tdb2: rework some io.c functions to encode errors in their pointer returns.
[ccan] / ccan / tdb2 / summary.c
1  /*
2    Trivial Database 2: 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 "private.h"
19 #include <assert.h>
20 #include <ccan/tally/tally.h>
21
22 static int count_hash(struct tdb_context *tdb,
23                       tdb_off_t hash_off, unsigned bits)
24 {
25         const tdb_off_t *h;
26         unsigned int i, count = 0;
27
28         h = tdb_access_read(tdb, hash_off, sizeof(*h) << bits, true);
29         if (TDB_PTR_IS_ERR(h)) {
30                 tdb->ecode = TDB_PTR_ERR(h);
31                 return -1;
32         }
33         for (i = 0; i < (1 << bits); i++)
34                 count += (h[i] != 0);
35
36         tdb_access_release(tdb, h);
37         return count;
38 }
39
40 static bool summarize(struct tdb_context *tdb,
41                       struct tally *hashes,
42                       struct tally *ftables,
43                       struct tally *fr,
44                       struct tally *keys,
45                       struct tally *data,
46                       struct tally *extra,
47                       struct tally *uncoal,
48                       struct tally *buckets,
49                       struct tally *chains)
50 {
51         tdb_off_t off;
52         tdb_len_t len;
53         tdb_len_t unc = 0;
54
55         for (off = sizeof(struct tdb_header); off < tdb->map_size; off += len) {
56                 const union {
57                         struct tdb_used_record u;
58                         struct tdb_free_record f;
59                         struct tdb_recovery_record r;
60                 } *p;
61                 /* We might not be able to get the whole thing. */
62                 p = tdb_access_read(tdb, off, sizeof(p->f), true);
63                 if (TDB_PTR_IS_ERR(p)) {
64                         tdb->ecode = TDB_PTR_ERR(p);
65                         return false;
66                 }
67                 if (p->r.magic == TDB_RECOVERY_INVALID_MAGIC
68                     || p->r.magic == TDB_RECOVERY_MAGIC) {
69                         if (unc) {
70                                 tally_add(uncoal, unc);
71                                 unc = 0;
72                         }
73                         len = sizeof(p->r) + p->r.max_len;
74                 } else if (frec_magic(&p->f) == TDB_FREE_MAGIC) {
75                         len = frec_len(&p->f);
76                         tally_add(fr, len);
77                         tally_add(buckets, size_to_bucket(len));
78                         len += sizeof(p->u);
79                         unc++;
80                 } else if (rec_magic(&p->u) == TDB_USED_MAGIC) {
81                         if (unc) {
82                                 tally_add(uncoal, unc);
83                                 unc = 0;
84                         }
85                         len = sizeof(p->u)
86                                 + rec_key_length(&p->u)
87                                 + rec_data_length(&p->u)
88                                 + rec_extra_padding(&p->u);
89
90                         tally_add(keys, rec_key_length(&p->u));
91                         tally_add(data, rec_data_length(&p->u));
92                         tally_add(extra, rec_extra_padding(&p->u));
93                 } else if (rec_magic(&p->u) == TDB_HTABLE_MAGIC) {
94                         int count = count_hash(tdb,
95                                                off + sizeof(p->u),
96                                                TDB_SUBLEVEL_HASH_BITS);
97                         if (count == -1)
98                                 return false;
99                         tally_add(hashes, count);
100                         tally_add(extra, rec_extra_padding(&p->u));
101                         len = sizeof(p->u)
102                                 + rec_data_length(&p->u)
103                                 + rec_extra_padding(&p->u);
104                 } else if (rec_magic(&p->u) == TDB_FTABLE_MAGIC) {
105                         len = sizeof(p->u)
