Squashed commit of the following: (#598)

headless/api/src/main/java/com/tencent/supersonic/headless/api/enums/AggOption.java

@@ -1,5 +1,10 @@
 package com.tencent.supersonic.headless.api.enums;
 
+/**
+ * Aggregation type of metric when query metric without aggregation method
+ * NATIVE: will not use Aggregation
+ * DEFAULT: will use the aggregation method define in the model
+ */
 public enum AggOption {
     NATIVE,
     AGGREGATION,

headless/api/src/main/java/com/tencent/supersonic/headless/api/enums/DatasourceQuery.java

@@ -1,6 +1,10 @@
 package com.tencent.supersonic.headless.api.enums;
 
-
+/**
+ * model datasource define type:
+ * sql_query : view sql begin as select
+ * table_query: dbName.tableName
+ */
 public enum DatasourceQuery {
 
     SQL_QUERY("sql_query"),

headless/api/src/main/java/com/tencent/supersonic/headless/api/enums/ModelSourceType.java

@@ -1,7 +1,12 @@
 package com.tencent.supersonic.headless.api.enums;
 
 import java.util.Objects;
-
+/**
+ * model source table type:
+ * FULL: table without time partition
+ * PARTITION: table with partition field
+ * ZIPPER: table with slowly changing dimension
+ */
 public enum ModelSourceType {
     FULL,
     PARTITION,

headless/core/src/main/java/com/tencent/supersonic/headless/core/adaptor/db/DbAdaptor.java

@@ -1,6 +1,8 @@
 package com.tencent.supersonic.headless.core.adaptor.db;
 
-
+/**
+ * Adapters for different query engines to obtain table, field, and time formatting methods
+ */
 public abstract class DbAdaptor {
 
     public abstract String getDateFormat(String dateType, String dateFormat, String column);

headless/core/src/main/java/com/tencent/supersonic/headless/core/executor/QueryExecutor.java

@@ -3,6 +3,9 @@ package com.tencent.supersonic.headless.core.executor;
 import com.tencent.supersonic.headless.api.response.QueryResultWithSchemaResp;
 import com.tencent.supersonic.headless.core.pojo.QueryStatement;
 
+/**
+ * Query data or execute sql from a query engine
+ */
 public interface QueryExecutor {
 
     boolean accept(QueryStatement queryStatement);

headless/core/src/main/java/com/tencent/supersonic/headless/core/manager/DimensionYamlManager.java

@@ -13,7 +13,9 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
-
+/**
+ *  manager to handle the dimension
+ */
 @Slf4j
 @Service
 public class DimensionYamlManager {

headless/core/src/main/java/com/tencent/supersonic/headless/core/manager/MetricYamlManager.java

@@ -15,7 +15,9 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
-
+/**
+ * manager to handle the metric
+ */
 @Slf4j
 @Service
 public class MetricYamlManager {

headless/core/src/main/java/com/tencent/supersonic/headless/core/manager/ModelYamlManager.java

@@ -24,7 +24,9 @@ import org.springframework.util.CollectionUtils;
 import java.util.Objects;
 import java.util.stream.Collectors;
 
-
+/**
+ * manager to handle the model
+ */
 @Service
 @Slf4j
 public class ModelYamlManager {

headless/core/src/main/java/com/tencent/supersonic/headless/core/optimizer/DetailQuery.java

@@ -10,6 +10,9 @@ import org.springframework.util.CollectionUtils;
 import java.util.Objects;
 import java.util.stream.Collectors;
 
+/**
+ * Remove the default metric added by the system when the query only has dimensions
+ */
 @Slf4j
 @Component("DetailQuery")
 public class DetailQuery implements QueryOptimizer {

headless/core/src/main/java/com/tencent/supersonic/headless/core/optimizer/QueryOptimizer.java

