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/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#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() { VERIFY(!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()
{
VERIFY(!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;
}
ErrorOr<void> try_handle_any_error()
{
if (!handle_any_error())
return {};
return Error::from_string_literal("Stream error");
}
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 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 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<Integral I>
InputStream& operator>>(InputStream& stream, I& value)
{
stream.read_or_error({ &value, sizeof(value) });
return stream;
}
template<Integral I>
OutputStream& operator<<(OutputStream& stream, I value)
{
stream.write_or_error({ &value, sizeof(value) });
return stream;
}
#ifndef KERNEL
template<FloatingPoint F>
InputStream& operator>>(InputStream& stream, F& value)
{
stream.read_or_error({ &value, sizeof(value) });
return stream;
}
template<FloatingPoint F>
OutputStream& operator<<(OutputStream& stream, F value)
{
stream.write_or_error({ &value, sizeof(value) });
return stream;
}
#endif
}
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