SNOW-1374896 unify structured types string representation (#1882)

Co-authored-by: sfc-gh-astachowski <antoni.stachowski@snowflake.com>

Build string representations of Snowflake structured types recursively to reuse existing converters designed for specific logical types (e.g. timestamps/binary)

https://snowflakecomputing.atlassian.net/browse/SNOW-1374896

src/main/java/net/snowflake/client/core/ResultUtil.java

@@ -251,7 +251,7 @@ public static String getSFTimeAsString(
    * @return boolean in string
    */
   public static String getBooleanAsString(boolean bool) {
-    return bool ? "TRUE" : "FALSE";
+    return bool ? "true" : "false";
   }
 
   /**

src/main/java/net/snowflake/client/core/arrow/ArrayConverter.java

@@ -2,7 +2,10 @@
 
 import net.snowflake.client.core.DataConversionContext;
 import net.snowflake.client.core.SFException;
+import net.snowflake.client.core.arrow.tostringhelpers.ArrowArrayStringRepresentationBuilder;
+import net.snowflake.client.jdbc.SnowflakeSQLException;
 import net.snowflake.client.jdbc.SnowflakeType;
+import org.apache.arrow.vector.FieldVector;
 import org.apache.arrow.vector.complex.ListVector;
 
 public class ArrayConverter extends AbstractArrowVectorConverter {
@@ -21,6 +24,25 @@ public Object toObject(int index) throws SFException {
 
   @Override
   public String toString(int index) throws SFException {
-    return vector.getObject(index).toString();
+    FieldVector vectorUnpacked = vector.getChildrenFromFields().get(0);
+    SnowflakeType logicalType =
+        ArrowVectorConverterUtil.getSnowflakeTypeFromFieldMetadata(vectorUnpacked.getField());
+
+    ArrowArrayStringRepresentationBuilder builder =
+        new ArrowArrayStringRepresentationBuilder(logicalType);
+
+    final ArrowVectorConverter converter;
+
+    try {
+      converter = ArrowVectorConverterUtil.initConverter(vectorUnpacked, context, columnIndex);
+    } catch (SnowflakeSQLException e) {
+      return vector.getObject(index).toString();
+    }
+
+    for (int i = vector.getElementStartIndex(index); i < vector.getElementEndIndex(index); i++) {
+      builder.appendValue(converter.toString(i));
+    }
+
+    return builder.toString();
   }
 }

src/main/java/net/snowflake/client/core/arrow/ArrowVectorConverterUtil.java

@@ -9,17 +9,28 @@
 import net.snowflake.client.jdbc.SnowflakeSQLLoggedException;
 import net.snowflake.client.jdbc.SnowflakeType;
 import net.snowflake.common.core.SqlState;
+import org.apache.arrow.vector.FieldVector;
 import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.complex.FixedSizeListVector;
 import org.apache.arrow.vector.complex.ListVector;
 import org.apache.arrow.vector.complex.MapVector;
 import org.apache.arrow.vector.complex.StructVector;
 import org.apache.arrow.vector.types.Types;
+import org.apache.arrow.vector.types.pojo.Field;
 
 @SnowflakeJdbcInternalApi
 public final class ArrowVectorConverterUtil {
   private ArrowVectorConverterUtil() {}
 
+  public static SnowflakeType getSnowflakeTypeFromFieldMetadata(Field field) {
+    Map<String, String> customMeta = field.getMetadata();
+    if (customMeta != null && customMeta.containsKey("logicalType")) {
+      return SnowflakeType.valueOf(customMeta.get("logicalType"));
+    }
+
+    return null;
+  }
+
   /**
    * Given an arrow vector (a single column in a single record batch), return an arrow vector
    * converter. Note, converter is built on top of arrow vector, so that arrow data can be converted
@@ -51,12 +62,11 @@ public static ArrowVectorConverter initConverter(
     Types.MinorType type = Types.getMinorTypeForArrowType(vector.getField().getType());
 
