Adds Compile-Time Thread.interrupted() checks (#398)

* Add Thread.interrupted() checks

lang/src/org/partiql/lang/CompilerPipeline.kt

@@ -20,6 +20,7 @@ import org.partiql.lang.eval.*
 import org.partiql.lang.eval.builtins.*
 import org.partiql.lang.eval.builtins.storedprocedure.StoredProcedure
 import org.partiql.lang.syntax.*
+import org.partiql.lang.util.interruptibleFold
 
 /**
  * Contains all of the information needed for processing steps.
@@ -180,7 +181,7 @@ interface CompilerPipeline  {
     }
 }
 
-private class CompilerPipelineImpl(
+internal class CompilerPipelineImpl(
     override val valueFactory: ExprValueFactory,
     private val parser: Parser,
     override val compileOptions: CompileOptions,
@@ -198,10 +199,15 @@ private class CompilerPipelineImpl(
     override fun compile(query: ExprNode): Expression {
         val context = StepContext(valueFactory, compileOptions, functions, procedures)
 
-        val preProcessedQuery = preProcessingSteps.fold(query) { currentExprNode, step ->
-            step(currentExprNode, context)
-        }
+        val preProcessedQuery = executePreProcessingSteps(query, context)
 
         return compiler.compile(preProcessedQuery)
     }
+
+    internal fun executePreProcessingSteps(
+        query: ExprNode,
+        context: StepContext
+    ) = preProcessingSteps.interruptibleFold(query) { currentExprNode, step ->
+        step(currentExprNode, context)
+    }
 }

lang/src/org/partiql/lang/ast/AstDeserialization.kt

@@ -248,7 +248,7 @@ class AstDeserializerBuilder(val ion: IonSystem) {
         }
 }
 
-private class AstDeserializerInternal(
+internal class AstDeserializerInternal(
     val astVersion: AstVersion,
     val ion: IonSystem,
     private val metaDeserializers: Map<String, MetaDeserializer>
@@ -262,7 +262,9 @@ private class AstDeserializerInternal(
         return deserializeExprNode(sexp)
     }
 
-    private fun validate(rootSexp: IonSexp) {
+    internal fun validate(rootSexp: IonSexp) {
+        checkThreadInterrupted()
+
         val nodeTag = rootSexp.nodeTag // Throws if nodeTag is invalid for the current AstVersion
         val nodeArgs = rootSexp.args
 
@@ -321,8 +323,9 @@ private class AstDeserializerInternal(
     /**
      * Given a serialized AST, return its [ExprNode] representation.
      */
-    private fun deserializeExprNode(metaOrTermOrExp: IonSexp): ExprNode =
-        deserializeSexpMetaOrTerm(metaOrTermOrExp) { target, metas ->
+    internal fun deserializeExprNode(metaOrTermOrExp: IonSexp): ExprNode {
+        checkThreadInterrupted()
+        return deserializeSexpMetaOrTerm(metaOrTermOrExp) { target, metas ->
             val nodeTag = target.nodeTag
             val targetArgs = target.args //args is an extension property--call it once for efficiency
             //.toList() forces immutability
@@ -417,6 +420,7 @@ private class AstDeserializerInternal(
                 NodeTag.TYPE -> errInvalidContext(nodeTag)
             }
         }
+    }
 
     private fun deserializeLit(targetArgs: List<IonValue>, metas: MetaContainer) = Literal(targetArgs.first(), metas)
     private fun deserializeMissing(metas: MetaContainer) = LiteralMissing(metas)

lang/src/org/partiql/lang/ast/AstSerialization.kt

@@ -20,6 +20,7 @@ import com.amazon.ion.IonSystem
 import org.partiql.lang.util.IonWriterContext
 import org.partiql.lang.util.asIonSexp
 import org.partiql.lang.util.case
+import org.partiql.lang.util.checkThreadInterrupted
 import kotlin.UnsupportedOperationException
 
