vinodkc commented on code in PR #39449:
URL: https://github.com/apache/spark/pull/39449#discussion_r1087034705
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/maskExpressions.scala:
##########
@@ -257,19 +271,272 @@ case class Mask(
otherChar = newChildren(4))
}
-case class MaskArgument(maskChar: Char, ignore: Boolean)
+// scalastyle:off line.size.limit
+@ExpressionDescription(
+ usage =
+ """_FUNC_(input[, charCount, upperChar, lowerChar, digitChar, otherChar])
- masks the first n characters of given string value.
+ The function masks the first n characters of the value with 'X' or 'x',
and numbers with 'n'.
+ This can be useful for creating copies of tables with sensitive
information removed.
+ Error behavior: null value as replacement argument will throw
AnalysisError.
+ """,
+ arguments = """
+ Arguments:
+ * input - string value to mask. Supported types: STRING, VARCHAR,
CHAR
+ * charCount - number of characters to be masked. Default value: 4
+ * upperChar - character to replace upper-case characters with. Specify
NULL to retain original character. Default value: 'X'
+ * lowerChar - character to replace lower-case characters with. Specify
NULL to retain original character. Default value: 'x'
+ * digitChar - character to replace digit characters with. Specify NULL
to retain original character. Default value: 'n'
+ * otherChar - character to replace all other characters with. Specify
NULL to retain original character. Default value: NULL
+ """,
+ examples = """
+ Examples:
+ > SELECT _FUNC_('abcd-EFGH-8765-4321');
+ xxxx-EFGH-8765-4321
+ > SELECT _FUNC_('abcd-EFGH-8765-4321', 9);
+ xxxx-XXXX-8765-4321
+ > SELECT _FUNC_('abcd-EFGH-8765-@$#', 14);
+ xxxx-XXXX-nnnn-@$#
+ > SELECT _FUNC_('abcd-EFGH-8765-@$#', 15, 'x', 'X', 'n', 'o');
+ XXXXoxxxxonnnno@$#
+ > SELECT _FUNC_('abcd-EFGH-8765-@$#', 20, 'x', 'X', 'n', 'o');
+ XXXXoxxxxonnnnoooo
+ > SELECT _FUNC_('AbCD123-@$#', 10,'Q', 'q', 'd', 'o');
+ QqQQdddooo#
+ > SELECT _FUNC_('AbCD123-@$#', 10, NULL, 'q', 'd', 'o');
+ AqCDdddooo#
+ > SELECT _FUNC_('AbCD123-@$#', 10, NULL, NULL, 'd', 'o');
+ AbCDdddooo#
+ > SELECT _FUNC_('AbCD123-@$#', 10, NULL, NULL, NULL, 'o');
+ AbCD123ooo#
+ > SELECT _FUNC_(NULL);
+ NULL
+ > SELECT _FUNC_(NULL, 1, NULL, NULL, 'o');
+ NULL
+ """,
+ since = "3.4.0",
+ group = "string_funcs")
+// scalastyle:on line.size.limit
+case class MaskFirstN(
+ input: Expression,
+ charCountExpr: Expression,
+ upperChar: Expression,
+ lowerChar: Expression,
+ digitChar: Expression,
+ otherChar: Expression)
+ extends SeptenaryExpression
+ with Maskable
+ with ExpectsInputTypes
+ with QueryErrorsBase {
+
+ def this(input: Expression) =
+ this(
+ input,
+ Literal(Mask.DEFAULT_CHAR_COUNT),
+ Literal(Mask.MASKED_UPPERCASE),
+ Literal(Mask.MASKED_LOWERCASE),
+ Literal(Mask.MASKED_DIGIT),
+ Literal(Mask.MASKED_IGNORE, StringType))
+
+ def this(input: Expression, charCountExpr: Expression) =
+ this(
+ input,
+ charCountExpr,
+ Literal(Mask.MASKED_UPPERCASE),
+ Literal(Mask.MASKED_LOWERCASE),
+ Literal(Mask.MASKED_DIGIT),
+ Literal(Mask.MASKED_IGNORE, StringType))
+
+ def this(input: Expression, charCountExpr: Expression, upperChar:
Expression) =
+ this(
+ input,
+ charCountExpr,
+ upperChar,
+ Literal(Mask.MASKED_LOWERCASE),
+ Literal(Mask.MASKED_DIGIT),
+ Literal(Mask.MASKED_IGNORE, StringType))
+
+ def this(
+ input: Expression,
+ charCountExpr: Expression,
+ upperChar: Expression,
+ lowerChar: Expression) =
+ this(
+ input,
+ charCountExpr,
+ upperChar,
+ lowerChar,
+ Literal(Mask.MASKED_DIGIT),
+ Literal(Mask.MASKED_IGNORE, StringType))
+
+ def this(
+ input: Expression,
+ charCountExpr: Expression,
+ upperChar: Expression,
+ lowerChar: Expression,
+ digitChar: Expression) =
+ this(
+ input,
+ charCountExpr,
+ upperChar,
+ lowerChar,
+ digitChar,
+ Literal(Mask.MASKED_IGNORE, StringType))
+
+ @transient
+ private lazy val charCount = {
+ val value = charCountExpr.eval().asInstanceOf[Int]
+ if (value < 0) 0 else value
+ }
+
+ override def checkInputDataTypes(): TypeCheckResult =
+ validateInputDataTypes(
+ super.checkInputDataTypes(),
+ Seq(
+ (upperChar, "upperChar"),
+ (lowerChar, "lowerChar"),
+ (digitChar, "digitChar"),
+ (otherChar, "otherChar")),
+ () =>
+ Seq(if (!charCountExpr.foldable) {
+ Some(
+ DataTypeMismatch(
+ errorSubClass = "NON_FOLDABLE_INPUT",
+ messageParameters = Map(
+ "inputName" -> "charCount",
+ "inputType" -> toSQLType(charCountExpr.dataType),
+ "inputExpr" -> toSQLExpr(charCountExpr))))
+ } else if (charCountExpr.eval() == null) {
+ Some(
+ DataTypeMismatch(
+ errorSubClass = "UNEXPECTED_NULL",
+ messageParameters = Map("exprName" -> "charCount")))
+ } else {
+ None
+ }))
+
+ /**
+ * Expected input types from child expressions. The i-th position in the
returned seq indicates
+ * the type requirement for the i-th child.
