ladybird/AK/Stream.h
Andrew Kaster 7d49ea9836 AK: Replace some SFINAE with requires clauses, clean up existing ones
Add requires clauses to constraints on InputStream and OutputStream
operator<< / operator>>. Make the constraint on String::number a
requires clause instead of SFINAE. Also, fix some unecessary IsSame in
Trie where specialized traits exist for the given use cases.
2020-12-30 13:28:49 +01:00

181 lines
5.5 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/Concepts.h>
#include <AK/Endian.h>
#include <AK/Forward.h>
#include <AK/Optional.h>
#include <AK/Span.h>
#include <AK/StdLibExtras.h>
namespace AK::Detail {
class Stream {
public:
virtual ~Stream() { ASSERT(!has_any_error()); }
virtual bool has_recoverable_error() const { return m_recoverable_error; }
virtual bool has_fatal_error() const { return m_fatal_error; }
virtual bool has_any_error() const { return has_recoverable_error() || has_fatal_error(); }
virtual bool handle_recoverable_error()
{
ASSERT(!has_fatal_error());
return exchange(m_recoverable_error, false);
}
virtual bool handle_fatal_error() { return exchange(m_fatal_error, false); }
virtual bool handle_any_error()
{
if (has_any_error()) {
m_recoverable_error = false;
m_fatal_error = false;
return true;
}
return false;
}
virtual void set_recoverable_error() const { m_recoverable_error = true; }
virtual void set_fatal_error() const { m_fatal_error = true; }
private:
mutable bool m_recoverable_error { false };
mutable bool m_fatal_error { false };
};
}
namespace AK {
class InputStream : public virtual AK::Detail::Stream {
public:
// Reads at least one byte unless none are requested or none are available. Does nothing
// and returns zero if there is already an error.
virtual size_t read(Bytes) = 0;
// If this function returns true, then no more data can be read. If read(Bytes) previously
// returned zero even though bytes were requested, then the inverse is true as well.
virtual bool unreliable_eof() const = 0;
// Some streams additionally define a method with the signature:
//
// bool eof() const;
//
// This method has the same semantics as unreliable_eof() but returns true if and only if no
// more data can be read. (A failed read is not necessary.)
virtual bool read_or_error(Bytes) = 0;
virtual bool discard_or_error(size_t count) = 0;
};
class OutputStream : public virtual AK::Detail::Stream {
public:
virtual size_t write(ReadonlyBytes) = 0;
virtual bool write_or_error(ReadonlyBytes) = 0;
};
class DuplexStream
: public InputStream
, public OutputStream {
};
inline InputStream& operator>>(InputStream& stream, Bytes bytes)
{
stream.read_or_error(bytes);
return stream;
}
inline OutputStream& operator<<(OutputStream& stream, ReadonlyBytes bytes)
{
stream.write_or_error(bytes);
return stream;
}
template<typename T>
InputStream& operator>>(InputStream& stream, LittleEndian<T>& value)
{
return stream >> Bytes { &value.m_value, sizeof(value.m_value) };
}
template<typename T>
OutputStream& operator<<(OutputStream& stream, LittleEndian<T> value)
{
return stream << ReadonlyBytes { &value.m_value, sizeof(value.m_value) };
}
template<typename T>
InputStream& operator>>(InputStream& stream, BigEndian<T>& value)
{
return stream >> Bytes { &value.m_value, sizeof(value.m_value) };
}
template<typename T>
OutputStream& operator<<(OutputStream& stream, BigEndian<T> value)
{
return stream << ReadonlyBytes { &value.m_value, sizeof(value.m_value) };
}
template<typename T>
InputStream& operator>>(InputStream& stream, Optional<T>& value)
{
T temporary;
stream >> temporary;
value = temporary;
return stream;
}
template<typename Integral>
InputStream& operator>>(InputStream& stream, Integral& value) requires IsIntegral<Integral>::value
{
stream.read_or_error({ &value, sizeof(value) });
return stream;
}
template<typename Integral>
OutputStream& operator<<(OutputStream& stream, Integral value) requires IsIntegral<Integral>::value
{
stream.write_or_error({ &value, sizeof(value) });
return stream;
}
#ifndef KERNEL
template<typename FloatingPoint>
InputStream& operator>>(InputStream& stream, FloatingPoint& value) requires IsFloatingPoint<FloatingPoint>::value
{
stream.read_or_error({ &value, sizeof(value) });
return stream;
}
template<typename FloatingPoint>
OutputStream& operator<<(OutputStream& stream, FloatingPoint value) requires IsFloatingPoint<FloatingPoint>::value
{
stream.write_or_error({ &value, sizeof(value) });
return stream;
}
#endif
}