1 /*
   2  * Copyright (c) 2019, Red Hat Inc.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.internal.platform;
  27 
  28 import java.io.IOException;
  29 import java.math.BigInteger;
  30 import java.nio.file.Path;
  31 import java.nio.file.Paths;
  32 import java.util.ArrayList;
  33 import java.util.List;
  34 import java.util.Optional;
  35 import java.util.function.Function;
  36 import java.util.stream.Stream;
  37 
  38 /**
  39  * Cgroup version agnostic controller logic
  40  *
  41  */
  42 public interface CgroupSubsystemController {
  43 
  44     public static final long RETVAL_UNLIMITED = -1;
  45     public static final long RETVAL_NOT_SUPPORTED = -2;
  46     public static final long RETVAL_ERROR = -3;
  47     public static final String EMPTY_STR = "";
  48 
  49     public String path();
  50 
  51     /**
  52      * getStringValue
  53      *
  54      * Return the first line of the file "parm" argument from the controller.
  55      *
  56      * TODO:  Consider using weak references for caching BufferedReader object.
  57      *
  58      * @param controller
  59      * @param parm
  60      * @return Returns the contents of the file specified by param.
  61      */
  62     public static String getStringValue(CgroupSubsystemController controller, String param) {
  63         if (controller == null) return null;
  64 
  65         try {
  66             return CgroupUtil.readStringValue(controller, param);
  67         }
  68         catch (IOException e) {
  69             return null;
  70         }
  71 
  72     }
  73 
  74     public static long getLongValueMatchingLine(CgroupSubsystemController controller,
  75                                                      String param,
  76                                                      String match,
  77                                                      Function<String, Long> conversion) {
  78         long retval = CgroupSubsystemController.RETVAL_UNLIMITED;
  79         try {
  80             Path filePath = Paths.get(controller.path(), param);
  81             List<String> lines = CgroupUtil.readAllLinesPrivileged(filePath);
  82             for (String line : lines) {
  83                 if (line.startsWith(match)) {
  84                     retval = conversion.apply(line);
  85                     break;
  86                 }
  87             }
  88         } catch (IOException e) {
  89             // Ignore. Default is unlimited.
  90         }
  91         return retval;
  92     }
  93 
  94     public static long getLongValue(CgroupSubsystemController controller,
  95                                     String parm,
  96                                     Function<String, Long> conversion) {
  97         String strval = getStringValue(controller, parm);
  98         return conversion.apply(strval);
  99     }
 100 
 101     public static double getDoubleValue(CgroupSubsystemController controller, String parm) {
 102         String strval = getStringValue(controller, parm);
 103 
 104         if (strval == null) return 0L;
 105 
 106         double retval = Double.parseDouble(strval);
 107 
 108         return retval;
 109     }
 110 
 111     /**
 112      * getSubSystemlongEntry
 113      *
 114      * Return the long value from the line containing the string "entryname"
 115      * within file "parm" in the "subsystem".
 116      *
 117      * TODO:  Consider using weak references for caching BufferedReader object.
 118      *
 119      * @param controller
 120      * @param parm
 121      * @param entryname
 122      * @return long value
 123      */
 124     public static long getLongEntry(CgroupSubsystemController controller, String parm, String entryname) {
 125         if (controller == null) return 0L;
 126 
 127         try (Stream<String> lines = CgroupUtil.readFilePrivileged(Paths.get(controller.path(), parm))) {
 128 
 129             Optional<String> result = lines.map(line -> line.split(" "))
 130                                            .filter(line -> (line.length == 2 &&
 131                                                    line[0].equals(entryname)))
 132                                            .map(line -> line[1])
 133                                            .findFirst();
 134 
 135             return result.isPresent() ? Long.parseLong(result.get()) : 0L;
 136         }
 137         catch (IOException e) {
 138             return 0L;
 139         }
 140     }
 141 
 142     /**
 143      * StringRangeToIntArray
 144      *
 145      * Convert a string in the form of  1,3-4,6 to an array of
 146      * integers containing all the numbers in the range.
 147      *
 148      * @param range
 149      * @return int[] containing a sorted list of processors or memory nodes
 150      */
 151     public static int[] stringRangeToIntArray(String range) {
 152         int[] ints = new int[0];
 153 
 154         if (range == null || EMPTY_STR.equals(range)) return ints;
 155 
 156         ArrayList<Integer> results = new ArrayList<>();
 157         String strs[] = range.split(",");
 158         for (String str : strs) {
 159             if (str.contains("-")) {
 160                 String lohi[] = str.split("-");
 161                 // validate format
 162                 if (lohi.length != 2) {
 163                     continue;
 164                 }
 165                 int lo = Integer.parseInt(lohi[0]);
 166                 int hi = Integer.parseInt(lohi[1]);
 167                 for (int i = lo; i <= hi; i++) {
 168                     results.add(i);
 169                 }
 170             }
 171             else {
 172                 results.add(Integer.parseInt(str));
 173             }
 174         }
 175 
 176         // sort results
 177         results.sort(null);
 178 
 179         // convert ArrayList to primitive int array
 180         ints = new int[results.size()];
 181         int i = 0;
 182         for (Integer n : results) {
 183             ints[i++] = n;
 184         }
 185 
 186         return ints;
 187     }
 188 
 189     public static long convertStringToLong(String strval, long overflowRetval) {
 190         long retval = 0;
 191         if (strval == null) return 0L;
 192 
 193         try {
 194             retval = Long.parseLong(strval);
 195         } catch (NumberFormatException e) {
 196             // For some properties (e.g. memory.limit_in_bytes) we may overflow
 197             // the range of signed long. In this case, return unlimited
 198             BigInteger b = new BigInteger(strval);
 199             if (b.compareTo(BigInteger.valueOf(Long.MAX_VALUE)) > 0) {
 200                 return overflowRetval;
 201             }
 202         }
 203         return retval;
 204     }
 205 
 206 }