git.ozlabs.org Git - ccan/blob - ccan/tdb/summary.c

   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 #include <ccan/tally/tally.h>
  20
  21 #define SUMMARY_FORMAT \
  22         "Size of file/data: %u/%zu\n" \
  23         "Number of records: %zu\n" \
  24         "Smallest/average/largest keys: %zu/%zu/%zu\n%s" \
  25         "Smallest/average/largest data: %zu/%zu/%zu\n%s" \
  26         "Smallest/average/largest padding: %zu/%zu/%zu\n%s" \
  27         "Number of dead records: %zu\n" \
  28         "Smallest/average/largest dead records: %zu/%zu/%zu\n%s" \
  29         "Number of free records: %zu\n" \
  30         "Smallest/average/largest free records: %zu/%zu/%zu\n%s" \
  31         "Number of hash chains: %zu\n" \
  32         "Smallest/average/largest hash chains: %zu/%zu/%zu\n%s" \
  33         "Number of uncoalesced records: %zu\n" \
  34         "Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n%s" \
  35         "Percentage keys/data/padding/free/dead/rechdrs&tailers/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
  36
  37 #define HISTO_WIDTH 70
  38 #define HISTO_HEIGHT 20
  39
  40 static size_t get_hash_length(struct tdb_context *tdb, unsigned int i)
  41 {
  42         tdb_off_t rec_ptr;
  43         size_t count = 0;
  44
  45         if (tdb_ofs_read(tdb, TDB_HASH_TOP(i), &rec_ptr) == -1)
  46                 return 0;
  47
  48         /* keep looking until we find the right record */
  49         while (rec_ptr) {
  50                 struct tdb_record r;
  51                 ++count;
  52                 if (tdb_rec_read(tdb, rec_ptr, &r) == -1)
  53                         return 0;
  54                 rec_ptr = r.next;
  55         }
  56         return count;
  57 }
  58
  59 char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
  60 {
  61         tdb_off_t off;
  62         struct tally *freet, *keys, *data, *dead, *extra, *hash, *uncoal;
  63         char *freeg, *keysg, *datag, *deadg, *extrag, *hashg, *uncoalg;
  64         struct tdb_record rec;
  65         char *ret = NULL;
  66         bool locked;
  67         size_t len, unc = 0;
  68
  69         freeg = keysg = datag = deadg = extrag = hashg = uncoalg = NULL;
  70
  71         /* Read-only databases use no locking at all: it's best-effort.
  72          * We may have a write lock already, so skip that case too. */
  73         if (tdb->read_only || tdb->allrecord_lock.count != 0) {
  74                 locked = false;
  75         } else {
  76                 if (tdb_lockall_read(tdb) == -1)
  77                         return NULL;
  78                 locked = true;
  79         }
  80
  81         freet = tally_new(HISTO_HEIGHT);
  82         keys = tally_new(HISTO_HEIGHT);
  83         data = tally_new(HISTO_HEIGHT);
  84         dead = tally_new(HISTO_HEIGHT);
  85         extra = tally_new(HISTO_HEIGHT);
  86         hash = tally_new(HISTO_HEIGHT);
  87         uncoal = tally_new(HISTO_HEIGHT);
  88         if (!freet || !keys || !data || !dead || !extra || !hash || !uncoal) {
  89                 tdb->ecode = TDB_ERR_OOM;
  90                 goto unlock;
  91         }
  92
  93         for (off = TDB_DATA_START(tdb->header.hash_size);
  94              off < tdb->map_size - 1;
  95              off += sizeof(rec) + rec.rec_len) {
  96                 if (tdb->methods->tdb_read(tdb, off, &rec, sizeof(rec),
  97                                            DOCONV()) == -1)
  98                         goto unlock;
  99                 switch (rec.magic) {
 100                 case TDB_MAGIC:
 101                         tally_add(keys, rec.key_len);
 102                         tally_add(data, rec.data_len);
 103                         tally_add(extra, rec.rec_len - (rec.key_len
 104                                                         + rec.data_len));
 105                         break;
 106                 case TDB_FREE_MAGIC:
 107                         tally_add(freet, rec.rec_len);
 108                         unc++;
 109                         break;
 110                 /* If we crash after ftruncate, we can get zeroes or fill. */
 111                 case TDB_RECOVERY_INVALID_MAGIC:
 112                 case 0x42424242:
 113                         unc++;
 114                         rec.rec_len = tdb_dead_space(tdb, off) - sizeof(rec);
 115                         /* Fall through */
