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/*
Trivial Database: human-readable summary code
Copyright (C) Rusty Russell 2010
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb_private.h"
#define SUMMARY_FORMAT \
"Size of file/data: %u/%zu\n" \
"Number of records: %zu\n" \
"Incompatible hash: %s\n" \
"Smallest/average/largest keys: %zu/%zu/%zu\n" \
"Smallest/average/largest data: %zu/%zu/%zu\n" \
"Smallest/average/largest padding: %zu/%zu/%zu\n" \
"Number of dead records: %zu\n" \
"Smallest/average/largest dead records: %zu/%zu/%zu\n" \
"Number of free records: %zu\n" \
"Smallest/average/largest free records: %zu/%zu/%zu\n" \
"Number of hash chains: %zu\n" \
"Smallest/average/largest hash chains: %zu/%zu/%zu\n" \
"Number of uncoalesced records: %zu\n" \
"Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n" \
"Percentage keys/data/padding/free/dead/rechdrs&tailers/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
/* We don't use tally module, to keep upstream happy. */
struct tally {
size_t min, max, total;
size_t num;
};
static void tally_init(struct tally *tally)
{
tally->total = 0;
tally->num = 0;
tally->min = tally->max = 0;
}
static void tally_add(struct tally *tally, size_t len)
{
if (tally->num == 0)
tally->max = tally->min = len;
else if (len > tally->max)
tally->max = len;
else if (len < tally->min)
tally->min = len;
tally->num++;
tally->total += len;
}
static size_t tally_mean(const struct tally *tally)
{
if (!tally->num)
return 0;
return tally->total / tally->num;
}
static size_t get_hash_length(struct tdb_context *tdb, unsigned int i)
{
tdb_off_t rec_ptr;
size_t count = 0;
if (tdb_ofs_read(tdb, TDB_HASH_TOP(i), &rec_ptr) == -1)
return 0;
/* keep looking until we find the right record */
while (rec_ptr) {
struct tdb_record r;
++count;
if (tdb_rec_read(tdb, rec_ptr, &r) == -1)
return 0;
rec_ptr = r.next;
}
return count;
}
_PUBLIC_ char *tdb_summary(struct tdb_context *tdb)
{
tdb_off_t off, rec_off;
struct tally freet, keys, data, dead, extra, hash, uncoal;
struct tdb_record rec;
char *ret = NULL;
bool locked;
size_t len, unc = 0;
struct tdb_record recovery;
/* Read-only databases use no locking at all: it's best-effort.
* We may have a write lock already, so skip that case too. */
if (tdb->read_only || tdb->allrecord_lock.count != 0) {
locked = false;
} else {
if (tdb_lockall_read(tdb) == -1)
return NULL;
locked = true;
}
if (tdb_recovery_area(tdb, tdb->methods, &rec_off, &recovery) != 0) {
goto unlock;
}
tally_init(&freet);
tally_init(&keys);
tally_init(&data);
tally_init(&dead);
tally_init(&extra);
tally_init(&hash);
tally_init(&uncoal);
for (off = TDB_DATA_START(tdb->hash_size);
off < tdb->map_size - 1;
off += sizeof(rec) + rec.rec_len) {
if (tdb->methods->tdb_read(tdb, off, &rec, sizeof(rec),
DOCONV()) == -1)
goto unlock;
switch (rec.magic) {
case TDB_MAGIC:
tally_add(&keys, rec.key_len);
tally_add(&data, rec.data_len);
tally_add(&extra, rec.rec_len - (rec.key_len
+ rec.data_len));
if (unc > 1)
tally_add(&uncoal, unc - 1);
unc = 0;
break;
case TDB_FREE_MAGIC:
tally_add(&freet, rec.rec_len);
unc++;
break;
/* If we crash after ftruncate, we can get zeroes or fill. */
case TDB_RECOVERY_INVALID_MAGIC:
case 0x42424242:
unc++;
/* If it's a valid recovery, we can trust rec_len. */
if (off != rec_off) {
rec.rec_len = tdb_dead_space(tdb, off)
- sizeof(rec);
}
/* Fall through */
case TDB_DEAD_MAGIC:
tally_add(&dead, rec.rec_len);
break;
default:
TDB_LOG((tdb, TDB_DEBUG_ERROR,
"Unexpected record magic 0x%x at offset %d\n",
rec.magic, off));
goto unlock;
}
}
if (unc > 1)
tally_add(&uncoal, unc - 1);
for (off = 0; off < tdb->hash_size; off++)
tally_add(&hash, get_hash_length(tdb, off));
/* 20 is max length of a %zu. */
len = strlen(SUMMARY_FORMAT) + 35*20 + 1;
ret = (char *)malloc(len);
if (!ret)
goto unlock;
snprintf(ret, len, SUMMARY_FORMAT,
tdb->map_size, keys.total+data.total,
keys.num,
(tdb->hash_fn == tdb_jenkins_hash)?"yes":"no",
keys.min, tally_mean(&keys), keys.max,
data.min, tally_mean(&data), data.max,
extra.min, tally_mean(&extra), extra.max,
dead.num,
dead.min, tally_mean(&dead), dead.max,
freet.num,
freet.min, tally_mean(&freet), freet.max,
hash.num,
hash.min, tally_mean(&hash), hash.max,
uncoal.total,
uncoal.min, tally_mean(&uncoal), uncoal.max,
keys.total * 100.0 / tdb->map_size,
data.total * 100.0 / tdb->map_size,
extra.total * 100.0 / tdb->map_size,
freet.total * 100.0 / tdb->map_size,
dead.total * 100.0 / tdb->map_size,
(keys.num + freet.num + dead.num)
* (sizeof(struct tdb_record) + sizeof(uint32_t))
* 100.0 / tdb->map_size,
tdb->hash_size * sizeof(tdb_off_t)
* 100.0 / tdb->map_size);
unlock:
if (locked) {
tdb_unlockall_read(tdb);
}
return ret;
}
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