aegis-storage

High-performance storage engine for the Aegis Database Platform.

Overview

aegis-storage provides the core storage layer with pluggable backends, write-ahead logging, MVCC transactions, and block-level compression. It serves as the foundation for all data persistence in Aegis.

Features

• Pluggable Backends - Memory and local filesystem backends
• Write-Ahead Logging (WAL) - Durability and crash recovery
• MVCC Transactions - Snapshot isolation with multi-version concurrency control
• Block Compression - LZ4 and Zstd compression support
• Buffer Pool - LRU-based page caching for optimal I/O

Architecture

┌─────────────────────────────────────┐
│          Storage API                │
├─────────────────────────────────────┤
│     Transaction Manager (MVCC)      │
├─────────────────────────────────────┤
│         Buffer Pool (LRU)           │
├─────────────────────────────────────┤
│      Write-Ahead Log (WAL)          │
├─────────────┬───────────────────────┤
│   Memory    │    Local FS Backend   │
│   Backend   │                       │
└─────────────┴───────────────────────┘

Modules

Usage

[dependencies]
aegis-storage = { path = "../aegis-storage" }

Example

use aegis_storage::{StorageEngine, StorageConfig};
use aegis_storage::backend::MemoryBackend;

// Create storage engine with memory backend
let config = StorageConfig::default();
let engine = StorageEngine::new(config)?;

// Begin a transaction
let tx = engine.begin_transaction()?;

// Write data
engine.put(&tx, b"key", b"value")?;

// Commit
engine.commit(tx)?;

// Read data
let value = engine.get(b"key")?;

Compression

use aegis_storage::block::{Block, CompressionType};

// Create compressed block
let block = Block::new(data)
    .with_compression(CompressionType::Lz4);

// Compression is automatic on write
engine.write_block(block)?;

Configuration

[storage]
backend = "local"              # "memory" or "local"
data_directory = "/var/aegis"
compression = "lz4"            # "none", "lz4", "zstd"
buffer_pool_size = "1GB"
wal_enabled = true
sync_on_commit = true

Performance

• Write throughput: ~500K ops/sec (memory backend)
• Read throughput: ~1M ops/sec (cached)
• Compression ratio: 2-10x depending on data

Tests

cargo test -p aegis-storage

Test count: 23 tests

License

Apache-2.0