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Diffstat (limited to 'common/summary.c')
| -rw-r--r-- | common/summary.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/common/summary.c b/common/summary.c new file mode 100644 index 0000000..a93eb93 --- /dev/null +++ b/common/summary.c @@ -0,0 +1,219 @@ + /* + 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: %llu/%zu\n" \ + "Header offset/logical size: %zu/%zu\n" \ + "Number of records: %zu\n" \ + "Incompatible hash: %s\n" \ + "Active/supported feature flags: 0x%08x/0x%08x\n" \ + "Robust mutexes locking: %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; + struct tdb_chainwalk_ctx chainwalk; + size_t count = 0; + + if (tdb_ofs_read(tdb, TDB_HASH_TOP(i), &rec_ptr) == -1) + return 0; + + tdb_chainwalk_init(&chainwalk, rec_ptr); + + /* keep looking until we find the right record */ + while (rec_ptr) { + struct tdb_record r; + bool ok; + ++count; + if (tdb_rec_read(tdb, rec_ptr, &r) == -1) + return 0; + rec_ptr = r.next; + ok = tdb_chainwalk_check(tdb, &chainwalk, rec_ptr); + if (!ok) { + return SIZE_MAX; + } + } + return count; +} + +_PUBLIC_ char *tdb_summary(struct tdb_context *tdb) +{ + off_t file_size; + tdb_off_t off, rec_off; + struct tally freet, keys, data, dead, extra, hashval, uncoal; + struct tdb_record rec; + char *ret = NULL; + bool locked; + size_t unc = 0; + int len; + 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(&hashval); + 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 %u\n", + rec.magic, off)); + goto unlock; + } + } + if (unc > 1) + tally_add(&uncoal, unc - 1); + + for (off = 0; off < tdb->hash_size; off++) + tally_add(&hashval, get_hash_length(tdb, off)); + + file_size = tdb->hdr_ofs + tdb->map_size; + + len = asprintf(&ret, SUMMARY_FORMAT, + (unsigned long long)file_size, keys.total+data.total, + (size_t)tdb->hdr_ofs, (size_t)tdb->map_size, + keys.num, + (tdb->hash_fn == tdb_jenkins_hash)?"yes":"no", + (unsigned)tdb->feature_flags, TDB_SUPPORTED_FEATURE_FLAGS, + (tdb->feature_flags & TDB_FEATURE_FLAG_MUTEX)?"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, + hashval.num, + hashval.min, tally_mean(&hashval), hashval.max, + uncoal.total, + uncoal.min, tally_mean(&uncoal), uncoal.max, + keys.total * 100.0 / file_size, + data.total * 100.0 / file_size, + extra.total * 100.0 / file_size, + freet.total * 100.0 / file_size, + dead.total * 100.0 / file_size, + (keys.num + freet.num + dead.num) + * (sizeof(struct tdb_record) + sizeof(uint32_t)) + * 100.0 / file_size, + tdb->hash_size * sizeof(tdb_off_t) + * 100.0 / file_size); + if (len == -1) { + goto unlock; + } + +unlock: + if (locked) { + tdb_unlockall_read(tdb); + } + return ret; +} |