hugging2021/local-gemma4-rag

1import { create, insert, search, removeMultiple } from 'https://cdn.jsdelivr.net/npm/@orama/orama@latest/+esm';2 3export class VectorDB {4  constructor() {5    this.db = null;6    this.isInitialized = false;7  }8 9  async init() {10    if (this.isInitialized) return;11 12    this.db = await create({13      schema: {14        text: 'string',15        fileName: 'string',16        embedding: 'vector[384]', // MiniLM-L6-v2 dimension17      },18      indexStyles: {19        embedding: 'cosine', // Recommended for normalized embeddings20      },21    });22 23    this.isInitialized = true;24    console.log('📦 Orama Vector DB initialized');25  }26 27  async addDocument(text, fileName, embedding) {28    if (!this.isInitialized) await this.init();29 30    return await insert(this.db, {31      text,32      fileName,33      embedding,34    });35  }36 37  async removeDocumentsByFileName(fileName) {38    if (!this.isInitialized) await this.init();39 40    // 1. Search for all documents with this filename41    const results = await search(this.db, {42      where: {43        fileName: fileName44      },45      limit: 1000 // A single file likely won't have more than 1000 chunks46    });47 48    const ids = results.hits.map(hit => hit.id);49    if (ids.length > 0) {50      await removeMultiple(this.db, ids);51      console.log(`🗑️ Removed ${ids.length} chunks for ${fileName}`);52    }53    return ids.length;54  }55 56  async query(vector, limit = 5) {57    if (!this.isInitialized) await this.init();58 59    const results = await search(this.db, {60      mode: 'vector',61      vector: {62        value: vector,63        property: 'embedding',64      },65      similarity: 0.5,66      limit: limit,67    });68 69    return results.hits.map(hit => ({70      text: hit.document.text,71      fileName: hit.document.fileName,72      score: hit.score,73    }));74  }75 76  async clear() {77    this.isInitialized = false;78    await this.init();79  }80}81 82// Singleton instance83export const db = new VectorDB();84