Module validation 

SSTable Validation Layer

Implements defense-in-depth validation for memory-mapped files to prevent crashes from corrupted, truncated, or tampered files.

Safety Guarantees

1. Pre-mmap validation: Verify file integrity before memory mapping
2. Magic number check: Ensure file is valid SSTable format
3. Size validation: Prevent reading beyond file boundaries
4. Checksum verification: Detect bit rot and tampering

Formal Safety Invariant

∀p ∈ MappedPages: validate_before_mmap(file) = Ok ⟹ p.valid = true

This establishes that all memory-mapped pages are valid before dereferencing.

Structs

SSTableValidator

SSTable validator for pre-mmap validation

Enums

ValidationError

Validation error types

Constants

FOOTER_SIZE

Footer size in bytes

MAGIC_NUMBER

SSTable magic number: “AFFv2025” in ASCII

MIN_SSTABLE_SIZE

Minimum valid SSTable size (header + at least one edge + footer) Header (8 bytes magic) + Edge (128 bytes) + Footer (144 bytes) = 280 bytes

Functions

validate_sstable_file

Validate SSTable file at path (convenience function)