IO utilities for copying data with context support and buffer pooling.

The io package provides enhanced IO operations including context-aware copying.

func CopyCloseWithContext(ctx context.Context, dst io.Writer, src io.Reader, sizeHint int) error
func CopyClose(dst io.Writer, src io.Reader, sizeHint int) error

// Basic copy
ioutils.CopyClose(resp.Body, out, 32*1024)

// Context-aware copy
ioutils.CopyCloseWithContext(ctx, w, upstream.Body, 8*1024)

• Uses 32KB default buffer
• Supports size hints for optimal allocation (optional)
• Uses synk.GetSizedBytesPool for buffer pooling to reduce GC pressure
• HTTP flusher support for streaming responses only (text/event-stream or chunked responses without a Content-Length)
• Automatic cleanup on context cancellation