Cache decoding failures

Author: adpi2

src/main/scala/ch/epfl/scala/decoder/internal/CachedBinaryDecoder.scala

@@ -6,17 +6,19 @@ import tastyquery.Symbols.*
 import ch.epfl.scala.decoder.*
 
 import scala.collection.concurrent.TrieMap
+import scala.util.Try
 
 class CachedBinaryDecoder(using Context, ThrowOrWarn) extends BinaryDecoder:
-  private val classCache: TrieMap[String, DecodedClass] = TrieMap.empty
-  private val methodCache: TrieMap[(String, binary.SignedName), DecodedMethod] = TrieMap.empty
-  private val liftedTreesCache: TrieMap[Symbol, Seq[LiftedTree[?]]] = TrieMap.empty
+  // even failures can be quite expensive, so we cache them
+  private val classCache: TrieMap[String, Try[DecodedClass]] = TrieMap.empty
+  private val methodCache: TrieMap[(String, binary.SignedName), Try[DecodedMethod]] = TrieMap.empty
+  private val liftedTreesCache: TrieMap[Symbol, Try[Seq[LiftedTree[?]]]] = TrieMap.empty
 
   override def decode(cls: binary.ClassType): DecodedClass =
-    classCache.getOrElseUpdate(cls.name, super.decode(cls))
+    classCache.getOrElseUpdate(cls.name, Try(super.decode(cls))).get
 
   override def decode(method: binary.Method): DecodedMethod =
-    methodCache.getOrElseUpdate((method.declaringClass.name, method.signedName), super.decode(method))
+    methodCache.getOrElseUpdate((method.declaringClass.name, method.signedName), Try(super.decode(method))).get
 
   override protected def collectAllLiftedTrees(owner: Symbol): Seq[LiftedTree[?]] =
-    liftedTreesCache.getOrElseUpdate(owner, super.collectAllLiftedTrees(owner))
+    liftedTreesCache.getOrElseUpdate(owner, Try(super.collectAllLiftedTrees(owner))).get