@@ -3,6 +3,9 @@ package com.tencent.supersonic.headless.core.optimizer;
 import com.tencent.supersonic.headless.api.request.QueryStructReq;
 import com.tencent.supersonic.headless.core.pojo.QueryStatement;
 
+/**
+ * the interface that rewrites QueryStatement with some optimization rules
+ */
 public interface QueryOptimizer {
     void rewrite(QueryStructReq queryStructCmd, QueryStatement queryStatement);
 }

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/HeadlessConverter.java

@@ -2,6 +2,9 @@ package com.tencent.supersonic.headless.core.parser;
 
 import com.tencent.supersonic.headless.core.pojo.QueryStatement;
 
+/**
+ * to supplement,translate the request Body
+ */
 public interface HeadlessConverter {
 
     boolean accept(QueryStatement queryStatement);

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/QueryParser.java

@@ -19,6 +19,9 @@ import java.util.List;
 import java.util.Objects;
 import java.util.stream.Collectors;
 
+/**
+ * logical parse from ParseSqlReq or MetricReq
+ */
 @Component
 @Slf4j
 @Primary

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/CalciteSqlParser.java

@@ -10,6 +10,9 @@ import com.tencent.supersonic.headless.core.parser.calcite.schema.RuntimeOptions
 import com.tencent.supersonic.headless.core.pojo.QueryStatement;
 import org.springframework.stereotype.Component;
 
+/**
+ * the calcite parse implements
+ */
 @Component("CalciteSqlParser")
 public class CalciteSqlParser implements SqlParser {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/Configuration.java

@@ -36,6 +36,9 @@ import org.apache.calcite.sql2rel.SqlToRelConverter;
 import org.apache.calcite.tools.FrameworkConfig;
 import org.apache.calcite.tools.Frameworks;
 
+/**
+ * global configuration of the calcite
+ */
 public class Configuration {
 
     public static Properties configProperties = new Properties();
@@ -94,7 +97,8 @@ public class Configuration {
         return SqlToRelConverter.config()
                 .withHintStrategyTable(strategies)
                 .withTrimUnusedFields(true)
-                .withExpand(true);
+                .withExpand(true)
+                .addRelBuilderConfigTransform(c -> c.withSimplify(false));
     }
 
     public static SqlToRelConverter getSqlToRelConverter(SqlValidatorScope scope, SqlValidator sqlValidator,

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/planner/AggPlanner.java

@@ -36,6 +36,9 @@ import java.util.ListIterator;
 import java.util.Objects;
 import java.util.Stack;
 
+/**
+ * parsing from query dimensions and metrics
+ */
 @Slf4j
 public class AggPlanner implements Planner {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/planner/Planner.java

@@ -5,6 +5,9 @@ import com.tencent.supersonic.headless.api.enums.AggOption;
 import com.tencent.supersonic.headless.core.pojo.QueryStatement;
 import com.tencent.supersonic.headless.core.parser.calcite.schema.HeadlessSchema;
 
+/**
+ * parse and generate SQL and other execute information
+ */
 public interface Planner {
 
     public void explain(QueryStatement queryStatement, AggOption aggOption) throws Exception;

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/schema/DataSourceTable.java

@@ -22,6 +22,9 @@ import org.apache.calcite.schema.TranslatableTable;
 import org.apache.calcite.schema.impl.AbstractTable;
 import org.apache.calcite.sql.type.SqlTypeName;
 
+/**
+ * customize the  AbstractTable
+ */
 public class DataSourceTable extends AbstractTable implements ScannableTable, TranslatableTable {
 
     private final String tableName;

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/schema/HeadlessSchema.java

@@ -16,6 +16,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+
 public class HeadlessSchema extends AbstractSchema {
 
     private final String rootPath;

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/schema/HeadlessSqlConformance.java

@@ -4,6 +4,9 @@ import org.apache.calcite.sql.fun.SqlLibrary;
 import org.apache.calcite.sql.validate.SqlConformance;
 import org.apache.calcite.sql.validate.SqlConformanceEnum;
 
