🏭 Registries & Caches

Status: Implemented (Feb 2026)

The Registries & Caches category represents a specialized pattern used in LibreFolio to manage highly volatile or heavily fragmented data, such as real-time market prices, FX conversion rates, and blob URLs.

Unlike standard stores that hold a single array of entities, a Registry acts as a dynamic factory and manager of many independent stores.

🗂️ Stores

Store	Location	Purpose
assetPriceStoreRegistry	assetPriceStoreRegistry.ts	Maintains an independent Svelte store for the price of each individual asset ID.
fxStoreRegistry	fxStoreRegistry.ts	Maintains an independent store for the current exchange rate of each specific base:target currency pair.
imagePreviewCache	files/imagePreviewCache.ts	Acts as an LRU cache or map for Blob URLs generated for image previews to prevent memory leaks.

📐 Architecture & Flow (The Registry Pattern)

If the Dashboard displays 50 different assets, having a single monolithic priceStore update 10 times a second would trigger reactivity across the entire UI constantly.

Instead, the Registry Pattern isolates reactivity:

---
config:
  layout: elk
---
graph TD
    API["🐍 WebSocket / SSE (Live Market Data)"]

    Registry["🏭 Registry Factory (e.g., assetPriceStoreRegistry)"]

    subgraph Isolated_Stores ["Isolated Stores"]
        S1["Store: AAPL Price"]
        S2["Store: TSLA Price"]
        S3["Store: BTC Price"]
    end

    UI1["UI: AAPL Row"]
    UI2["UI: TSLA Row"]
    UI_Port["🧠 portfolioStore (Aggregator)"]

    API -->|Bulk Price Update| Registry
    Registry -->|Routes 140.50| S1
    Registry -->|Routes 200.10| S2
    Registry -->|Routes 65000| S3

    S1 -->|Subscribes| UI1
    S2 -->|Subscribes| UI2

    S1 -->|Subscribes| UI_Port
    S2 -->|Subscribes| UI_Port
    S3 -->|Subscribes| UI_Port

🧠 How it Works

1. Requesting a Store: When a UI component like AssetRow renders, it asks the registry for a store: const price = assetPriceStoreRegistry.getStore("AAPL").
2. Lazy Initialization: If the store for "AAPL" doesn't exist, the registry creates it, initiates an API/WebSocket subscription for that specific ticker, and returns the store.
3. Isolated Reactivity: When the price of AAPL changes, only the AAPL store updates. The TSLA row does not re-render, saving immense CPU overhead.
4. Cleanup: When components unmount, the registry can detect that "AAPL" has 0 subscribers and unsubscribe from the backend stream to save bandwidth.