lib/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 tdb_off_t count_hash(struct tdb_context *tdb,
  23                             tdb_off_t hash_off, unsigned bits)
  24 {
  25         const tdb_off_t *h;
  26         tdb_off_t count = 0;
  27         unsigned int i;
  28
  29         h = tdb_access_read(tdb, hash_off, sizeof(*h) << bits, true);
  30         if (TDB_PTR_IS_ERR(h)) {
  31                 return TDB_PTR_ERR(h);
  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 enum TDB_ERROR 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 *chains)
  49 {
  50         tdb_off_t off;
  51         tdb_len_t len;
  52         tdb_len_t unc = 0;
  53
  54         for (off = sizeof(struct tdb_header);
  55              off < tdb->file->map_size;
  56              off += len) {
  57                 const union {
  58                         struct tdb_used_record u;
  59                         struct tdb_free_record f;
  60                         struct tdb_recovery_record r;
  61                 } *p;
  62                 /* We might not be able to get the whole thing. */
  63                 p = tdb_access_read(tdb, off, sizeof(p->f), true);
  64                 if (TDB_PTR_IS_ERR(p)) {
  65                         return TDB_PTR_ERR(p);
  66                 }
  67                 if (frec_magic(&p->f) != TDB_FREE_MAGIC) {
  68                         if (unc > 1) {
  69                                 tally_add(uncoal, unc);
  70                                 unc = 0;
  71                         }
  72                 }
  73
  74                 if (p->r.magic == TDB_RECOVERY_INVALID_MAGIC
  75                     || p->r.magic == TDB_RECOVERY_MAGIC) {
  76                         len = sizeof(p->r) + p->r.max_len;
  77                 } else if (frec_magic(&p->f) == TDB_FREE_MAGIC) {
  78                         len = frec_len(&p->f);
  79                         tally_add(fr, len);
  80                         len += sizeof(p->u);
  81                         unc++;
  82                 } else if (rec_magic(&p->u) == TDB_USED_MAGIC) {
  83                         len = sizeof(p->u)
  84                                 + rec_key_length(&p->u)
  85                                 + rec_data_length(&p->u)
  86                                 + rec_extra_padding(&p->u);
  87
  88                         tally_add(keys, rec_key_length(&p->u));
  89                         tally_add(data, rec_data_length(&p->u));
  90                         tally_add(extra, rec_extra_padding(&p->u));
  91                 } else if (rec_magic(&p->u) == TDB_HTABLE_MAGIC) {
  92                         tdb_off_t count = count_hash(tdb,
  93                                                      off + sizeof(p->u),
  94                                                      TDB_SUBLEVEL_HASH_BITS);
  95                         if (TDB_OFF_IS_ERR(count)) {
  96                                 return count;
  97                         }
  98                         tally_add(hashes, count);
  99                         tally_add(extra, rec_extra_padding(&p->u));
 100                         len = sizeof(p->u)
 101                                 + rec_data_length(&p->u)
 102                                 + rec_extra_padding(&p->u);
 103                 } else if (rec_magic(&p->u) == TDB_FTABLE_MAGIC) {
 104                         len = sizeof(p->u)
 105                                 + rec_data_length(&p->u)
 106                                 + rec_extra_padding(&p->u);
 107                         tally_add(ftables, rec_data_length(&p->u));
 108                         tally_add(extra, rec_extra_padding(&p->u));
 109                 } else if (rec_magic(&p->u) == TDB_CHAIN_MAGIC) {
 110                         len = sizeof(p->u)
 111                                 + rec_data_length(&p->u)
 112                                 + rec_extra_padding(&p->u);