 116                 case TDB_DEAD_MAGIC:
 117                         tally_add(dead, rec.rec_len);
 118                         break;
 119                 default:
 120                         TDB_LOG((tdb, TDB_DEBUG_ERROR,
 121                                  "Unexpected record magic 0x%x at offset %d\n",
 122                                  rec.magic, off));
 123                         goto unlock;
 124                 }
 125
 126                 if (unc &&
 127                     (rec.magic == TDB_MAGIC || rec.magic == TDB_DEAD_MAGIC)) {
 128                         tally_add(uncoal, unc);
 129                         unc = 0;
 130                 }
 131         }
 132         if (unc)
 133                 tally_add(uncoal, unc);
 134
 135         for (off = 0; off < tdb->header.hash_size; off++)
 136                 tally_add(hash, get_hash_length(tdb, off));
 137
 138         if (flags & TDB_SUMMARY_HISTOGRAMS) {
 139                 freeg = tally_histogram(freet, HISTO_WIDTH, HISTO_HEIGHT);
 140                 keysg = tally_histogram(keys, HISTO_WIDTH, HISTO_HEIGHT);
 141                 datag = tally_histogram(data, HISTO_WIDTH, HISTO_HEIGHT);
 142                 deadg = tally_histogram(dead, HISTO_WIDTH, HISTO_HEIGHT);
 143                 extrag = tally_histogram(extra, HISTO_WIDTH, HISTO_HEIGHT);
 144                 hashg = tally_histogram(hash, HISTO_WIDTH, HISTO_HEIGHT);
 145                 uncoalg = tally_histogram(uncoal, HISTO_WIDTH, HISTO_HEIGHT);
 146         }
 147
 148         /* 20 is max length of a %zu. */
 149         len = strlen(SUMMARY_FORMAT) + 29*20 + 1
 150                 + (freeg ? strlen(freeg) : 0)
 151                 + (keysg ? strlen(keysg) : 0)
 152                 + (datag ? strlen(datag) : 0)
 153                 + (deadg ? strlen(deadg) : 0)
 154                 + (extrag ? strlen(extrag) : 0)
 155                 + (hashg ? strlen(hashg) : 0)
 156                 + (uncoalg ? strlen(uncoalg) : 0);
 157         ret = malloc(len);
 158         if (!ret)
 159                 goto unlock;
 160
 161         sprintf(ret, SUMMARY_FORMAT,
 162                 tdb->map_size, tally_total(keys, NULL)+tally_total(data, NULL),
 163                 tally_num(keys),
 164                 tally_min(keys), tally_mean(keys), tally_max(keys),
 165                 keysg ? keysg : "",
 166                 tally_min(data), tally_mean(data), tally_max(data),
 167                 datag ? datag : "",
 168                 tally_min(extra), tally_mean(extra), tally_max(extra),
 169                 extrag ? extrag : "",
 170                 tally_num(dead),
 171                 tally_min(dead), tally_mean(dead), tally_max(dead),
 172                 deadg ? deadg : "",
 173                 tally_num(freet),
 174                 tally_min(freet), tally_mean(freet), tally_max(freet),
 175                 freeg ? freeg : "",
 176                 tally_num(hash),
 177                 tally_min(hash), tally_mean(hash), tally_max(hash),
 178                 hashg ? hashg : "",
 179                 tally_total(uncoal, NULL),
 180                 tally_min(uncoal), tally_mean(uncoal), tally_max(uncoal),
 181                 uncoalg ? uncoalg : "",
 182                 tally_total(keys, NULL) * 100.0 / tdb->map_size,
 183                 tally_total(data, NULL) * 100.0 / tdb->map_size,
 184                 tally_total(extra, NULL) * 100.0 / tdb->map_size,
 185                 tally_total(freet, NULL) * 100.0 / tdb->map_size,
 186                 tally_total(dead, NULL) * 100.0 / tdb->map_size,
 187                 (tally_num(keys) + tally_num(freet) + tally_num(dead))
 188                 * (sizeof(struct tdb_record) + sizeof(uint32_t))
 189                 * 100.0 / tdb->map_size,
 190                 tdb->header.hash_size * sizeof(tdb_off_t)
 191                 * 100.0 / tdb->map_size);
 192
 193 unlock:
 194         free(freeg);
 195         free(keysg);
 196         free(datag);
 197         free(deadg);
 198         free(extrag);
 199         free(hashg);
 200         free(uncoalg);
 201         free(freet);
 202         free(keys);
 203         free(data);
 204         free(dead);
 205         free(extra);
 206         free(hash);
 207         free(uncoal);
 208         if (locked) {
 209                 tdb_unlockall_read(tdb);
 210         }
 211         return ret;
 212 }