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