 113                         tally_add(chains, 1);
 114                         tally_add(extra, rec_extra_padding(&p->u));
 115                 } else {
 116                         len = dead_space(tdb, off);
 117                         if (TDB_OFF_IS_ERR(len)) {
 118                                 return len;
 119                         }
 120                 }
 121                 tdb_access_release(tdb, p);
 122         }
 123         if (unc)
 124                 tally_add(uncoal, unc);
 125         return TDB_SUCCESS;
 126 }
 127
 128 #define SUMMARY_FORMAT \
 129         "Size of file/data: %zu/%zu\n" \
 130         "Number of records: %zu\n" \
 131         "Smallest/average/largest keys: %zu/%zu/%zu\n%s" \
 132         "Smallest/average/largest data: %zu/%zu/%zu\n%s" \
 133         "Smallest/average/largest padding: %zu/%zu/%zu\n%s" \
 134         "Number of free records: %zu\n" \
 135         "Smallest/average/largest free records: %zu/%zu/%zu\n%s" \
 136         "Number of uncoalesced records: %zu\n" \
 137         "Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n%s" \
 138         "Toplevel hash used: %u of %u\n" \
 139         "Number of chains: %zu\n" \
 140         "Number of subhashes: %zu\n" \
 141         "Smallest/average/largest subhash entries: %zu/%zu/%zu\n%s" \
 142         "Percentage keys/data/padding/free/rechdrs/freehdrs/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
 143
 144 #define BUCKET_SUMMARY_FORMAT_A                                 \
 145         "Free bucket %zu: total entries %zu.\n"                 \
 146         "Smallest/average/largest length: %zu/%zu/%zu\n%s"
 147 #define BUCKET_SUMMARY_FORMAT_B                                 \
 148         "Free bucket %zu-%zu: total entries %zu.\n"             \
 149         "Smallest/average/largest length: %zu/%zu/%zu\n%s"
 150
 151 #define HISTO_WIDTH 70
 152 #define HISTO_HEIGHT 20
 153
 154 enum TDB_ERROR tdb_summary(struct tdb_context *tdb,
 155                            enum tdb_summary_flags flags,
 156                            char **summary)
 157 {
 158         tdb_len_t len;
 159         struct tally *ftables, *hashes, *freet, *keys, *data, *extra, *uncoal,
 160                 *chains;
 161         char *hashesg, *freeg, *keysg, *datag, *extrag, *uncoalg;
 162         enum TDB_ERROR ecode;
 163
 164         hashesg = freeg = keysg = datag = extrag = uncoalg = NULL;
 165
 166         ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
 167         if (ecode != TDB_SUCCESS) {
 168                 return tdb->last_error = ecode;
 169         }
 170
 171         ecode = tdb_lock_expand(tdb, F_RDLCK);
 172         if (ecode != TDB_SUCCESS) {
 173                 tdb_allrecord_unlock(tdb, F_RDLCK);
 174                 return tdb->last_error = ecode;
 175         }
 176
 177         /* Start stats off empty. */
 178         ftables = tally_new(HISTO_HEIGHT);
 179         hashes = tally_new(HISTO_HEIGHT);
 180         freet = tally_new(HISTO_HEIGHT);
 181         keys = tally_new(HISTO_HEIGHT);
 182         data = tally_new(HISTO_HEIGHT);
 183         extra = tally_new(HISTO_HEIGHT);
 184         uncoal = tally_new(HISTO_HEIGHT);
 185         chains = tally_new(HISTO_HEIGHT);
 186         if (!ftables || !hashes || !freet || !keys || !data || !extra
 187             || !uncoal || !chains) {
 188                 ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
 189                                    "tdb_summary: failed to allocate"
 190                                    " tally structures");
 191                 goto unlock;
 192         }
 193
 194         ecode = summarize(tdb, hashes, ftables, freet, keys, data, extra,
 195                           uncoal, chains);
 196         if (ecode != TDB_SUCCESS) {
 197                 goto unlock;
 198         }
 199
 200         if (flags & TDB_SUMMARY_HISTOGRAMS) {
 201                 hashesg = tally_histogram(hashes, HISTO_WIDTH, HISTO_HEIGHT);
