TAJO-1415: Window frame support

tajo-algebra/src/main/java/org/apache/tajo/algebra/WindowSpec.java

@@ -120,69 +120,69 @@ public boolean equals(Object obj) {
 
   }
 
-  public static enum WindowFrameUnit {
+  public enum WindowFrameUnit {
     ROW,
     RANGE
   }
 
-  public static enum WindowFrameStartBoundType {
+  public enum WindowFrameBoundType {
     UNBOUNDED_PRECEDING,
-    CURRENT_ROW,
-    PRECEDING
-  }
-
-  public static enum WindowFrameEndBoundType {
     UNBOUNDED_FOLLOWING,
     CURRENT_ROW,
+    PRECEDING,
     FOLLOWING
   }
 
   public static class WindowFrame implements Cloneable {
     @Expose private WindowFrameUnit unit;
-    @Expose private WindowStartBound startBound;
-    @Expose private WindowEndBound endBound;
+    @Expose private WindowBound startBound;
+    @Expose private WindowBound endBound;
 
-    public WindowFrame(WindowFrameUnit unit, WindowStartBound startBound) {
+    public WindowFrame(WindowFrameUnit unit, WindowBound startBound) {
       this.unit = unit;
       this.startBound = startBound;
     }
 
-    public WindowFrame(WindowFrameUnit unit, WindowStartBound startBound, WindowEndBound endBound) {
+    public WindowFrame(WindowFrameUnit unit, WindowBound startBound, WindowBound endBound) {
       this(unit, startBound);
       this.endBound = endBound;
     }
 
-    public WindowStartBound getStartBound() {
+    public WindowFrameUnit getFrameUnit() {
+      return unit;
+    }
+
+    public WindowBound getStartBound() {
       return startBound;
     }
 
     public boolean hasEndBound() {
       return endBound != null;
     }
 
-    public WindowEndBound getEndBound() {
+    public WindowBound getEndBound() {
       return endBound;
     }
 
     @Override
     public Object clone() throws CloneNotSupportedException {
       WindowFrame frame = (WindowFrame) super.clone();
       frame.unit = unit;
-      frame.startBound = (WindowStartBound) startBound.clone();
-      frame.endBound = (WindowEndBound) endBound.clone();
+      frame.startBound = (WindowBound) startBound.clone();
+      frame.endBound = (WindowBound) endBound.clone();
       return frame;
     }
   }
 
-  public static class WindowStartBound implements Cloneable {
-    @Expose private WindowFrameStartBoundType boundType;
+  public static class WindowBound implements Cloneable {
+    @Expose private WindowFrameBoundType boundType;
     @Expose private Expr number;
 
-    public WindowStartBound(WindowFrameStartBoundType type) {
+    public WindowBound(WindowFrameBoundType type) {
       this.boundType = type;
     }
 
-    public WindowFrameStartBoundType getBoundType() {
+    public WindowFrameBoundType getBoundType() {
       return boundType;
     }
 
@@ -200,43 +200,10 @@ public Expr getNumber() {
 
     @Override
     public Object clone() throws CloneNotSupportedException {
-      WindowStartBound start = (WindowStartBound) super.clone();
+      WindowBound start = (WindowBound) super.clone();
       start.boundType = boundType;
       start.number = (Expr) number.clone();
       return start;
     }
   }
-
-  public static class WindowEndBound implements Cloneable {
-    @Expose private WindowFrameEndBoundType boundType;
-    @Expose private Expr number;
-
-    public WindowEndBound(WindowFrameEndBoundType type) {
-      this.boundType = type;
-    }
-
-    public WindowFrameEndBoundType getBoundType() {
-      return boundType;
-    }
-
-    public boolean hasNumber() {
-      return this.number != null;
-    }
-
-    public void setNumber(Expr number) {
-      this.number = number;
-    }
-
-    public Expr getNumber() {
-      return number;
-    }
-
-    @Override
-    public Object clone() throws CloneNotSupportedException {
-      WindowEndBound end = (WindowEndBound) super.clone();
-      end.boundType = boundType;
-      end.number = (Expr) number.clone();
-      return end;
-    }
-  }
 }

tajo-core/src/main/antlr4/org/apache/tajo/engine/parser/SQLParser.g4

@@ -1197,6 +1197,7 @@ window_frame_extent
 window_frame_start_bound
   : UNBOUNDED PRECEDING
   | unsigned_value_specification PRECEDING // window_frame_preceding
+  | unsigned_value_specification FOLLOWING // window_frame_following FOLLOWING
   | CURRENT ROW
   ;
 
@@ -1206,6 +1207,7 @@ window_frame_between
 
 window_frame_end_bound
   : UNBOUNDED FOLLOWING
+  | unsigned_value_specification PRECEDING // window_frame_preceding
   | unsigned_value_specification FOLLOWING // window_frame_following FOLLOWING
   | CURRENT ROW
   ;

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValue.java → tajo-core/src/main/java/org/apache/tajo/engine/function/window/CurrentValue.java

@@ -24,41 +24,34 @@
 import org.apache.tajo.plan.function.WindowAggFunc;
 import org.apache.tajo.storage.Tuple;
 
-public abstract class FirstValue extends WindowAggFunc<Datum> {
+public abstract class CurrentValue extends WindowAggFunc<Datum> {
 
-  public FirstValue(Column[] columns) {
+  public CurrentValue(Column[] columns) {
     super(columns);
   }
 
