Module file_chunk 

File Chunk Value Object

This module provides the FileChunk value object, which represents an immutable chunk of file data for processing within the adaptive pipeline system. It follows Domain-Driven Design principles and ensures data integrity throughout processing.

Overview

The file chunk value object provides:

• Immutable Data: Once created, chunks cannot be modified
• Unique Identity: Each chunk has a unique UUID for tracking
• Sequence Ordering: Chunks maintain sequence numbers for reassembly
• Integrity Verification: Optional checksums for data integrity
• Metadata Tracking: Creation timestamps and processing metadata

Design Principles

The file chunk follows Domain-Driven Design value object principles:

• Immutability: Once created, chunks cannot be modified
• Value Semantics: Chunks are compared by value, not identity
• Self-Validation: Chunks validate their own data integrity
• Rich Behavior: Chunks provide methods for common operations

Chunk Structure

Core Data

• ID: Unique UUID for chunk identification and tracking
• Sequence Number: Position in the original file for reassembly
• Offset: Byte offset in the original file
• Size: Validated chunk size within system limits
• Data: The actual chunk data bytes

Metadata

• Checksum: Optional SHA-256 checksum for integrity verification
• Is Final: Flag indicating if this is the last chunk in a file
• Created At: UTC timestamp of chunk creation

Usage Examples

Basic Chunk Creation

Chunk with Checksum

Chunk Processing Chain

Chunk Validation

Data Integrity

Sequence Validation

Performance Considerations

Memory Usage

• Data Storage: Chunks store data in Vec<u8> for efficient access
• Metadata Overhead: Minimal metadata overhead per chunk
• Cloning: Chunks can be cloned efficiently for processing

Processing Efficiency

• Immutable Design: Prevents accidental mutations during processing
• Builder Pattern: Efficient creation of modified chunks
• Lazy Checksum: Checksums are calculated only when needed

Memory Management

• Automatic Cleanup: Chunks are automatically cleaned up when dropped
• Reference Counting: Use Arc<FileChunk> for shared ownership
• Streaming: Chunks can be processed in streaming fashion

Thread Safety

The file chunk is fully thread-safe:

• Immutable: Once created, chunks cannot be modified
• Send + Sync: Chunks can be safely sent between threads
• No Shared State: No mutable shared state to synchronize

Serialization

JSON Serialization

Binary Serialization

Integration

The file chunk integrates with:

• File Processing: Core unit of file processing operations
• Pipeline Stages: Passed between processing stages
• Storage Systems: Serialized for persistent storage
• Network Transport: Transmitted between distributed components

Error Handling

Validation Errors

• Invalid Size: Chunk size outside valid bounds
• Invalid Data: Corrupted or invalid chunk data
• Checksum Mismatch: Data integrity verification failures
• Sequence Errors: Invalid sequence numbers or ordering

Recovery Strategies

• Retry Logic: Automatic retry for transient failures
• Fallback Processing: Alternative processing for corrupted chunks
• Error Reporting: Detailed error context for debugging

Future Enhancements

Planned enhancements include:

• Compression: Built-in compression for chunk data
• Encryption: Encrypted chunk data for security
• Streaming: Streaming chunk processing for large files
• Caching: Intelligent caching of frequently accessed chunks

Structs

FileChunk

Represents an immutable chunk of file data for processing