1 /*
   2  * Copyright (c) 1997, 2012, 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 com.sun.xml.internal.org.jvnet.mimepull;
  27 
  28 import java.io.InputStream;
  29 import java.io.IOException;
  30 
  31 /**
  32  * Constructs a InputStream from a linked list of {@link Chunk}s.
  33  *
  34  * @author Kohsuke Kawaguchi
  35  * @author Jitendra Kotamraju
  36  */
  37 final class ChunkInputStream extends InputStream {
  38     Chunk current;
  39     int offset;
  40     int len;
  41     final MIMEMessage msg;
  42     final MIMEPart part;
  43     byte[] buf;
  44 
  45     public ChunkInputStream(MIMEMessage msg, MIMEPart part, Chunk startPos) {
  46         this.current = startPos;
  47         len = current.data.size();
  48         buf = current.data.read();
  49         this.msg = msg;
  50         this.part = part;
  51     }
  52 
  53     @Override
  54     public int read(byte b[], int off, int sz) throws IOException {
  55         if (!fetch()) {
  56             return -1;
  57         }
  58 
  59         sz = Math.min(sz, len-offset);
  60         System.arraycopy(buf,offset,b,off,sz);
  61         return sz;
  62     }
  63 
  64     public int read() throws IOException {
  65         if (!fetch()) {
  66             return -1;
  67         }
  68         return (buf[offset++] & 0xff);
  69     }
  70 
  71     /**
  72      * Gets to the next chunk if we are done with the current one.
  73      * @return
  74      */
  75     private boolean fetch() {
  76         if (current == null) {
  77             throw new IllegalStateException("Stream already closed");
  78         }
  79         while(offset==len) {
  80             while(!part.parsed && current.next == null) {
  81                 msg.makeProgress();
  82             }
  83             current = current.next;
  84 
  85             if (current == null) {
  86                 return false;
  87             }
  88             this.offset = 0;
  89             this.buf = current.data.read();
  90             this.len = current.data.size();
  91         }
  92         return true;
  93     }
  94 
  95     @Override
  96     public void close() throws IOException {
  97         super.close();
  98         current = null;
  99     }
 100 }