106                                 + rec_data_length(&p->u)
107                                 + rec_extra_padding(&p->u);
108                         tally_add(ftables, rec_data_length(&p->u));
109                         tally_add(extra, rec_extra_padding(&p->u));
110                 } else if (rec_magic(&p->u) == TDB_CHAIN_MAGIC) {
111                         len = sizeof(p->u)
112                                 + rec_data_length(&p->u)
113                                 + rec_extra_padding(&p->u);
114                         tally_add(chains, 1);
115                         tally_add(extra, rec_extra_padding(&p->u));
116                 } else
117                         len = dead_space(tdb, off);
118                 tdb_access_release(tdb, p);
119         }
120         if (unc)
121                 tally_add(uncoal, unc);
122         return true;
123 }
124
125 #define SUMMARY_FORMAT \
126         "Size of file/data: %zu/%zu\n" \
127         "Number of records: %zu\n" \
128         "Smallest/average/largest keys: %zu/%zu/%zu\n%s" \
129         "Smallest/average/largest data: %zu/%zu/%zu\n%s" \
130         "Smallest/average/largest padding: %zu/%zu/%zu\n%s" \
131         "Number of free records: %zu\n" \
132         "Smallest/average/largest free records: %zu/%zu/%zu\n%s" \
133         "Number of uncoalesced records: %zu\n" \
134         "Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n%s" \
135         "Number of free lists: %zu\n%s" \
136         "Toplevel hash used: %u of %u\n" \
137         "Number of chains: %zu\n" \
138         "Number of subhashes: %zu\n" \
139         "Smallest/average/largest subhash entries: %zu/%zu/%zu\n%s" \
140         "Percentage keys/data/padding/free/rechdrs/freehdrs/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
141
142 #define BUCKET_SUMMARY_FORMAT_A                                 \
143         "Free bucket %zu: total entries %zu.\n"                 \
144         "Smallest/average/largest length: %zu/%zu/%zu\n%s"
145 #define BUCKET_SUMMARY_FORMAT_B                                 \
146         "Free bucket %zu-%zu: total entries %zu.\n"             \
147         "Smallest/average/largest length: %zu/%zu/%zu\n%s"
148
149 #define HISTO_WIDTH 70
150 #define HISTO_HEIGHT 20
151
152 char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
153 {
154         tdb_len_t len;
155         struct tally *ftables, *hashes, *freet, *keys, *data, *extra, *uncoal,
156                 *buckets, *chains;
157         char *hashesg, *freeg, *keysg, *datag, *extrag, *uncoalg, *bucketsg;
158         char *ret = NULL;
159         enum TDB_ERROR ecode;
160
161         hashesg = freeg = keysg = datag = extrag = uncoalg = bucketsg = NULL;
162
163         ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
164         if (ecode != TDB_SUCCESS) {
165                 tdb->ecode = ecode;
166                 return NULL;
167         }
168
169         ecode = tdb_lock_expand(tdb, F_RDLCK);
170         if (ecode != TDB_SUCCESS) {
171                 tdb->ecode = ecode;
172                 tdb_allrecord_unlock(tdb, F_RDLCK);
173                 return NULL;
174         }
175
176         /* Start stats off empty. */
177         ftables = tally_new(HISTO_HEIGHT);
178         hashes = tally_new(HISTO_HEIGHT);
179         freet = tally_new(HISTO_HEIGHT);
180         keys = tally_new(HISTO_HEIGHT);
181         data = tally_new(HISTO_HEIGHT);
182         extra = tally_new(HISTO_HEIGHT);
183         uncoal = tally_new(HISTO_HEIGHT);
184         buckets = tally_new(HISTO_HEIGHT);
185         chains = tally_new(HISTO_HEIGHT);
186         if (!ftables || !hashes || !freet || !keys || !data || !extra
187             || !uncoal || !buckets || !chains) {
188                 tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
189                            "tdb_summary: failed to allocate tally structures");
190                 goto unlock;
191         }
192
193         if (!summarize(tdb, hashes, ftables, freet, keys, data, extra, uncoal,
194                        buckets, chains))
195                 goto unlock;
196
