source: trunk/server/lib/tdb/common/summary.c

Last change on this file was 987, checked in by Silvan Scherrer, 9 years ago

samba server: fix crlf in tdb trunk code
File size: 5.4 KB
Line 
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: %u/%zu\n" \
22 "Number of records: %zu\n" \
23 "Smallest/average/largest keys: %zu/%zu/%zu\n" \
24 "Smallest/average/largest data: %zu/%zu/%zu\n" \
25 "Smallest/average/largest padding: %zu/%zu/%zu\n" \
26 "Number of dead records: %zu\n" \
27 "Smallest/average/largest dead records: %zu/%zu/%zu\n" \
28 "Number of free records: %zu\n" \
29 "Smallest/average/largest free records: %zu/%zu/%zu\n" \
30 "Number of hash chains: %zu\n" \
31 "Smallest/average/largest hash chains: %zu/%zu/%zu\n" \
32 "Number of uncoalesced records: %zu\n" \
33 "Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n" \
34 "Percentage keys/data/padding/free/dead/rechdrs&tailers/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
35
36/* We don't use tally module, to keep upstream happy. */
37struct tally {
38 size_t min, max, total;
39 size_t num;
40};
41
42static void tally_init(struct tally *tally)
43{
44 tally->total = 0;
45 tally->num = 0;
46 tally->min = tally->max = 0;
47}
48
49static void tally_add(struct tally *tally, size_t len)
50{
51 if (tally->num == 0)
52 tally->max = tally->min = len;
53 else if (len > tally->max)
54 tally->max = len;
55 else if (len < tally->min)
56 tally->min = len;
57 tally->num++;
58 tally->total += len;
59}
60
61static size_t tally_mean(const struct tally *tally)
62{
63 if (!tally->num)
64 return 0;
65 return tally->total / tally->num;
66}
67
68static size_t get_hash_length(struct tdb_context *tdb, unsigned int i)
69{
70 tdb_off_t rec_ptr;
71 size_t count = 0;
72
73 if (tdb_ofs_read(tdb, TDB_HASH_TOP(i), &rec_ptr) == -1)
74 return 0;
75
76 /* keep looking until we find the right record */
77 while (rec_ptr) {
78 struct tdb_record r;
79 ++count;
80 if (tdb_rec_read(tdb, rec_ptr, &r) == -1)
81 return 0;
82 rec_ptr = r.next;
83 }
84 return count;
85}
86
87_PUBLIC_ char *tdb_summary(struct tdb_context *tdb)
88{
89 tdb_off_t off, rec_off;
90 struct tally freet, keys, data, dead, extra, hash, uncoal;
91 struct tdb_record rec;
92 char *ret = NULL;
93 bool locked;
94 size_t len, unc = 0;
95 struct tdb_record recovery;
96
97 /* Read-only databases use no locking at all: it's best-effort.
98 * We may have a write lock already, so skip that case too. */
99 if (tdb->read_only || tdb->allrecord_lock.count != 0) {
100 locked = false;
101 } else {
102 if (tdb_lockall_read(tdb) == -1)
103 return NULL;
104 locked = true;
105 }
106
107 if (tdb_recovery_area(tdb, tdb->methods, &rec_off, &recovery) != 0) {
108 goto unlock;
109 }
110
111 tally_init(&freet);
112 tally_init(&keys);
113 tally_init(&data);
114 tally_init(&dead);
115 tally_init(&extra);
116 tally_init(&hash);
117 tally_init(&uncoal);
118
119 for (off = TDB_DATA_START(tdb->header.hash_size);
120 off < tdb->map_size - 1;
121 off += sizeof(rec) + rec.rec_len) {
122 if (tdb->methods->tdb_read(tdb, off, &rec, sizeof(rec),
123 DOCONV()) == -1)
124 goto unlock;
125 switch (rec.magic) {
126 case TDB_MAGIC:
127 tally_add(&keys, rec.key_len);
128 tally_add(&data, rec.data_len);
129 tally_add(&extra, rec.rec_len - (rec.key_len
130 + rec.data_len));
131 if (unc > 1)
132 tally_add(&uncoal, unc - 1);
133 unc = 0;
134 break;
135 case TDB_FREE_MAGIC:
136 tally_add(&freet, rec.rec_len);
137 unc++;
138 break;
139 /* If we crash after ftruncate, we can get zeroes or fill. */
140 case TDB_RECOVERY_INVALID_MAGIC:
141 case 0x42424242:
142 unc++;
143 /* If it's a valid recovery, we can trust rec_len. */
144 if (off != rec_off) {
145 rec.rec_len = tdb_dead_space(tdb, off)
146 - sizeof(rec);
147 }
148 /* Fall through */
149 case TDB_DEAD_MAGIC:
150 tally_add(&dead, rec.rec_len);
151 break;
152 default:
153 TDB_LOG((tdb, TDB_DEBUG_ERROR,
154 "Unexpected record magic 0x%x at offset %d\n",
155 rec.magic, off));
156 goto unlock;
157 }
158 }
159 if (unc > 1)
160 tally_add(&uncoal, unc - 1);
161
162 for (off = 0; off < tdb->header.hash_size; off++)
163 tally_add(&hash, get_hash_length(tdb, off));
164
165 /* 20 is max length of a %zu. */
166 len = strlen(SUMMARY_FORMAT) + 35*20 + 1;
167 ret = (char *)malloc(len);
168 if (!ret)
169 goto unlock;
170
171 snprintf(ret, len, SUMMARY_FORMAT,
172 tdb->map_size, keys.total+data.total,
173 keys.num,
174 keys.min, tally_mean(&keys), keys.max,
175 data.min, tally_mean(&data), data.max,
176 extra.min, tally_mean(&extra), extra.max,
177 dead.num,
178 dead.min, tally_mean(&dead), dead.max,
179 freet.num,
180 freet.min, tally_mean(&freet), freet.max,
181 hash.num,
182 hash.min, tally_mean(&hash), hash.max,
183 uncoal.total,
184 uncoal.min, tally_mean(&uncoal), uncoal.max,
185 keys.total * 100.0 / tdb->map_size,
186 data.total * 100.0 / tdb->map_size,
187 extra.total * 100.0 / tdb->map_size,
188 freet.total * 100.0 / tdb->map_size,
189 dead.total * 100.0 / tdb->map_size,
190 (keys.num + freet.num + dead.num)
191 * (sizeof(struct tdb_record) + sizeof(uint32_t))
192 * 100.0 / tdb->map_size,
193 tdb->header.hash_size * sizeof(tdb_off_t)
194 * 100.0 / tdb->map_size);
195
196unlock:
197 if (locked) {
198 tdb_unlockall_read(tdb);
199 }
200 return ret;
201}
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