Module Overview¶

The DocuSnap-Backend system consists of five core functional modules that work together to implement the system's main features. This page provides an overview of these core modules.

Core Module Composition¶

Through analysis of the DocuSnap-Backend codebase, we have identified the following five core functional modules:

1. Task Processing Module: Manages task queues, allocates worker threads, and coordinates asynchronous task processing
2. OCR Processing Module: Processes image recognition requests and converts images to text
3. LLM Processing Module: Builds prompts, calls LLM API, and processes LLM responses
4. Security & Encryption Module: Implements end-to-end encryption and protects data transmission security
5. Cache & Persistence Module: Manages storage, retrieval, and cleanup of task status and results

These modules together form the core functional architecture of DocuSnap-Backend, with each module responsible for a specific functional area and interacting through clear interfaces and data flows.

Module Relationship Diagram¶

The following diagram shows the relationships and interactions between the five core modules:

From the diagram, we can see that:

• The Task Processing Module is at the center of the system, coordinating the work of other modules
• The OCR Processing Module and LLM Processing Module work closely together to complete document and form processing
• The Security & Encryption Module and Cache & Persistence Module provide support services for other modules
• All modules interact with the Task Processing Module, forming a coordinated working whole

Module Responsibilities Overview¶

1. Task Processing Module¶

The Task Processing Module is the core coordinator of the system, responsible for managing the lifecycle and workflow of tasks.

Main Responsibilities: - Receiving and validating client requests - Managing task queues and task status - Coordinating the allocation and execution of worker threads - Implementing processing strategies for different types of tasks - Coordinating the work of other modules

Key Components: - Task queue - Worker thread pool - Task status management - Processing strategy selector

2. OCR Processing Module¶

The OCR Processing Module is responsible for image text recognition, converting document and form images into text content.

Main Responsibilities: - Handling image preprocessing and format conversion - Calling OCR services for text recognition - Processing multiple images in parallel - Merging and organizing OCR results

Key Components: - OCR service client - Image processing tools - Parallel processing controller - Result merger

3. LLM Processing Module¶

The LLM Processing Module is responsible for text analysis and information extraction, utilizing the capabilities of large language models to understand document content.

Main Responsibilities: - Building appropriate prompts based on task type - Calling LLM API for text analysis - Parsing and processing LLM responses - Generating structured processing results

Key Components: - Prompt builder - LLM API client - Response parser - Result formatter

4. Security & Encryption Module¶

The Security & Encryption Module is responsible for protecting the security of the system and data, implementing end-to-end encryption and request validation.

Main Responsibilities: - Implementing RSA and AES hybrid encryption - Validating the integrity and authenticity of requests - Protecting the security of sensitive data transmission - Managing encryption keys and security configurations

Key Components: - RSA encryptor/decryptor - AES encryptor/decryptor - Hash validator - Key manager

5. Cache & Persistence Module¶

The Cache & Persistence Module is responsible for managing the storage and retrieval of system data, improving system performance and reliability.

Main Responsibilities: - Managing SQLite database connections - Storing and retrieving task status and results - Implementing caching mechanisms to avoid repeated computation - Periodically cleaning up expired data

Key Components: - Database connection manager - Task data store - Cache query handler - Data cleaner

Module Design Principles¶

The core module design of DocuSnap-Backend follows these principles:

1. Single Responsibility Principle: Each module focuses on a specific functional area
2. Clear Interface Principle: Modules interact through clearly defined interfaces
3. Low Coupling, High Cohesion Principle: Reducing dependencies between modules while enhancing functional associations within modules
4. Extensibility Principle: Module design facilitates extension and addition of new features
5. Testability Principle: Module functions can be independently tested and verified

Through these design principles, DocuSnap-Backend has achieved a modular architecture that is structurally clear, functionally well-defined, and easy to maintain and extend.

In the following pages, we will provide detailed descriptions of the design, implementation, and key code examples for each core module.