bundles/org.simantics.databoard/src/org/simantics/databoard/accessor/binary/BinaryByte.java

   1 /*******************************************************************************
   2  *  Copyright (c) 2010 Association for Decentralized Information Management in
   3  *  Industry THTH ry.
   4  *  All rights reserved. This program and the accompanying materials
   5  *  are made available under the terms of the Eclipse Public License v1.0
   6  *  which accompanies this distribution, and is available at
   7  *  http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  *  Contributors:
  10  *      VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.databoard.accessor.binary;
  13
  14 import java.io.IOException;
  15
  16 import org.simantics.databoard.Bindings;
  17 import org.simantics.databoard.accessor.Accessor;
  18 import org.simantics.databoard.accessor.ByteAccessor;
  19 import org.simantics.databoard.accessor.error.AccessorConstructionException;
  20 import org.simantics.databoard.accessor.error.AccessorException;
  21 import org.simantics.databoard.accessor.error.ReferenceException;
  22 import org.simantics.databoard.accessor.event.Event;
  23 import org.simantics.databoard.accessor.event.ValueAssigned;
  24 import org.simantics.databoard.accessor.file.FileByteAccessor;
  25 import org.simantics.databoard.accessor.impl.AccessorParams;
  26 import org.simantics.databoard.accessor.impl.ListenerEntry;
  27 import org.simantics.databoard.accessor.interestset.ByteInterestSet;
  28 import org.simantics.databoard.accessor.reference.ChildReference;
  29 import org.simantics.databoard.binding.Binding;
  30 import org.simantics.databoard.binding.ByteBinding;
  31 import org.simantics.databoard.binding.error.BindingException;
  32 import org.simantics.databoard.type.ByteType;
  33 import org.simantics.databoard.util.binary.Blob;
  34
  35 public class BinaryByte extends BinaryObject implements ByteAccessor, FileByteAccessor {
  36
  37         public BinaryByte(BinaryObject parent, Blob blob, ByteType type, AccessorParams params)
  38         throws AccessorConstructionException {
  39                 super(parent, blob, type, params);
  40                 try {
  41                         blob.setLength(1L);
  42                 } catch (IOException e) {
  43                         throw new AccessorConstructionException(e);
  44                 }
  45         }
  46
  47         @Override
  48         public ByteType type() {
  49                 return (ByteType) type;
  50         }
  51
  52         @Override
  53         public byte getValue() throws AccessorException {
  54                 assert b.isOpen();
  55                 readLock();
  56                 try {
  57                         b.position(0L);
  58                         return b.readByte();
  59                 } catch (IOException e) {
  60                         throw new AccessorException(e);
  61                 } finally {
  62                         readUnlock();
  63                 }
  64         }
  65
  66         @Override
  67         Event applyLocal(Event e, boolean makeRollback) throws AccessorException {
  68                 Event rollback = makeRollback ? new ValueAssigned( Bindings.BYTE, getValue() ) : null;
  69                 if (e instanceof ValueAssigned) {
  70                         ValueAssigned va = (ValueAssigned) e;
  71                         if (va.newValue == null) throw new AccessorException("Byte value expected, got null");
  72                         setValueNoflush(va.newValue.getBinding(), va.newValue.getValue());
  73                         return rollback;
  74                 } else {
  75                         throw new AccessorException("Cannot apply "+e.getClass().getName()+" to Byte");
  76                 }
  77         }
  78
  79         @SuppressWarnings("unchecked")
  80         @Override
  81         public <T extends Accessor> T getComponent(ChildReference reference)
  82                         throws AccessorConstructionException {
  83                 if (reference==null) return (T) this;
  84                 throw new ReferenceException(reference.getClass()+" is not a subreference of ByteType");
  85         }
  86
  87         @Override
  88         public Object getValue(Binding binding) throws AccessorException {
  89                 try {
  90                         ByteBinding bb = (ByteBinding) binding;
  91                         byte v = getValue();
  92                         return bb.create(v);
  93                 } catch(BindingException e) {
  94                         throw new AccessorException(e);
  95                 }
  96         }
  97
  98         public void setValueNoflush(byte newValue) throws AccessorException {
  99                 assert b.isOpen();
 100                 writeLock();
 101                 try {
 102                         // Set value
 103                         b.position(0);
 104                         b.write( newValue );
 105
 106                         // Notify
 107                         ListenerEntry le = listeners;
 108                         while (le!=null) {
 109                                 ByteInterestSet is = le.getInterestSet();
 110                                 if (is.inNotifications()) {
 111                                         Event e = new ValueAssigned( Bindings.BYTE, is.inValues() ? newValue : null );
 112                                         emitEvent(le, e);
 113                                 }
 114                                 le = le.next;
 115                         }
 116
 117                 } catch (IOException e) {
 118                         throw new AccessorException(e);
 119                 } finally {
 120                         writeUnlock();
 121                 }
 122         }
 123         @Override
 124         public void setValue(byte newValue) throws AccessorException {
 125                 assert b.isOpen();
 126                 writeLock();
 127                 try {
 128                         setValueNoflush(newValue);
 129                         b.flush();
 130                 } catch (IOException e) {
 131                         throw new AccessorException(e);
 132                 } finally {
 133                         writeUnlock();
 134                 }
 135         }
 136
 137         @Override
 138         public void setValueNoflush(Binding binding, Object newValue)
 139                         throws AccessorException {
 140                 try {
 141                         byte nv = ((ByteBinding)binding).getValue_(newValue);
 142                         setValueNoflush(nv);
 143                 } catch (BindingException e) {
 144                         throw new AccessorException(e);
 145                 }
 146         }
 147
 148
 149
 150 }
 151