From c03073bddd45e31d6e174ad617823b6a5b04e48e Mon Sep 17 00:00:00 2001
From: softsimon <softsimon@protonmail.com>
Date: Mon, 2 Nov 2020 22:06:51 +0700
Subject: [PATCH] FIx: Write cache sync on exit.

---
 backend/src/api/disk-cache.ts | 40 +++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/backend/src/api/disk-cache.ts b/backend/src/api/disk-cache.ts
index 6cf7114ca..e3d6491a5 100644
--- a/backend/src/api/disk-cache.ts
+++ b/backend/src/api/disk-cache.ts
@@ -9,23 +9,17 @@ import logger from '../logger';
 class DiskCache {
   private static FILE_NAME = './cache.json';
   private static FILE_NAME_2 = './cache2.json';
+  private static CHUNK_SIZE = 50000;
   constructor() {
     if (!cluster.isMaster) {
       return;
     }
-    /*
-    if (!fs.existsSync(DiskCache.FILE_NAME)) {
-      fs.closeSync(fs.openSync(DiskCache.FILE_NAME, 'w'));
-      logger.info('Disk cache file created');
-    }
-    */
-    process.on('SIGINT', async () => {
-      await this.$saveCacheToDisk();
+    process.on('SIGINT', () => {
+      this.saveCacheToDiskSync();
       process.exit(2);
     });
-
-    process.on('SIGTERM', async () => {
-      await this.$saveCacheToDisk();
+    process.on('SIGTERM', () => {
+      this.saveCacheToDiskSync();
       process.exit(2);
     });
   }
@@ -35,9 +29,9 @@ class DiskCache {
       return;
     }
     try {
-      logger.debug('Writing mempool and blocks data to disk cache...');
-      const mempoolChunk_1 = Object.fromEntries(Object.entries(memPool.getMempool()).splice(0, 50000));
-      const mempoolChunk_2 = Object.fromEntries(Object.entries(memPool.getMempool()).splice(50000));
+      logger.debug('Writing mempool and blocks data to disk cache (async)...');
+      const mempoolChunk_1 = Object.fromEntries(Object.entries(memPool.getMempool()).splice(0, DiskCache.CHUNK_SIZE));
+      const mempoolChunk_2 = Object.fromEntries(Object.entries(memPool.getMempool()).splice(DiskCache.CHUNK_SIZE));
       await fsPromises.writeFile(DiskCache.FILE_NAME, JSON.stringify({
         blocks: blocks.getBlocks(),
         mempool: mempoolChunk_1
@@ -51,6 +45,24 @@ class DiskCache {
     }
   }
 
+  saveCacheToDiskSync(): void {
+    try {
+      logger.debug('Writing mempool and blocks data to disk cache...');
+      const mempoolChunk_1 = Object.fromEntries(Object.entries(memPool.getMempool()).splice(0, DiskCache.CHUNK_SIZE));
+      const mempoolChunk_2 = Object.fromEntries(Object.entries(memPool.getMempool()).splice(DiskCache.CHUNK_SIZE));
+      fs.writeFileSync(DiskCache.FILE_NAME, JSON.stringify({
+        blocks: blocks.getBlocks(),
+        mempool: mempoolChunk_1
+      }), {flag: 'w'});
+      fs.writeFileSync(DiskCache.FILE_NAME_2, JSON.stringify({
+        mempool: mempoolChunk_2
+      }), {flag: 'w'});
+      logger.debug('Mempool and blocks data saved to disk cache');
+    } catch (e) {
+      logger.warn('Error writing to cache file: ' + e.message || e);
+    }
+  }
+
   loadMempoolCache() {
     if (!fs.existsSync(DiskCache.FILE_NAME)) {
       return;