AbstractPacket xref

View Javadoc

    1   /***
    2    *
    3    * Copyright 2004 Protique Ltd
    4    *
    5    * Licensed under the Apache License, Version 2.0 (the "License");
    6    * you may not use this file except in compliance with the License.
    7    * You may obtain a copy of the License at
    8    *
    9    * http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   **/
    18
    19  package org.codehaus.activemq.message;
    20
    21  import java.util.Iterator;
    22  import org.codehaus.activemq.util.BitArray;
    23  import EDU.oswego.cs.dl.util.concurrent.CopyOnWriteArraySet;
    24
    25  /***
    26   * Abstract class for a transportable Packet
    27   *
    28   * @version $Revision: 1.19 $
    29   */
    30  public abstract class AbstractPacket implements Packet {
    31
    32      /***
    33       * Message flag indexes (used for writing/reading to/from a Stream
    34       */
    35      static final int RECEIPT_REQUIRED_INDEX = 0;
    36      static final int BROKERS_VISITED_INDEX =1;
    37      private String id;
    38      protected BitArray bitArray;
    39      private  boolean receiptRequired;
    40      private transient int memoryUsage = 2048;
    41      private transient int memoryUsageReferenceCount;
    42
    43      private CopyOnWriteArraySet brokersVisited;
    44
    45      protected AbstractPacket(){
    46          this.bitArray = new BitArray();
    47      }
    48
    49      /***
    50       * @return the unique id for this Packet
    51       */
    52      public String getId() {
    53          return this.id;
    54      }
    55
    56      /***
    57       * Set the unique id for this Packet
    58       *
    59       * @param newId
    60       */
    61      public void setId(String newId) {
    62          this.id = newId;
    63      }
    64
    65      /***
    66       * @return true if a Recipt is required
    67       */
    68      public boolean isReceiptRequired() {
    69          return this.receiptRequired;
    70      }
    71
    72      /***
    73       * @return false since most packets are not receipt packets
    74       */
    75      public boolean isReceipt() {
    76          return false;
    77      }
    78
    79      /***
    80       * Set if a Recipt if required on receiving this Packet
    81       *
    82       * @param value
    83       */
    84      public void setReceiptRequired(boolean value) {
    85          this.receiptRequired = value;
    86      }
    87
    88      /***
    89       * Retrieve if a JMS Message type or not
    90       *
    91       * @return true if it is a JMS Message
    92       */
    93      public boolean isJMSMessage() {
    94          return false;
    95      }
    96
    97      /***
    98       * Tests equality with another instance
    99       *
    100      * @param obj - the other instance to test equality with
    101      * @return Returns true if the objects are equilvant
    102      */
    103     public boolean equals(Object obj) {
    104         boolean result = this == obj;
    105         if (!result && obj != null && obj instanceof AbstractPacket) {
    106             AbstractPacket other = (AbstractPacket) obj;
    107             result = other.getId().equals(this.getId());
    108         }
    109         return result;
    110     }
    111
    112     /***
    113      * @return Returns hash code for this instance
    114      */
    115     public int hashCode() {
    116         return this.id != null ? this.id.hashCode() : super.hashCode();
    117     }
    118
    119     /***
    120      * Get a hint about how much memory this Packet is consuming
    121      *
    122      * @return an aproximation of the current memory used by this instance
    123      */
    124     public int getMemoryUsage() {
    125         return memoryUsage;
    126     }
    127
    128     /***
    129      * Set a hint about how mujch memory this packet is consuming
    130      *
    131      * @param newMemoryUsage
    132      */
    133     public void setMemoryUsage(int newMemoryUsage) {
    134         this.memoryUsage = newMemoryUsage;
    135     }
    136
    137     /***
    138      * Increment reference count for bounded memory collections
    139      *
    140      * @return the incremented reference value
    141      * @see org.codehaus.activemq.message.util.MemoryBoundedQueue
    142      */
    143     public synchronized int incrementMemoryReferenceCount() {
    144         return ++memoryUsageReferenceCount;
    145     }
    146
    147     /***
    148      * Decrement reference count for bounded memory collections
    149      *
    150      * @return the decremented reference value
    151      * @see org.codehaus.activemq.message.util.MemoryBoundedQueue
    152      */
    153     public synchronized int decrementMemoryReferenceCount() {
    154         return --memoryUsageReferenceCount;
    155     }
    156
    157     /***
    158      * @return the current reference count for bounded memory collections
    159      * @see org.codehaus.activemq.message.util.MemoryBoundedQueue
    160      */
    161     public synchronized int getMemoryUsageReferenceCount() {
    162         return memoryUsageReferenceCount;
    163     }
    164
    165     /***
    166      * As the packet passes through the broker add the broker to the visited list
    167      *
    168      * @param brokerName the name of the broker
    169      */
    170     public void addBrokerVisited(String brokerName) {
    171         initializeBrokersVisited();
    172         brokersVisited.add(brokerName);
    173     }
    174
    175     /***
    176      * test to see if the named broker has already seen this packet
    177      *
    178      * @param brokerName the name of the broker
    179      * @return true if the packet has visited the broker
    180      */
    181     public boolean hasVisited(String brokerName) {
    182         if (brokersVisited == null){
    183             return false;
    184         }
    185         return brokersVisited.contains(brokerName);
    186     }
    187
    188     /***
    189      * @return Returns the brokersVisited.
