Merge pull request #407 from kerie/type-resolve-only-once2

性能优化，自定义类型解析对于每个java文件只处理一次

p3c-pmd/src/main/java/com/alibaba/p3c/pmd/lang/java/rule/AbstractAliRule.java

@@ -15,12 +15,17 @@
  */
 package com.alibaba.p3c.pmd.lang.java.rule;
 
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
 import com.alibaba.p3c.pmd.I18nResources;
 import com.alibaba.p3c.pmd.fix.FixClassTypeResolver;
 
+import net.sourceforge.pmd.RuleContext;
 import net.sourceforge.pmd.lang.ast.Node;
 import net.sourceforge.pmd.lang.java.ast.ASTCompilationUnit;
 import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
+import org.apache.commons.lang3.StringUtils;
 
 /**
  * re calculate node type
@@ -29,11 +34,29 @@ import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
  * @date 2016/11/20
  */
 public abstract class AbstractAliRule extends AbstractJavaRule {
+
+    private static final Map<String, Boolean> TYPE_RESOLVER_MAP = new ConcurrentHashMap<>(16);
+
+    private static final String EMPTY_FILE_NAME = "n/a";
+    private static final String DELIMITER = "-";
+
     @Override
     public Object visit(ASTCompilationUnit node, Object data) {
-        FixClassTypeResolver classTypeResolver = new FixClassTypeResolver(AbstractAliRule.class.getClassLoader());
-        node.setClassTypeResolver(classTypeResolver);
-        node.jjtAccept(classTypeResolver, data);
+        // Each CompilationUnit will be scanned only once by custom type resolver.
+        String sourceCodeFilename = ((RuleContext)data).getSourceCodeFilename();
+
+        // Do type resolve if file name is empty(unit tests).
+        if (StringUtils.isBlank(sourceCodeFilename) || EMPTY_FILE_NAME.equals(sourceCodeFilename)) {
+            resolveType(node, data);
+            return super.visit(node, data);
+        }
+
+        // If file name is not empty, use filename + hashcode to identify a compilation unit.
+        String uniqueId = sourceCodeFilename + DELIMITER + node.hashCode();
+        if (!TYPE_RESOLVER_MAP.containsKey(uniqueId)) {
+            resolveType(node, data);
+            TYPE_RESOLVER_MAP.put(uniqueId, true);
+        }
         return super.visit(node, data);
     }
 
@@ -57,5 +80,11 @@ public abstract class AbstractAliRule extends AbstractJavaRule {
         super.addViolationWithMessage(data, node,
             String.format(I18nResources.getMessageWithExceptionHandled(message), args));
     }
+
+    private void resolveType(ASTCompilationUnit node, Object data) {
+        FixClassTypeResolver classTypeResolver = new FixClassTypeResolver(AbstractAliRule.class.getClassLoader());
+        node.setClassTypeResolver(classTypeResolver);
+        node.jjtAccept(classTypeResolver, data);
+    }
 }