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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 
     18 package android.filterfw.core;
     19 
     20 /**
     21  * @hide
     22  */
     23 public class StreamPort extends InputPort {
     24 
     25     private Frame mFrame;
     26     private boolean mPersistent;
     27 
     28     public StreamPort(Filter filter, String name) {
     29         super(filter, name);
     30     }
     31 
     32     @Override
     33     public void clear() {
     34         if (mFrame != null) {
     35             mFrame.release();
     36             mFrame = null;
     37         }
     38     }
     39 
     40     @Override
     41     public void setFrame(Frame frame) {
     42         assignFrame(frame, true);
     43     }
     44 
     45     @Override
     46     public void pushFrame(Frame frame) {
     47         assignFrame(frame, false);
     48     }
     49 
     50     protected synchronized void assignFrame(Frame frame, boolean persistent) {
     51         assertPortIsOpen();
     52         checkFrameType(frame, persistent);
     53 
     54         if (persistent) {
     55             if (mFrame != null) {
     56                 mFrame.release();
     57             }
     58         } else if (mFrame != null) {
     59             throw new RuntimeException(
     60                 "Attempting to push more than one frame on port: " + this + "!");
     61         }
     62         mFrame = frame.retain();
     63         mFrame.markReadOnly();
     64         mPersistent = persistent;
     65     }
     66 
     67     @Override
     68     public synchronized Frame pullFrame() {
     69         // Make sure we have a frame
     70         if (mFrame == null) {
     71             throw new RuntimeException("No frame available to pull on port: " + this + "!");
     72         }
     73 
     74         // Return a retained result
     75         Frame result = mFrame;
     76         if (mPersistent) {
     77             mFrame.retain();
     78         } else {
     79             mFrame = null;
     80         }
     81         return result;
     82     }
     83 
     84     @Override
     85     public synchronized boolean hasFrame() {
     86         return mFrame != null;
     87     }
     88 
     89     @Override
     90     public String toString() {
     91         return "input " + super.toString();
     92     }
     93 
     94     @Override
     95     public synchronized void transfer(FilterContext context) {
     96         if (mFrame != null) {
     97             checkFrameManager(mFrame, context);
     98         }
     99     }
    100 }
    101