   @Override
   public FunctionContext newContext() {
-    return new FirstValueContext();
+    return new CurrentValueContext();
   }
 
   @Override
   public void eval(FunctionContext ctx, Tuple params) {
-    FirstValueContext firstValueCtx = (FirstValueContext)ctx;
-    if(firstValueCtx.isSet == false) {
-      firstValueCtx.isSet = true;
-      if (params.get(0).isNotNull()) {
-        firstValueCtx.first = params.get(0);
+    CurrentValueContext currentValueCtx = (CurrentValueContext)ctx;
+      if (params.get(0) == null || params.get(0).isNull()) {
+        currentValueCtx.current = NullDatum.get();
+      } else {
+        currentValueCtx.current = params.get(0);
       }
-    }
   }
 
   @Override
   public Datum terminate(FunctionContext ctx) {
-    if (((FirstValueContext) ctx).first == null) {
-      return NullDatum.get();
-    }
-    else {
-      return ((FirstValueContext) ctx).first;
-    }
+    return ((CurrentValueContext) ctx).current;
   }
 
-  protected static class FirstValueContext implements FunctionContext {
-    boolean isSet = false;
-    Datum first = null;
+  protected static class CurrentValueContext implements FunctionContext {
+    Datum current = null;
   }
 
 }

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueDate.java

@@ -31,7 +31,7 @@
     returnType = Type.DATE,
     paramTypes = {@ParamTypes(paramTypes = {Type.DATE})}
 )
-public class FirstValueDate extends FirstValue {
+public class FirstValueDate extends CurrentValue {
 
   public FirstValueDate() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueDouble.java

@@ -31,7 +31,7 @@
     returnType = Type.FLOAT8,
     paramTypes = {@ParamTypes(paramTypes = {Type.FLOAT8})}
 )
-public class FirstValueDouble extends FirstValue {
+public class FirstValueDouble extends CurrentValue {
 
   public FirstValueDouble() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueFloat.java

@@ -31,7 +31,7 @@
     returnType = Type.FLOAT4,
     paramTypes = {@ParamTypes(paramTypes = {Type.FLOAT4})}
 )
-public class FirstValueFloat extends FirstValue {
+public class FirstValueFloat extends CurrentValue {
 
   public FirstValueFloat() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueInt.java

@@ -31,7 +31,7 @@
     returnType = Type.INT4,
     paramTypes = {@ParamTypes(paramTypes = {Type.INT4})}
 )
-public class FirstValueInt extends FirstValue {
+public class FirstValueInt extends CurrentValue {
 
   public FirstValueInt() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueLong.java

@@ -31,7 +31,7 @@
     returnType = Type.INT8,
     paramTypes = {@ParamTypes(paramTypes = {Type.INT8})}
 )
-public class FirstValueLong extends FirstValue {
+public class FirstValueLong extends CurrentValue {
 
   public FirstValueLong() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueString.java

@@ -31,7 +31,7 @@
     returnType = Type.TEXT,
     paramTypes = {@ParamTypes(paramTypes = {Type.TEXT})}
 )
-public class FirstValueString extends FirstValue {
+public class FirstValueString extends CurrentValue {
 
   public FirstValueString() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueTime.java

@@ -31,7 +31,7 @@
     returnType = Type.TIME,
     paramTypes = {@ParamTypes(paramTypes = {Type.TIME})}
 )
-public class FirstValueTime extends FirstValue {
+public class FirstValueTime extends CurrentValue {
 
   public FirstValueTime() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/window/FirstValueTimestamp.java

@@ -31,7 +31,7 @@
     returnType = Type.TIMESTAMP,
     paramTypes = {@ParamTypes(paramTypes = {Type.TIMESTAMP})}
 )
-public class FirstValueTimestamp extends FirstValue {
+public class FirstValueTimestamp extends CurrentValue {
 
   public FirstValueTimestamp() {
     super(new Column[] {

tajo-core/src/main/java/org/apache/tajo/engine/function/builtin/LastValueDate.java → tajo-core/src/main/java/org/apache/tajo/engine/function/window/LastValueDate.java

@@ -16,31 +16,25 @@
  * limitations under the License.
  */
 
-package org.apache.tajo.engine.function.builtin;
+package org.apache.tajo.engine.function.window;
 
-import org.apache.tajo.catalog.CatalogUtil;
 import org.apache.tajo.catalog.Column;
 import org.apache.tajo.common.TajoDataTypes;
 import org.apache.tajo.engine.function.annotation.Description;
 import org.apache.tajo.engine.function.annotation.ParamTypes;
 
 @Description(
     functionName = "last_value",
-    description = "the last value of expr",
-    example = "> SELECT last_value(expr);",
+    description = "the last value of retrieved rows",
+    example = "> SELECT last_value(column) OVER();",
     returnType = TajoDataTypes.Type.DATE,
     paramTypes = {@ParamTypes(paramTypes = {TajoDataTypes.Type.DATE})}
 )
-public class LastValueDate extends LastValue {
+public class LastValueDate extends CurrentValue {
 
   public LastValueDate() {
     super(new Column[] {
         new Column("expr", TajoDataTypes.Type.DATE)
     });
   }
-
-  @Override
-  public TajoDataTypes.DataType getPartialResultType() {
-    return CatalogUtil.newSimpleDataType(TajoDataTypes.Type.DATE);
-  }
 }