change PIMap::at and add const to PIMap and PIBinaryLog

libs/main/io_devices/pibinarylog.h

@@ -251,7 +251,7 @@ public:
 	void setHeader(const PIByteArray & header);
 
 	//! Get custom file header
-	PIByteArray getHeader();
+	PIByteArray getHeader() const;
 
 #ifdef DOXYGEN
 	//! Read one message from binlog file, with ID contains in "filterID" or any ID, if "filterID" is empty
@@ -462,9 +462,9 @@ inline PICout operator<<(PICout s, const PIBinaryLog::BinLogInfo & bi) {
 	}
 	s << "read records " << bi.records_count << " in " << bi.records.size() << " types, log size " << bi.log_size;
 	s << "\nlog start " << bi.start_time << " , log end " << bi.end_time;
-	PIVector<int> keys = bi.records.keys();
+	const auto keys = bi.records.keys();
 	for (int i: keys) {
-		PIBinaryLog::BinLogRecordInfo bri = bi.records.at(i);
+		const auto & bri(bi.records.at(i));
 		s << "\n  record id " << bri.id << " , count " << bri.count;
 		s << "\n    record start " << bri.start_time << " , end " << bri.end_time;
 		s << "\n    record size " << bri.minimum_size << " - " << bri.maximum_size;