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                       struct tally *chains)
  48 {
  49         tdb_off_t off;
  50         tdb_len_t len;
  51         tdb_len_t unc = 0;
  52
  53         for (off = sizeof(struct tdb_header); off < tdb->map_size; off += len) {
  54                 const union {
  55                         struct tdb_used_record u;
  56                         struct tdb_free_record f;
  57                         struct tdb_recovery_record r;
  58                 } *p;
  59                 /* We might not be able to get the whole thing. */
  60                 p = tdb_access_read(tdb, off, sizeof(p->f), true);
  61                 if (!p)
  62                         return false;
  63                 if (p->r.magic == TDB_RECOVERY_INVALID_MAGIC
  64                     || p->r.magic == TDB_RECOVERY_MAGIC) {
  65                         if (unc) {
  66                                 tally_add(uncoal, unc);
  67                                 unc = 0;
  68                         }
  69                         len = sizeof(p->r) + p->r.max_len;
  70                 } else if (frec_magic(&p->f) == TDB_FREE_MAGIC) {
  71                         len = frec_len(&p->f);
  72                         tally_add(free, len);
  73                         tally_add(buckets, size_to_bucket(len));
  74                         len += sizeof(p->u);
  75                         unc++;
  76                 } else if (rec_magic(&p->u) == TDB_MAGIC) {
  77                         if (unc) {
  78                                 tally_add(uncoal, unc);
  79                                 unc = 0;
  80                         }
  81                         len = sizeof(p->u)
  82                                 + rec_key_length(&p->u)
  83                                 + rec_data_length(&p->u)
  84                                 + rec_extra_padding(&p->u);
  85
  86                         /* FIXME: Use different magic for hashes, flists. */
  87                         if (!rec_key_length(&p->u) && rec_hash(&p->u) < 3) {
  88                                 if (rec_hash(&p->u) == 0) {
  89                                         int count = count_hash(tdb,
  90                                                         off + sizeof(p->u),
  91                                                         TDB_SUBLEVEL_HASH_BITS);
  92                                         if (count == -1)
  93                                                 return false;
  94                                         tally_add(hashes, count);
  95                                 } else if (rec_hash(&p->u) == 1) {
  96                                         tally_add(flists,
  97                                                   rec_data_length(&p->u));
  98                                 } else if (rec_hash(&p->u) == 2) {
  99                                         tally_add(chains, 1);
 100                                 }
 101                         } else {
 102                                 tally_add(keys, rec_key_length(&p->u));
 103                                 tally_add(data, rec_data_length(&p->u));
 104                         }
 105                         tally_add(extra, rec_extra_padding(&p->u));
 106                 } else
 107                         len = dead_space(tdb, off);
 108                 tdb_access_release(tdb, p);
 109         }
 110         if (unc)
 111                 tally_add(uncoal, unc);
 112         return true;
 113 }
 114
 115 #define SUMMARY_FORMAT \
 116         "Size of file/data: %zu/%zu\n" \
 117         "Number of records: %zu\n" \
 118         "Smallest/average/largest keys: %zu/%zu/%zu\n%s" \
 119         "Smallest/average/largest data: %zu/%zu/%zu\n%s" \
 120         "Smallest/average/largest padding: %zu/%zu/%zu\n%s" \
 121         "Number of free records: %zu\n" \
 122         "Smallest/average/largest free records: %zu/%zu/%zu\n%s" \
 123         "Number of uncoalesced records: %zu\n" \
 124         "Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n%s" \
 125         "Number of free lists: %zu\n%s" \
 126         "Toplevel hash used: %u of %u\n" \
 127         "Number of chains: %zu\n" \
 128         "Number of subhashes: %zu\n" \
 129         "Smallest/average/largest subhash entries: %zu/%zu/%zu\n%s" \
 130         "Percentage keys/data/padding/free/rechdrs/freehdrs/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
 131
 132 #define BUCKET_SUMMARY_FORMAT_A                                 \
 133         "Free bucket %zu: total entries %zu.\n"                 \
 134         "Smallest/average/largest length: %zu/%zu/%zu\n%s"
 135 #define BUCKET_SUMMARY_FORMAT_B                                 \
 136         "Free bucket %zu-%zu: total entries %zu.\n"             \
 137         "Smallest/average/largest length: %zu/%zu/%zu\n%s"
 138
 139 #define HISTO_WIDTH 70
 140 #define HISTO_HEIGHT 20
 141
 142 char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
 143 {
 144         tdb_len_t len;
 145         struct tally *flists, *hashes, *freet, *keys, *data, *extra, *uncoal,
 146                 *buckets, *chains;
 147         char *hashesg, *freeg, *keysg, *datag, *extrag, *uncoalg, *bucketsg;
 148         char *ret = NULL;
 149
 150         hashesg = freeg = keysg = datag = extrag = uncoalg = bucketsg = NULL;
 151
