bundles/org.simantics.databoard/src/org/simantics/databoard/binding/classfactory/SignatureVisitor.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2011 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.binding.classfactory;
  13
  14 import java.util.IdentityHashMap;
  15
  16 import org.simantics.databoard.Datatypes;
  17 import org.simantics.databoard.type.ArrayType;
  18 import org.simantics.databoard.type.BooleanType;
  19 import org.simantics.databoard.type.ByteType;
  20 import org.simantics.databoard.type.Datatype;
  21 import org.simantics.databoard.type.DoubleType;
  22 import org.simantics.databoard.type.FloatType;
  23 import org.simantics.databoard.type.IntegerType;
  24 import org.simantics.databoard.type.LongType;
  25 import org.simantics.databoard.type.MapType;
  26 import org.simantics.databoard.type.OptionalType;
  27 import org.simantics.databoard.type.RecordType;
  28 import org.simantics.databoard.type.StringType;
  29 import org.simantics.databoard.type.UnionType;
  30 import org.simantics.databoard.type.VariantType;
  31
  32 /**
  33  * Signature Visitor builds a signature string from a datatype.
  34  * The argument is StringBuilder.
  35  *
  36  * Signature is construtructed with the following notation.
  37  *
  38  *   s                        StringType
  39  *   z                        BooleanType
  40  *   d                        DoubleType
  41  *   f                        FloatType
  42  *   i                        IntegerType
  43  *   b                        ByteType
  44  *   j                        LongType
  45  *   R                        Referable RecordType
  46  *   o*                       OptionalType, * denotes componentType
  47  *   a*                       ArrayType, * denotes componentType
  48  *   r**e                     RecordType, ** denotes fields
  49  *   u                        UnionType, * denotes components
  50  *   m**                      MapType, ** denotes keyType and valueType
  51  *   t                        Datatype
  52  *
  53  * For example, The signature of UUID.class is "rjje"
  54  *
  55  * @author toni.kalajainen
  56  */
  57 public class SignatureVisitor implements Datatype.Visitor1 {
  58
  59         public StringBuilder sb = new StringBuilder();
  60         public int hashcode = 0xbcbcbca;
  61         public IdentityHashMap<Datatype, Boolean> visited = new IdentityHashMap<Datatype, Boolean>();
  62
  63         public static String toSignature(Datatype type)
  64         {
  65                 SignatureVisitor sv = new SignatureVisitor();
  66                 type.accept( sv, null );
  67                 String sig = sv.sb.toString();
  68                 return sig;
  69         }
  70
  71         @Override
  72         public void visit(ArrayType b, Object obj) {
  73                 sb.append('a');
  74                 b.componentType.accept(this, obj);
  75                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
  76         }
  77
  78         @Override
  79         public void visit(BooleanType b, Object obj) {
  80                 sb.append('z');
  81                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
  82         }
  83
  84         @Override
  85         public void visit(DoubleType b, Object obj) {
  86                 sb.append('d');
  87                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
  88         }
  89
  90         @Override
  91         public void visit(FloatType b, Object obj) {
  92                 sb.append('f');
  93                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
  94         }
  95
  96         @Override
  97         public void visit(IntegerType b, Object obj) {
  98                 sb.append('i');
  99                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 100         }
 101
 102         @Override
 103         public void visit(ByteType b, Object obj) {
 104                 sb.append('b');
 105                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 106         }
 107
 108         @Override
 109         public void visit(LongType b, Object obj) {
 110                 sb.append('j');
 111                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 112         }
 113
 114         @Override
 115         public void visit(OptionalType b, Object obj) {
 116                 sb.append('o');
 117                 b.componentType.accept(this, sb);
 118                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 119         }
 120
 121         @Override
 122         public void visit(RecordType b, Object obj) {
 123                 if ( wasVisited(b) ) {
 124                         sb.append('R');
 125                         return;
 126                 }
 127                 if ( b.isReferable() ) {
 128                         sb.append('R');
 129                         return;
 130                 }
 131
 132                 sb.append('r');
 133                 for (int i=0; i<b.getComponentCount(); i++) {
 134                         b.getComponentType(i).accept(this, sb);
 135                 }
 136                 sb.append('e');
 137
 138                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 139                 for (int i=0; i<b.getComponentCount(); i++) {
 140                         hashcode = 13*hashcode + b.getComponent(i).name.hashCode();
 141                 }
 142         }
 143
 144         @Override
 145         public void visit(StringType b, Object obj) {
 146                 sb.append('s');
 147                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 148         }
 149
 150         @Override
 151         public void visit(UnionType b, Object obj) {
 152                 if ( b.equals( Datatypes.getDatatypeUnchecked(Datatype.class) )) {
 153                         sb.append("t");
 154                         return;
 155                 }
 156                 if ( wasVisited(b) ) {
 157                         sb.append('U');
 158                         return;
 159                 }
 160                 sb.append('u');
 161                 for (int i=0; i<b.getComponentCount(); i++) {
 162                         b.getComponentType(i).accept(this, sb);
 163                 }
 164                 sb.append('e');
 165                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 166         }
 167
 168         @Override
 169         public void visit(VariantType b, Object obj) {
 170                 sb.append('v');
 171                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 172         }
 173
 174         @Override
 175         public void visit(MapType b, Object obj) {
 176                 if ( wasVisited(b) ) return;
 177                 sb.append('m');
 178                 b.keyType.accept(this, obj);
 179                 b.valueType.accept(this, obj);
 180                 hashcode = 13*hashcode + b.getClass().getName().hashCode() + 133*b.metadataHashCode();
 181         }
 182
 183         /**
 184          * Visit and return if was visited
 185          * @param type
 186          * @return
 187          */
 188         boolean wasVisited(Datatype type) {
 189                 Boolean result = visited.put(type, Boolean.TRUE);
 190                 return result == null ? false : result;
 191         }
 192 }