Remove FieldDescription in Struct/ArrayMetadata in favour of DataType (#3484)

This basically
#3395 put over
main, minus the UUID support. I think bringing this in as a
"enhancement" separately will declutter the future UUID support PR.

Author: g31pranjal

fdb-relational-api/src/main/java/com/apple/foundationdb/relational/api/ArrayMetaData.java

@@ -21,7 +21,9 @@
 package com.apple.foundationdb.relational.api;
 
 import com.apple.foundationdb.relational.api.exceptions.ErrorCode;
+import com.apple.foundationdb.relational.api.metadata.DataType;
 
+import javax.annotation.Nonnull;
 import java.sql.SQLException;
 import java.sql.Wrapper;
 
@@ -59,4 +61,13 @@ default StructMetaData getElementStructMetaData() throws SQLException {
      * @throws SQLException if the type of the column is not an array, or if something else goes wrong.
      */
     ArrayMetaData getElementArrayMetaData() throws SQLException;
+
+    /**
+     * Get the {@link DataType} object equivalent of this metadata.
+     *
+     * @return the datatype object.
+     * @throws SQLException if something goes wrong.
+     */
+    @Nonnull
+    DataType.ArrayType asRelationalType() throws SQLException;
 }

fdb-relational-api/src/main/java/com/apple/foundationdb/relational/api/FieldDescription.java

@@ -42,7 +42,9 @@ public interface RelationalArrayBuilder {
 
     RelationalArrayBuilder addString(@Nonnull String value) throws SQLException;
 
-    RelationalArrayBuilder addLong(@Nonnull long value) throws SQLException;
+    RelationalArrayBuilder addLong(long value) throws SQLException;
+
+    RelationalArrayBuilder addObject(@Nonnull Object value) throws SQLException;
 
     RelationalArrayBuilder addStruct(RelationalStruct struct) throws SQLException;
 }

fdb-relational-api/src/main/java/com/apple/foundationdb/relational/api/RelationalArrayBuilder.java

@@ -21,15 +21,14 @@
 package com.apple.foundationdb.relational.api;
 
 import com.apple.foundationdb.annotation.API;
-
 import com.apple.foundationdb.relational.api.exceptions.ErrorCode;
 import com.apple.foundationdb.relational.api.exceptions.RelationalException;
-
+import com.apple.foundationdb.relational.api.metadata.DataType;
 import com.google.common.base.Suppliers;
 
 import javax.annotation.Nonnull;
+import java.sql.DatabaseMetaData;
 import java.sql.SQLException;
-import java.sql.Types;
 import java.util.Objects;
 import java.util.function.Supplier;
 
@@ -39,41 +38,42 @@
 @API(API.Status.EXPERIMENTAL)
 public final class RelationalArrayMetaData implements ArrayMetaData {
 
-    private final FieldDescription element;
+    private final DataType.ArrayType type;
 
     private final Supplier<Integer> hashCodeSupplier;
 
-    private RelationalArrayMetaData(@Nonnull FieldDescription element) {
-        this.element = element;
+    private RelationalArrayMetaData(@Nonnull DataType.ArrayType type) {
+        this.type = type;
         this.hashCodeSupplier = Suppliers.memoize(this::calculateHashCode);
     }
 
-    public static RelationalArrayMetaData ofPrimitive(int sqlType, int nullable) {
-        return new RelationalArrayMetaData(FieldDescription.primitive("VALUE", sqlType, nullable));
-    }
-
-    public static RelationalArrayMetaData ofStruct(@Nonnull StructMetaData metaData, int nullable) {
-        return new RelationalArrayMetaData(FieldDescription.struct("VALUE", nullable, metaData));
+    @Nonnull
+    public static RelationalArrayMetaData of(@Nonnull DataType.ArrayType type) {
+        return new RelationalArrayMetaData(type);
     }
 