197         if (flags & TDB_SUMMARY_HISTOGRAMS) {
198                 hashesg = tally_histogram(hashes, HISTO_WIDTH, HISTO_HEIGHT);
199                 freeg = tally_histogram(freet, HISTO_WIDTH, HISTO_HEIGHT);
200                 keysg = tally_histogram(keys, HISTO_WIDTH, HISTO_HEIGHT);
201                 datag = tally_histogram(data, HISTO_WIDTH, HISTO_HEIGHT);
202                 extrag = tally_histogram(extra, HISTO_WIDTH, HISTO_HEIGHT);
203                 uncoalg = tally_histogram(uncoal, HISTO_WIDTH, HISTO_HEIGHT);
204                 bucketsg = tally_histogram(buckets, HISTO_WIDTH, HISTO_HEIGHT);
205         }
206
207         /* 20 is max length of a %llu. */
208         len = strlen(SUMMARY_FORMAT) + 33*20 + 1
209                 + (hashesg ? strlen(hashesg) : 0)
210                 + (freeg ? strlen(freeg) : 0)
211                 + (keysg ? strlen(keysg) : 0)
212                 + (datag ? strlen(datag) : 0)
213                 + (extrag ? strlen(extrag) : 0)
214                 + (uncoalg ? strlen(uncoalg) : 0)
215                 + (bucketsg ? strlen(bucketsg) : 0);
216
217         ret = malloc(len);
218         if (!ret)
219                 goto unlock;
220
221         len = sprintf(ret, SUMMARY_FORMAT,
222                       (size_t)tdb->map_size,
223                       tally_num(keys) + tally_num(data),
224                       tally_num(keys),
225                       tally_min(keys), tally_mean(keys), tally_max(keys),
226                       keysg ? keysg : "",
227                       tally_min(data), tally_mean(data), tally_max(data),
228                       datag ? datag : "",
229                       tally_min(extra), tally_mean(extra), tally_max(extra),
230                       extrag ? extrag : "",
231                       tally_num(freet),
232                       tally_min(freet), tally_mean(freet), tally_max(freet),
233                       freeg ? freeg : "",
234                       tally_total(uncoal, NULL),
235                       tally_min(uncoal), tally_mean(uncoal), tally_max(uncoal),
236                       uncoalg ? uncoalg : "",
237                       tally_num(buckets),
238                       bucketsg ? bucketsg : "",
239                       count_hash(tdb, offsetof(struct tdb_header, hashtable),
240                                  TDB_TOPLEVEL_HASH_BITS),
241                       1 << TDB_TOPLEVEL_HASH_BITS,
242                       tally_num(chains),
243                       tally_num(hashes),
244                       tally_min(hashes), tally_mean(hashes), tally_max(hashes),
245                       hashesg ? hashesg : "",
246                       tally_total(keys, NULL) * 100.0 / tdb->map_size,
247                       tally_total(data, NULL) * 100.0 / tdb->map_size,
248                       tally_total(extra, NULL) * 100.0 / tdb->map_size,
249                       tally_total(freet, NULL) * 100.0 / tdb->map_size,
250                       (tally_num(keys) + tally_num(freet) + tally_num(hashes))
251                       * sizeof(struct tdb_used_record) * 100.0 / tdb->map_size,
252                       tally_num(ftables) * sizeof(struct tdb_freetable)
253                       * 100.0 / tdb->map_size,
254                       (tally_num(hashes)
255                        * (sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS)
256                        + (sizeof(tdb_off_t) << TDB_TOPLEVEL_HASH_BITS)
257                        + sizeof(struct tdb_chain) * tally_num(chains))
258                       * 100.0 / tdb->map_size);
259
260 unlock:
261         free(hashesg);
262         free(freeg);
263         free(keysg);
264         free(datag);
265         free(extrag);
266         free(uncoalg);
267         free(bucketsg);
268         free(hashes);
269         free(buckets);
270         free(freet);
271         free(keys);
272         free(data);
273         free(extra);
274         free(uncoal);
275         free(ftables);
276         free(chains);
277
278         tdb_allrecord_unlock(tdb, F_RDLCK);
279         tdb_unlock_expand(tdb, F_RDLCK);
280         return ret;
281 }