+/**
+ * customize the  SqlConformance
+ */
 public class HeadlessSqlConformance implements SqlConformance {
 
     @Override

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/schema/HeadlessSqlTypeFactoryImpl.java

@@ -4,6 +4,9 @@ import java.nio.charset.Charset;
 import org.apache.calcite.rel.type.RelDataTypeSystem;
 import org.apache.calcite.sql.type.SqlTypeFactoryImpl;
 
+/**
+ * customize the  SqlTypeFactoryImpl
+ */
 public class HeadlessSqlTypeFactoryImpl extends SqlTypeFactoryImpl {
 
     public HeadlessSqlTypeFactoryImpl(RelDataTypeSystem typeSystem) {

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/schema/SemanticSqlDialect.java

@@ -10,6 +10,9 @@ import org.apache.calcite.sql.SqlWriter;
 import org.apache.calcite.sql.validate.SqlConformance;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
+/**
+ * customize the  SqlDialect
+ */
 public class SemanticSqlDialect extends SqlDialect {
 
     public static final Context DEFAULT_CONTEXT = SqlDialect.EMPTY_CONTEXT

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/schema/ViewExpanderImpl.java

@@ -5,6 +5,9 @@ import org.apache.calcite.plan.RelOptTable;
 import org.apache.calcite.rel.RelRoot;
 import org.apache.calcite.rel.type.RelDataType;
 
+/**
+ * customize the  ViewExpander
+ */
 public class ViewExpanderImpl implements RelOptTable.ViewExpander {
     public ViewExpanderImpl() {
     }

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/Renderer.java

@@ -20,6 +20,9 @@ import lombok.Data;
 import org.apache.calcite.sql.SqlNode;
 import org.apache.calcite.sql.validate.SqlValidatorScope;
 
+/**
+ * process TableView
+ */
 @Data
 public abstract class Renderer {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/S2SQLSqlValidatorImpl.java

@@ -5,6 +5,9 @@ import org.apache.calcite.sql.SqlOperatorTable;
 import org.apache.calcite.sql.validate.SqlValidatorCatalogReader;
 import org.apache.calcite.sql.validate.SqlValidatorImpl;
 
+/**
+ * customize the  SqlValidatorImpl
+ */
 public class S2SQLSqlValidatorImpl extends SqlValidatorImpl {
 
     public S2SQLSqlValidatorImpl(SqlOperatorTable opTab, SqlValidatorCatalogReader catalogReader,

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/TableView.java

@@ -12,6 +12,9 @@ import org.apache.calcite.sql.SqlNodeList;
 import org.apache.calcite.sql.SqlSelect;
 import org.apache.calcite.sql.parser.SqlParserPos;
 
+/**
+ * basic query project
+ */
 @Data
 public class TableView {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/node/SemanticNode.java

@@ -42,6 +42,9 @@ import org.apache.calcite.sql.validate.SqlValidatorScope;
 import org.apache.calcite.sql2rel.SqlToRelConverter;
 import org.apache.commons.lang3.StringUtils;
 
+/**
+ * model item node
+ */
 public abstract class SemanticNode {
 
     public static Set<SqlKind> AGGREGATION_KIND = new HashSet<>();

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/node/extend/LateralViewExplodeNode.java

@@ -11,6 +11,9 @@ import org.apache.calcite.sql.SqlNodeList;
 import org.apache.calcite.sql.SqlOperator;
 import org.apache.calcite.sql.SqlWriter;
 
+/**
+ * extend node to handle lateral explode view
+ */
 public class LateralViewExplodeNode extends ExtendNode {
 
     public final String sqlNameView = "view";

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/optimizer/FilterToGroupScanRule.java

@@ -26,6 +26,10 @@ import org.apache.calcite.util.ImmutableBitSet;
 import org.apache.calcite.util.Pair;
 import org.apache.commons.lang3.tuple.Triple;
 
