From e548326977cee6a49343a1313c4c677e7a2d40e5 Mon Sep 17 00:00:00 2001
From: alikia2x <ziwen243@outlook.com>
Date: Fri, 12 Jul 2024 01:11:32 +0800
Subject: [PATCH] update: logic of loading data

---
 src/lib/server/database/loadData.ts | 32 ++++++++++++++-----------
 src/lib/server/dirHash.ts           | 36 +++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 13 deletions(-)
 create mode 100644 src/lib/server/dirHash.ts

diff --git a/src/lib/server/database/loadData.ts b/src/lib/server/database/loadData.ts
index e00f4bb..ad1848a 100644
--- a/src/lib/server/database/loadData.ts
+++ b/src/lib/server/database/loadData.ts
@@ -1,33 +1,39 @@
 import fs from 'fs';
 import { globalMemoryStorage, songData, songNameCache } from '$lib/server/cache.js';
+import { getDirectoryHash } from '../dirHash';
+
+const dataPath = './data/song/';
 
 export async function loadData() {
-    const LastLoaded: number | undefined  = globalMemoryStorage.get("lastLoadData");
+    const LastLoaded: number | undefined = globalMemoryStorage.get('lastLoadData');
+    const LastHash: string | undefined = globalMemoryStorage.get('lastDataDirHash');
     const currentTime = new Date().getTime();
+    const currentHash = getDirectoryHash(dataPath);
     // Already loaded.
-    if (LastLoaded && currentTime - LastLoaded < 3600) {
+    if (LastLoaded && LastHash && currentTime - LastLoaded < 120 * 1000 && currentHash === LastHash) {
         return;
     }
 
-    const dataPath = "./data/song/";
-    const songList = fs.readdirSync(dataPath)
-        .map(fileName => {
-            if (fileName.endsWith(".json"))
-                return fileName.slice(0, fileName.length - 5);
+    const songList = fs
+        .readdirSync(dataPath)
+        .map((fileName) => {
+            if (fileName.endsWith('.json')) return fileName.slice(0, fileName.length - 5);
             else return null;
         })
-        .filter(fileName => fileName !== null);
+        .filter((fileName) => fileName !== null);
+    songData.flushAll();
+    songNameCache.flushAll();
     for (const songID of songList) {
         try {
-            const fileContentString = fs.readFileSync(dataPath + songID + ".json").toString();
+            const fileContentString = fs.readFileSync(dataPath + songID + '.json').toString();
             const data = JSON.parse(fileContentString);
             songData.set(songID, data);
             const metadata: MusicMetadata = data;
             songNameCache.set(metadata.name, metadata);
-        }
-        catch {
+        } catch {
             console.error(`[load-song-data] Could not load song ID ${songID}`);
         }
     }
-    globalMemoryStorage.set("lastLoadData", new Date().getTime());
-}
\ No newline at end of file
+    globalMemoryStorage.set('lastLoadData', new Date().getTime());
+    globalMemoryStorage.set('lastDataDirHash', getDirectoryHash(dataPath));
+}
diff --git a/src/lib/server/dirHash.ts b/src/lib/server/dirHash.ts
new file mode 100644
index 0000000..856ca5c
--- /dev/null
+++ b/src/lib/server/dirHash.ts
@@ -0,0 +1,36 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import * as crypto from 'crypto';
+
+// Function to get hash for a given directory
+export function getDirectoryHash(dir: string): string {
+    const fileDetails: string[] = [];
+
+    // Recursive function to traverse the directory
+    function traverseDirectory(currentDir: string): void {
+        const files = fs.readdirSync(currentDir);
+
+        files.forEach(file => {
+            const filePath = path.join(currentDir, file);
+            const stats = fs.statSync(filePath);
+
+            if (stats.isDirectory()) {
+                traverseDirectory(filePath);
+            } else {
+                // Collect file path and last modification time
+                fileDetails.push(`${filePath}:${stats.mtimeMs}`);
+            }
+        });
+    }
+
+    traverseDirectory(dir);
+
+    // Sort file details to ensure consistent hash
+    fileDetails.sort();
+
+    // Create hash from file details
+    const hash = crypto.createHash('sha256');
+    hash.update(fileDetails.join('|'));
+
+    return hash.digest('hex');
+}
\ No newline at end of file