Conduct non-functional refactoring for EventLogger

- Fixed all javadocs across the class to make them consistent to each
  other;
- Reordered modifiers where needed;
- String literal changed to reflect new name of the class.

Bug: b/243116883
Test: N/A
Change-Id: I27c2deb7d3bdf34bac45603221aaa4378450a999

services/core/java/com/android/server/utils/EventLogger.java

@@ -25,20 +25,32 @@ import java.lang.annotation.RetentionPolicy;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.LinkedList;
+import java.util.Locale;
 
+/**
+ * Logs human-readable events for debugging purposes.
+ */
 public class EventLogger {
 
-    // ring buffer of events to log.
+    /** Identifies the source of events. */
+    private final String mTag;
+
+    /** Stores the events using a ring buffer. */
     private final LinkedList<Event> mEvents;
 
-    private final String mTitle;
-
-    // the maximum number of events to keep in log
+    /**
+     * The maximum number of events to keep in {@code mEvents}.
+     *
+     * <p>Calling {@link #log} when the size of {@link #mEvents} matches the threshold will
+     * cause the oldest event to be evicted.
+     */
     private final int mMemSize;
 
-    public static abstract class Event {
-        // formatter for timestamps
-        private final static SimpleDateFormat sFormat = new SimpleDateFormat("MM-dd HH:mm:ss:SSS");
+    public abstract static class Event {
+
+        /** Timestamps formatter. */
+        private static final SimpleDateFormat sFormat =
+                new SimpleDateFormat("MM-dd HH:mm:ss:SSS", Locale.US);
 
         private final long mTimestamp;
 
@@ -114,7 +126,7 @@ public class EventLogger {
          * Timestamp information will be automatically added, do not include it.
          * @return a string representation of the event that occurred.
          */
-        abstract public String eventToString();
+        public abstract String eventToString();
     }
 
     public static class StringEvent extends Event {
@@ -133,12 +145,12 @@ public class EventLogger {
     /**
      * Constructor for logger.
      * @param size the maximum number of events to keep in log
-     * @param title the string displayed before the recorded log
+     * @param tag the string displayed before the recorded log
      */
-    public EventLogger(int size, String title) {
+    public EventLogger(int size, String tag) {
         mEvents = new LinkedList<Event>();
         mMemSize = size;
-        mTitle = title;
+        mTag = tag;
     }
 
     public synchronized void log(Event evt) {
@@ -170,7 +182,7 @@ public class EventLogger {
     }
 
     public synchronized void dump(PrintWriter pw) {
-        pw.println("Audio event log: " + mTitle);
+        pw.println("Events log: " + mTag);
         for (Event evt : mEvents) {
             pw.println(evt.toString());
         }