 /**
@@ -73,6 +74,7 @@ private class AstSerializerImpl(val astVersion: AstVersion, val ion: IonSystem):
 
     private fun IonWriterContext.writeExprNode(expr: ExprNode): Unit =
         writeAsTerm(expr.metas) {
+            checkThreadInterrupted()
             sexp {
                 when (expr) {
                     // Leaf nodes

lang/src/org/partiql/lang/ast/ExprNodeToStatement.kt

@@ -3,6 +3,7 @@ package org.partiql.lang.ast
 import com.amazon.ionelement.api.emptyMetaContainer
 import com.amazon.ionelement.api.toIonElement
 import org.partiql.lang.domains.PartiqlAst
+import org.partiql.lang.util.checkThreadInterrupted
 import org.partiql.pig.runtime.SymbolPrimitive
 import org.partiql.pig.runtime.asPrimitive
 
@@ -67,6 +68,7 @@ private fun ExprNode.toAstExec() : PartiqlAst.Statement {
 }
 
 fun ExprNode.toAstExpr(): PartiqlAst.Expr {
+    checkThreadInterrupted()
     val node = this
     val metas = this.metas.toIonElementMetaContainer()
 

lang/src/org/partiql/lang/ast/StatementToExprNode.kt

@@ -6,6 +6,7 @@ import com.amazon.ion.IonSystem
 import com.amazon.ionelement.api.toIonValue
 import org.partiql.lang.domains.PartiqlAst
 import org.partiql.lang.domains.PartiqlAst.*
+import org.partiql.lang.util.checkThreadInterrupted
 
 import org.partiql.pig.runtime.SymbolPrimitive
 import org.partiql.lang.ast.SetQuantifier as ExprNodeSetQuantifier  // Conflicts with PartiqlAst.SetQuantifier
@@ -69,6 +70,7 @@ private class StatementTransformer(val ion: IonSystem) {
         this.map { it.toExprNode() }
 
     private fun Expr.toExprNode(): ExprNode {
+        checkThreadInterrupted()
         val metas = this.metas.toPartiQlMetaContainer()
         return when (this) {
             is Expr.Missing -> LiteralMissing(metas)

lang/src/org/partiql/lang/ast/ast.kt

@@ -24,19 +24,35 @@ import java.util.*
 sealed class AstNode : Iterable<AstNode> {
 
     /**
-     * returns all the children nodes.
+     * Returns all the children nodes.
+     *
+     * This property is [deprecated](see https://github.com/partiql/partiql-lang-kotlin/issues/396).  Use
+     * one of the following PIG-generated classes to analyze AST nodes instead:
+     *
+     * - [org.partiql.lang.domains.PartiqlAst.Visitor]
+     * - [org.partiql.lang.domains.PartiqlAst.VisitorFold]
      */
+    @Deprecated("DO NOT USE - see kdoc, see https://github.com/partiql/partiql-lang-kotlin/issues/396")
     abstract val children: List<AstNode>
 
     /**
      * Depth first iterator over all nodes.
+     *
+     * While collecting child nodes, throws [InterruptedException] if the [Thread.interrupted] flag has been set.
+     *
+     * This property is [deprecated](see https://github.com/partiql/partiql-lang-kotlin/issues/396).  Use
+     * one of the following PIG-generated classes to analyze AST nodes instead:
+     *
+     * - [org.partiql.lang.domains.PartiqlAst.Visitor]
+     * - [org.partiql.lang.domains.PartiqlAst.VisitorFold]
      */
+    @Deprecated("DO NOT USE - see kdoc for alternatives")
     override operator fun iterator(): Iterator<AstNode> {
         val allNodes = mutableListOf<AstNode>()
 
         fun depthFirstSequence(node: AstNode) {
             allNodes.add(node)
-            node.children.map { depthFirstSequence(it) }
+            node.children.interruptibleMap { depthFirstSequence(it) }
         }
 
         depthFirstSequence(this)

lang/src/org/partiql/lang/ast/passes/AstRewriterBase.kt

@@ -15,6 +15,7 @@
 package org.partiql.lang.ast.passes
 
 import org.partiql.lang.ast.*
+import org.partiql.lang.util.checkThreadInterrupted
 
