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-rw-r--r--common/summary.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/common/summary.c b/common/summary.c
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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: %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;
+}