DRILL-7361: Support MAP (DICT) type in schema file

exec/java-exec/src/test/java/org/apache/drill/TestSchemaCommands.java

@@ -708,8 +708,15 @@ public void testDescribeStatement() throws Exception {
 
       String statement = "CREATE OR REPLACE SCHEMA \n"
         + "(\n"
-        + "`col1` DATE FORMAT 'yyyy-MM-dd' DEFAULT '-1', \n"
-        + "`col2` INT NOT NULL FORMAT 'yyyy-MM-dd' PROPERTIES { 'drill.strict' = 'true', 'some_column_prop' = 'some_column_val' }\n"
+        + "`col_date` DATE FORMAT 'yyyy-MM-dd' DEFAULT '-1', \n"
+        + "`col_int` INT NOT NULL FORMAT 'yyyy-MM-dd' PROPERTIES { 'drill.strict' = 'true', 'some_column_prop' = 'some_column_val' }, \n"
+        + "`col_array_int` ARRAY<INT>, \n"
+        + "`col_nested_array_int` ARRAY<ARRAY<INT>>, \n"
+        + "`col_map_required` MAP<INT, VARCHAR NOT NULL>, \n"
+        + "`col_map_optional` MAP<INT, VARCHAR>, \n"
+        + "`col_map_array` ARRAY<MAP<INT, VARCHAR>>, \n"
+        + "`col_struct` STRUCT<`s1` INT, `s2` VARCHAR NOT NULL>, \n"
+        + "`col_struct_array` ARRAY<STRUCT<`s1` INT, `s2` VARCHAR NOT NULL>>\n"
         + ") \n"
         + "FOR TABLE dfs.tmp.`table_describe_statement` \n"
         + "PROPERTIES (\n"

exec/vector/src/main/antlr4/org/apache/drill/exec/record/metadata/schema/parser/SchemaParser.g4

@@ -31,14 +31,16 @@ columns: column_def (COMMA column_def)*;
 
 column_def: column property_values?;
 
-column: (primitive_column | struct_column | simple_array_column | complex_array_column);
+column: (primitive_column | struct_column | map_column | simple_array_column | complex_array_column);
 
 primitive_column: column_id simple_type nullability? format_value? default_value?;
 
 simple_array_column: column_id simple_array_type nullability?;
 
 struct_column: column_id struct_type nullability?;
 
+map_column: column_id map_type nullability?;
+
 complex_array_column: column_id complex_array_type nullability?;
 
 column_id
@@ -63,14 +65,37 @@ simple_type
 | INTERVAL # interval
 ;
 
-complex_type: (simple_array_type | complex_array_type);
+array_type: (simple_array_type | complex_array_type);
+
+simple_array_type: ARRAY LEFT_ANGLE_BRACKET simple_array_value_type RIGHT_ANGLE_BRACKET;
 
-simple_array_type: ARRAY LEFT_ANGLE_BRACKET (simple_type | struct_type) RIGHT_ANGLE_BRACKET;
+simple_array_value_type
+: simple_type # array_simple_type_def
+| struct_type # array_struct_type_def
+| map_type # array_map_type_def
+;
 
-complex_array_type: ARRAY LEFT_ANGLE_BRACKET complex_type RIGHT_ANGLE_BRACKET;
+complex_array_type: ARRAY LEFT_ANGLE_BRACKET array_type RIGHT_ANGLE_BRACKET;
 
 struct_type: STRUCT LEFT_ANGLE_BRACKET columns RIGHT_ANGLE_BRACKET;
 
+map_type: MAP LEFT_ANGLE_BRACKET map_key_type_def COMMA map_value_type_def RIGHT_ANGLE_BRACKET;
+
+map_key_type_def: map_key_type nullability?;
+
+map_key_type
+: simple_type # map_key_simple_type_def
+;
+
+map_value_type_def: map_value_type nullability?;
+
+map_value_type
+: simple_type # map_value_simple_type_def
+| struct_type # map_value_struct_type_def
+| map_type # map_value_map_type_def
+| array_type # map_value_array_type_def
+;
+
 nullability: NOT NULL;
 
 format_value: FORMAT string_value;

exec/vector/src/main/java/org/apache/drill/exec/record/metadata/AbstractMapColumnMetadata.java