     // each column's metadata
-    Map<String, String> customMeta = vector.getField().getMetadata();
+    SnowflakeType st = getSnowflakeTypeFromFieldMetadata(vector.getField());
     if (type == Types.MinorType.DECIMAL) {
       // Note: Decimal vector is different from others
       return new DecimalToScaledFixedConverter(vector, idx, context);
-    } else if (!customMeta.isEmpty()) {
-      SnowflakeType st = SnowflakeType.valueOf(customMeta.get("logicalType"));
+    } else if (st != null) {
       switch (st) {
         case ANY:
         case CHAR:
@@ -216,4 +226,10 @@ public static ArrowVectorConverter initConverter(
         "Unexpected Arrow Field for ",
         type.toString());
   }
+
+  public static ArrowVectorConverter initConverter(
+      FieldVector vector, DataConversionContext context, int columnIndex)
+      throws SnowflakeSQLException {
+    return initConverter(vector, context, context.getSession(), columnIndex);
+  }
 }

src/main/java/net/snowflake/client/core/arrow/BitToBooleanConverter.java

@@ -58,7 +58,7 @@ public Object toObject(int index) {
 
   @Override
   public String toString(int index) {
-    return isNull(index) ? null : toBoolean(index) ? "TRUE" : "FALSE";
+    return isNull(index) ? null : toBoolean(index) ? "true" : "false";
   }
 
   @Override

src/main/java/net/snowflake/client/core/arrow/MapConverter.java

@@ -4,7 +4,10 @@
 import java.util.stream.Collectors;
 import net.snowflake.client.core.DataConversionContext;
 import net.snowflake.client.core.SFException;
+import net.snowflake.client.core.arrow.tostringhelpers.ArrowObjectStringRepresentationBuilder;
+import net.snowflake.client.jdbc.SnowflakeSQLException;
 import net.snowflake.client.jdbc.SnowflakeType;
+import org.apache.arrow.vector.FieldVector;
 import org.apache.arrow.vector.complex.MapVector;
 import org.apache.arrow.vector.util.JsonStringHashMap;
 
@@ -28,6 +31,30 @@ public Object toObject(int index) throws SFException {
 
   @Override
   public String toString(int index) throws SFException {
-    return vector.getObject(index).toString();
+    ArrowObjectStringRepresentationBuilder builder = new ArrowObjectStringRepresentationBuilder();
+
+    FieldVector vectorUnpacked = vector.getChildrenFromFields().get(0);
+
+    FieldVector keys = vectorUnpacked.getChildrenFromFields().get(0);
+    FieldVector values = vectorUnpacked.getChildrenFromFields().get(1);
+    final ArrowVectorConverter keyConverter;
+    final ArrowVectorConverter valueConverter;
+
+    SnowflakeType valueLogicalType =
+        ArrowVectorConverterUtil.getSnowflakeTypeFromFieldMetadata(values.getField());
+
+    try {
+      keyConverter = ArrowVectorConverterUtil.initConverter(keys, context, columnIndex);
+      valueConverter = ArrowVectorConverterUtil.initConverter(values, context, columnIndex);
+    } catch (SnowflakeSQLException e) {
+      return vector.getObject(index).toString();
+    }
+
+    for (int i = vector.getElementStartIndex(index); i < vector.getElementEndIndex(index); i++) {
+      builder.appendKeyValue(
+          keyConverter.toString(i), valueConverter.toString(i), valueLogicalType);
+    }
+
+    return builder.toString();
   }
 }

src/main/java/net/snowflake/client/core/arrow/StructConverter.java

@@ -3,7 +3,10 @@
 import net.snowflake.client.core.DataConversionContext;
 import net.snowflake.client.core.SFException;
 import net.snowflake.client.core.SnowflakeJdbcInternalApi;
+import net.snowflake.client.core.arrow.tostringhelpers.ArrowObjectStringRepresentationBuilder;
+import net.snowflake.client.jdbc.SnowflakeSQLException;
 import net.snowflake.client.jdbc.SnowflakeType;
+import org.apache.arrow.vector.FieldVector;
 import org.apache.arrow.vector.complex.StructVector;
 
 @SnowflakeJdbcInternalApi
@@ -23,6 +26,19 @@ public Object toObject(int index) throws SFException {
 