 /**
  * Provides a minimal interface for an AST rewriter implementation.
@@ -28,11 +29,12 @@ interface AstRewriter {
  * This is the base-class for an AST rewriter which simply makes an exact copy of the original AST.
  * Simple rewrites can be performed by inheritors.
  */
-@Deprecated("New rewriters should implement PIG's PartiqlAst.VisitorTransform instead")
+@Deprecated("New rewriters should implement PIG's VisitorTransformBase instead")
 open class AstRewriterBase : AstRewriter {
 
-    override fun rewriteExprNode(node: ExprNode): ExprNode =
-        when (node) {
+    override fun rewriteExprNode(node: ExprNode): ExprNode {
+        checkThreadInterrupted()
+        return when (node) {
             is Literal           -> rewriteLiteral(node)
             is LiteralMissing    -> rewriteLiteralMissing(node)
             is VariableReference -> rewriteVariableReference(node)
@@ -55,6 +57,7 @@ open class AstRewriterBase : AstRewriter {
             is DateTimeType.Date -> rewriteDate(node)
             is DateTimeType.Time -> rewriteTime(node)
         }
+    }
 
     open fun rewriteMetas(itemWithMetas: HasMetas): MetaContainer = itemWithMetas.metas
 

lang/src/org/partiql/lang/ast/passes/AstVisitor.kt

@@ -27,7 +27,7 @@ import org.partiql.lang.ast.*
  *
  *  One `visit*` function is included for each base type in the AST.
  */
-@Deprecated("Use AstNode#iterator() or AstNode#children()")
+@Deprecated("Use org.lang.partiql.domains.PartiqlAst.Visitor instead")
 interface AstVisitor {
     /**
      * Invoked by [AstWalker] for every instance of [ExprNode] encountered.

lang/src/org/partiql/lang/ast/passes/AstWalker.kt

@@ -28,6 +28,7 @@ open class AstWalker(private val visitor: AstVisitor) {
 
     protected open fun walkExprNode(vararg exprs: ExprNode?) {
         exprs.filterNotNull().forEach { expr: ExprNode ->
+            checkThreadInterrupted()
             visitor.visitExprNode(expr)
 
             when (expr) {

lang/src/org/partiql/lang/eval/EvaluatingCompiler.kt

@@ -28,7 +28,6 @@ import org.partiql.lang.eval.visitors.PartiqlAstSanityValidator
 import org.partiql.lang.syntax.SqlParser
 import org.partiql.lang.util.*
 import java.math.*
-import java.time.LocalDate
 import java.util.*
 import kotlin.collections.*
 
@@ -207,6 +206,10 @@ internal class EvaluatingCompiler(
 
     /**
      * Compiles an [ExprNode] tree to an [Expression].
+     *
+     * Checks [Thread.interrupted] before every expression and sub-expression is compiled
+     * and throws [InterruptedException] if [Thread.interrupted] it has been set in the
+     * hope that long running compilations may be aborted by the caller.
      */
     fun compile(originalAst: ExprNode): Expression {
         val visitorTransformer = compileOptions.visitorTransformMode.createVisitorTransform()
@@ -257,7 +260,13 @@ internal class EvaluatingCompiler(
      */
     fun eval(ast: ExprNode, session: EvaluationSession): ExprValue = compile(ast).eval(session)
 
+    /**
+     * Compiles the specified [ExprNode] into a [ThunkEnv].
+     *
+     * This function will [InterruptedException] if [Thread.interrupted] has been set.
+     */
     private fun compileExprNode(expr: ExprNode): ThunkEnv {
+        checkThreadInterrupted()
         return when (expr) {
             is Literal           -> compileLiteral(expr)
             is LiteralMissing    -> compileLiteralMissing(expr)

lang/src/org/partiql/lang/eval/visitors/FromSourceAliasVisitorTransform.kt

@@ -15,9 +15,9 @@ import org.partiql.pig.runtime.SymbolPrimitive
  *
  * If provided with a query that has all of the from source aliases already specified, an exact clone is returned.
  */
-class FromSourceAliasVisitorTransform : PartiqlAst.VisitorTransform() {
+class FromSourceAliasVisitorTransform : VisitorTransformBase() {
 
