Avoid repeated reading of file contents from disk while building stubs

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt

@@ -67,6 +67,8 @@ abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C : Any,
     private fun ProtoContainer.Class.toBinaryClass(): KotlinJvmBinaryClass? =
             (source as? KotlinJvmBinarySourceElement)?.binaryClass
 
+    protected open fun getCachedFileContent(kotlinClass: KotlinJvmBinaryClass): ByteArray? = null
+
     override fun loadClassAnnotations(container: ProtoContainer.Class): List<A> {
         val kotlinClass = container.toBinaryClass() ?: error("Class for loading annotations is not found: ${container.debugFqName()}")
 
@@ -79,7 +81,7 @@ abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C : Any,
 
             override fun visitEnd() {
             }
-        })
+        }, getCachedFileContent(kotlinClass))
 
         return result
     }
@@ -294,7 +296,7 @@ abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C : Any,
                     }
                 }
             }
-        })
+        }, getCachedFileContent(kotlinClass))
 
         return Storage(memberAnnotations, propertyConstants)
     }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/KotlinJvmBinaryClass.kt

@@ -29,9 +29,9 @@ interface KotlinJvmBinaryClass {
      */
     val location: String
 
-    fun loadClassAnnotations(visitor: AnnotationVisitor)
+    fun loadClassAnnotations(visitor: AnnotationVisitor, cachedContents: ByteArray?)
 
-    fun visitMembers(visitor: MemberVisitor)
+    fun visitMembers(visitor: MemberVisitor, cachedContents: ByteArray?)
 
     val classHeader: KotlinClassHeader