Bridge

Bridge

Path: src/modbus/Bridge.h

Revision History:

• Initial documentation

A Bridge component that enables inter-component messaging and remote method invocation in an ESP32-based system. It allows components to register member functions that can be called via a message passing mechanism, typically triggered by Modbus commands.

REQUIREMENTS

• No specific hardware pins required
• Software dependencies for messaging and component management

PROVIDES

• SComponentInfo: A structure that stores information about registered component methods
  • Stores component key, instance pointer, method name, and function pointer
• Bridge: Main class that manages component method registration and message handling
  • Inherits from Component base class

FEATURES

• Register component member functions for remote invocation
• Message routing between components
• Method lookup by component ID and method name
• Debug support for listing registered methods
• Support for component discovery for Modbus management

DEPENDENCIES

• Component: Base class for all components
• WString: String manipulation
• xtypes: Type definitions
• enums: Enumeration definitions
• macros: Macro definitions
• Vector: Container for storing component information
• Streaming: Stream output utilities

BEHAVIOUR

The Bridge acts as a message router between components. It maintains a registry of component methods and handles method invocation based on message parameters.

TODOS

PERFORMANCE

• The current implementation uses dynamic memory allocation for component registration which could lead to heap fragmentation. Consider using a fixed-size pool for SComponentInfo objects.
• Message parsing could be optimized for cases with large numbers of registered components.

SECURITY

• There is no authentication mechanism for method invocation. Consider adding a permission system.
• Method invocation through Modbus should be validated to prevent buffer overflows and other security issues.

COMPLIANCE

• Ensure proper memory management to comply with embedded system best practices.
• Test for compliance with industrial communication standards when used with Modbus.

RECOMMENDATIONS

• Use descriptive method names and consistent component IDs to make debugging easier.
• Keep registered method count below the MAX_COMPONENTS limit (defined in configuration).
• When adding new components, always register their methods during initialization.
• Consider implementing an unregister mechanism for dynamically loaded/unloaded components.