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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.android.google.gce.gceservice;
     17 
     18 import android.util.Log;
     19 import java.io.File;
     20 import java.io.FileNotFoundException;
     21 import java.util.ArrayList;
     22 import java.util.Collections;
     23 import java.util.Scanner;
     24 
     25 /** A job that checks for any new tombstones before reporting VIRTUAL_DEVICE_BOOT_COMPLETED.
     26  *
     27  */
     28 public class TombstoneChecker extends JobBase {
     29     private static final String LOG_TAG = "GceTombstoneChecker";
     30     private static final String sSnapshotDir = "/data/tombstones";
     31     private static final String sSnapshotFile = "/ts_snap.txt";
     32     private static final String sTsExceptionMessage = "GceTombstoneChecker internal error. ";
     33     private static final String sTsFilePrefix = "tombstone";
     34     private final GceFuture<Boolean> mPassed = new GceFuture<Boolean>("GceTombstoneChecker");
     35     private ArrayList<Record> mPreBootRecords = new ArrayList<Record>();
     36     private ArrayList<Record> mPostBootRecords = new ArrayList<Record>();
     37 
     38     public TombstoneChecker() {
     39         super(LOG_TAG);
     40     }
     41 
     42 
     43     @Override
     44     public int execute() {
     45         if (mPassed.isDone()) {
     46             return 0;
     47         }
     48 
     49         try {
     50             readPreBootSnapshot();
     51             capturePostBootSnapshot();
     52             if (seenNewTombstones()) {
     53                 Log.e(LOG_TAG, "Tombstones created during boot. ");
     54                 for (int i = 0; i < mPostBootRecords.size(); i++) {
     55                     Log.i(LOG_TAG, mPostBootRecords.get(i).getFileName());
     56                 }
     57                 mPassed.set(new Exception("Tombstones created. "));
     58             } else {
     59                 mPassed.set(true);
     60             }
     61         } catch(Exception e) {
     62             Log.e(LOG_TAG, sTsExceptionMessage + e);
     63             mPassed.set(new Exception(sTsExceptionMessage, e));
     64         }
     65 
     66         return 0;
     67     }
     68 
     69     @Override
     70     public void onDependencyFailed(Exception e) {
     71         mPassed.set(e);
     72     }
     73 
     74     public GceFuture<Boolean> getTombstoneResult() {
     75         return mPassed;
     76     }
     77 
     78     private void capturePostBootSnapshot() throws Exception {
     79         File dir = new File(sSnapshotDir);
     80         File[] files = dir.listFiles();
     81 
     82         // In K & L, /data/tombstones directory is not created during boot. So
     83         // dir.listFiles() can return null.
     84         if (files == null) {
     85             return;
     86         }
     87 
     88         for (int i = 0; i < files.length; i++) {
     89             if (files[i].isFile() && files[i].getName().startsWith(sTsFilePrefix)) {
     90                 long ctime = files[i].lastModified() / 1000;
     91                 mPostBootRecords.add(new Record(files[i].getName(), ctime));
     92             }
     93         }
     94         Collections.sort(mPostBootRecords);
     95 
     96         return;
     97     }
     98 
     99     private void readPreBootSnapshot() throws Exception {
    100         File file = new File(sSnapshotFile);
    101         if (!file.isFile()) {
    102             throw new FileNotFoundException(sSnapshotFile);
    103         }
    104 
    105         Scanner scanner = new Scanner(file);
    106         while (scanner.hasNext()) {
    107             String[] fields = scanner.nextLine().split(" ");
    108             mPreBootRecords.add(new Record(fields[0], Long.parseLong(fields[1])));
    109         }
    110         Collections.sort(mPreBootRecords);
    111 
    112         return;
    113     }
    114 
    115     private boolean seenNewTombstones() {
    116         return !isEqual(mPreBootRecords, mPostBootRecords);
    117     }
    118 
    119     private boolean isEqual(ArrayList<Record> preBoot, ArrayList<Record> postBoot) {
    120         postBoot.removeAll(preBoot);
    121         if (postBoot.size() != 0) {
    122             return false;
    123         }
    124 
    125         return true;
    126     }
    127 
    128     private class Record implements Comparable<Record> {
    129         private String mFilename;
    130         private long mCtime;
    131 
    132         public Record(String filename, long ctime) {
    133             this.mFilename = filename;
    134             this.mCtime = ctime;
    135         }
    136 
    137         public String getFileName() {
    138             return mFilename;
    139         }
    140 
    141         public int compareTo(Record r) {
    142             if (this == r) {
    143                 return 0;
    144             }
    145 
    146             return (mFilename.compareTo(r.mFilename));
    147         }
    148 
    149         public boolean equals(Object o) {
    150             if (o == null) {
    151                 return false;
    152             }
    153 
    154             if (this == o) {
    155                 return true;
    156             }
    157 
    158             Record r = (Record) o;
    159             return (mFilename.equals(r.mFilename) && (mCtime == r.mCtime));
    160         }
    161 
    162         public String toString() {
    163             StringBuilder sb = new StringBuilder();
    164             sb.append(mFilename).append(" ").append(String.valueOf(mCtime));
    165             return sb.toString();
    166         }
    167     }
    168 }
    169