-    private class InnerFromSourceAliasVisitorTransform : PartiqlAst.VisitorTransform() {
+    private class InnerFromSourceAliasVisitorTransform : VisitorTransformBase() {
         private var fromSourceCounter = 0
 
         override fun transformFromSourceScan_asAlias(node: PartiqlAst.FromSource.Scan): SymbolPrimitive? {

lang/src/org/partiql/lang/eval/visitors/GroupByItemAliasVisitorTransform.kt

@@ -33,7 +33,7 @@ import org.partiql.pig.runtime.SymbolPrimitive
  *
  * If provided with a query with all of the group by item aliases already specified, an exact clone is returned.
  */
-class GroupByItemAliasVisitorTransform(var nestLevel: Int = 0) : PartiqlAst.VisitorTransform() {
+class GroupByItemAliasVisitorTransform(var nestLevel: Int = 0) : VisitorTransformBase() {
 
     override fun transformGroupBy(node: PartiqlAst.GroupBy): PartiqlAst.GroupBy {
         return PartiqlAst.build {

lang/src/org/partiql/lang/eval/visitors/PipelinedVisitorTransform.kt

@@ -1,6 +1,7 @@
 package org.partiql.lang.eval.visitors
 
 import org.partiql.lang.domains.PartiqlAst
+import org.partiql.lang.util.interruptibleFold
 
 /**
  * A simple visitor transformer that provides a pipeline of transformers to be executed in sequential order.
@@ -11,7 +12,7 @@ class PipelinedVisitorTransform(vararg transformers: PartiqlAst.VisitorTransform
     private val transformerList =  transformers.toList()
 
     override fun transformStatement(node: PartiqlAst.Statement): PartiqlAst.Statement =
-        transformerList.fold(node) {
+        transformerList.interruptibleFold(node) {
             intermediateNode, transformer ->
             transformer.transformStatement(intermediateNode)
         }