+ *
+ * The possible values at each position are:
+ * 1. a specific data type, e.g. LongType, StringType. 2. a non-leaf
abstract data type, e.g.
+ * NumericType, IntegralType, FractionalType.
+ */
+ override def inputTypes: Seq[AbstractDataType] =
+ Seq(StringType, IntegerType, StringType, StringType, StringType,
StringType)
+
+ override def nullable: Boolean = true
+
+ /**
+ * Default behavior of evaluation according to the default nullability of
QuinaryExpression. If
+ * subclass of QuinaryExpression override nullable, probably should also
override this.
+ */
+ override def eval(input: InternalRow): Any = {
+ Mask.mask_first_n(
+ children(0).eval(input),
+ charCount,
+ children(2).eval(input),
+ children(3).eval(input),
+ children(4).eval(input),
+ children(5).eval(input))
+ }
+
+ /**
+ * Returns Java source code that can be compiled to evaluate this
expression. The default
+ * behavior is to call the eval method of the expression. Concrete
expression implementations
+ * should override this to do actual code generation.
+ *
+ * @param ctx
+ * a [[CodegenContext]]
+ * @param ev
+ * an [[ExprCode]] with unique terms.
+ * @return
+ * an [[ExprCode]] containing the Java source code to generate the given
expression
+ */
+ override protected def doGenCode(ctx: CodegenContext, ev: ExprCode):
ExprCode =
+ defineCodeGen(
+ ctx,
+ ev,
+ (input, count, upperChar, lowerChar, digitChar, otherChar, inputOpt) => {
+ s"org.apache.spark.sql.catalyst.expressions.Mask." +
+ s"mask_first_n($input, $charCount,$upperChar, $lowerChar,
$digitChar, $otherChar);"
+ })
+
+ /**
+ * Short hand for generating septenary evaluation code. If either of the
sub-expressions is
+ * null, the result of this computation is assumed to be null.
+ *
+ * @param f
+ * function that accepts the 7 non-null evaluation result names of
children and returns Java
+ * code to compute the output.
+ */
+ override protected def nullSafeCodeGen(
+ ctx: CodegenContext,
+ ev: ExprCode,
+ f: (String, String, String, String, String, String, Option[String]) =>
String): ExprCode = {
+ val firstGen = children(0).genCode(ctx)
+ val secGen = children(1).genCode(ctx)
+ val thirdGen = children(2).genCode(ctx)
+ val fourthGen = children(3).genCode(ctx)
+ val fifthGen = children(4).genCode(ctx)
+ val sixthGen = children(5).genCode(ctx)
+ val resultCode =
+ f(
+ firstGen.value,
+ secGen.value,
+ thirdGen.value,
+ fourthGen.value,
+ fifthGen.value,
+ sixthGen.value,
+ None)
+ ev.copy(
+ code = code"""
+ ${firstGen.code}
+ ${thirdGen.code}
+ ${fourthGen.code}
+ ${fifthGen.code}
+ ${CodeGenerator.javaType(dataType)} ${ev.value} =
${CodeGenerator.defaultValue(dataType)};
+ $resultCode""",
+ isNull = FalseLiteral)
+ }
+
+ /**
+ * Returns the [[DataType]] of the result of evaluating this expression. It
is invalid to query
+ * the dataType of an unresolved expression (i.e., when `resolved` == false).
+ */
+ override def dataType: DataType = StringType
+
+ /**
+ * Returns a Seq of the children of this node. Children should not change.
Immutability required
+ * for containsChild optimization
+ */
+ override def children: Seq[Expression] =
+ Seq(input, charCountExpr, upperChar, lowerChar, digitChar, otherChar)
+
+ override protected def withNewChildrenInternal(
+ newChildren: IndexedSeq[Expression]): MaskFirstN =
+ copy(
+ input = newChildren(0),
+ charCountExpr = newChildren(1),
+ upperChar = newChildren(2),
+ lowerChar = newChildren(3),
+ digitChar = newChildren(4),
+ otherChar = newChildren(5))
+}
object Mask {
// Default character to replace upper-case characters
- private val MASKED_UPPERCASE = 'X'
+ val MASKED_UPPERCASE = 'X'
// Default character to replace lower-case characters
- private val MASKED_LOWERCASE = 'x'
+ val MASKED_LOWERCASE = 'x'
// Default character to replace digits
- private val MASKED_DIGIT = 'n'
+ val MASKED_DIGIT = 'n'
// This value helps to retain original value in the input by ignoring the
replacement rules
- private val MASKED_IGNORE = null
+ val MASKED_IGNORE = null
+ // Default number of characters to be masked
+ val DEFAULT_CHAR_COUNT = 4
Review Comment:
Done
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