also accept "][safepoint" as indicator of java unified logging format

Author: chewiebug

src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderFactory.java

@@ -152,8 +152,9 @@ else if (s.contains("<AF")) {
             if (getLogger().isLoggable(Level.INFO)) getLogger().info("File format: IBM <1.3.0");
             return new DataReaderIBM1_3_0(gcResource, in);
         }
-        // ...][info][gc       ] Using Shenandoah <or any other gc algorithm in unified jvm logging format>
-        else if (s.contains("][gc")) {
+        // ...][info][gc        ]
+        // or ...][info][safepoint ] Using java unified jvm logging format
+        else if (s.contains("][gc") || s.contains("][safepoint")) {
             if (getLogger().isLoggable(Level.INFO)) getLogger().info("File format: Oracle / OpenJDK unified jvm logging");
             return new DataReaderUnifiedJvmLogging(gcResource, in);
         }

src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFactory.java

@@ -373,4 +373,12 @@ public void testOracleShenandoahJ8Simple() throws Exception {
         assertDataReader(DataReaderSun1_6_0.class, dr.getClass());
     }
 
+    @Test
+    public void testOpenJdkJulRollover() throws IOException {
+        DataReaderFactory factory = new DataReaderFactory();
+        DataReader dr = factory.getDataReader(new GcResourceFile("byteArray"), new ByteArrayInputStream((
+                "[2019-09-17T20:20:29.824+0000][19.163s][info ][safepoint                   ] Total time for which application threads were stopped: 0.0047914 seconds, Stopping threads took: 0.0000103 seconds\n\n").getBytes()));
+        assertDataReader(DataReaderUnifiedJvmLogging.class, dr.getClass());
+    }
+
 }