submarine-security/spark-security/spark-2/src/main/scala/org/apache/submarine/spark/security/parser/SubmarineSqlParser.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.submarine.spark.security.parser

import org.antlr.v4.runtime.{CharStreams, CommonTokenStream}
import org.antlr.v4.runtime.atn.PredictionMode
import org.antlr.v4.runtime.misc.ParseCancellationException
import org.apache.spark.sql.AnalysisException
import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
import org.apache.spark.sql.catalyst.expressions.Expression
import org.apache.spark.sql.catalyst.parser.{ParseErrorListener, ParseException, ParserInterface, PostProcessor}
import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
import org.apache.spark.sql.catalyst.trees.Origin
import org.apache.spark.sql.types.{DataType, StructType}

class SubmarineSqlParser(val delegate: ParserInterface) extends ParserInterface {

  private val astBuilder = new SubmarineSqlAstBuilder

  override def parsePlan(sqlText: String): LogicalPlan = parse(sqlText) { parser =>
    astBuilder.visit(parser.singleStatement()) match {
      case plan: LogicalPlan => plan
      case _ => delegate.parsePlan(sqlText)
    }
  }

  // scalastyle:off line.size.limit
  /**
    * Fork from `org.apache.spark.sql.catalyst.parser.AbstractSqlParser#parse(java.lang.String, scala.Function1)`.
    *
    * @see https://github.com/apache/spark/blob/v2.4.4/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/ParseDriver.scala#L81
    */
  // scalastyle:on
  private def parse[T](command: String)(toResult: SubmarineSqlBaseParser => T): T = {
    val lexer = new SubmarineSqlBaseLexer(new UpperCaseCharStream(CharStreams.fromString(command)))
    lexer.removeErrorListeners()
    lexer.addErrorListener(ParseErrorListener)

    val tokenStream = new CommonTokenStream(lexer)
    val parser = new SubmarineSqlBaseParser(tokenStream)
    parser.addParseListener(PostProcessor)
    parser.removeErrorListeners()
    parser.addErrorListener(ParseErrorListener)

    try {
      try {
        // first, try parsing with potentially faster SLL mode
        parser.getInterpreter.setPredictionMode(PredictionMode.SLL)
        toResult(parser)
      } catch {
        case e: ParseCancellationException =>
          // if we fail, parse with LL mode
          tokenStream.seek(0) // rewind input stream
          parser.reset()

          // Try Again.
          parser.getInterpreter.setPredictionMode(PredictionMode.LL)
          toResult(parser)
      }
    } catch {
      case e: ParseException if e.command.isDefined =>
        throw e
      case e: ParseException =>
        throw e.withCommand(command)
      case e: AnalysisException =>
        val position = Origin(e.line, e.startPosition)
        throw new ParseException(Option(command), e.message, position, position)
    }
  }

  override def parseExpression(sqlText: String): Expression = {
    delegate.parseExpression(sqlText)
  }

  override def parseTableIdentifier(sqlText: String): TableIdentifier = {
    delegate.parseTableIdentifier(sqlText)
  }

  override def parseFunctionIdentifier(sqlText: String): FunctionIdentifier = {
    delegate.parseFunctionIdentifier(sqlText)
  }

  override def parseTableSchema(sqlText: String): StructType = {
    delegate.parseTableSchema(sqlText)
  }

  override def parseDataType(sqlText: String): DataType = {
    delegate.parseDataType(sqlText)
  }
}