@@ -22,8 +22,6 @@
 import org.apache.drill.common.types.TypeProtos.MinorType;
 import org.apache.drill.exec.record.MaterializedField;
 
-import java.util.stream.Collectors;
-
 /**
  * Describes a base column type for map, dict, repeated map and repeated dict. All are tuples that have a tuple
  * schema as part of the column definition.
@@ -100,43 +98,29 @@ public TupleMetadata parentTuple() {
   @Override
   public MaterializedField schema() {
     MaterializedField field = emptySchema();
-    for (MaterializedField member : schema.toFieldList()) {
-      field.addChild(member);
-    }
+    schema.toFieldList().forEach(field::addChild);
     return field;
   }
 
   @Override
   public MaterializedField emptySchema() {
     return MaterializedField.create(name,
-        MajorType.newBuilder()
-            .setMinorType(type)
-            .setMode(mode)
-            .build());
+      MajorType.newBuilder()
+        .setMinorType(type)
+        .setMode(mode)
+        .build());
   }
 
   @Override
   public String typeString() {
-    StringBuilder builder = new StringBuilder();
-    if (isArray()) {
-      builder.append("ARRAY<");
-    }
-    builder.append(getStringType())
-        .append("<").append(
-            tupleSchema().toMetadataList().stream()
-              .map(ColumnMetadata::columnString)
-              .collect(Collectors.joining(", "))
-        )
-        .append(">");
-    if (isArray()) {
-      builder.append(">");
-    }
-    return builder.toString();
+    String typeString = internalTypeString();
+    return isArray() ? "ARRAY<" + typeString + ">" : typeString;
   }
 
   /**
-   * Returns string representation of type like {@code "STRUCT"} or {@code "MAP"}
-   * @return column type
+   * Returns specific type string representation of the type that extends this class.
+   *
+   * @return type string representation
    */
-  protected abstract String getStringType();
+  protected abstract String internalTypeString();
 }

exec/vector/src/main/java/org/apache/drill/exec/record/metadata/DictColumnMetadata.java

@@ -21,6 +21,8 @@
 import org.apache.drill.exec.record.MaterializedField;
 import org.apache.drill.exec.vector.complex.DictVector;
 
+import java.util.stream.Collectors;
+
 public class DictColumnMetadata extends AbstractMapColumnMetadata {
 
   /**
@@ -79,8 +81,32 @@ public boolean isDict() {
   }
 
   @Override
-  protected String getStringType() {
-    return "MAP";
+  protected String internalTypeString() {
+    StringBuilder builder = new StringBuilder()
+      .append("MAP<");
+
+    ColumnMetadata key = keyColumnMetadata();
+    ColumnMetadata value = valueColumnMetadata();
+
+    // sometimes dict key and value are added after creating metadata class,
+    // and if `typeString` method was called prematurely, for example, in case of error
+    // add whatever was added in a form of columns with key / value names
+    if (key == null || value == null) {
+      builder.append(tupleSchema().toMetadataList().stream()
+        .map(ColumnMetadata::columnString)
+        .collect(Collectors.joining(", ")));
+    } else {
+      builder.append(key.typeString())
+        .append(", ")
+        .append(value.typeString());
+
+      if (TypeProtos.DataMode.REQUIRED == value.mode()) {
+        builder.append(" NOT NULL");
+      }
+    }
+
+    builder.append(">");
+    return builder.toString();
   }
 
   @Override

exec/vector/src/main/java/org/apache/drill/exec/record/metadata/MapColumnMetadata.java

@@ -21,6 +21,8 @@
 import org.apache.drill.common.types.TypeProtos.MinorType;
 import org.apache.drill.exec.record.MaterializedField;
 
+import java.util.stream.Collectors;
+
 /**
  * Describes a map and repeated map. Both are tuples that have a tuple
  * schema as part of the column definition.
@@ -71,7 +73,11 @@ public boolean isMap() {
   }
 
   @Override
-  protected String getStringType() {
-    return "STRUCT";
+  protected String internalTypeString() {
+    return "STRUCT<"
+      + tupleSchema().toMetadataList().stream()
+          .map(ColumnMetadata::columnString)
+          .collect(Collectors.joining(", "))
+      + ">";
   }
 }