Update fiber scheduler to support Ruby 4.1

lib/rage/fiber_scheduler.rb

@@ -3,8 +3,12 @@
 require "resolv"
 
 class Rage::FiberScheduler
+  # @private
   MAX_READ = 65536
 
+  # @private
+  VERSION = defined?(IO::Buffer::VERSION) && IO::Buffer::VERSION >= 3 ? 4 : 3
+
   # Initialize the scheduler, storing the root fiber and an empty DNS cache.
   def initialize
     @root_fiber = Fiber.current
@@ -29,43 +33,49 @@ def io_wait(io, events, timeout = nil)
   end
 
   # Read data from an I/O object into a buffer, pausing the fiber between reads.
-  def io_read(io, buffer, length, offset = 0)
-    length_to_read = if length == 0
-      buffer.size > MAX_READ ? MAX_READ : buffer.size
-    else
-      length
+  if VERSION == 4
+    def io_read(io, buffer, offset, length)
+      ::Iodine::Scheduler.read(io.fileno, buffer, length, offset)
     end
-
-    while true
-      string = ::Iodine::Scheduler.read(io.fileno, length_to_read, offset)
-
-      if string.nil?
-        return offset
+  else
+    def io_read(io, buffer, length, offset = 0)
+      length_to_read = if length == 0
+        buffer.size > MAX_READ ? MAX_READ : buffer.size
+      else
+        length
       end
 
-      if string.empty?
-        return -Errno::EAGAIN::Errno
-      end
+      while true
+        result = ::Iodine::Scheduler.read(io.fileno, buffer, length_to_read, offset)
 
-      buffer.set_string(string, offset)
+        if result == 0
+          return offset
+        elsif result < 0
+          next if result == -Errno::EINTR::Errno
+          return -Errno::EAGAIN::Errno
+        end
 
-      size = string.bytesize
-      offset += size
-      return offset if size < length_to_read || size >= buffer.size
+        offset += result
+        return offset if result < length_to_read || result >= buffer.size
 
-      Fiber.pause
+        Fiber.pause
+      end
     end
   end
 
   unless ENV["RAGE_DISABLE_IO_WRITE"]
     # Write data from a buffer to an I/O object.
-    def io_write(io, buffer, length, offset = 0)
-      bytes_to_write = length
-      bytes_to_write = buffer.size if length == 0
-
-      ::Iodine::Scheduler.write(io.fileno, buffer.get_string, bytes_to_write, offset)
+    if VERSION == 4
+      def io_write(io, buffer, offset, length)
+        ::Iodine::Scheduler.write(io.fileno, buffer, length, offset)
+      end
+    else
+      def io_write(io, buffer, length, offset = 0)
+        bytes_to_write = length
+        bytes_to_write = buffer.size if length == 0
 
-      bytes_to_write - offset
+        ::Iodine::Scheduler.write_async(io.fileno, buffer, bytes_to_write, offset)
+      end
     end
   end
 

rage.gemspec

@@ -29,7 +29,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "thor", "~> 1.0"
   spec.add_dependency "rack", "< 4"
-  spec.add_dependency "rage-iodine", "~> 5.5"
+  spec.add_dependency "rage-iodine", "~> 6.0"
   spec.add_dependency "zeitwerk", "~> 2.6"
   spec.add_dependency "rack-test", "~> 2.1"
   spec.add_dependency "rake", ">= 12.0"