Added #

Core Architecture

• FilesystemRaid — top-level orchestrator with full write/read/delete/list/recover API
• FilesystemRaidBuilder — fluent builder for ergonomic configuration
• RaidStrategy interface — clean contract for all RAID implementations

RAID Levels

• RAID 0 (Striping): parallel writes/reads, zero overhead, no fault tolerance
• RAID 1 (Mirroring): full data copy to all disks, tolerates N-1 disk failures
• RAID 5 (Striping with distributed parity): balanced performance + redundancy, tolerates 1 disk failure; distributed parity with left-symmetric rotation

Parity Engine

• ParityCalculator — XOR-based parity with single-chunk and full-stripe recovery
• ReedSolomonCodec — GF(2⁸) Reed-Solomon codec with Vandermonde matrix encoding; tolerates multiple disk failures (configurable parity shard count)
• ParityRecovery — high-level coordinator; switches between XOR and RS automatically

Storage Layer

• DiskManager — low-level disk I/O with health probing, write retry, simulated failures
• ChunkHandler — encode/decode pipeline (compress → encrypt → checksum)
• FileRegistry — JSON-backed per-disk file catalogue
• StorageInfo — aggregated capacity and utilisation statistics

Utilities

• ChunkSplitter — zero-copy split/merge with zero-padding and length restoration
• FileHasher — SHA-256 / MD5 helpers with constant-time comparison
• RaidCompression — DEFLATE with 4-byte magic header for transparent detection
• RaidEncryption / ChunkHandler.encryptChunk — AES-256-CBC with random IV per chunk
• RaidLogger / OperationLogger — levelled structured logging with ANSI colour

Models

• RaidConfig — immutable config with derived efficiency and fault-tolerance helpers
• DiskStatus — disk health snapshot with utilisation metrics
• ChunkMetadata — JSON-serialisable per-chunk metadata (checksum, compression, encryption flags)
• RecoveryReport — detailed recovery outcome with per-file and per-disk records

Exceptions

• RaidConfigurationException, DiskFailedException, ChunkNotFoundException, RaidFileNotFoundException, InsufficientSpaceException, CorruptedDataException, RaidNotRecoverableException, TooManyDiskFailuresException, RaidRecoveryException, MetadataException, ParityException

Tests

• parity_test.dart — XOR calculation, stripe recovery, rotation
• reed_solomon_test.dart — encode, 1-shard recovery, 2-shard recovery, round-trips
• chunk_splitter_test.dart — split, merge, pad, equalise, round-trips
• disk_manager_test.dart — init, write, read, delete, failure simulation
• raid_0_test.dart — write/read, delete, failure, 1 MiB round-trip
• raid_1_test.dart — mirroring, 2-disk failure, recovery
• raid_5_test.dart — data/parity disk failure, recovery, builder
• integration_test.dart — full end-to-end scenarios for all RAID levels

Examples

• basic_usage.dart — minimal write/read/recover demo
• nas_setup.dart — home NAS simulation with health monitoring
• recovery_example.dart — all four recovery scenarios side-by-side

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[Unreleased] #

Planned #

• RAID 6 support (double-parity, tolerates 2 disk failures)
• Async health callback / event stream for real-time monitoring
• Hot-spare disk support for automatic online rebuilds
• S3-compatible backend adapter (store chunks on object storage)
• Web UI dashboard for disk health and array status
• Benchmark suite (throughput, latency, recovery time)