DRILL-166 Update CodeGenerator code to support more generic signatures.

sandbox/prototype/common/src/main/java/org/apache/drill/common/expression/IfExpression.java

@@ -18,6 +18,7 @@
 package org.apache.drill.common.expression;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 import org.apache.drill.common.expression.IfExpression.IfCondition;
@@ -28,9 +29,12 @@
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Iterators;
+import com.google.common.collect.Lists;
 import com.google.common.collect.UnmodifiableIterator;
 
-public class IfExpression extends LogicalExpressionBase implements Iterable<IfCondition>{
+public class IfExpression extends LogicalExpressionBase{
 	static final Logger logger = LoggerFactory.getLogger(IfExpression.class);
 
 	public final ImmutableList<IfCondition> conditions;
@@ -106,9 +110,22 @@ public static Builder newBuilder(){
 	}
 
 
-	@Override
-	public UnmodifiableIterator<IfCondition> iterator() {
-		return conditions.iterator();
-	}
-
+  public Iterable<IfCondition> conditionIterable(){
+
+    return ImmutableList.copyOf(conditions);
+  }
+
+  @Override
+  public Iterator<LogicalExpression> iterator() {
+    List<LogicalExpression> children = Lists.newLinkedList();
+
+    for(IfCondition ic : conditions){
+      children.add(ic.condition);
+      children.add(ic.expression);
+    }
+    children.add(this.elseExpression);
+    return children.iterator();
+  }
+
+
 }

sandbox/prototype/common/src/main/java/org/apache/drill/common/expression/LogicalExpression.java

@@ -43,7 +43,7 @@
 
 //@JsonDeserialize(using = LogicalExpression.De.class)  // Excluded as we need to register this with the DrillConfig.
 @JsonSerialize(using = LogicalExpression.Se.class)
-public interface LogicalExpression {
+public interface LogicalExpression extends Iterable<LogicalExpression>{
   static final Logger logger = LoggerFactory.getLogger(LogicalExpression.class);
 
   public abstract MajorType getMajorType();

sandbox/prototype/common/src/main/java/org/apache/drill/common/expression/SchemaPath.java

@@ -17,6 +17,7 @@
  ******************************************************************************/
 package org.apache.drill.common.expression;
 
+import java.util.Iterator;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -26,6 +27,7 @@
 import org.apache.drill.common.types.TypeProtos.MajorType;
 import org.apache.drill.common.types.Types;
 
+import com.google.common.collect.Iterators;
 import com.google.protobuf.DescriptorProtos.UninterpretedOption.NamePart;
 
 public class SchemaPath extends LogicalExpressionBase {
@@ -131,6 +133,11 @@ public boolean equals(Object obj) {
     return true;
   }
 
+  @Override
+  public Iterator<LogicalExpression> iterator() {
+    return Iterators.emptyIterator();
+  }
+
   @Override
   public String toString() {
     return "SchemaPath [rootSegment=" + rootSegment + "]";

sandbox/prototype/common/src/main/java/org/apache/drill/common/expression/ValueExpressions.java

@@ -17,12 +17,16 @@
  ******************************************************************************/
 package org.apache.drill.common.expression;
 
+import java.util.Iterator;
+
 import org.apache.drill.common.expression.visitors.ExprVisitor;
 import org.apache.drill.common.types.TypeProtos.DataMode;
 import org.apache.drill.common.types.TypeProtos.MajorType;
 import org.apache.drill.common.types.TypeProtos.MinorType;
 import org.apache.drill.common.types.Types;
 
+import com.google.common.collect.Iterators;
+
 public class ValueExpressions {
 
   public static LogicalExpression getNumericExpression(String s, ExpressionPosition ep) {
@@ -54,6 +58,12 @@ protected ValueExpression(String value, ExpressionPosition pos) {
     }
 
     protected abstract V parseValue(String s);
+
+    @Override
+    public Iterator<LogicalExpression> iterator() {
+      return Iterators.emptyIterator();
+    }
+
 
