ext/javax.mail.mbox/src/com/sun/mail/mbox/UNIXInbox.java

   1 /*
   2  * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v. 2.0, which is available at
   6  * http://www.eclipse.org/legal/epl-2.0.
   7  *
   8  * This Source Code may also be made available under the following Secondary
   9  * Licenses when the conditions for such availability set forth in the
  10  * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
  11  * version 2 with the GNU Classpath Exception, which is available at
  12  * https://www.gnu.org/software/classpath/license.html.
  13  *
  14  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  15  */
  16
  17 package com.sun.mail.mbox;
  18
  19 import java.io.*;
  20
  21 public class UNIXInbox extends UNIXFolder implements InboxFile {
  22     private final String user;
  23
  24     private static final long serialVersionUID = 651261842162777620L;
  25
  26     /*
  27      * Superclass UNIXFile loads the library containing all the
  28      * native code and sets the "loaded" flag if successful.
  29      */
  30
  31     public UNIXInbox(String user, String name) {
  32         super(name);
  33         this.user = user;
  34         if (user == null)
  35             throw new NullPointerException("user name is null in UNIXInbox");
  36     }
  37
  38     public boolean lock(String mode) {
  39         if (lockType == NATIVE) {
  40             if (!loaded)
  41                 return false;
  42             if (!maillock(user, 5))
  43                 return false;
  44         }
  45         if (!super.lock(mode)) {
  46             if (loaded)
  47                 mailunlock();
  48             return false;
  49         }
  50         return true;
  51     }
  52
  53     public void unlock() {
  54         super.unlock();
  55         if (loaded)
  56             mailunlock();
  57     }
  58
  59     public void touchlock() {
  60         if (loaded)
  61             touchlock0();
  62     }
  63
  64     private transient RandomAccessFile lockfile; // the user's ~/.Maillock file
  65     private transient String lockfileName;      // its name
  66
  67     public boolean openLock(String mode) {
  68         if (mode.equals("r"))
  69             return true;
  70         if (lockfileName == null) {
  71             String home = System.getProperty("user.home");
  72             lockfileName = home + File.separator + ".Maillock";
  73         }
  74         try {
  75             lockfile = new RandomAccessFile(lockfileName, mode);
  76             boolean ret;
  77             switch (lockType) {
  78             case NONE:
  79                 ret = true;
  80                 break;
  81             case NATIVE:
  82             default:
  83                 ret = UNIXFile.lock(lockfile.getFD(), mode);
  84                 break;
  85             case JAVA:
  86                 ret = lockfile.getChannel().
  87                     tryLock(0L, Long.MAX_VALUE, !mode.equals("rw")) != null;
  88                 break;
  89             }
  90             if (!ret)
  91                 closeLock();
  92             return ret;
  93         } catch (IOException ex) {
  94         }
  95         return false;
  96     }
  97
  98     public void closeLock() {
  99         if (lockfile == null)
 100             return;
 101         try {
 102             lockfile.close();
 103         } catch (IOException ex) {
 104         } finally {
 105             lockfile = null;
 106         }
 107     }
 108
 109     public boolean equals(Object o) {
 110         if (!(o instanceof UNIXInbox))
 111             return false;
 112         UNIXInbox other = (UNIXInbox)o;
 113         return user.equals(other.user) && super.equals(other);
 114     }
 115
 116     public int hashCode() {
 117         return super.hashCode() + user.hashCode();
 118     }
 119
 120     private native boolean maillock(String user, int retryCount);
 121     private native void mailunlock();
 122     private native void touchlock0();
 123 }