bundles/org.simantics.databoard/src/org/simantics/databoard/serialization/SerializerFactory.java

   1 package org.simantics.databoard.serialization;\r
   2 \r
   3 import java.util.HashMap;\r
   4 import java.util.Map;\r
   5 \r
   6 import org.simantics.databoard.binding.Binding;\r
   7 \r
   8 /**\r
   9  *\r
  10  * \r
  11  * @author Toni Kalajainen\r
  12  */\r
  13 public abstract class SerializerFactory implements SerializerScheme {\r
  14 \r
  15         /**\r
  16          * Map of failed constructions. \r
  17          */\r
  18         protected Map<Binding, SerializerConstructionException> failures = new HashMap<Binding, SerializerConstructionException>();\r
  19         \r
  20         /**\r
  21          * Repository where serializers are placed. \r
  22          */\r
  23         Map<Binding, Serializer> repository;    \r
  24         \r
  25         /**\r
  26          * Map that contains in incomplete constructions.\r
  27          */\r
  28         Map<Binding, Serializer> inprogress = new HashMap<Binding, Serializer>();\r
  29         \r
  30         /**\r
  31          * Construct a new serializer.\r
  32          */\r
  33         public SerializerFactory() {\r
  34                 this.repository = new HashMap<Binding, Serializer>();\r
  35         }\r
  36         \r
  37         /**\r
  38          * Construct a new serializer factory that places constructed serializers\r
  39          * into user given repository.\r
  40          * \r
  41          * @param repository\r
  42          */\r
  43         public SerializerFactory(Map<Binding, Serializer> repository) {\r
  44                 this.repository = repository;\r
  45         }\r
  46         \r
  47         public Map<Binding, Serializer> getRepository() {\r
  48                 return repository;\r
  49         }\r
  50         \r
  51         /**\r
  52          * Constructs a serilizer for a binding. Implement this.\r
  53          * It should use the inprogress -map for construction of \r
  54          * serializers that have component types.\r
  55          * \r
  56          *  e.g. \r
  57          *   inprogress.put(binding, notCompletelyConstructedSerializer);\r
  58          *   Serializer componentSerializer = construct( componentBinding );\r
  59          *   notCompletelyConstructedSerializer.setComponent( componentSerializer );\r
  60          *   inprogress.remove(binding);\r
  61          *   \r
  62          * try-finally is not needed.\r
  63          * \r
  64          * @param request\r
  65          * @return\r
  66          * @throws SerializerConstructionException\r
  67          */\r
  68         protected abstract Serializer doConstruct(Binding request) throws SerializerConstructionException;\r
  69         \r
  70         public Serializer construct(Binding request) throws SerializerConstructionException\r
  71         {\r
  72                 // Optimization: if binding provides a cached serializer, just return it.\r
  73                 { Serializer ser = request.cachedSerializer(); if (ser != null) return ser; } \r
  74                 { Serializer ser = repository.get(request); if(ser != null) return ser; }\r
  75                 { Serializer ser = inprogress.get(request); if(ser != null) return ser; }\r
  76                 { SerializerConstructionException e = failures.get(request); if(e != null) throw e; }\r
  77                 \r
  78                 // Start construction\r
  79                 try {                   \r
  80                         Serializer binding = doConstruct(request);\r
  81                         repository.put(request, binding);\r
  82                         request.cacheSerializer(binding);\r
  83                         return binding;\r
  84                 } catch (SerializerConstructionException e) {\r
  85                         inprogress.remove( request );\r
  86                         failures.put(request, e);\r
  87                         throw e;\r
  88                 }\r
  89         }\r
  90 \r
  91         @Override\r
  92         public Serializer getSerializer(Binding binding)\r
  93                         throws SerializerConstructionException {                \r
  94                 return construct(binding);\r
  95         }\r
  96         \r
  97         public Serializer getSerializerUnchecked(Binding binding)\r
  98                         throws RuntimeSerializerConstructionException {\r
  99                 try {\r
 100                         return construct(binding);\r
 101                 } catch (SerializerConstructionException e) {\r
 102                         throw new RuntimeSerializerConstructionException(e);\r
 103                 }\r
 104         }       \r
 105         \r
 106         \r
 107 }\r