method to use db from cache

vlcn-io · Dec 1, 2023 · 5f8858f · 5f8858f
1 parent 57f1a8f
commit 5f8858f
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Showing 2 changed files with 17 additions and 2 deletions.
diff --git a/packages/ws-server/src/DB.ts b/packages/ws-server/src/DB.ts
@@ -338,14 +338,19 @@ export function getDbPath(dbName: string, config: Config) {
   return path.join(config.dbFolder, dbName);
 }
 
-function getSchemaPath(schemaName: string, config: Config) {
+export function getSchemaPath(schemaName: string, config: Config) {
   if (hasPathParts(schemaName)) {
     throw new Error(`${schemaName} must not include '..', '/', or '\\'`);
   }
 
   return path.join(config.schemaFolder, schemaName);
 }
 
+export function getResidentSchemaVersion(schemaName: string, config: Config) {
+  const content = fs.readFileSync(getSchemaPath(schemaName, config), "utf-8");
+  return cryb64(content);
+}
+
 function hasPathParts(s: string) {
   return s.includes("..") || s.includes("/") || s.includes("\\");
 }
diff --git a/packages/ws-server/src/DBCache.ts b/packages/ws-server/src/DBCache.ts
@@ -1,4 +1,4 @@
-import { IDB } from "./DB.js";
+import { IDB, getResidentSchemaVersion } from "./DB.js";
 import { IDBFactory } from "./DBFactory.js";
 import { Config } from "./config.js";
 import FSNotify from "./fs/FSNotify.js";
@@ -34,6 +34,16 @@ export default class DBCache {
     return ret[0];
   }
 
+  async use(roomId: string, schemaName: string, cb: (db: IDB) => unknown) {
+    const version = getResidentSchemaVersion(schemaName, this.#config);
+    const db = await this.getAndRef(roomId, schemaName, version);
+    try {
+      await cb(db);
+    } finally {
+      this.unref(roomId);
+    }
+  }
+
   async getAndRef(roomId: string, schemaName: string, schemaVersion: bigint) {
     logger.info(`Get db from cache for room "${roomId}"`);
     let entry = this.#dbs.get(roomId);