Github user pwendell commented on a diff in the pull request:
https://github.com/apache/spark/pull/207#discussion_r10869065
--- Diff:
tools/src/main/scala/org/apache/spark/tools/GenerateMIMAIgnore.scala ---
@@ -0,0 +1,157 @@
+/*
+ * 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.spark.tools
+
+import java.io.File
+import java.util.jar.JarFile
+
+import scala.collection.mutable
+import scala.collection.JavaConversions._
+import scala.reflect.runtime.universe.runtimeMirror
+import scala.util.Try
+
+/**
+ * A tool for generating classes to be excluded during binary checking
with MIMA. It is expected
+ * that this tool is run with ./spark-class.
+ *
+ * MIMA itself only supports JVM-level visibility and doesn't account for
package-private classes.
+ * This tool looks at all currently package-private classes and generates
exclusions for them. Note
+ * that this approach is not sound. It can lead to false positives if we
move or rename a previously
+ * package-private class. It can lead to false negatives if someone
explicitly makes a class
+ * package-private that wasn't before. This exists only to help catch
certain classes of changes
+ * which might be difficult to catch during review.
+ */
+object GenerateMIMAIgnore {
+ private val classLoader = Thread.currentThread().getContextClassLoader
+ private val mirror = runtimeMirror(classLoader)
+
+ private def classesPrivateWithin(packageName: String): Set[String] = {
+
+ val classes = getClasses(packageName, classLoader)
+ val privateClasses = mutable.HashSet[String]()
+
+ def isPackagePrivate(className: String) = {
+ try {
+ /* Couldn't figure out if it's possible to determine a-priori
whether a given symbol
+ is a module or class. */
+
+ val privateAsClass = mirror
+ .staticClass(className)
+ .privateWithin
+ .fullName
+ .startsWith(packageName)
+
+ val privateAsModule = mirror
+ .staticModule(className)
+ .privateWithin
+ .fullName
+ .startsWith(packageName)
+
+ privateAsClass || privateAsModule
+ } catch {
+ case _: Throwable => {
+ println("Error determining visibility: " + className)
+ false
+ }
+ }
+ }
+
+ for (className <- classes) {
+ val directlyPrivateSpark = isPackagePrivate(className)
+
+ /* Inner classes defined within a private[spark] class or object are
effectively
+ invisible, so we account for them as package private. */
+ val indirectlyPrivateSpark = {
+ val maybeOuter = className.toString.takeWhile(_ != '$')
+ if (maybeOuter != className) {
+ isPackagePrivate(maybeOuter)
+ } else {
+ false
+ }
+ }
+ if (directlyPrivateSpark || indirectlyPrivateSpark) privateClasses
+= className
+ }
+ privateClasses.flatMap(c => Seq(c, c.replace("$", "#"))).toSet
+ }
+
+ def main(args: Array[String]) {
+ scala.tools.nsc.io.File(".mima-excludes").
+ writeAll(classesPrivateWithin("org.apache.spark").mkString("\n"))
+ println("Created : .mima-excludes in current directory.")
+ }
+
+ /**
+ * Get all classes in a package from a jar file.
+ */
+ private def getAllClasses(jarPath: String, packageName: String) = {
+ val jar = new JarFile(new File(jarPath))
+ val enums =
jar.entries().map(_.getName).filter(_.startsWith(packageName))
+ val classes = mutable.HashSet[Class[_]]()
+ for (entry <- enums) {
+ if (!entry.endsWith("/") && !entry.endsWith("MANIFEST.MF") &&
!entry.endsWith("properties")) {
+ classes += Class.forName(entry.trim.replaceAll(".class",
"").replace('/', '.'))
+ }
+ }
+ classes
+ }
+
+ private def shouldExclude(name: String) = {
+ // Heuristic to remove JVM classes that do not correspond to
user-facing classes in Scala
+ Try(mirror.staticClass(name)).isFailure ||
+ name.contains("anon") ||
+ name.endsWith("class") ||
--- End diff --
The scala compiler creates some extra classes called, e.g.
```
Error determining visibility:
org.apache.spark.repl.SparkMemberHandlers$class
Error determining visibility: org.apache.spark.AccumulatorParam$class
Error determining visibility:
org.apache.spark.streaming.receivers.Receiver$class
Error determining visibility:
org.apache.spark.util.random.RandomSampler$class
```
I don't really know what those are for but they aren't user-facing so I
think we can exclude them.
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