   @Override
   public String toString(int index) throws SFException {
-    return structVector.getObject(index).toString();
+    ArrowObjectStringRepresentationBuilder builder = new ArrowObjectStringRepresentationBuilder();
+    for (String childName : structVector.getChildFieldNames()) {
+      FieldVector fieldVector = structVector.getChild(childName);
+      SnowflakeType logicalType =
+          ArrowVectorConverterUtil.getSnowflakeTypeFromFieldMetadata(fieldVector.getField());
+      try {
+        ArrowVectorConverter converter =
+            ArrowVectorConverterUtil.initConverter(fieldVector, context, columnIndex);
+        builder.appendKeyValue(childName, converter.toString(index), logicalType);
+      } catch (SnowflakeSQLException e) {
+        return structVector.getObject(index).toString();
+      }
+    }
+    return builder.toString();
   }
 }

src/main/java/net/snowflake/client/core/arrow/tostringhelpers/ArrowArrayStringRepresentationBuilder.java

@@ -0,0 +1,19 @@
+package net.snowflake.client.core.arrow.tostringhelpers;
+
+import net.snowflake.client.core.SnowflakeJdbcInternalApi;
+import net.snowflake.client.jdbc.SnowflakeType;
+
+@SnowflakeJdbcInternalApi
+public class ArrowArrayStringRepresentationBuilder extends ArrowStringRepresentationBuilderBase {
+
+  private final SnowflakeType valueType;
+
+  public ArrowArrayStringRepresentationBuilder(SnowflakeType valueType) {
+    super(",", "[", "]");
+    this.valueType = valueType;
+  }
+
+  public ArrowStringRepresentationBuilderBase appendValue(String value) {
+    return add(quoteIfNeeded(value, valueType));
+  }
+}

src/main/java/net/snowflake/client/core/arrow/tostringhelpers/ArrowObjectStringRepresentationBuilder.java

@@ -0,0 +1,21 @@
+package net.snowflake.client.core.arrow.tostringhelpers;
+
+import java.util.StringJoiner;
+import net.snowflake.client.core.SnowflakeJdbcInternalApi;
+import net.snowflake.client.jdbc.SnowflakeType;
+
+@SnowflakeJdbcInternalApi
+public class ArrowObjectStringRepresentationBuilder extends ArrowStringRepresentationBuilderBase {
+
+  public ArrowObjectStringRepresentationBuilder() {
+    super(",", "{", "}");
+  }
+
+  public ArrowStringRepresentationBuilderBase appendKeyValue(
+      String key, String value, SnowflakeType valueType) {
+    StringJoiner joiner = new StringJoiner(": ");
+    joiner.add('"' + key + '"');
+    joiner.add(quoteIfNeeded(value, valueType));
+    return add(joiner.toString());
+  }
+}

src/main/java/net/snowflake/client/core/arrow/tostringhelpers/ArrowStringRepresentationBuilderBase.java

@@ -0,0 +1,53 @@
+package net.snowflake.client.core.arrow.tostringhelpers;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.StringJoiner;
+import net.snowflake.client.core.SnowflakeJdbcInternalApi;
+import net.snowflake.client.jdbc.SnowflakeType;
+
+@SnowflakeJdbcInternalApi
+public abstract class ArrowStringRepresentationBuilderBase {
+  private final StringJoiner joiner;
+  private static final Set<SnowflakeType> quotableTypes;
+
+  static {
+    quotableTypes = new HashSet<>();
+    quotableTypes.add(SnowflakeType.ANY);
+    quotableTypes.add(SnowflakeType.CHAR);
+    quotableTypes.add(SnowflakeType.TEXT);
+    quotableTypes.add(SnowflakeType.VARIANT);
+    quotableTypes.add(SnowflakeType.BINARY);
+    quotableTypes.add(SnowflakeType.DATE);
+    quotableTypes.add(SnowflakeType.TIME);
+    quotableTypes.add(SnowflakeType.TIMESTAMP_LTZ);
+    quotableTypes.add(SnowflakeType.TIMESTAMP_NTZ);
+    quotableTypes.add(SnowflakeType.TIMESTAMP_TZ);
+  }
+
+  public ArrowStringRepresentationBuilderBase(String delimiter, String prefix, String suffix) {
+    joiner = new StringJoiner(delimiter, prefix, suffix);
+  }
+
+  protected ArrowStringRepresentationBuilderBase add(String string) {
+    joiner.add(string);
+    return this;
+  }
+
+  private boolean shouldQuoteValue(SnowflakeType type) {
+    return quotableTypes.contains(type);
+  }
+
+  protected String quoteIfNeeded(String string, SnowflakeType type) {
+    if (shouldQuoteValue(type)) {
+      return '"' + string + '"';
+    }
+
+    return string;
+  }
+
+  @Override
+  public String toString() {
+    return joiner.toString();
+  }
+}

