| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.services.bytecode.VMTypeIdCacheable |
| 4 | |
| 5 | Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.services.bytecode; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.cache.Cacheable; |
| 24 | import org.apache.derby.iapi.services.cache.CacheManager; |
| 25 | |
| 26 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 27 | |
| 28 | import org.apache.derby.iapi.services.classfile.ClassHolder; |
| 29 | |
| 30 | /** |
| 31 | * This class implements a Cacheable for a Byte code generator cache of |
| 32 | * VMTypeIds. It maps a Java class or type name to a VM type ID. |
| 33 | */ |
| 34 | class VMTypeIdCacheable implements Cacheable { |
| 35 | /* The VM name of the Java class name */ |
| 36 | // either a Type (java type) or a String (method descriptor) |
| 37 | private Object descriptor; |
| 38 | |
| 39 | /* This is the identity */ |
| 40 | private Object key; |
| 41 | |
| 42 | /* Cacheable interface */ |
| 43 | |
| 44 | /** @see Cacheable#clearIdentity */ |
| 45 | public void clearIdentity() { |
| 46 | } |
| 47 | |
| 48 | /** @see Cacheable#getIdentity */ |
| 49 | public Object getIdentity() { |
| 50 | return key; |
| 51 | } |
| 52 | |
| 53 | /** @see Cacheable#createIdentity */ |
| 54 | public Cacheable createIdentity(Object key, Object createParameter) { |
| 55 | if (SanityManager.DEBUG) { |
| 56 | SanityManager.THROWASSERT("VMTypeIdCacheable.create() called!"); |
| 57 | } |
| 58 | return this; |
| 59 | } |
| 60 | |
| 61 | /** @see Cacheable#setIdentity */ |
| 62 | public Cacheable setIdentity(Object key) { |
| 63 | |
| 64 | this.key = key; |
| 65 | if (key instanceof String) { |
| 66 | /* The identity is the Java class name */ |
| 67 | String javaName = (String) key; |
| 68 | |
| 69 | /* Get the VM type name associated with the Java class name */ |
| 70 | String vmName = ClassHolder.convertToInternalDescriptor(javaName); |
| 71 | descriptor = new Type(javaName, vmName); |
| 72 | } |
| 73 | else |
| 74 | { |
| 75 | descriptor = ((BCMethodDescriptor) key).buildMethodDescriptor(); |
| 76 | } |
| 77 | |
| 78 | return this; |
| 79 | } |
| 80 | |
| 81 | /** @see Cacheable#clean */ |
| 82 | public void clean(boolean remove) { |
| 83 | /* No such thing as a dirty cache entry */ |
| 84 | return; |
| 85 | } |
| 86 | |
| 87 | /** @see Cacheable#isDirty */ |
| 88 | public boolean isDirty() { |
| 89 | /* No such thing as a dirty cache entry */ |
| 90 | return false; |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | ** Class specific methods. |
| 95 | */ |
| 96 | |
| 97 | /** |
| 98 | * Get the VM Type name (java/lang/Object) that is associated with this Cacheable |
| 99 | */ |
| 100 | |
| 101 | Object descriptor() { |
| 102 | return descriptor; |
| 103 | } |
| 104 | } |