Loop thru all DBs and show their stats

This is quick and dirty, should be integrated into mdb_stat.

libraries/libmdb/mdb_stata.c

+/* mdb_stat.c - memory-mapped database status tool */
+/*
+ * Copyright 2011 Howard Chu, Symas Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mdb.h"
+
+int main(int argc,char * argv[])
+{
+	int rc;
+	MDB_env *env;
+	MDB_txn *txn;
+	MDB_dbi dbi;
+	MDB_stat mst;
+	MDB_cursor *cursor;
+	MDB_val key;
+	char *envname = argv[1];
+
+	rc = mdb_env_create(&env);
+
+	mdb_env_set_maxdbs(env, 4);
+
+	rc = mdb_env_open(env, envname, MDB_RDONLY, 0);
+	if (rc) {
+		printf("mdb_env_open failed, error %d\n", rc);
+		exit(1);
+	}
+	rc = mdb_txn_begin(env, NULL, 1, &txn);
+	if (rc) {
+		printf("mdb_txn_begin failed, error %d\n", rc);
+		exit(1);
+	}
+	rc = mdb_open(txn, NULL, 0, &dbi);
+	if (rc) {
+		printf("mdb_open failed, error %d\n", rc);
+		exit(1);
+	}
+   
+	rc = mdb_stat(txn, dbi, &mst);
+	printf("Page size: %u\n", mst.ms_psize);
+	printf("Tree depth: %u\n", mst.ms_depth);
+	printf("Branch pages: %zu\n", mst.ms_branch_pages);
+	printf("Leaf pages: %zu\n", mst.ms_leaf_pages);
+	printf("Overflow pages: %zu\n", mst.ms_overflow_pages);
+	printf("Entries: %zu\n", mst.ms_entries);
+
+	rc = mdb_cursor_open(txn, dbi, &cursor);
+	while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT)) == 0) {
+		char *str = malloc(key.mv_size+1);
+		MDB_dbi db2;
+		memcpy(str, key.mv_data, key.mv_size);
+		str[key.mv_size] = '\0';
+		printf("\n%s\n", str);
+		rc = mdb_open(txn, str, 0, &db2);
+		if (rc) break;
+		free(str);
+		rc = mdb_stat(txn, db2, &mst);
+		printf("Tree depth: %u\n", mst.ms_depth);
+		printf("Branch pages: %zu\n", mst.ms_branch_pages);
+		printf("Leaf pages: %zu\n", mst.ms_leaf_pages);
+		printf("Overflow pages: %zu\n", mst.ms_overflow_pages);
+		printf("Entries: %zu\n", mst.ms_entries);
+		mdb_close(env, db2);
+	}
+	mdb_cursor_close(cursor);
+	mdb_close(env, dbi);
+	mdb_txn_abort(txn);
+	mdb_env_close(env);
+
+	return 0;
+}