Doclea MCP

import type { SQLiteDatabase } from "@/database/sqlite"; import type { EmbeddingClient } from "./provider"; /** * Computes a SHA-256 hash of the content for cache key */ async function hashContent(content: string): Promise<string> { const encoder = new TextEncoder(); const data = encoder.encode(content); const hashBuffer = await crypto.subtle.digest("SHA-256", data); const hashArray = Array.from(new Uint8Array(hashBuffer)); return hashArray.map((b) => b.toString(16).padStart(2, "0")).join(""); } /** * Wraps an embedding client with SQLite-based caching */ export class CachedEmbeddingClient implements EmbeddingClient { constructor( private client: EmbeddingClient, private db: SQLiteDatabase, private model: string, ) {} async embed(text: string): Promise<number[]> { const contentHash = await hashContent(text); // Check cache first const cached = this.db.getCachedEmbedding(contentHash, this.model); if (cached) { return cached; } // Generate embedding const embedding = await this.client.embed(text); // Cache it this.db.setCachedEmbedding(contentHash, this.model, embedding); return embedding; } async embedBatch(texts: string[]): Promise<number[][]> { if (texts.length === 0) return []; // Compute hashes for all texts const hashes = await Promise.all(texts.map((t) => hashContent(t))); // Check cache for all const cachedMap = this.db.getCachedEmbeddingsBatch(hashes, this.model); // Find which texts need embedding const uncachedIndices: number[] = []; const uncachedTexts: string[] = []; for (let i = 0; i < texts.length; i++) { const hash = hashes[i]; if (hash && !cachedMap.has(hash)) { uncachedIndices.push(i); uncachedTexts.push(texts[i] as string); } } // Generate embeddings for uncached texts let newEmbeddings: number[][] = []; if (uncachedTexts.length > 0) { newEmbeddings = await this.client.embedBatch(uncachedTexts); // Cache the new embeddings for (let i = 0; i < uncachedIndices.length; i++) { const idx = uncachedIndices[i]; const hash = hashes[idx as number]; const embedding = newEmbeddings[i]; if (hash && embedding) { this.db.setCachedEmbedding(hash, this.model, embedding); } } } // Assemble results in original order const results: number[][] = []; let uncachedIdx = 0; for (let i = 0; i < texts.length; i++) { const hash = hashes[i]; if (hash) { const cached = cachedMap.get(hash); if (cached) { results.push(cached); } else { const embedding = newEmbeddings[uncachedIdx]; if (embedding) { results.push(embedding); } uncachedIdx++; } } } return results; } }