io.rb in lightio-0.4.2

- old
+ new

@@ -10,14 +10,22 @@
       # helper methods
       def convert_to_io(io)
         unless io.respond_to?(:to_io)
           raise TypeError, "no implicit conversion of #{io.class} into IO"
         end
-        to_io = io.to_io
+        to_io = io.is_a?(LightIO::Library::IO) ? io : io.to_io
         unless to_io.is_a?(LightIO::Library::IO)
-          raise TypeError, "can't process raw IO, use LightIO::IO._wrap(obj) to wrap it" if to_io.is_a?(::IO)
-          raise TypeError, "can't convert #{io.class} to IO (#{io.class}#to_io gives #{to_io.class})"
+          raise TypeError, "can't convert #{io.class} to IO (#{io.class}#to_io gives #{to_io.class})" unless to_io.is_a?(::IO)
+
+          # try wrap raw io instead of raise error
+          wrapped_io = to_io.instance_variable_get(:@_lightio_wrapped_io)
+          unless wrapped_io
+            wrapped_io = LightIO::Library::IO._wrap(to_io)
+            to_io.instance_variable_set(:@_lightio_wrapped_io, wrapped_io)
+          end
+          to_io = wrapped_io
+          # raise TypeError, "can't process raw IO, use LightIO::IO._wrap(obj) to wrap it"
         end
         to_io
       end
 
       def get_io_watcher(io)
@@ -49,11 +57,31 @@
           ensure
             w.close
             r.close
           end
         end
-        # [r, w]
         [wrap_to_library(r), wrap_to_library(w)]
+      end
+
+      def copy_stream(*args)
+        raise ArgumentError, "wrong number of arguments (given #{args.size}, expected 2..4)" unless (2..4).include?(args.size)
+        src, dst, copy_length, src_offset = args
+        src = src.respond_to?(:to_io) ? src.to_io : LightIO::Library::File.open(src, 'r') unless src.is_a?(IO)
+        dst = dst.respond_to?(:to_io) ? dst.to_io : LightIO::Library::File.open(dst, 'w') unless dst.is_a?(IO)
+        buf_size = 4096
+        copy_chars = 0
+        buf_size = [buf_size, copy_length].min if copy_length
+        src.seek(src_offset) if src_offset
+        while (buf = src.read(buf_size))
+          size = dst.write(buf)
+          copy_chars += size
+          if copy_length
+            copy_length -= size
+            break if copy_length.zero?
+            buf_size = [buf_size, copy_length].min
+          end
+        end
+        copy_chars
       end
 
       def select(read_fds, write_fds=nil, _except_fds=nil, timeout=nil)
         timer = timeout && Time.now
         read_fds ||= []