    190      */
    191     public String getBrokersVisitedAsString() {
    192         String result = "";
    193         if (brokersVisited != null && !brokersVisited.isEmpty()){
    194             for (Iterator i = brokersVisited.iterator(); i.hasNext();){
    195                 result += i.next().toString() + ",";
    196             }
    197         }
    198         return result;
    199     }
    200
    201
    202     /***
    203      * @return pretty print of this Packet
    204      */
    205     public String toString() {
    206         return getPacketTypeAsString(getPacketType()) + ": " + getId();
    207     }
    208
    209
    210     protected static String getPacketTypeAsString(int type) {
    211         String packetTypeStr = "";
    212         switch (type) {
    213             case ACTIVEMQ_MESSAGE:
    214                 packetTypeStr = "ACTIVEMQ_MESSAGE";
    215                 break;
    216             case ACTIVEMQ_TEXT_MESSAGE:
    217                 packetTypeStr = "ACTIVEMQ_TEXT_MESSAGE";
    218                 break;
    219             case ACTIVEMQ_OBJECT_MESSAGE:
    220                 packetTypeStr = "ACTIVEMQ_OBJECT_MESSAGE";
    221                 break;
    222             case ACTIVEMQ_BYTES_MESSAGE:
    223                 packetTypeStr = "ACTIVEMQ_BYTES_MESSAGE";
    224                 break;
    225             case ACTIVEMQ_STREAM_MESSAGE:
    226                 packetTypeStr = "ACTIVEMQ_STREAM_MESSAGE";
    227                 break;
    228             case ACTIVEMQ_MAP_MESSAGE:
    229                 packetTypeStr = "ACTIVEMQ_MAP_MESSAGE";
    230                 break;
    231             case ACTIVEMQ_MSG_ACK:
    232                 packetTypeStr = "ACTIVEMQ_MSG_ACK";
    233                 break;
    234             case RECEIPT_INFO:
    235                 packetTypeStr = "RECEIPT_INFO";
    236                 break;
    237             case CONSUMER_INFO:
    238                 packetTypeStr = "CONSUMER_INFO";
    239                 break;
    240             case PRODUCER_INFO:
    241                 packetTypeStr = "PRODUCER_INFO";
    242                 break;
    243             case TRANSACTION_INFO:
    244                 packetTypeStr = "TRANSACTION_INFO";
    245                 break;
    246             case XA_TRANSACTION_INFO:
    247                 packetTypeStr = "XA_TRANSACTION_INFO";
    248                 break;
    249             case ACTIVEMQ_BROKER_INFO:
    250                 packetTypeStr = "ACTIVEMQ_BROKER_INFO";
    251                 break;
    252             case ACTIVEMQ_CONNECTION_INFO:
    253                 packetTypeStr = "ACTIVEMQ_CONNECTION_INFO";
    254                 break;
    255             case SESSION_INFO:
    256                 packetTypeStr = "SESSION_INFO";
    257                 break;
    258             default :
    259                 packetTypeStr = "UNKNOWN PACKET TYPE: " + type;
    260         }
    261         return packetTypeStr;
    262     }
    263
    264     /***
    265      * A helper method used when implementing equals() which returns true if the objects are identical or equal handling
    266      * nulls properly
    267      * @param left
    268      * @param right
    269      *
    270      * @return true if the objects are the same or equal or both null
    271      */
    272     protected boolean equals(Object left, Object right) {
    273         return left == right || (left != null && left.equals(right));
    274     }
    275
    276     /***
    277      * Initializes another message with current values from this instance
    278      *
    279      * @param other the other ActiveMQMessage to initialize
    280      */
    281     protected void initializeOther(AbstractPacket other) {
    282         initializeBrokersVisited();
    283         other.id = this.id;
    284         other.receiptRequired = this.receiptRequired;
    285         CopyOnWriteArraySet set = this.brokersVisited;
    286         if (set != null && !set.isEmpty()){
    287             other.brokersVisited = new CopyOnWriteArraySet(set);
    288         }
    289     }
    290
    291     synchronized void initializeBrokersVisited(){
    292         if (this.brokersVisited == null){
    293             this.brokersVisited = new CopyOnWriteArraySet();
    294         }
    295     }
    296
    297     /***
    298      * @return Returns the brokersVisited.
    299      */
    300     Object[] getBrokersVisited() {
    301         if (brokersVisited == null || brokersVisited.isEmpty()){
    302             return null;
    303         }
    304         return brokersVisited.toArray();
    305     }
    306
    307     /***
    308      * @return Returns the bitArray.
    309      */
    310     public BitArray getBitArray() {
    311         return bitArray;
    312     }
    313     /***
    314      * @param bitArray The bitArray to set.
    315      */
    316     public void setBitArray(BitArray bitArray) {
    317         this.bitArray = bitArray;
    318     }
    319 }