lang/src/org/partiql/lang/eval/visitors/SelectListItemAliasVisitorTransform.kt

@@ -32,7 +32,7 @@ import org.partiql.pig.runtime.SymbolPrimitive
  *
  * ```
  */
-class SelectListItemAliasVisitorTransform : PartiqlAst.VisitorTransform() {
+class SelectListItemAliasVisitorTransform : VisitorTransformBase() {
 
     override fun transformProjectionProjectList(node: PartiqlAst.Projection.ProjectList): PartiqlAst.Projection {
         return PartiqlAst.build {

lang/src/org/partiql/lang/eval/visitors/SelectStarVisitorTransform.kt

@@ -5,7 +5,7 @@ import org.partiql.lang.ast.UniqueNameMeta
 import org.partiql.lang.domains.PartiqlAst
 import org.partiql.lang.eval.errNoContext
 
-class SelectStarVisitorTransform : PartiqlAst.VisitorTransform() {
+class SelectStarVisitorTransform : VisitorTransformBase() {
 
     /**
      * Copies all parts of [PartiqlAst.Expr.Select] except [newProjection] for [PartiqlAst.Projection].

lang/src/org/partiql/lang/eval/visitors/StaticTypeVisitorTransform.kt

@@ -60,7 +60,7 @@ enum class StaticTypeVisitorTransformConstraints {
  */
 class StaticTypeVisitorTransform(private val ion: IonSystem,
                                  globalBindings: Bindings<StaticType>,
-                                 constraints: Set<StaticTypeVisitorTransformConstraints> = setOf()) : PartiqlAst.VisitorTransform() {
+                                 constraints: Set<StaticTypeVisitorTransformConstraints> = setOf()) : VisitorTransformBase() {
 
     /** Used to allow certain binding lookups to occur directly in the global scope. */
     private val globalEnv = wrapBindings(globalBindings, 0)

lang/src/org/partiql/lang/eval/visitors/SubstitutionVisitorTransform.kt

@@ -35,7 +35,7 @@ data class SubstitutionPair(val target: PartiqlAst.Expr, val replacement: Partiq
  *
  * This class is `open` to allow subclasses to restrict the nodes to which the substitution should occur.
  */
-open class SubstitutionVisitorTransform(protected val substitutions: Map<PartiqlAst.Expr, SubstitutionPair>): PartiqlAst.VisitorTransform() {
+open class SubstitutionVisitorTransform(protected val substitutions: Map<PartiqlAst.Expr, SubstitutionPair>): VisitorTransformBase() {
 
     /**
      * If [node] matches any of the target nodes in [substitutions], replaces the node with the replacement.
@@ -59,7 +59,7 @@ open class SubstitutionVisitorTransform(protected val substitutions: Map<Partiql
      * After .copy() and copying metas is added to PIG (https://github.com/partiql/partiql-ir-generator/pull/53) change
      * this and its usages to use .copy().
      */
-    inner class MetaVisitorTransform(private val newMetas: MetaContainer) : PartiqlAst.VisitorTransform() {
+    inner class MetaVisitorTransform(private val newMetas: MetaContainer) : VisitorTransformBase() {
         override fun transformMetas(metas: MetaContainer): MetaContainer = newMetas
     }
 

lang/src/org/partiql/lang/eval/visitors/VisitorTransformBase.kt

@@ -1,11 +1,23 @@
 package org.partiql.lang.eval.visitors
 
 import org.partiql.lang.domains.PartiqlAst
+import org.partiql.lang.util.checkThreadInterrupted
 
 /**
- * Base-class for visitor transforms that provides additional functions outside of [PartiqlAst.VisitorTransform].
+ * Base-class for visitor transforms that provides additional `transform*` functions that outside of
+ * the PIG-generated [PartiqlAst.VisitorTransform] class and adds a [Thread.interrupted] check
+ * to [transformExpr].
+ *
+ * All transforms should derive from this class instead of [PartiqlAst.VisitorTransform] so that they can
+ * be interrupted if they take a long time to process large ASTs.
  */
 abstract class VisitorTransformBase : PartiqlAst.VisitorTransform() {
+
+    override fun transformExpr(node: PartiqlAst.Expr): PartiqlAst.Expr {
+        checkThreadInterrupted()
+        return super.transformExpr(node)
+    }
+
     /**
      * Transforms the [PartiqlAst.Expr.Select] expression following the PartiQL evaluation order. That is:
      *

lang/src/org/partiql/lang/eval/visitors/VisitorTransforms.kt

@@ -24,6 +24,6 @@ fun basicVisitorTransforms() = PipelinedVisitorTransform(
 
 /** A stateless visitor transform that returns the input. */
 @JvmField
-internal val IDENTITY_VISITOR_TRANSFORM: PartiqlAst.VisitorTransform = object : PartiqlAst.VisitorTransform() {
+internal val IDENTITY_VISITOR_TRANSFORM: PartiqlAst.VisitorTransform = object : VisitorTransformBase() {
     override fun transformStatement(node: PartiqlAst.Statement): PartiqlAst.Statement = node
 }

lang/src/org/partiql/lang/syntax/SqlParser.kt

@@ -1039,12 +1039,17 @@ class SqlParser(private val ion: IonSystem) : Parser {
     /**
      * Parses the given token list.
      *
+     * Throws [InterruptedException] if [Thread.interrupted] is set. This is the best place to do
+     * that for the parser because this is the main function called to parse an expression and so
+     * is called quite frequently during parsing by many parts of the parser.
+     *
      * @param precedence The precedence of the current expression parsing.
      *                   A negative value represents the "top-level" parsing.
      *
      * @return The parse tree for the given expression.
      */
     internal fun List<Token>.parseExpression(precedence: Int = -1): ParseNode {
+        checkThreadInterrupted()
         var expr = parseUnaryTerm()
         var rem = expr.remaining
 
@@ -2815,6 +2820,7 @@ class SqlParser(private val ion: IonSystem) : Parser {
      * If [dmlListTokenSeen] is true, it means it has been encountered at least once before while traversing the parse tree.
      */
     private fun validateTopLevelNodes(node: ParseNode, level: Int, topLevelTokenSeen: Boolean, dmlListTokenSeen: Boolean) {
+        checkThreadInterrupted()
         val isTopLevelType = when (node.type.isDml) {
             // DML_LIST token type allows multiple DML keywords to be used in the same statement.
             // Hence, DML keyword tokens are not treated as top level tokens if present with the DML_LIST token type