class IO::Stream::Buffered

def self.open(path, mode = "r+", **options)
	stream = self.new(::File.open(path, mode), **options)
	
	return stream unless block_given?
	
	begin
		yield stream
	ensure
		stream.close
	end
end

def self.wrap(io, **options)
	if io.respond_to?(:buffered=)
		io.buffered = false
	elsif io.respond_to?(:sync=)
		io.sync = true
	end
	
	stream = self.new(io, **options)
	
	return stream unless block_given?
	
	begin
		yield stream
	ensure
		stream.close
	end
end

def close_read
	@io.close_read
end

def close_write
	super
ensure
	@io.close_write
end

def closed?
	@io.closed?
end

def initialize(io, ...)
	super(...)
	
	@io = io
	if io.respond_to?(:timeout)
		@timeout = io.timeout
	else
		@timeout = nil
	end
end

def readable?
	super && @io.readable?
end

def sysclose
	# https://bugs.ruby-lang.org/issues/20723
	Thread.new{@io.close}.join
end

def sysclose
	@io.close
end

def sysread(size, buffer)
	# Come on Ruby, why couldn't this just return `nil`? EOF is not exceptional. Every file has one.
	while true
		result = @io.read_nonblock(size, buffer, exception: false)
		
		case result
		when :wait_readable
			@io.wait_readable(@io.timeout) or raise ::IO::TimeoutError, "read timeout"
		when :wait_writable
			@io.wait_writable(@io.timeout) or raise ::IO::TimeoutError, "write timeout"
		else
			return result
		end
	end
rescue Errno::EBADF
	raise ::IOError, "stream closed"
end

def syswrite(buffer)
	# This fails due to re-entrancy issues with a concurrent call to `sysclose`.
	# return @io.write(buffer)
	
	while true
		result = @io.write_nonblock(buffer, exception: false)
		
		case result
		when :wait_readable
			@io.wait_readable(@io.timeout) or raise ::IO::TimeoutError, "read timeout"
		when :wait_writable
			@io.wait_writable(@io.timeout) or raise ::IO::TimeoutError, "write timeout"
		else
			if result == buffer.bytesize
				return
			else
				buffer = buffer.byteslice(result, buffer.bytesize)
			end
		end
	end
end

def to_io
	@io.to_io
end