mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-15 10:52:30 +00:00
93 lines
2.3 KiB
C++
93 lines
2.3 KiB
C++
//
|
|
// StreamUtil.h
|
|
//
|
|
// Library: Foundation
|
|
// Package: Streams
|
|
// Module: StreamUtil
|
|
//
|
|
// Stream implementation support.
|
|
//
|
|
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef Foundation_StreamUtil_INCLUDED
|
|
#define Foundation_StreamUtil_INCLUDED
|
|
|
|
|
|
#include "Poco/Foundation.h"
|
|
|
|
|
|
// poco_ios_init
|
|
//
|
|
// This is a workaround for a bug in the Dinkumware
|
|
// implementation of iostreams.
|
|
//
|
|
// Calling basic_ios::init() multiple times for the
|
|
// same basic_ios instance results in a memory leak
|
|
// caused by the ios' locale being allocated more than
|
|
// once, each time overwriting the old pointer.
|
|
// This usually occurs in the following scenario:
|
|
//
|
|
// class MyStreamBuf: public std::streambuf
|
|
// {
|
|
// ...
|
|
// };
|
|
//
|
|
// class MyIOS: public virtual std::ios
|
|
// {
|
|
// public:
|
|
// MyIOS()
|
|
// {
|
|
// init(&_buf);
|
|
// }
|
|
// protected:
|
|
// MyStreamBuf _buf;
|
|
// };
|
|
//
|
|
// class MyIStream: public MyIOS, public std::istream
|
|
// {
|
|
// ...
|
|
// };
|
|
//
|
|
// In this scenario, std::ios::init() is called twice
|
|
// (the first time by the MyIOS constructor, the second
|
|
// time by the std::istream constructor), resulting in
|
|
// two locale objects being allocated, the pointer second
|
|
// one overwriting the pointer to the first one and thus
|
|
// causing a memory leak.
|
|
//
|
|
// The workaround is to call init() only once for each
|
|
// stream object - by the istream, ostream or iostream
|
|
// constructor, and not calling init() in ios-derived
|
|
// base classes.
|
|
//
|
|
// Some stream implementations, however, require that
|
|
// init() is called in the MyIOS constructor.
|
|
// Therefore we replace each call to init() with
|
|
// the poco_ios_init macro defined below.
|
|
//
|
|
// Also this macro will adjust exceptions() flags, since by default std::ios
|
|
// will hide exceptions, while in ClickHouse it is better to pass them through.
|
|
|
|
|
|
#if !defined(POCO_IOS_INIT_HACK)
|
|
// Microsoft Visual Studio with Dinkumware STL (but not STLport)
|
|
#endif
|
|
|
|
|
|
#if defined(POCO_IOS_INIT_HACK)
|
|
# define poco_ios_init(buf)
|
|
#else
|
|
# define poco_ios_init(buf) do { \
|
|
init(buf); \
|
|
this->exceptions(std::ios::failbit | std::ios::badbit); \
|
|
} while (0)
|
|
#endif
|
|
|
|
|
|
#endif // Foundation_StreamUtil_INCLUDED
|