Module incremental 

Incremental diffing with result caching.

This module provides caching and incremental computation for SBOM diffs, dramatically improving performance when comparing related SBOMs (e.g., successive builds where only a few components change).

How It Works

1. Content Hashing: Each SBOM section (components, dependencies, licenses, vulnerabilities) has a separate content hash.
2. Change Detection: Before recomputing, we check if each section changed.
3. Partial Recomputation: Only sections that changed are recomputed.
4. Result Caching: Full results are cached for exact SBOM pair matches.

Performance Gains

• Exact cache hit: O(1) lookup
• Partial change: Only recompute changed sections (typically 10-50% of work)
• Cold start: Same as regular diff

Structs

CacheStats

Statistics for cache performance.

CachedDiffResult

A cached diff result with metadata.

ChangedSections

Indicates which sections changed between two SBOMs.

DiffCache

Thread-safe cache for diff results.

DiffCacheConfig

Configuration for the diff cache.

DiffCacheKey

Key for full diff cache lookup.

IncrementalDiffEngine

A diff engine wrapper that supports incremental computation and caching.

IncrementalDiffResult

Result of an incremental diff operation.

SectionHashes

Section-level hashes for incremental change detection.

Enums

CacheHitType

Type of cache hit achieved.