copy_file_range: move wrapper to Ruby for keyword arg handling

Keyword args allows for a smaller interface for common use,
while retaining the capability to use offsets for both input and
output.  The current (2.4) Ruby C API for keyword args is slow
and creates too many garbage objects.  As with our splice
wrapper, use a pure Ruby wrapper around an internal C function.

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/sleepy_penguin/cfr.rb b/lib/sleepy_penguin/cfr.rb
new file mode 100644
index 0000000..af94499
--- /dev/null
+++ b/lib/sleepy_penguin/cfr.rb
@@ -0,0 +1,6 @@
+module SleepyPenguin
+  def self.copy_file_range(io_in, io_out, len, flags = 0,
+                           off_in: nil, off_out: nil)
+    __cfr(io_in, off_in, io_out, off_out, len, flags)
+  end
+end