     @Override
-    public int isElementNullable() throws SQLException {
-        return element.isNullable();
+    public int isElementNullable() {
+        if (type.getElementType().isNullable()) {
+            return DatabaseMetaData.columnNullable;
+        } else {
+            return DatabaseMetaData.columnNoNulls;
+        }
     }
 
     @Override
     public String getElementName() throws SQLException {
-        return element.getName();
+        return "VALUE";
     }
 
     @Override
     public int getElementType() throws SQLException {
-        return element.getSqlTypeCode();
+        return type.getElementType().getJdbcSqlCode();
     }
 
     @Override
-    public String getElementTypeName() throws SQLException {
-        return SqlTypeNamesSupport.getSqlTypeName(element.getSqlTypeCode());
+    public String getElementTypeName() {
+        return SqlTypeNamesSupport.getSqlTypeName(type.getElementType().getJdbcSqlCode());
     }
 
     /**
@@ -86,10 +86,10 @@ public String getElementTypeName() throws SQLException {
      */
     @Override
     public StructMetaData getElementStructMetaData() throws SQLException {
-        if (element.getSqlTypeCode() != Types.STRUCT) {
+        if (type.getElementType().getCode() != DataType.Code.STRUCT) {
             throw new RelationalException("Element is not of STRUCT type", ErrorCode.CANNOT_CONVERT_TYPE).toSqlException();
         }
-        return element.getFieldMetaData();
+        return RelationalStructMetaData.of((DataType.StructType) type.getElementType());
     }
 
     /**
@@ -102,15 +102,21 @@ public StructMetaData getElementStructMetaData() throws SQLException {
      */
     @Override
     public ArrayMetaData getElementArrayMetaData() throws SQLException {
-        if (element.getSqlTypeCode() != Types.ARRAY) {
+        if (type.getElementType().getCode() != DataType.Code.ARRAY) {
             throw new RelationalException("Element is not of ARRAY type", ErrorCode.CANNOT_CONVERT_TYPE).toSqlException();
         }
-        return element.getArrayMetaData();
+        return RelationalArrayMetaData.of((DataType.ArrayType) type.getElementType());
+    }
+
+    @Nonnull
+    @Override
+    public DataType.ArrayType asRelationalType() throws SQLException {
+        return type;
     }
 
     @Nonnull
-    public FieldDescription getElementField() {
-        return element;
+    public DataType getElementDataType() {
+        return type.getElementType();
     }
 
     @Override
@@ -132,7 +138,7 @@ public boolean equals(Object other) {
         if (otherMetadata == this) {
             return true;
         }
-        return element.equals(otherMetadata.element);
+        return type.equals(otherMetadata.type);
     }
 
     @Override
@@ -141,7 +147,7 @@ public int hashCode() {
     }
 
     private int calculateHashCode() {
-        return Objects.hash(element);
+        return Objects.hash(type);
     }
 
 }

fdb-relational-api/src/main/java/com/apple/foundationdb/relational/api/RelationalArrayMetaData.java

@@ -40,8 +40,6 @@ public interface RelationalStructBuilder {
 
     RelationalStructBuilder addBoolean(String fieldName, boolean b) throws SQLException;
 
-    RelationalStructBuilder addShort(String fieldName, short b) throws SQLException;
-
     RelationalStructBuilder addLong(String fieldName, long l) throws SQLException;
 
     RelationalStructBuilder addFloat(String fieldName, float f) throws SQLException;
@@ -52,7 +50,7 @@ public interface RelationalStructBuilder {
 
     RelationalStructBuilder addString(String fieldName, @Nullable String s) throws SQLException;
 
-    RelationalStructBuilder addObject(String fieldName, @Nullable Object obj, int targetSqlType) throws SQLException;
+    RelationalStructBuilder addObject(String fieldName, @Nullable Object obj) throws SQLException;
 
     RelationalStructBuilder addStruct(String fieldName, @Nonnull RelationalStruct struct) throws SQLException;