : tally_add(&hashval, get_hash_length(tdb, off));
179 :
180 6 : file_size = tdb->hdr_ofs + tdb->map_size;
181 :
182 72 : len = asprintf(&ret, SUMMARY_FORMAT,
183 6 : (unsigned long long)file_size, keys.total+data.total,
184 12 : (size_t)tdb->hdr_ofs, (size_t)tdb->map_size,
185 : keys.num,
186 6 : (tdb->hash_fn == tdb_jenkins_hash)?"yes":"no",
187 6 : (unsigned)tdb->feature_flags, TDB_SUPPORTED_FEATURE_FLAGS,
188 6 : (tdb->feature_flags & TDB_FEATURE_FLAG_MUTEX)?"yes":"no",
189 : keys.min, tally_mean(&keys), keys.max,
190 : data.min, tally_mean(&data), data.max,
191 : extra.min, tally_mean(&extra), extra.max,
192 : dead.num,
193 : dead.min, tally_mean(&dead), dead.max,
194 : freet.num,
195 : freet.min, tally_mean(&freet), freet.max,
196 : hashval.num,
197 : hashval.min, tally_mean(&hashval), hashval.max,
198 : uncoal.total,
199 : uncoal.min, tally_mean(&uncoal), uncoal.max,
200 6 : keys.total * 100.0 / file_size,
201 6 : data.total * 100.0 / file_size,
202 6 : extra.total * 100.0 / file_size,
203 6 : freet.total * 100.0 / file_size,
204 6 : dead.total * 100.0 / file_size,
205 6 : (keys.num + freet.num + dead.num)
206 6 : * (sizeof(struct tdb_record) + sizeof(uint32_t))
207 6 : * 100.0 / file_size,
208 6 : tdb->hash_size * sizeof(tdb_off_t)
209 6 : * 100.0 / file_size);
210 6 : if (len == -1) {
211 0 : goto unlock;
212 : }
213 :
214 12 : unlock:
215 6 : if (locked) {
216 6 : tdb_unlockall_read(tdb);
217 : }
218 6 : return ret;
219 : }
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