1 /*

     2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

     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.jfr.internal.consumer;

    27 

    28 import java.io.IOException;

    29 import java.nio.file.DirectoryStream;

    30 import java.nio.file.Path;

    31 import java.util.ArrayList;

    32 import java.util.Collections;

    33 import java.util.HashMap;

    34 import java.util.HashSet;

    35 import java.util.List;

    36 import java.util.Map;

    37 import java.util.NavigableMap;

    38 import java.util.Set;

    39 import java.util.SortedMap;

    40 import java.util.TreeMap;

    41 

    42 import jdk.jfr.internal.LogLevel;

    43 import jdk.jfr.internal.LogTag;

    44 import jdk.jfr.internal.Logger;

    45 import jdk.jfr.internal.Repository;

    46 import jdk.jfr.internal.SecuritySupport.SafePath;

    47 

    48 public final class RepositoryFiles {

    49     private static final Object WAIT_OBJECT = new Object();

    50     public static void notifyNewFile() {

    51         synchronized (WAIT_OBJECT) {

    52             WAIT_OBJECT.notifyAll();

    53         }

    54     }

    55 

    56     private final FileAccess fileAccess;

    57     private final NavigableMap<Long, Path> pathSet = new TreeMap<>();

    58     private final Map<Path, Long> pathLookup = new HashMap<>();

    59     private final Path repository;

    60     private final Object waitObject;

    61 

    62     private volatile boolean closed;

    63 

    64     RepositoryFiles(FileAccess fileAccess, Path repository) {

    65         this.repository = repository;

    66         this.fileAccess = fileAccess;

    67         this.waitObject = repository == null ? WAIT_OBJECT : new Object();

    68     }

    69 

    70     long getTimestamp(Path p) {

    71         return pathLookup.get(p);

    72     }

    73 

    74     Path lastPath() {

    75         if (waitForPaths()) {

    76             return pathSet.lastEntry().getValue();

    77         }

    78         return null; // closed

    79     }

    80 

    81     Path firstPath(long startTimeNanos) {

    82         if (waitForPaths()) {

    83             // Pick closest chunk before timestamp

    84             Long time = pathSet.floorKey(startTimeNanos);

    85             if (time != null) {

    86                 startTimeNanos = time;

    87             }

    88             return path(startTimeNanos);

    89         }

    90         return null; // closed

    91     }

    92 

    93     private boolean waitForPaths() {

    94         while (!closed) {

    95             try {

    96                 if (updatePaths()) {

    97                     break;

    98                 }

    99             } catch (IOException e) {

   100                 Logger.log(LogTag.JFR_SYSTEM_STREAMING, LogLevel.DEBUG, "IOException during repository file scan " + e.getMessage());

   101                 // This can happen if a chunk is being removed

   102                 // between the file was discovered and an instance

   103                 // was accessed, or if new file has been written yet

   104                 // Just ignore, and retry later.

   105             }

   106             nap();

   107         }

   108         return !closed;

   109     }

   110 

   111     Path nextPath(long startTimeNanos) {

   112         if (closed) {

   113             return null;

   114         }

   115         // Try to get the 'exact' path first

   116         // to avoid skipping files if repository

   117         // is updated while DirectoryStream

   118         // is traversing it

   119         Path path = pathSet.get(startTimeNanos);

   120         if (path != null) {

   121             return path;

   122         }

   123         // Update paths

   124         try {

   125             updatePaths();

   126         } catch (IOException e) {

   127             // ignore

   128         }

   129         // try to get the next file

   130         return path(startTimeNanos);

   131     }

   132 

   133     private Path path(long timestamp) {

   134         if (closed) {

   135             return null;

   136         }

   137         while (true) {

   138             SortedMap<Long, Path> after = pathSet.tailMap(timestamp);

   139             if (!after.isEmpty()) {

   140                 Path path = after.get(after.firstKey());

   141                 if (Logger.shouldLog(LogTag.JFR_SYSTEM_STREAMING, LogLevel.TRACE)) {

   142                     Logger.log(LogTag.JFR_SYSTEM_STREAMING, LogLevel.TRACE, "Return path " + path + " for start time nanos " + timestamp);

   143                 }

   144                 return path;

   145             }

   146             if (!waitForPaths()) {

   147                 return null; // closed

   148             }

   149         }

   150     }

   151 

   152     private void nap() {

   153         try {

   154             synchronized (waitObject) {

   155                 waitObject.wait(1000);

   156             }

   157         } catch (InterruptedException e) {

   158             // ignore

   159         }

   160     }

   161 

   162     private boolean updatePaths() throws IOException {

   163         boolean foundNew = false;

   164         Path repoPath = repository;

   165         if (repoPath == null) {

   166             // Always get the latest repository if 'jcmd JFR.configure

   167             // repositorypath=...' has been executed

   168             SafePath sf = Repository.getRepository().getRepositoryPath();

   169             if (sf == null) {

   170                 return false; // not initialized

   171             }

   172             repoPath = sf.toPath();

   173         }

   174 

   175         try (DirectoryStream<Path> dirStream = fileAccess.newDirectoryStream(repoPath)) {

   176             List<Path> added = new ArrayList<>();

   177             Set<Path> current = new HashSet<>();

   178             for (Path p : dirStream) {

   179                 if (!pathLookup.containsKey(p)) {

   180                     String s = p.toString();

   181                     if (s.endsWith(".jfr")) {

   182                         added.add(p);

   183                         Logger.log(LogTag.JFR_SYSTEM_STREAMING, LogLevel.DEBUG, "New file found: " + p.toAbsolutePath());

   184                     }

   185                     current.add(p);

   186                 }

   187             }

   188             List<Path> removed = new ArrayList<>();

   189             for (Path p : pathLookup.keySet()) {

   190                 if (!current.contains(p)) {

   191                     removed.add(p);

   192                 }

   193             }

   194 

   195             for (Path remove : removed) {

   196                 Long time = pathLookup.get(remove);

   197                 pathSet.remove(time);

   198                 pathLookup.remove(remove);

   199             }

   200             Collections.sort(added, (p1, p2) -> p1.compareTo(p2));

   201             for (Path p : added) {

   202                 // Only add files that have a complete header

   203                 // as the JVM may be in progress writing the file

   204                 long size = fileAccess.fileSize(p);

   205                 if (size >= ChunkHeader.headerSize()) {

   206                     long startNanos = readStartTime(p);

   207                     pathSet.put(startNanos, p);

   208                     pathLookup.put(p, startNanos);

   209                     foundNew = true;

   210                 }

   211             }

   212             return foundNew;

   213         }

   214     }

   215 

   216     private long readStartTime(Path p) throws IOException {

   217         try (RecordingInput in = new RecordingInput(p.toFile(), fileAccess, 100)) {

   218             Logger.log(LogTag.JFR_SYSTEM_PARSER, LogLevel.INFO, "Parsing header for chunk start time");

   219             ChunkHeader c = new ChunkHeader(in);

   220             return c.getStartNanos();

   221         }

   222     }

   223 

   224     void close() {

   225         synchronized (waitObject) {

   226             this.closed = true;

   227             waitObject.notify();

   228         }

   229     }

   230 }