aegis-memory

Memory management and allocation for the Aegis Database Platform.

Overview

aegis-memory provides efficient memory management primitives including arena allocators and buffer pools. It's designed for high-performance database operations where memory allocation patterns are predictable.

Features

• Arena Allocators - Fast bump allocation with batch deallocation
• Memory Pools - Pre-allocated fixed-size block pools
• Zero-Copy Operations - Minimize memory copies where possible
• Thread-Safe - Lock-free and lock-based options

Modules

Usage

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

Arena Allocator

The arena allocator is ideal for request-scoped allocations where all memory can be freed at once:

use aegis_memory::arena::Arena;

// Create an arena with 1MB initial capacity
let arena = Arena::new(1024 * 1024);

// Allocate memory (very fast - just bumps a pointer)
let buffer = arena.alloc(1024);

// Use the buffer...
buffer[0] = 42;

// Reset frees all allocations at once (O(1))
arena.reset();

Benefits

Design

Arena Memory Layout:
┌────────────────────────────────────────────┐
│ Block 1                                    │
│ ┌─────────┬─────────┬─────────┬──────────┐│
│ │ Alloc 1 │ Alloc 2 │ Alloc 3 │   Free   ││
│ └─────────┴─────────┴─────────┴──────────┘│
├────────────────────────────────────────────┤
│ Block 2 (allocated when Block 1 full)     │
│ ┌─────────┬──────────────────────────────┐│
│ │ Alloc 4 │           Free               ││
│ └─────────┴──────────────────────────────┘│
└────────────────────────────────────────────┘

Benchmarks

Run benchmarks:

cargo bench -p aegis-memory

Typical results:

• Arena allocation: ~5ns per allocation
• Standard allocation: ~25ns per allocation
• Arena reset: ~100ns (constant, regardless of allocation count)

Tests

cargo test -p aegis-memory

Test count: 5 tests

License

Apache-2.0