src/test/java/net/snowflake/client/TestUtil.java

@@ -144,4 +144,14 @@ public static void expectSnowflakeLoggedFeatureNotSupportedException(MethodRaise
       assertEquals(ex.getClass().getSimpleName(), "SnowflakeLoggedFeatureNotSupportedException");
     }
   }
+
+  /**
+   * Compares two string values both values are cleaned of whitespaces
+   *
+   * @param expected expected value
+   * @param actual actual value
+   */
+  public static void assertEqualsIgnoringWhitespace(String expected, String actual) {
+    assertEquals(expected.replaceAll("\\s+", ""), actual.replaceAll("\\s+", ""));
+  }
 }

src/test/java/net/snowflake/client/core/arrow/BitToBooleanConverterTest.java

@@ -73,7 +73,7 @@ public void testConvertToString() throws SFException {
       } else {
         assertThat(boolVal, is(expectedValues.get(i)));
         assertThat(objectVal, is(expectedValues.get(i)));
-        assertThat(stringVal, is(expectedValues.get(i).toString().toUpperCase()));
+        assertThat(stringVal, is(expectedValues.get(i).toString()));
         if (boolVal) {
           assertThat((byte) 0x1, is(converter.toBytes(i)[0]));
         } else {

src/test/java/net/snowflake/client/core/json/StringConverterTest.java

@@ -59,10 +59,10 @@ public void testConvertingString() throws SFException {
 
   @Test
   public void testConvertingBoolean() throws SFException {
-    assertEquals("TRUE", stringConverter.getString(true, Types.BOOLEAN, Types.BOOLEAN, 0));
-    assertEquals("TRUE", stringConverter.getString("true", Types.BOOLEAN, Types.BOOLEAN, 0));
-    assertEquals("FALSE", stringConverter.getString(false, Types.BOOLEAN, Types.BOOLEAN, 0));
-    assertEquals("FALSE", stringConverter.getString("false", Types.BOOLEAN, Types.BOOLEAN, 0));
+    assertEquals("true", stringConverter.getString(true, Types.BOOLEAN, Types.BOOLEAN, 0));
+    assertEquals("true", stringConverter.getString("true", Types.BOOLEAN, Types.BOOLEAN, 0));
+    assertEquals("false", stringConverter.getString(false, Types.BOOLEAN, Types.BOOLEAN, 0));
+    assertEquals("false", stringConverter.getString("false", Types.BOOLEAN, Types.BOOLEAN, 0));
   }
 
   @Test

src/test/java/net/snowflake/client/jdbc/ResultSetJsonVsArrowIT.java

@@ -1501,12 +1501,12 @@ public void testBoolean() throws SQLException {
         ResultSet rs = statement.executeQuery("select * from " + table)) {
       assertTrue(rs.next());
       assertTrue(rs.getBoolean(1));
-      assertEquals("TRUE", rs.getString(1));
+      assertEquals("true", rs.getString(1));
       assertTrue(rs.next());
       assertFalse(rs.getBoolean(1));
       assertTrue(rs.next());
       assertFalse(rs.getBoolean(1));
-      assertEquals("FALSE", rs.getString(1));
+      assertEquals("false", rs.getString(1));
       assertFalse(rs.next());
       statement.execute("drop table if exists " + table);
     }

src/test/java/net/snowflake/client/jdbc/ResultSetLatestIT.java

@@ -1176,9 +1176,9 @@ public void testGetObjectWithType() throws SQLException {
       assertResultValueAndType(statement, Double.valueOf("1.1"), "f", Double.class);
       assertResultValueAndType(statement, Double.valueOf("2.2"), "d", Double.class);
       assertResultValueAndType(statement, BigDecimal.valueOf(3.3), "bd", BigDecimal.class);
-      assertResultValueAndType(statement, "FALSE", "bool", String.class);
+      assertResultValueAndType(statement, "false", "bool", String.class);
       assertResultValueAndType(statement, Boolean.FALSE, "bool", Boolean.class);
-      assertResultValueAndType(statement, Long.valueOf(0), "bool", Long.class);
+      assertResultValueAndType(statement, 0L, "bool", Long.class);
       assertResultValueAsString(
           statement,
           new SnowflakeTimestampWithTimezone(