blob: 3fd87250a4a9135b0905170a1af267e260033700 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
|
# The goal of this is to use a synthetic (non-IO) reader
# to trigger the read/write loop of IO.copy_stream,
# bypassing in-kernel mechanisms like sendfile for zero copy,
# so we wrap the /dev/zero IO object:
class Zero
def initialize
@n = 100000
@in = File.open('/dev/zero', 'rb')
end
def read(len, buf)
return if (@n -= 1) == 0
@in.read(len, buf)
end
end
begin
src = Zero.new
dst = File.open(IO::NULL, 'wb')
n = IO.copy_stream(src, dst)
rescue Errno::ENOENT
# not *nix
end if IO.respond_to?(:copy_stream) && IO.const_defined?(:NULL)
|
