ohair@286: /*
mkos@384:  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package com.sun.xml.internal.org.jvnet.mimepull;
ohair@286: 
ohair@286: import java.io.*;
ohair@286: import java.nio.ByteBuffer;
ohair@286: 
ohair@286: /**
ohair@286:  * Represents an attachment part in a MIME message. MIME message parsing is done
ohair@286:  * lazily using a pull parser, so the part may not have all the data. {@link #read}
ohair@286:  * and {@link #readOnce} may trigger the actual parsing the message. In fact,
ohair@286:  * parsing of an attachment part may be triggered by calling {@link #read} methods
alanb@368:  * on some other attachment parts. All this happens behind the scenes so the
ohair@286:  * application developer need not worry about these details.
ohair@286:  *
ohair@286:  * @author Jitendra Kotamraju
ohair@286:  */
ohair@286: final class DataHead {
ohair@286: 
ohair@286:     /**
ohair@286:      * Linked list to keep the part's content
ohair@286:      */
ohair@286:     volatile Chunk head, tail;
ohair@286: 
ohair@286:     /**
ohair@286:      * If the part is stored in a file, non-null.
ohair@286:      */
ohair@286:     DataFile dataFile;
ohair@286: 
ohair@286:     private final MIMEPart part;
ohair@286: 
ohair@286:     boolean readOnce;
ohair@286:     volatile long inMemory;
ohair@286: 
ohair@286:     /**
ohair@286:      * Used only for debugging. This records where readOnce() is called.
ohair@286:      */
ohair@286:     private Throwable consumedAt;
ohair@286: 
ohair@286:     DataHead(MIMEPart part) {
ohair@286:         this.part = part;
ohair@286:     }
ohair@286: 
ohair@286:     void addBody(ByteBuffer buf) {
ohair@286:         synchronized(this) {
ohair@286:             inMemory += buf.limit();
ohair@286:         }
ohair@286:         if (tail != null) {
ohair@286:             tail = tail.createNext(this, buf);
ohair@286:         } else {
ohair@286:             head = tail = new Chunk(new MemoryData(buf, part.msg.config));
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     void doneParsing() {
ohair@286:     }
ohair@286: 
ohair@286:     void moveTo(File f) {
ohair@286:         if (dataFile != null) {
ohair@286:             dataFile.renameTo(f);
ohair@286:         } else {
ohair@286:             try {
ohair@286:                 OutputStream os = new FileOutputStream(f);
alanb@368:                 try {
alanb@368:                     InputStream in = readOnce();
alanb@368:                     byte[] buf = new byte[8192];
alanb@368:                     int len;
alanb@368:                     while((len=in.read(buf)) != -1) {
alanb@368:                         os.write(buf, 0, len);
alanb@368:                     }
alanb@368:                 } finally {
alanb@368:                     if (os != null) {
alanb@368:                         os.close();
alanb@368:                     }
ohair@286:                 }
ohair@286:             } catch(IOException ioe) {
ohair@286:                 throw new MIMEParsingException(ioe);
ohair@286:             }
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     void close() {
mkos@384:         head = tail = null;
ohair@286:         if (dataFile != null) {
ohair@286:             dataFile.close();
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286: 
ohair@286:     /**
ohair@286:      * Can get the attachment part's content multiple times. That means
ohair@286:      * the full content needs to be there in memory or on the file system.
ohair@286:      * Calling this method would trigger parsing for the part's data. So
ohair@286:      * do not call this unless it is required(otherwise, just wrap MIMEPart
ohair@286:      * into a object that returns InputStream for e.g DataHandler)
ohair@286:      *
ohair@286:      * @return data for the part's content
ohair@286:      */
ohair@286:     public InputStream read() {
ohair@286:         if (readOnce) {
ohair@286:             throw new IllegalStateException("readOnce() is called before, read() cannot be called later.");
ohair@286:         }
ohair@286: 
ohair@286:         // Trigger parsing for the part
ohair@286:         while(tail == null) {
ohair@286:             if (!part.msg.makeProgress()) {
ohair@286:                 throw new IllegalStateException("No such MIME Part: "+part);
ohair@286:             }
ohair@286:         }
ohair@286: 
ohair@286:         if (head == null) {
ohair@286:             throw new IllegalStateException("Already read. Probably readOnce() is called before.");
ohair@286:         }
ohair@286:         return new ReadMultiStream();
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Used for an assertion. Returns true when readOnce() is not already called.
ohair@286:      * or otherwise throw an exception.
