Store block first seen in db

backend/src/utils/file-read.ts

@@ -0,0 +1,58 @@
+import * as fs from 'fs';
+import logger from '../logger';
+import config from '../config';
+
+function readFile(filePath: string, bufferSize?: number): string[] {
+  const fileSize = fs.statSync(filePath).size;
+  const chunkSize = bufferSize || fileSize;
+  const fileDescriptor = fs.openSync(filePath, 'r');
+  const buffer = Buffer.alloc(chunkSize);
+
+  fs.readSync(fileDescriptor, buffer, 0, chunkSize, fileSize - chunkSize);
+  fs.closeSync(fileDescriptor);
+
+  const lines = buffer.toString('utf8', 0, chunkSize).split('\n');
+  return lines;
+}
+
+function extractDateFromLogLine(line: string): number | undefined {
+  // Extract time from log: "2021-08-31T12:34:56Z" or "2021-08-31T12:34:56.123456Z"
+  const dateMatch = line.match(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d{6})?Z/);
+  if (!dateMatch) {
+    return undefined;
+  }
+
+  const dateStr = dateMatch[0];
+  const date = new Date(dateStr);
+  let timestamp = Math.floor(date.getTime() / 1000); // Remove decimal (microseconds are added later)
+
+  const timePart = dateStr.split('T')[1];
+  const microseconds = timePart.split('.')[1] || '';
+
+  if (!microseconds) {
+    return timestamp;
+  }
+
+  return parseFloat(timestamp + '.' + microseconds);
+}
+
+export function getRecentFirstSeen(hash: string): number | undefined {
+  const debugLogPath = config.CORE_RPC.DEBUG_LOG_PATH;
+  if (debugLogPath) {
+    try {
+      // Read the last few lines of debug.log
+      const lines = readFile(debugLogPath, 2048);
+
+      for (let i = lines.length - 1; i >= 0; i--) {
+        const line = lines[i];
+        if (line && line.includes(`Saw new header hash=${hash}`)) {
+          return extractDateFromLogLine(line);
+        }
+      }
+    } catch (e) {
+      logger.err(`Cannot parse block first seen time from Core logs. Reason: ` + (e instanceof Error ? e.message : e));
+    }
+  }
+
+  return undefined;
+}