Rework on OpenSearchDataType: parse, store and use mapping information (#180)

Rework on `OpenSearchDataType`:
* Add data types for those classes are not defined in `ExprCoreType`.
* Address #180 (comment)
* Remove `TextKeywordValue`.
* Add changes according to the PR review. #180
* Update `IndexMapping::parseMapping` function.
* Add `OpenSearchDataType::resolve` function.
* Add new constructor for `OpenSearchTextType`.
* Make `fields` and `properties` in `OpenSearchDataType` readonly. Update tests and mapping parser.
* Move `getFields` from `OpenSearchDataType` to `OpenSearchTextType`. Update tests.
* Rewrite `traverseAndFlatten` according to #180 (comment)
* Minor comment fix.
* A fix to avoid breaking changes.
* `typeName` and `legacyTypeName` to return different type names.
* Change `typeof` function and corresponding tests.
* Move `convertTextToKeyword` from `ScriptUtils` to `OpenSearchTextType`. Update tests.
* Update UT for `typeof` function.
* Make all instances of `OpenSearchDataType` and of derived types singletones as much as possible.
* Make string representations of all `ExprType`s uppercase.
* Remove functions from `IndexMapping` used in tests only.

Signed-off-by: Yury-Fridlyand <[email protected]>
Signed-off-by: Yury-Fridlyand <[email protected]>

Author: Yury-Fridlyand

core/src/main/java/org/opensearch/sql/data/model/AbstractExprValue.java

@@ -21,7 +21,7 @@ public int compareTo(ExprValue other) {
       throw new IllegalStateException(
            String.format("[BUG] Unreachable, Comparing with NULL or MISSING is undefined"));
     }
-    if ((this.isNumber() && other.isNumber()) || this.type() == other.type()) {
+    if ((this.isNumber() && other.isNumber()) || this.type().equals(other.type())) {
       return compare(other);
     } else {
       throw new ExpressionEvaluationException(

core/src/main/java/org/opensearch/sql/data/type/ExprCoreType.java

@@ -81,9 +81,9 @@ public enum ExprCoreType implements ExprType {
    */
   private static final Map<ExprCoreType, String> LEGACY_TYPE_NAME_MAPPING =
       new ImmutableMap.Builder<ExprCoreType, String>()
-          .put(STRUCT, "object")
-          .put(ARRAY, "nested")
-          .put(STRING, "keyword")
+          .put(STRUCT, "OBJECT")
+          .put(ARRAY, "NESTED")
+          .put(STRING, "KEYWORD")
           .build();
 
   private static final Set<ExprType> NUMBER_TYPES =

core/src/main/java/org/opensearch/sql/expression/system/SystemFunctions.java

@@ -41,7 +41,7 @@ public Pair<FunctionSignature, FunctionBuilder> resolve(
             arguments -> new FunctionExpression(BuiltinFunctionName.TYPEOF.getName(), arguments) {
               @Override
               public ExprValue valueOf(Environment<Expression, ExprValue> valueEnv) {
-                return new ExprStringValue(getArguments().get(0).type().toString());
+                return new ExprStringValue(getArguments().get(0).type().legacyTypeName());
               }
 
               @Override

core/src/test/java/org/opensearch/sql/data/type/ExprTypeTest.java

@@ -76,9 +76,9 @@ public void getParent() {
 
   @Test
   void legacyName() {
-    assertEquals("keyword", STRING.legacyTypeName());
-    assertEquals("nested", ARRAY.legacyTypeName());
-    assertEquals("object", STRUCT.legacyTypeName());
+    assertEquals("KEYWORD", STRING.legacyTypeName());
+    assertEquals("NESTED", ARRAY.legacyTypeName());
+    assertEquals("OBJECT", STRUCT.legacyTypeName());
     assertEquals("integer", INTEGER.legacyTypeName().toLowerCase());
   }
 

core/src/test/java/org/opensearch/sql/expression/system/SystemFunctionsTest.java

@@ -47,7 +47,7 @@ public class SystemFunctionsTest {
   void typeof() {
     assertEquals(STRING, dsl.typeof(DSL.literal(1)).type());
 
-    assertEquals("ARRAY", typeofGetValue(new ExprCollectionValue(List.of())));
+    assertEquals("NESTED", typeofGetValue(new ExprCollectionValue(List.of())));
     assertEquals("BOOLEAN", typeofGetValue(ExprBooleanValue.of(false)));
     assertEquals("BYTE", typeofGetValue(new ExprByteValue(0)));
     assertEquals("DATE", typeofGetValue(new ExprDateValue(LocalDate.now())));
@@ -58,8 +58,8 @@ void typeof() {
     assertEquals("INTERVAL", typeofGetValue(new ExprIntervalValue(Duration.ofDays(0))));
     assertEquals("LONG", typeofGetValue(new ExprLongValue(0)));
     assertEquals("SHORT", typeofGetValue(new ExprShortValue(0)));
-    assertEquals("STRING", typeofGetValue(new ExprStringValue("")));
-    assertEquals("STRUCT", typeofGetValue(new ExprTupleValue(new LinkedHashMap<>())));
+    assertEquals("KEYWORD", typeofGetValue(new ExprStringValue("")));
+    assertEquals("OBJECT", typeofGetValue(new ExprTupleValue(new LinkedHashMap<>())));
     assertEquals("TIME", typeofGetValue(new ExprTimeValue(LocalTime.now())));
     assertEquals("TIMESTAMP", typeofGetValue(new ExprTimestampValue(Instant.now())));
     assertEquals("UNDEFINED", typeofGetValue(ExprNullValue.of()));