   }
 
@@ -109,6 +119,11 @@ public <T, V, E extends Exception> T accept(ExprVisitor<T, V, E> visitor, V valu
       return visitor.visitDoubleConstant(this, value);
     }
 
+    @Override
+    public Iterator<LogicalExpression> iterator() {
+      return Iterators.emptyIterator();
+    }
+
   }
 
   public static class LongExpression extends LogicalExpressionBase {
@@ -135,6 +150,12 @@ public MajorType getMajorType() {
     public <T, V, E extends Exception> T accept(ExprVisitor<T, V, E> visitor, V value) throws E {
       return visitor.visitLongConstant(this, value);
     }
+
+    @Override
+    public Iterator<LogicalExpression> iterator() {
+      return Iterators.emptyIterator();
+    }
+
   }
 
   public static class QuotedString extends ValueExpression<String> {

sandbox/prototype/common/src/main/java/org/apache/drill/common/expression/visitors/AggregateChecker.java

@@ -54,7 +54,7 @@ public Boolean visitFunctionCall(FunctionCall call) {
 
   @Override
   public Boolean visitIfExpression(IfExpression ifExpr) {
-    for(IfCondition c : ifExpr){
+    for(IfCondition c : ifExpr.conditions){
       if(c.condition.accept(this, null) || c.expression.accept(this, null)) return true;
     }
     return ifExpr.elseExpression.accept(this, null);

sandbox/prototype/common/src/main/java/org/apache/drill/common/expression/visitors/ConstantChecker.java

@@ -47,9 +47,10 @@ public Boolean visitFunctionCall(FunctionCall call) {
 
   @Override
   public Boolean visitIfExpression(IfExpression ifExpr) {
-    for(IfCondition c : ifExpr){
+    for(IfCondition c : ifExpr.conditions){
       if(!c.condition.accept(this, null) || !c.expression.accept(this, null)) return false;
     }
+    if(!ifExpr.elseExpression.accept(this, null)) return false;
     return true;
   }
 

sandbox/prototype/exec/java-exec/pom.xml

@@ -22,6 +22,11 @@
       <artifactId>asm-commons</artifactId>
       <version>4.1</version>
     </dependency>
+    <dependency>
+      <groupId>com.thoughtworks.paranamer</groupId>
+      <artifactId>paranamer</artifactId>
+      <version>2.5.6</version>
+    </dependency>
     <dependency>
       <groupId>com.sun.codemodel</groupId>
       <artifactId>codemodel</artifactId>
@@ -58,6 +63,11 @@
       <artifactId>metrics-core</artifactId>
       <version>3.0.0-BETA1</version>
     </dependency>
+    <dependency>
+      <groupId>javax.inject</groupId>
+      <artifactId>javax.inject</artifactId>
+      <version>1</version>
+    </dependency>    
     <dependency>
       <groupId>org.apache.drill</groupId>
       <artifactId>common</artifactId>

sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/compile/TemplateClassDefinition.java

@@ -17,21 +17,36 @@
  ******************************************************************************/
 package org.apache.drill.exec.compile;
 
-
+import org.apache.drill.exec.compile.sig.CodeGeneratorSignature;
+import org.apache.drill.exec.compile.sig.DefaultGeneratorSignature;
+import org.apache.drill.exec.compile.sig.SignatureHolder;
 
 public class TemplateClassDefinition<T>{
 
+  static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(TemplateClassDefinition.class);
+
   private final Class<T> externalInterface;
   private final String templateClassName;
   private final Class<?> internalInterface;
-  private final Class<?> evalReturnType;
-
-  public TemplateClassDefinition(Class<T> externalInterface, String templateClassName, Class<?> internalInterface, Class<?> evalReturnType) {
+  private final SignatureHolder signature;
+
+  public TemplateClassDefinition(Class<T> externalInterface, String templateClassName, Class<?> internalInterface) {
+    this(externalInterface, templateClassName, internalInterface, DefaultGeneratorSignature.class);
+  }
+
+  public <X extends CodeGeneratorSignature> TemplateClassDefinition(Class<T> externalInterface, String templateClassName, Class<?> internalInterface, Class<X> signature) {
     super();
     this.externalInterface = externalInterface;
     this.templateClassName = templateClassName;
     this.internalInterface = internalInterface;
-    this.evalReturnType = evalReturnType;
+    SignatureHolder holder = null;
+    try{
+      holder = new SignatureHolder(signature);
+    }catch(Exception ex){
+      logger.error("Failure while trying to build signature holder for signature. {}", signature.getSimpleName(), ex);
+    }
+    this.signature = holder;
+
   }
 
