示例#1
0
 /**
  * A normal reduce operator's rowObjectInspector looks like a struct containing nested key/value
  * structs that contain the column values: { key: { reducesinkkey0:int }, value: { _col0:int,
  * _col1:int, .. } }
  *
  * <p>While the rowObjectInspector looks the same for vectorized queries during compilation time,
  * within the tasks at query execution the rowObjectInspector has changed to a flatter structure
  * without nested key/value structs: { 'key.reducesinkkey0':int, 'value._col0':int,
  * 'value._col1':int, .. }
  *
  * <p>Trying to fetch 'key.reducesinkkey0' by name from the list of flattened ObjectInspectors
  * does not work because the '.' gets interpreted as a field member, even though it is a flattened
  * list of column values. This workaround converts the column name referenced in the ExprNodeDesc
  * from a nested field name (key.reducesinkkey0) to key_reducesinkkey0, simply by replacing '.'
  * with '_'.
  *
  * @param source
  * @return
  */
 public static ExprNodeDesc flattenExpr(ExprNodeDesc source) {
   if (source instanceof ExprNodeGenericFuncDesc) {
     // all children expression should be resolved
     ExprNodeGenericFuncDesc function = (ExprNodeGenericFuncDesc) source.clone();
     List<ExprNodeDesc> newChildren = flattenExprList(function.getChildren());
     for (ExprNodeDesc newChild : newChildren) {
       if (newChild == null) {
         // Could not resolve all of the function children, fail
         return null;
       }
     }
     function.setChildren(newChildren);
     return function;
   }
   if (source instanceof ExprNodeColumnDesc) {
     ExprNodeColumnDesc column = (ExprNodeColumnDesc) source;
     // Create a new ColumnInfo, replacing STRUCT.COLUMN with STRUCT_COLUMN
     String newColumn = column.getColumn().replace('.', '_');
     return new ExprNodeColumnDesc(source.getTypeInfo(), newColumn, column.getTabAlias(), false);
   }
   if (source instanceof ExprNodeFieldDesc) {
     // field expression should be resolved
     ExprNodeFieldDesc field = (ExprNodeFieldDesc) source.clone();
     ExprNodeDesc fieldDesc = flattenExpr(field.getDesc());
     if (fieldDesc == null) {
       return null;
     }
     field.setDesc(fieldDesc);
     return field;
   }
   // constant or null expr, just return
   return source;
 }
示例#2
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 public static ArrayList<ExprNodeDesc> clone(List<ExprNodeDesc> sources) {
   ArrayList<ExprNodeDesc> result = new ArrayList<ExprNodeDesc>();
   for (ExprNodeDesc expr : sources) {
     result.add(expr.clone());
   }
   return result;
 }
示例#3
0
 public static ExprNodeDesc backtrack(
     ExprNodeDesc source, Operator<?> current, Operator<?> terminal, boolean foldExpr)
     throws SemanticException {
   Operator<?> parent = getSingleParent(current, terminal);
   if (parent == null) {
     return source;
   }
   if (source instanceof ExprNodeGenericFuncDesc) {
     // all children expression should be resolved
     ExprNodeGenericFuncDesc function = (ExprNodeGenericFuncDesc) source.clone();
     List<ExprNodeDesc> children = backtrack(function.getChildren(), current, terminal, foldExpr);
     for (ExprNodeDesc child : children) {
       if (child == null) {
         // Could not resolve all of the function children, fail
         return null;
       }
     }
     function.setChildren(children);
     if (foldExpr) {
       // fold after replacing, if possible
       ExprNodeDesc foldedFunction = ConstantPropagateProcFactory.foldExpr(function);
       if (foldedFunction != null) {
         return foldedFunction;
       }
     }
     return function;
   }
   if (source instanceof ExprNodeColumnDesc) {
     ExprNodeColumnDesc column = (ExprNodeColumnDesc) source;
     return backtrack(column, parent, terminal);
   }
   if (source instanceof ExprNodeFieldDesc) {
     // field expression should be resolved
     ExprNodeFieldDesc field = (ExprNodeFieldDesc) source.clone();
     ExprNodeDesc fieldDesc = backtrack(field.getDesc(), current, terminal, foldExpr);
     if (fieldDesc == null) {
       return null;
     }
     field.setDesc(fieldDesc);
     return field;
   }
   // constant or null expr, just return
   return source;
 }