Module buddy_allocator 

👎Deprecated since 0.2.0: Use jemalloc feature instead. See buddy_allocator module docs for migration.

Buddy Allocator for SochDB Memory Management

DEPRECATION NOTICE

This module is deprecated and will be removed in a future release.

Recommendation: Use jemalloc Instead

Enable the jemalloc feature in your Cargo.toml:

sochdb-core = { version = "...", features = ["jemalloc"] }

Why jemalloc is preferred:

1. Production-proven: Used by Firefox, Facebook, Redis, RocksDB
2. Thread-local caching: Eliminates lock contention on hot paths
3. Better fragmentation handling: Size-class based allocation
4. Automatic memory return: Returns memory to OS via madvise
5. No maintenance burden: Well-tested, battle-hardened code

Issues with this custom allocator:

1. Virtual address tracking only: Does not manage real memory
2. Lock contention: RwLock on every allocation
3. No memory reclamation: Never returns memory to OS
4. Internal fragmentation: Buddy allocation wastes ~50% for small allocs

Migration Path

If you are using BuddyAllocator or SlabAllocator directly:

// Before (deprecated):
let allocator = BuddyAllocator::new(64 * 1024 * 1024)?;
let addr = allocator.allocate(1024)?;

// After (recommended):
// Simply enable the jemalloc feature and use standard allocation:
let buffer: Vec<u8> = Vec::with_capacity(1024);

Original Documentation

Implements a buddy system allocator for efficient power-of-2 memory block allocation. Key features:

• O(1) allocation and deallocation for available blocks
• Automatic block splitting and merging
• Memory coalescing to reduce fragmentation
• Thread-safe with fine-grained locking
• Support for multiple memory pools

Structs

BlockHeaderDeprecated

Block header stored at the beginning of each block

BuddyAllocatorDeprecated

Multi-pool buddy allocator

BuddyArenaDeprecated

Arena allocator using buddy allocator for backing storage

BuddyStatsDeprecated

Statistics for the buddy allocator

MemoryPoolDeprecated

A single memory pool managed by the buddy allocator

SlabAllocatorDeprecated

Slab allocator built on top of buddy allocator for fixed-size objects

TypedBuddyAllocatorDeprecated

A typed buddy allocator for allocating objects of a specific type

Enums

BuddyErrorDeprecated

Error types for buddy allocator operations

Constants

DEFAULT_POOL_SIZEDeprecated

Default pool size (64 MB)

MAX_BLOCK_SIZEDeprecated

Maximum block size (1 GB)

MIN_BLOCK_SIZEDeprecated

Minimum block size (16 bytes)

Functions

buddy_addrDeprecated

Calculate buddy address for a given address and order

order_to_sizeDeprecated

Calculate the size for a given order

size_to_orderDeprecated

Calculate the order (log2) for a given size