I/O Abstraction

Purpose

Understanding Cabriolet’s platform-independent I/O layer.

References

Abstraction Layer

Architecture 

Application Code
       ↓
┌──────────────┐
│  IOSystem    │  Factory for handles
└──────┬───────┘
       │ creates
       ▼
┌──────────────┐
│   Handle     │  Abstract interface
└──────┬───────┘
       │ implements
   ┌───┴────┬──────────┐
   ▼        ▼          ▼
FileHandle  MemoryHandle  CustomHandle
   │            │
Platform   In-Memory
Specific    Buffer

Benefits

  • Platform independence: Same code on Windows/Linux/macOS

  • Testability: Easy to mock with memory handles

  • Extensibility: Add custom storage backends

  • Consistency: Uniform interface for all I/O

Handle Interface

All handles implement:

class Handle
  def read(size)
    # Read up to size bytes
  end

  def write(data)
    # Write data
  end

  def seek(offset, whence = IO::SEEK_SET)
    # Seek to position
  end

  def tell
    # Return current position
  end

  def eof?
    # Check if at end
  end

  def size
    # Total size
  end

  def close
    # Clean up resources
  end
end

Implementation Types

FileHandle

Direct file system access:

handle = Cabriolet::System::FileHandle.new('archive.cab', 'rb')
data = handle.read(1024)
handle.close

MemoryHandle

In-memory buffer:

data = File.binread('archive.cab')
handle = Cabriolet::System::MemoryHandle.new(data)

Custom Handles

Network, database, cloud storage, etc.

Performance considerations

  • Buffering: Critical for performance

  • Sequential access: Much faster than random

  • Memory vs I/O: Trade-offs based on use case

Bibliography