ohair@286:      *
ohair@286:      * <p>
ohair@286:      * Calling this method also marks the stream as 'consumed'
ohair@286:      *
ohair@286:      * @return true if readOnce() is not called before
ohair@286:      */
alanb@368:     @SuppressWarnings("ThrowableInitCause")
ohair@286:     private boolean unconsumed() {
ohair@286:         if (consumedAt != null) {
ohair@286:             AssertionError error = new AssertionError("readOnce() is already called before. See the nested exception from where it's called.");
ohair@286:             error.initCause(consumedAt);
ohair@286:             throw error;
ohair@286:         }
ohair@286:         consumedAt = new Exception().fillInStackTrace();
ohair@286:         return true;
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Can get the attachment part's content only once. The content
ohair@286:      * will be lost after the method. Content data is not be stored
ohair@286:      * on the file system or is not kept in the memory for the
ohair@286:      * following case:
ohair@286:      *   - Attachement parts contents are accessed sequentially
ohair@286:      *
ohair@286:      * In general, take advantage of this when the data is used only
ohair@286:      * once.
ohair@286:      *
ohair@286:      * @return data for the part's content
ohair@286:      */
ohair@286:     public InputStream readOnce() {
ohair@286:         assert unconsumed();
ohair@286:         if (readOnce) {
ohair@286:             throw new IllegalStateException("readOnce() is called before. It can only be called once.");
ohair@286:         }
ohair@286:         readOnce = true;
ohair@286:         // Trigger parsing for the part
ohair@286:         while(tail == null) {
ohair@286:             if (!part.msg.makeProgress() && tail == null) {
ohair@286:                 throw new IllegalStateException("No such Part: "+part);
ohair@286:             }
ohair@286:         }
ohair@286:         InputStream in = new ReadOnceStream();
ohair@286:         head = null;
ohair@286:         return in;
ohair@286:     }
ohair@286: 
ohair@286:     class ReadMultiStream extends InputStream {
ohair@286:         Chunk current;
ohair@286:         int offset;
ohair@286:         int len;
ohair@286:         byte[] buf;
ohair@286:         boolean closed;
ohair@286: 
ohair@286:         public ReadMultiStream() {
ohair@286:             this.current = head;
ohair@286:             len = current.data.size();
ohair@286:             buf = current.data.read();
ohair@286:         }
ohair@286: 
ohair@286:         @Override
ohair@286:         public int read(byte b[], int off, int sz) throws IOException {
alanb@368:             if (!fetch()) {
alanb@368:                 return -1;
alanb@368:             }
ohair@286: 
ohair@286:             sz = Math.min(sz, len-offset);
ohair@286:             System.arraycopy(buf,offset,b,off,sz);
ohair@286:             offset += sz;
ohair@286:             return sz;
ohair@286:         }
ohair@286: 
alanb@368:         @Override
ohair@286:         public int read() throws IOException {
ohair@286:             if (!fetch()) {
ohair@286:                 return -1;
ohair@286:             }
ohair@286:             return (buf[offset++] & 0xff);
ohair@286:         }
ohair@286: 
ohair@286:         void adjustInMemoryUsage() {
ohair@286:             // Nothing to do in this case.
ohair@286:         }
ohair@286: 
ohair@286:         /**
ohair@286:          * Gets to the next chunk if we are done with the current one.
ohair@286:          * @return true if any data available
ohair@286:          * @throws IOException when i/o error
ohair@286:          */
ohair@286:         private boolean fetch() throws IOException {
ohair@286:             if (closed) {
ohair@286:                 throw new IOException("Stream already closed");
ohair@286:             }
ohair@286:             if (current == null) {
ohair@286:                 return false;
ohair@286:             }
ohair@286: 
ohair@286:             while(offset==len) {
ohair@286:                 while(!part.parsed && current.next == null) {
ohair@286:                     part.msg.makeProgress();
ohair@286:                 }
ohair@286:                 current = current.next;
ohair@286: 
ohair@286:                 if (current == null) {
ohair@286:                     return false;
ohair@286:                 }
ohair@286:                 adjustInMemoryUsage();
ohair@286:                 this.offset = 0;
ohair@286:                 this.buf = current.data.read();
ohair@286:                 this.len = current.data.size();
ohair@286:             }
ohair@286:             return true;
ohair@286:         }
ohair@286: 
alanb@368:         @Override
ohair@286:         public void close() throws IOException {
ohair@286:             super.close();
ohair@286:             current = null;
ohair@286:             closed = true;
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     final class ReadOnceStream extends ReadMultiStream {
ohair@286: 
ohair@286:         @Override
ohair@286:         void adjustInMemoryUsage() {
ohair@286:             synchronized(DataHead.this) {
ohair@286:                 inMemory -= current.data.size();    // adjust current memory usage
ohair@286:             }
ohair@286:         }
ohair@286: 
ohair@286:     }
ohair@286: 
ohair@286: 
ohair@286: }