 202                 freeg = tally_histogram(freet, HISTO_WIDTH, HISTO_HEIGHT);
 203                 keysg = tally_histogram(keys, HISTO_WIDTH, HISTO_HEIGHT);
 204                 datag = tally_histogram(data, HISTO_WIDTH, HISTO_HEIGHT);
 205                 extrag = tally_histogram(extra, HISTO_WIDTH, HISTO_HEIGHT);
 206                 uncoalg = tally_histogram(uncoal, HISTO_WIDTH, HISTO_HEIGHT);
 207         }
 208
 209         /* 20 is max length of a %llu. */
 210         len = strlen(SUMMARY_FORMAT) + 33*20 + 1
 211                 + (hashesg ? strlen(hashesg) : 0)
 212                 + (freeg ? strlen(freeg) : 0)
 213                 + (keysg ? strlen(keysg) : 0)
 214                 + (datag ? strlen(datag) : 0)
 215                 + (extrag ? strlen(extrag) : 0)
 216                 + (uncoalg ? strlen(uncoalg) : 0);
 217
 218         *summary = malloc(len);
 219         if (!*summary) {
 220                 ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
 221                                    "tdb_summary: failed to allocate string");
 222                 goto unlock;
 223         }
 224
 225         sprintf(*summary, SUMMARY_FORMAT,
 226                 (size_t)tdb->file->map_size,
 227                 tally_total(keys, NULL) + tally_total(data, NULL),
 228                 tally_num(keys),
 229                 tally_min(keys), tally_mean(keys), tally_max(keys),
 230                 keysg ? keysg : "",
 231                 tally_min(data), tally_mean(data), tally_max(data),
 232                 datag ? datag : "",
 233                 tally_min(extra), tally_mean(extra), tally_max(extra),
 234                 extrag ? extrag : "",
 235                 tally_num(freet),
 236                 tally_min(freet), tally_mean(freet), tally_max(freet),
 237                 freeg ? freeg : "",
 238                 tally_total(uncoal, NULL),
 239                 tally_min(uncoal), tally_mean(uncoal), tally_max(uncoal),
 240                 uncoalg ? uncoalg : "",
 241                 (unsigned)count_hash(tdb, offsetof(struct tdb_header,
 242                                                    hashtable),
 243                                      TDB_TOPLEVEL_HASH_BITS),
 244                 1 << TDB_TOPLEVEL_HASH_BITS,
 245                 tally_num(chains),
 246                 tally_num(hashes),
 247                 tally_min(hashes), tally_mean(hashes), tally_max(hashes),
 248                 hashesg ? hashesg : "",
 249                 tally_total(keys, NULL) * 100.0 / tdb->file->map_size,
 250                 tally_total(data, NULL) * 100.0 / tdb->file->map_size,
 251                 tally_total(extra, NULL) * 100.0 / tdb->file->map_size,
 252                 tally_total(freet, NULL) * 100.0 / tdb->file->map_size,
 253                 (tally_num(keys) + tally_num(freet) + tally_num(hashes))
 254                 * sizeof(struct tdb_used_record) * 100.0 / tdb->file->map_size,
 255                 tally_num(ftables) * sizeof(struct tdb_freetable)
 256                 * 100.0 / tdb->file->map_size,
 257                 (tally_num(hashes)
 258                  * (sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS)
 259                  + (sizeof(tdb_off_t) << TDB_TOPLEVEL_HASH_BITS)
 260                  + sizeof(struct tdb_chain) * tally_num(chains))
 261                 * 100.0 / tdb->file->map_size);
 262
 263 unlock:
 264         free(hashesg);
 265         free(freeg);
 266         free(keysg);
 267         free(datag);
 268         free(extrag);
 269         free(uncoalg);
 270         free(hashes);
 271         free(freet);
 272         free(keys);
 273         free(data);
 274         free(extra);
 275         free(uncoal);
 276         free(ftables);
 277         free(chains);
 278
 279         tdb_allrecord_unlock(tdb, F_RDLCK);
 280         tdb_unlock_expand(tdb, F_RDLCK);
 281         return tdb->last_error = ecode;
 282 }