tdb: implement tdb_summary.

Including pretty graphs!

ccan/tdb/_info

@@ -73,6 +73,7 @@ int main(int argc, char *argv[])
 		return 1;
 
 	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/tally\n");
 		return 0;
 	}
 

ccan/tdb/summary.c

@@ -0,0 +1,190 @@
+ /* 
+   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;
+}

ccan/tdb/tdb.h

@@ -65,6 +65,9 @@ enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK,
 		TDB_ERR_NOEXIST, TDB_ERR_EINVAL, TDB_ERR_RDONLY,
 		TDB_ERR_NESTING};
 
+/* flags for tdb_summary. Logical or to combine. */
+enum tdb_summary_flags { TDB_SUMMARY_HISTOGRAMS = 1 };
+
 /* debugging uses one of the following levels */
 enum tdb_debug_level {TDB_DEBUG_FATAL = 0, TDB_DEBUG_ERROR, 
 		      TDB_DEBUG_WARNING, TDB_DEBUG_TRACE};
@@ -175,6 +178,7 @@ 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, enum tdb_summary_flags flags);
 
 extern TDB_DATA tdb_null;
 

ccan/tdb/tools/Makefile

@@ -1,4 +1,4 @@
-LDLIBS:=../../tdb.o ../../hash.o
+LDLIBS:=../../tdb.o ../../tally.o
 CFLAGS:=-I../../.. -Wall -O3 #-g -pg
 LDFLAGS:=-L../../..
 

ccan/tdb/tools/tdbtool.c

@@ -21,7 +21,6 @@
 */
 
 #include <ccan/tdb/tdb.h>
-#include <ccan/hash/hash.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <ctype.h>
@@ -46,7 +45,6 @@ static int disable_mmap;
 enum commands {
 	CMD_CREATE_TDB,
 	CMD_OPEN_TDB,
-	CMD_OPENJH_TDB,
 	CMD_TRANSACTION_START,
 	CMD_TRANSACTION_COMMIT,
 	CMD_TRANSACTION_CANCEL,
@@ -80,7 +78,6 @@ typedef struct {
 COMMAND_TABLE cmd_table[] = {
 	{"create",	CMD_CREATE_TDB},
 	{"open",	CMD_OPEN_TDB},
-	{"openjh",	CMD_OPENJH_TDB},
 	{"transaction_start",	CMD_TRANSACTION_START},
 	{"transaction_commit",	CMD_TRANSACTION_COMMIT},
 	{"transaction_cancel",	CMD_TRANSACTION_CANCEL},
@@ -236,19 +233,14 @@ static void create_tdb(const char *tdbname)
 	}
 }
 
-static unsigned int jenkins_hash(TDB_DATA *key)
-{
-	return hash_any(key->dptr, key->dsize, 0);
-}
-
-static void open_tdb(const char *tdbname, tdb_hash_func hashfn)
+static void open_tdb(const char *tdbname)
 {
 	struct tdb_logging_context log_ctx;
 	log_ctx.log_fn = tdb_log;
 
 	if (tdb) tdb_close(tdb);
 	tdb = tdb_open_ex(tdbname, 0, disable_mmap?TDB_NOMMAP:0, O_RDWR, 0600,
-			  &log_ctx, hashfn);
+			  &log_ctx, NULL);
 	if (!tdb) {
 		printf("Could not open %s: %s\n", tdbname, strerror(errno));
 	}
@@ -420,12 +412,14 @@ 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, TDB_SUMMARY_HISTOGRAMS);
+
+	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)
@@ -586,11 +580,7 @@ static int do_command(void)
 		return 0;
 	case CMD_OPEN_TDB:
 		bIterate = 0;
-		open_tdb(arg1, NULL);
-		return 0;
-	case CMD_OPENJH_TDB:
-		bIterate = 0;
-		open_tdb(arg1, jenkins_hash);
+		open_tdb(arg1);
 		return 0;
 	case CMD_SYSTEM:
 		/* Shell command */
@@ -686,7 +676,6 @@ static int do_command(void)
 			return 0;
 		case CMD_CREATE_TDB:
 		case CMD_OPEN_TDB:
-		case CMD_OPENJH_TDB:
 		case CMD_SYSTEM:
 		case CMD_QUIT:
 			/*