--- /dev/null
+ /*
+ 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"
+#include <ccan/tally/tally.h>
+
+#define SUMMARY_FORMAT \
+ "Size of file: %zu\n" \
+ "Number of records: %zu\n" \
+ "Smallest/average/largest records: %zu/%zu/%zu\n%s" \
+ "Smallest/average/largest padding: %zu/%zu/%zu\n%s" \
+ "Number of dead records: %zu\n" \
+ "Smallest/average/largest dead records: %zu/%zu/%zu\n%s" \
+ "Number of free records: %zu\n" \
+ "Smallest/average/largest free records: %zu/%zu/%zu\n%s" \
+ "Number of hash chains: %zu\n" \
+ "Smallest/average/largest hash chains: %zu/%zu/%zu\n%s" \
+ "Total data = %zu (%.0f%%)\n"
+
+#define HISTO_WIDTH 70
+#define HISTO_HEIGHT 20
+
+/* Slow, but should be very rare. */
+static size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
+{
+ size_t len;
+
+ for (len = 0; off + len < tdb->map_size; len++) {
+ char c;
+ if (tdb->methods->tdb_read(tdb, off, &c, 1, 0))
+ return 0;
+ if (c != 0 && c != 0x42)
+ break;
+ }
+ return len;
+}
+
+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;
+}
+
+char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
+{
+ tdb_off_t off;
+ struct tally *freet, *used, *dead, *extra, *hash;
+ char *freeg, *usedg, *deadg, *extrag, *hashg;
+ struct tdb_record rec;
+ char *ret = NULL;
+ bool locked;
+ size_t len;
+
+ /* 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;
+ }
+
+ freet = tally_new(100);
+ used = tally_new(100);
+ dead = tally_new(100);
+ extra = tally_new(100);
+ hash = tally_new(100);
+ if (!freet || !used || !dead || !extra || !hash) {
+ tdb->ecode = TDB_ERR_OOM;
+ goto unlock;
+ }
+
+ for (off = TDB_DATA_START(tdb->header.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(used, rec.key_len + rec.data_len);
+ tally_add(extra, rec.rec_len - (rec.key_len
+ + rec.data_len));
+ break;
+ case TDB_FREE_MAGIC:
+ tally_add(freet, sizeof(rec) + rec.rec_len);
+ break;
+ /* If we crash after ftruncate, we can get zeroes or fill. */
+ case TDB_RECOVERY_INVALID_MAGIC:
+ case 0x42424242:
+ rec.rec_len = dead_space(tdb, off) - sizeof(rec);
+ /* Fall through */
+ case TDB_DEAD_MAGIC:
+ tally_add(dead, sizeof(rec) + 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;
+ }
+ }
+
+ for (off = 0; off < tdb->header.hash_size; off++)
+ tally_add(hash, get_hash_length(tdb, off));
+
+ if (flags & TDB_SUMMARY_HISTOGRAMS) {
+ freeg = tally_histogram(freet, HISTO_WIDTH, HISTO_HEIGHT);
+ usedg = tally_histogram(used, HISTO_WIDTH, HISTO_HEIGHT);
+ deadg = tally_histogram(dead, HISTO_WIDTH, HISTO_HEIGHT);
+ extrag = tally_histogram(extra, HISTO_WIDTH, HISTO_HEIGHT);
+ hashg = tally_histogram(hash, HISTO_WIDTH, HISTO_HEIGHT);
+ } else {
+ freeg = usedg = deadg = extrag = hashg = NULL;
+ }
+
+ /* 20 is max length of a %zu. */
+ len = strlen(SUMMARY_FORMAT) + 22*20 + 1
+ + (freeg ? strlen(freeg) : 0)
+ + (usedg ? strlen(usedg) : 0)
+ + (deadg ? strlen(deadg) : 0)
+ + (extrag ? strlen(extrag) : 0)
+ + (hashg ? strlen(hashg) : 0);
+ ret = malloc(len);
+ if (!ret)
+ goto unlock;
+
+ sprintf(ret, SUMMARY_FORMAT,
+ tdb->map_size,
+ tally_num(used),
+ tally_min(used), tally_mean(used), tally_max(used),
+ usedg ? usedg : "",
+ tally_min(extra), tally_mean(extra), tally_max(extra),
+ extrag ? extrag : "",
+ tally_num(dead),
+ tally_min(dead), tally_mean(dead), tally_max(dead),
+ deadg ? deadg : "",
+ tally_num(freet),
+ tally_min(freet), tally_mean(freet), tally_max(freet),
+ freeg ? freeg : "",
+ tally_num(hash),
+ tally_min(hash), tally_mean(hash), tally_max(hash),
+ hashg ? hashg : "",
+ tally_total(used, NULL),
+ tally_total(used, NULL) * 100.0 / tdb->map_size);
+
+unlock:
+ free(freeg);
+ free(usedg);
+ free(deadg);
+ free(extrag);
+ free(hashg);
+ free(freet);
+ free(used);
+ free(dead);
+ free(extra);
+ free(hash);
+ if (locked) {
+ tdb_unlockall_read(tdb);
+ }
+ return ret;
+}
projects / ccan / blobdiff