ZeroTierOne/ext/opentelemetry-cpp-1.21.0/exporters/ostream/test/ostream_capture.h
2025-07-11 10:37:21 -07:00

60 lines
1.3 KiB
C++

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include <iostream>
#include <sstream>
#include <string>
OPENTELEMETRY_BEGIN_NAMESPACE
namespace exporter
{
namespace ostream
{
namespace test
{
/**
* The OStreamCapture captures from the specified stream for its lifetime
*/
class OStreamCapture
{
public:
/**
* Create a OStreamCapture which will capture the output of the ostream that it was constructed
* with for the lifetime of the instance.
*/
OStreamCapture(std::ostream &ostream) : stream_(ostream), buf_(ostream.rdbuf())
{
stream_.rdbuf(captured_.rdbuf());
}
~OStreamCapture() { stream_.rdbuf(buf_); }
/**
* Returns the captured data from the stream.
*/
std::string GetCaptured() const { return captured_.str(); }
private:
std::ostream &stream_;
std::streambuf *buf_;
std::stringstream captured_;
};
/**
* Helper method to invoke the passed func while recording the output of the specified stream and
* return the output afterwards.
*/
template <typename Func>
std::string WithOStreamCapture(std::ostream &stream, Func func)
{
OStreamCapture capture(stream);
func();
return capture.GetCaptured();
}
} // namespace test
} // namespace ostream
} // namespace exporter
OPENTELEMETRY_END_NAMESPACE