+/**
+ *  push down the time filter into group using the RuntimeOptions defined minMaxTime
+ *
+ */
 public class FilterToGroupScanRule extends RelRule<Config>
         implements TransformationRule {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/render/FilterRender.java

@@ -23,6 +23,9 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+/**
+ * process query specified filtering information
+ */
 public class FilterRender extends Renderer {
 
     @Override

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/render/JoinRender.java

@@ -41,6 +41,9 @@ import java.util.Queue;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+/**
+ * process the join conditions when the source number is greater than 1
+ */
 @Slf4j
 public class JoinRender extends Renderer {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/render/OutputRender.java

@@ -18,6 +18,9 @@ import org.apache.calcite.sql.parser.SqlParserPos;
 import org.apache.calcite.sql.validate.SqlValidatorScope;
 import org.springframework.util.CollectionUtils;
 
+/**
+ * process the query result items from query request
+ */
 public class OutputRender extends Renderer {
 
     @Override

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/calcite/sql/render/SourceRender.java

@@ -32,6 +32,9 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.stream.Collectors;
 
+/**
+ * process the table view from the defined data model schema
+ */
 @Slf4j
 public class SourceRender extends Renderer {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/converter/CalculateAggConverter.java

@@ -24,7 +24,9 @@ import java.util.List;
 import java.util.Objects;
 import java.util.stream.Collectors;
 
-
+/**
+ * supplement the QueryStatement when query with custom aggregation method
+ */
 @Component("CalculateAggConverter")
 @Slf4j
 public class CalculateAggConverter implements HeadlessConverter {

headless/core/src/main/java/com/tencent/supersonic/headless/core/parser/converter/ParserDefaultConverter.java

@@ -17,6 +17,9 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.stream.Collectors;
 
+/**
+ * HeadlessConverter default implement
+ */
 @Component("ParserDefaultConverter")
 @Slf4j
 public class ParserDefaultConverter implements HeadlessConverter {

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/ComponentFactory.java

@@ -16,6 +16,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+/**
+ * HeadlessConverter QueryOptimizer QueryExecutor object factory
+ */
 public class ComponentFactory {
 
     private static List<HeadlessConverter> headlessConverters = new ArrayList<>();

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/DataTransformUtils.java

@@ -11,6 +11,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+/**
+ * transform query results to return the users
+ */
 public class DataTransformUtils {
 
     public static List<Map<String, Object>> transform(List<Map<String, Object>> originalData, String metric,

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/JdbcDataSourceUtils.java

@@ -27,6 +27,9 @@ import static com.tencent.supersonic.common.pojo.Constants.NEW_LINE_CHAR;
 import static com.tencent.supersonic.common.pojo.Constants.PATTERN_JDBC_TYPE;
 import static com.tencent.supersonic.common.pojo.Constants.SPACE;
 
+/**
+ * tools functions about jdbc
+ */
 @Slf4j
 public class JdbcDataSourceUtils {
 

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/SqlGenerateUtils.java

@@ -35,6 +35,9 @@ import static com.tencent.supersonic.common.pojo.Constants.MONTH;
 import static com.tencent.supersonic.common.pojo.Constants.UNDERLINE;
 import static com.tencent.supersonic.common.pojo.Constants.WEEK;
 
+/**
+ * tools functions to analyze queryStructReq
+ */
 @Component
 @Slf4j
 public class SqlGenerateUtils {

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/SqlUtils.java

@@ -29,7 +29,9 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.stereotype.Component;
 
-
+/**
+ * tools functions about sql query
+ */
 @Slf4j
 @Component
 public class SqlUtils {

headless/core/src/main/java/com/tencent/supersonic/headless/core/utils/SysTimeDimensionBuilder.java

@@ -9,6 +9,9 @@ import lombok.extern.slf4j.Slf4j;
 
 import java.util.List;
 
+/**
+ * generate system time dimension tools
+ */
 @Slf4j
 public class SysTimeDimensionBuilder {