Memory Arenas

Memory Arenas

MindFry uses arenas — pre-allocated memory pools — for zero-GC performance.

Psyche Arena

The Psyche Arena stores active lineages in a contiguous memory block.

pub struct PsycheArena {
    data: Vec<Lineage>,
    generations: Vec<u32>,
    free_list: Vec<usize>,
}

Operations

Operation	Complexity	Description
create	O(1)	Pop from free list
get	O(1)	Direct index access
remove	O(1)	Push to free list

Generational IDs

To prevent use-after-free bugs, IDs include a generation:

pub struct LineageId {
    index: u32,
    generation: u32,
}

Strata Arena

The Strata Arena stores historical engrams in ring buffers.

pub struct StrataArena {
    rings: Vec<RingBuffer<Engram>>,
    depth: usize, // Default: 64
}

Each lineage has a fixed-depth history. When full, oldest entries are overwritten.

Bond Graph

The Bond Graph uses Compressed Sparse Row (CSR) format for efficient traversal.

Adjacency Matrix (dense):    CSR (sparse):
    A  B  C  D               values: [0.8, 0.6, 0.5]
A [ 0 .8  0  0 ]             col_idx: [1, 2, 3]
B [ 0  0 .6  0 ]             row_ptr: [0, 1, 2, 3]
C [ 0  0  0 .5 ]
D [ 0  0  0  0 ]

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See Dynamics for how decay and propagation work.