|
1
2
12 package com.versant.core.jdo.query.mem;
13
14
15 import com.versant.lib.bcel.Constants;
16 import com.versant.lib.bcel.classfile.JavaClass;
17 import com.versant.lib.bcel.generic.ClassGen;
18 import com.versant.lib.bcel.generic.InstructionFactory;
19
20 import com.versant.core.metadata.ClassMetaData;
21 import com.versant.core.metadata.ModelMetaData;
22 import com.versant.core.jdo.*;
23 import com.versant.core.jdo.query.ParamNode;
24 import com.versant.core.jdo.query.ParseException;
25
26 import java.util.HashMap  ;
27 import java.util.Map ;
28 import java.lang.reflect.Method ;
29 import java.lang.reflect.InvocationTargetException ;
30 import java.io.File ;
31 import java.io.FileOutputStream ;
32 import java.io.IOException ;
33
34 import com.versant.core.common.BindingSupportImpl;
35
36
40 public class MemQueryCompiler {
41
42 private final ModelMetaData jmd;
43 private final ClassLoader loader;
44 private Map compiledQueryMap = new HashMap ();
45 private long clsCounter;
46 private Method defineClass;
47
48 public MemQueryCompiler(ModelMetaData jmd, ClassLoader loader) {
49 this.jmd = jmd;
50 this.loader = loader;
51
52 try {
53 defineClass = ClassLoader .class.getDeclaredMethod("defineClass",
54 new Class []{String .class, byte[].class, Integer.TYPE,
55 Integer.TYPE});
56 } catch (NoSuchMethodException e) {
57 throw BindingSupportImpl.getInstance().internal(e.toString(), e);
59 }
60 defineClass.setAccessible(true);
61
62 }
63
64 public synchronized BCodeQuery compile(QueryDetails queryParams, Object [] params) {
65 BCodeQuery bCodeQuery = (BCodeQuery)compiledQueryMap.get(queryParams);
66 if (bCodeQuery != null) return bCodeQuery;
67
68
69 boolean toFilter = true;
70 if (queryParams.getFilter() == null || queryParams.getFilter().equals(
71 "true")) {
72 toFilter = false;
73 } else {
74 toFilter = true;
75 }
76
77 ClassMetaData classMetaData = jmd.getClassMetaData(
78 queryParams.getCandidateClass());
79 String name = getQClsName();
80 ClassGen classGen = new ClassGen(name, BCodeQuery.class.getName(),
81 "<generated>", Constants.ACC_PUBLIC | Constants.ACC_SUPER,
82 null);
83 InstructionFactory factory = new InstructionFactory(classGen);
84 classGen.addEmptyConstructor(Constants.ACC_PUBLIC);
85
86 CompiledMemQuery compiledMemQuery = new CompiledMemQuery(jmd);
87 try {
88 compiledMemQuery.compile(queryParams);
89 } catch (ParseException e) {
90 throw BindingSupportImpl.getInstance().exception(e.getMessage());
91 }
92
93 if (toFilter) {
94 ByteCodeQVisitor byteCodeQVisitor =
95 new ByteCodeQVisitor(classGen, factory, name,
96 classMetaData, compiledMemQuery);
97 byteCodeQVisitor.setParamMap(
98 createParamMap(params, compiledMemQuery));
99 compiledMemQuery.filter.visit(byteCodeQVisitor, null);
100 byteCodeQVisitor.finish();
101 }
102
103 if (queryParams.getOrdering() != null) {
104 ByteCodeQCompareVisitor byteCodeQCompareVisitor = new ByteCodeQCompareVisitor(
105 classGen, factory, name, classMetaData);
106 for (int i = 0; i < compiledMemQuery.orders.length; i++) {
107 compiledMemQuery.orders[i].visit(byteCodeQCompareVisitor, null);
108 }
109 byteCodeQCompareVisitor.finish();
110 }
111
112 JavaClass javaClass = classGen.getJavaClass();
113 try {
114 bCodeQuery = (BCodeQuery)defineClass(javaClass.getBytes(), null).newInstance();
115 compiledQueryMap.put(queryParams, bCodeQuery);
116 } catch (Exception e) {
117 if (BindingSupportImpl.getInstance().isOwnException(e)) {
118 throw (RuntimeException )e;
119 }
120 throw BindingSupportImpl.getInstance().internal(e.getMessage(), e);
121 }
122
123 return bCodeQuery;
124 }
125
126 private Map createParamMap(Object [] params,
127 CompiledMemQuery compiledMemQuery) {
128 Map m = new HashMap ();
129 if (compiledMemQuery.params == null) {
130 return m;
131 }
132 for (int i = 0; i < compiledMemQuery.params.length; i++) {
133 ParamNode param = compiledMemQuery.params[i];
134 m.put(param.getIdentifier(), params[i]);
135 }
136 return m;
137 }
138
139 private Class defineClass(byte[] bytecode, File dir) {
140 try {
141 Class cls = (Class )defineClass.invoke(loader, new Object []{null,
142 bytecode, new Integer (0), new Integer (bytecode.length)});
143 if (dir != null) {
144 File f = new File (dir, cls.getName() + ".class");
145 try {
146 FileOutputStream o = new FileOutputStream (f);
147 o.write(bytecode, 0, bytecode.length);
148 o.close();
149 } catch (IOException x) {
150 throw BindingSupportImpl.getInstance().runtime(
151 "Error writing to " + f + ": " + x, x);
152 }
153 }
154 return cls;
155 } catch (InvocationTargetException e) {
156 Throwable t = e.getTargetException();
157 throw BindingSupportImpl.getInstance().internal(t.toString(), t);
158 } catch (Exception x) {
159 throw BindingSupportImpl.getInstance().internal(x.toString(), x);
160 }
161 }
162
163 private synchronized String getQClsName() {
164 return "VOA_QUERY_" + clsCounter++;
165 }
166
167 }
168 |
Popular Tags |
Java API By Example, From Geeks To Geeks.