tdb: tdb_summary() support.

Autobuild-User: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-Date: Wed Dec 29 10:12:05 CET 2010 on sn-devel-104

lib/tdb/common/check.c

@@ -308,7 +308,7 @@ static bool tdb_check_free_record(struct tdb_context *tdb,
 }
 
 /* Slow, but should be very rare. */
-static size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
+size_t tdb_dead_space(struct tdb_context *tdb, tdb_off_t off)
 {
 	size_t len;
 
@@ -406,7 +406,7 @@ _PUBLIC_ int tdb_check(struct tdb_context *tdb,
 				found_recovery = true;
 				break;
 			}
-			dead = dead_space(tdb, off);
+			dead = tdb_dead_space(tdb, off);
 			if (dead < sizeof(rec))
 				goto corrupt;
 

lib/tdb/common/summary.c

@@ -0,0 +1,192 @@
+ /* 
+   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" \
+	"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;
+	struct tally freet, keys, data, dead, extra, hash, uncoal;
+	struct tdb_record rec;
+	char *ret = NULL;
+	bool locked;
+	size_t len, unc = 0;
+
+	/* 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;
+	}
+
+	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->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(&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++;
+			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->header.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 = malloc(len);
+	if (!ret)
+		goto unlock;
+
+	sprintf(ret, SUMMARY_FORMAT,
+		tdb->map_size, keys.total+data.total,
+		keys.num,
+		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->header.hash_size * sizeof(tdb_off_t)
+		* 100.0 / tdb->map_size);
+
+unlock:
+	if (locked) {
+		tdb_unlockall_read(tdb);
+	}
+	return ret;
+}

lib/tdb/common/tdb_private.h

@@ -274,3 +274,4 @@ int tdb_transaction_recover(struct tdb_context *tdb);
 void tdb_header_hash(struct tdb_context *tdb,
 		     uint32_t *magic1_hash, uint32_t *magic2_hash);
 unsigned int tdb_old_hash(TDB_DATA *key);
+size_t tdb_dead_space(struct tdb_context *tdb, tdb_off_t off);

lib/tdb/include/tdb.h

@@ -168,6 +168,7 @@ void tdb_dump_all(struct tdb_context *tdb);
 int tdb_printfreelist(struct tdb_context *tdb);
 int tdb_validate_freelist(struct tdb_context *tdb, int *pnum_entries);
 int tdb_freelist_size(struct tdb_context *tdb);
+char *tdb_summary(struct tdb_context *tdb);
 
 extern TDB_DATA tdb_null;
 

lib/tdb/libtdb.m4

@@ -13,7 +13,7 @@ if test x"$tdbdir" = "x"; then
    AC_MSG_ERROR([cannot find tdb source in $tdbpaths])
 fi
 TDB_OBJ="common/tdb.o common/dump.o common/transaction.o common/error.o common/traverse.o"
-TDB_OBJ="$TDB_OBJ common/freelist.o common/freelistcheck.o common/io.o common/lock.o common/open.o common/check.o common/hash.o"
+TDB_OBJ="$TDB_OBJ common/freelist.o common/freelistcheck.o common/io.o common/lock.o common/open.o common/check.o common/hash.o common/summary.o"
 AC_SUBST(TDB_OBJ)
 AC_SUBST(LIBREPLACEOBJ)
 

lib/tdb/tools/tdbtool.c

@@ -409,12 +409,14 @@ static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA key, TDB_DATA dbuf, void *
 
 static void info_tdb(void)
 {
-	int count;
-	total_bytes = 0;
-	if ((count = tdb_traverse(tdb, traverse_fn, NULL)) == -1)
+	char *summary = tdb_summary(tdb);
+
+	if (!summary) {
 		printf("Error = %s\n", tdb_errorstr(tdb));
-	else
-		printf("%d records totalling %d bytes\n", count, total_bytes);
+	} else {
+		printf("%s", summary);
+		free(summary);
+	}
 }
 
 static void speed_tdb(const char *tlimit)

lib/tdb/wscript

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 
 APPNAME = 'tdb'
-VERSION = '1.2.8'
+VERSION = '1.2.9'
 
 blddir = 'bin'
 
@@ -60,7 +60,7 @@ def build(bld):
     COMMON_SRC = bld.SUBDIR('common',
                             '''check.c error.c tdb.c traverse.c
                             freelistcheck.c lock.c dump.c freelist.c
-                            io.c open.c transaction.c hash.c''')
+                            io.c open.c transaction.c hash.c summary.c''')
 
     if bld.env.standalone_tdb:
         bld.env.PKGCONFIGDIR = '${LIBDIR}/pkgconfig'