docs/user/dql/functions.rst

@@ -3125,5 +3125,5 @@ Example::
     +----------------+---------------+-----------------+------------------+
     | typeof(date)   | typeof(int)   | typeof(now())   | typeof(column)   |
     |----------------+---------------+-----------------+------------------|
-    | DATE           | INTEGER       | DATETIME        | STRUCT           |
+    | DATE           | INTEGER       | DATETIME        | OBJECT           |
     +----------------+---------------+-----------------+------------------+

docs/user/ppl/functions/system.rst

@@ -27,5 +27,5 @@ Example::
     +----------------+---------------+-----------------+------------------+
     | typeof(date)   | typeof(int)   | typeof(now())   | typeof(column)   |
     |----------------+---------------+-----------------+------------------|
-    | DATE           | INTEGER       | DATETIME        | STRUCT           |
+    | DATE           | INTEGER       | DATETIME        | OBJECT           |
     +----------------+---------------+-----------------+------------------+

integ-test/src/test/java/org/opensearch/sql/ppl/SystemFunctionIT.java

@@ -33,7 +33,7 @@ public void typeof_sql_types() throws IOException {
             TEST_INDEX_DATATYPE_NUMERIC));
     // TODO: test null in PPL
     verifyDataRows(response,
-        rows("STRING", "DOUBLE", "INTEGER", "LONG", "INTERVAL"));
+        rows("KEYWORD", "DOUBLE", "INTEGER", "LONG", "INTERVAL"));
 
     response = executeQuery(String.format("source=%s | eval "
         + "`timestamp` = typeof(CAST('1961-04-12 09:07:00' AS TIMESTAMP)),"
@@ -68,7 +68,7 @@ public void typeof_opensearch_types() throws IOException {
         + " | fields `text`, `date`, `boolean`, `object`, `keyword`, `ip`, `binary`, `geo_point`",
             TEST_INDEX_DATATYPE_NONNUMERIC));
     verifyDataRows(response,
-        rows("OPENSEARCH_TEXT", "TIMESTAMP", "BOOLEAN", "STRUCT", "STRING",
-                "OPENSEARCH_IP", "OPENSEARCH_BINARY", "OPENSEARCH_GEO_POINT"));
+        rows("TEXT", "TIMESTAMP", "BOOLEAN", "OBJECT", "KEYWORD",
+                "IP", "BINARY", "GEO_POINT"));
   }
 }

integ-test/src/test/java/org/opensearch/sql/sql/SystemFunctionIT.java

@@ -27,7 +27,7 @@ public void typeof_sql_types() {
     JSONObject response = executeJdbcRequest("SELECT typeof('pewpew'), typeof(NULL), typeof(1.0),"
         + "typeof(12345), typeof(1234567891011), typeof(INTERVAL 2 DAY);");
     verifyDataRows(response,
-        rows("STRING", "UNDEFINED", "DOUBLE", "INTEGER", "LONG", "INTERVAL"));
+        rows("KEYWORD", "UNDEFINED", "DOUBLE", "INTEGER", "LONG", "INTERVAL"));
 
     response = executeJdbcRequest("SELECT"
         + " typeof(CAST('1961-04-12 09:07:00' AS TIMESTAMP)),"
@@ -54,7 +54,7 @@ public void typeof_opensearch_types() {
         //+ ", typeof(nested_value)"
         + " from %s;", TEST_INDEX_DATATYPE_NONNUMERIC));
     verifyDataRows(response,
-        rows("OPENSEARCH_TEXT", "TIMESTAMP", "BOOLEAN", "STRUCT", "STRING",
-                "OPENSEARCH_IP", "OPENSEARCH_BINARY", "OPENSEARCH_GEO_POINT"));
+        rows("TEXT", "TIMESTAMP", "BOOLEAN", "OBJECT", "KEYWORD",
+                "IP", "BINARY", "GEO_POINT"));
   }
 }

opensearch/src/main/java/org/opensearch/sql/opensearch/data/type/OpenSearchBinaryType.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+
+package org.opensearch.sql.opensearch.data.type;
+
+import static org.opensearch.sql.data.type.ExprCoreType.UNKNOWN;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+
+/**
+ * The type of a binary value. See
+ * <a href="https://opensearch.org/docs/latest/opensearch/supported-field-types/binary/">doc</a>
+ */
+@EqualsAndHashCode(callSuper = false)
+public class OpenSearchBinaryType extends OpenSearchDataType {
+
+  @Getter
+  private static final OpenSearchBinaryType instance = new OpenSearchBinaryType();
+
+  private OpenSearchBinaryType() {
+    super(MappingType.Binary);
+    exprCoreType = UNKNOWN;
+  }
+
+  @Override
+  protected OpenSearchDataType cloneEmpty() {
+    return instance;
+  }
+}