   public Class<T> getExternalInterface() {
@@ -46,8 +61,15 @@ public String getTemplateClassName() {
     return templateClassName;
   }
 
-  public Class<?> getEvalReturnType() {
-    return evalReturnType;
+  public SignatureHolder getSignature(){
+    return signature;
   }
+
+  @Override
+  public String toString() {
+    return "TemplateClassDefinition [externalInterface=" + externalInterface + ", templateClassName="
+        + templateClassName + ", internalInterface=" + internalInterface + ", signature=" + signature + "]";
+  }
+
 
 }

sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/compile/sig/CodeGeneratorArgument.java

@@ -0,0 +1,23 @@
+package org.apache.drill.exec.compile.sig;
+
+
+public class CodeGeneratorArgument {
+
+  private final String name;
+  private final Class<?> type;
+
+  public CodeGeneratorArgument(String name, Class<?> type) {
+    super();
+    this.name = name;
+    this.type = type;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public Class<?> getType() {
+    return type;
+  }
+
+}

sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/compile/sig/CodeGeneratorMethod.java

@@ -0,0 +1,60 @@
+package org.apache.drill.exec.compile.sig;
+
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.Iterator;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterators;
+import com.thoughtworks.paranamer.AnnotationParanamer;
+import com.thoughtworks.paranamer.Paranamer;
+
+public class CodeGeneratorMethod implements Iterable<CodeGeneratorArgument>{
+  static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(CodeGeneratorMethod.class);
+
+  private final String methodName;
+  private final Class<?> returnType;
+  private final CodeGeneratorArgument[] arguments;
+  private final Class<?>[] exs;
+  private final Method underlyingMethod;
+
+  public CodeGeneratorMethod(Method m){
+    this.underlyingMethod = m;
+    this.methodName = m.getName();
+    this.returnType = m.getReturnType();
+//    Paranamer para = new BytecodeReadingParanamer();
+    Paranamer para = new AnnotationParanamer();
+    String[] parameterNames = para.lookupParameterNames(m, true);
+    if(parameterNames == null) throw new RuntimeException(String.format("Unable to read the parameter names for method %s.  This is likely due to the class files not including the appropriate debugging information.  Look up java -g for more information.", m));
+    Class<?>[] types = m.getParameterTypes();
+    if(parameterNames.length != types.length) throw new RuntimeException(String.format("Unexpected number of parameter names %s.  Expected %s on method %s.", Arrays.toString(parameterNames), Arrays.toString(types), m.toGenericString()));
+    arguments = new CodeGeneratorArgument[parameterNames.length];
+    for(int i =0 ; i < parameterNames.length; i++){
+      arguments[i] = new CodeGeneratorArgument(parameterNames[i], types[i]);
+    }
+    exs = m.getExceptionTypes();
+  }
+
+  public String getMethodName() {
+    return methodName;
+  }
+  public Class<?> getReturnType() {
+    return returnType;
+  }
+
+  public Iterable<Class<?>> getThrowsIterable(){
+    return ImmutableList.copyOf(exs);
+  }
+
+  @Override
+  public Iterator<CodeGeneratorArgument> iterator() {
+    return Iterators.forArray(arguments);
+  }
+
+  @Override
+  public String toString() {
+    return "CodeGeneratorMethod [" + underlyingMethod.toGenericString() + "]";
+  }
+
+
+}

sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/compile/sig/CodeGeneratorSignature.java

@@ -0,0 +1,5 @@
+package org.apache.drill.exec.compile.sig;
+
+
+public interface CodeGeneratorSignature {
+}