Using a single array instead of a list of array for trcking events

In case events come out of order, the list is not properly initialized which can lead to missing invalid states Bug: 127282292 Change-Id: I3b4784b8e3eec890e80e62c2ea613e1ba84b6c95
2019-03-04 08:54:15 -08:00
parent 84eb812bcd
commit 5654949bd0
9 changed files with 181 additions and 104 deletions
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.logging;
+
+
+import java.io.PrintWriter;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+
+/**
+ * A utility class to record and log events. Events are stored in a fixed size array and old logs
+ * are purged as new events come.
+ */
+public class EventLogArray {
+
+    private static final int TYPE_ONE_OFF = 0;
+    private static final int TYPE_FLOAT = 1;
+    private static final int TYPE_INTEGER = 2;
+    private static final int TYPE_BOOL_TRUE = 3;
+    private static final int TYPE_BOOL_FALSE = 4;
+
+    private final String name;
+    private final EventEntry[] logs;
+    private int nextIndex;
+
+    public EventLogArray(String name, int size) {
+        this.name = name;
+        logs = new EventEntry[size];
+        nextIndex = 0;
+    }
+
+    public void addLog(String event) {
+        addLog(TYPE_ONE_OFF, event, 0);
+    }
+
+    public void addLog(String event, int extras) {
+        addLog(TYPE_INTEGER, event, extras);
+    }
+
+    public void addLog(String event, float extras) {
+        addLog(TYPE_FLOAT, event, extras);
+    }
+
+    public void addLog(String event, boolean extras) {
+        addLog(extras ? TYPE_BOOL_TRUE : TYPE_BOOL_FALSE, event, 0);
+    }
+
+    private void addLog(int type, String event, float extras) {
+        // Merge the logs if its a duplicate
+        int last = (nextIndex + logs.length - 1) % logs.length;
+        int secondLast = (nextIndex + logs.length - 2) % logs.length;
+        if (isEntrySame(logs[last], type, event) && isEntrySame(logs[secondLast], type, event)) {
+            logs[last].update(type, event, extras);
+            logs[secondLast].duplicateCount++;
+            return;
+        }
+
+        if (logs[nextIndex] == null) {
+            logs[nextIndex] = new EventEntry();
+        }
+        logs[nextIndex].update(type, event, extras);
+        nextIndex = (nextIndex + 1) % logs.length;
+    }
+
+    public void dump(String prefix, PrintWriter writer) {
+        writer.println(prefix + name + " event history:");
+        SimpleDateFormat sdf = new SimpleDateFormat("  HH:mm:ss.SSSZ  ", Locale.US);
+        Date date = new Date();
+
+        for (int i = 0; i < logs.length; i++) {
+            EventEntry log = logs[(nextIndex + logs.length - i - 1) % logs.length];
+            if (log == null) {
+                continue;
+            }
+            date.setTime(log.time);
+
+            StringBuilder msg = new StringBuilder(prefix).append(sdf.format(date))
+                    .append(log.event);
+            switch (log.type) {
+                case TYPE_BOOL_FALSE:
+                    msg.append(": false");
+                    break;
+                case TYPE_BOOL_TRUE:
+                    msg.append(": true");
+                    break;
+                case TYPE_FLOAT:
+                    msg.append(": ").append(log.extras);
+                    break;
+                case TYPE_INTEGER:
+                    msg.append(": ").append((int) log.extras);
+                    break;
+                default: // fall out
+            }
+            if (log.duplicateCount > 0) {
+                msg.append(" & ").append(log.duplicateCount).append(" similar events");
+            }
+            writer.println(msg);
+        }
+    }
+
+    private boolean isEntrySame(EventEntry entry, int type, String event) {
+        return entry != null && entry.type == type && entry.event.equals(event);
+    }
+
+    /** A single event entry. */
+    private static class EventEntry {
+
+        private int type;
+        private String event;
+        private float extras;
+        private long time;
+        private int duplicateCount;
+
+        public void update(int type, String event, float extras) {
+            this.type = type;
+            this.event = event;
+            this.extras = extras;
+            time = System.currentTimeMillis();
+            duplicateCount = 0;
+        }
+    }
+}