 152         if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false) != 0)
 153                 return NULL;
 154
 155         if (tdb_lock_expand(tdb, F_RDLCK) != 0) {
 156                 tdb_allrecord_unlock(tdb, F_RDLCK);
 157                 return NULL;
 158         }
 159
 160         /* Start stats off empty. */
 161         flists = tally_new(HISTO_HEIGHT);
 162         hashes = tally_new(HISTO_HEIGHT);
 163         freet = tally_new(HISTO_HEIGHT);
 164         keys = tally_new(HISTO_HEIGHT);
 165         data = tally_new(HISTO_HEIGHT);
 166         extra = tally_new(HISTO_HEIGHT);
 167         uncoal = tally_new(HISTO_HEIGHT);
 168         buckets = tally_new(HISTO_HEIGHT);
 169         chains = tally_new(HISTO_HEIGHT);
 170         if (!flists || !hashes || !freet || !keys || !data || !extra
 171             || !uncoal || !buckets || !chains) {
 172                 tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_ERROR,
 173                            "tdb_summary: failed to allocate tally structures");
 174                 goto unlock;
 175         }
 176
 177         if (!summarize(tdb, hashes, flists, freet, keys, data, extra, uncoal,
 178                        buckets, chains))
 179                 goto unlock;
 180
 181         if (flags & TDB_SUMMARY_HISTOGRAMS) {
 182                 hashesg = tally_histogram(hashes, HISTO_WIDTH, HISTO_HEIGHT);
 183                 freeg = tally_histogram(freet, HISTO_WIDTH, HISTO_HEIGHT);
 184                 keysg = tally_histogram(keys, HISTO_WIDTH, HISTO_HEIGHT);
 185                 datag = tally_histogram(data, HISTO_WIDTH, HISTO_HEIGHT);
 186                 extrag = tally_histogram(extra, HISTO_WIDTH, HISTO_HEIGHT);
 187                 uncoalg = tally_histogram(uncoal, HISTO_WIDTH, HISTO_HEIGHT);
 188                 bucketsg = tally_histogram(buckets, HISTO_WIDTH, HISTO_HEIGHT);
 189         }
 190
 191         /* 20 is max length of a %llu. */
 192         len = strlen(SUMMARY_FORMAT) + 33*20 + 1
 193                 + (hashesg ? strlen(hashesg) : 0)
 194                 + (freeg ? strlen(freeg) : 0)
 195                 + (keysg ? strlen(keysg) : 0)
 196                 + (datag ? strlen(datag) : 0)
 197                 + (extrag ? strlen(extrag) : 0)
 198                 + (uncoalg ? strlen(uncoalg) : 0)
 199                 + (bucketsg ? strlen(bucketsg) : 0);
 200
 201         ret = malloc(len);
 202         if (!ret)
 203                 goto unlock;
 204
 205         len = sprintf(ret, SUMMARY_FORMAT,
 206                       (size_t)tdb->map_size,
 207                       tally_num(keys) + tally_num(data),
 208                       tally_num(keys),
 209                       tally_min(keys), tally_mean(keys), tally_max(keys),
 210                       keysg ? keysg : "",
 211                       tally_min(data), tally_mean(data), tally_max(data),
 212                       datag ? datag : "",
 213                       tally_min(extra), tally_mean(extra), tally_max(extra),
 214                       extrag ? extrag : "",
 215                       tally_num(freet),
 216                       tally_min(freet), tally_mean(freet), tally_max(freet),
 217                       freeg ? freeg : "",
 218                       tally_total(uncoal, NULL),
 219                       tally_min(uncoal), tally_mean(uncoal), tally_max(uncoal),
 220                       uncoalg ? uncoalg : "",
 221                       tally_num(buckets),
 222                       bucketsg ? bucketsg : "",
 223                       count_hash(tdb, offsetof(struct tdb_header, hashtable),
 224                                  TDB_TOPLEVEL_HASH_BITS),
 225                       1 << TDB_TOPLEVEL_HASH_BITS,
 226                       tally_num(chains),
 227                       tally_num(hashes),
 228                       tally_min(hashes), tally_mean(hashes), tally_max(hashes),
 229                       hashesg ? hashesg : "",
 230                       tally_total(keys, NULL) * 100.0 / tdb->map_size,
 231                       tally_total(data, NULL) * 100.0 / tdb->map_size,
 232                       tally_total(extra, NULL) * 100.0 / tdb->map_size,
 233                       tally_total(freet, NULL) * 100.0 / tdb->map_size,
 234                       (tally_num(keys) + tally_num(freet) + tally_num(hashes))
 235                       * sizeof(struct tdb_used_record) * 100.0 / tdb->map_size,
 236                       tally_num(flists) * sizeof(struct tdb_freelist)
 237                       * 100.0 / tdb->map_size,
 238                       (tally_num(hashes)
 239                        * (sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS)
 240                        + (sizeof(tdb_off_t) << TDB_TOPLEVEL_HASH_BITS)
 241                        + sizeof(struct tdb_chain) * tally_num(chains))
 242                       * 100.0 / tdb->map_size);
 243
 244 unlock:
 245         free(hashesg);
 246         free(freeg);
 247         free(keysg);
 248         free(datag);
 249         free(extrag);
 250         free(uncoalg);
 251         free(bucketsg);
 252         free(hashes);
 253         free(buckets);
 254         free(freet);
 255         free(keys);
 256         free(data);
 257         free(extra);
 258         free(uncoal);
 259         free(chains);
 260
 261         tdb_allrecord_unlock(tdb, F_RDLCK);
 262         tdb_unlock_expand(tdb, F_RDLCK);
 263         return ret;
 264 }