Add flat classpath implementation for zip and jar files

This commit adds an implementation of flat classpath which can handle
both jar and vanilla zip files. In fact there are two versions - for
a class- and a sourcepath. Both extend ZipArchiveFileLookup which
provides common logic.

They use FileZipArchive. @gkossakowski made a comparison of different
ways of handling zips and jars (e.g. using javac's ZipFileIndex). He
stated that general efficiency of FileZipArchive, taking into account
various parameters, is the best.

FileZipArchive is slightly changed. From now it allows to find the
entry for directory in all directory entries without iterating all
entries regardless of a type. Thanks to that we can simply find
a directory for a package - like in the case of DirectoryFileLookup.

There's also added possibility to cache classpath representation of
classpath elements from jar and zip files across compiler instances.
The cache is just a map AbstractFile -> FlatClassPath. It should
reduce the number of created classpath and file instances e.g. in the
case of many ScalaPresentationCompilers in Scala IDE.

To prevent the possibility to avoid a cache, caches are created as
a part of factories responsible for the creation of these types of
the flat classpath.

1 files changed, 67 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala b/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala
new file mode 100644
index 0000000000..1d0de57779
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2014 Contributor. All rights reserved.
+ */
+package scala.tools.nsc.classpath
+
+import java.io.File
+import java.net.URL
+import scala.collection.Seq
+import scala.reflect.io.AbstractFile
+import scala.reflect.io.FileZipArchive
+import FileUtils.AbstractFileOps
+
+/**
+ * A trait allowing to look for classpath entries of given type in zip and jar files.
+ * It provides common logic for classes handling class and source files.
+ * It's aware of things like e.g. META-INF directory which is correctly skipped.
+ */
+trait ZipArchiveFileLookup[FileEntryType <: ClassRepClassPathEntry] extends FlatClassPath {
+  val zipFile: File
+
+  assert(zipFile != null, "Zip file in ZipArchiveFileLookup cannot be null")
+
+  override def asURLs: Seq[URL] = Seq(zipFile.toURI.toURL)
+  override def asClassPathStrings: Seq[String] = Seq(zipFile.getPath)
+
+  private val archive = new FileZipArchive(zipFile)
+
+  override private[nsc] def packages(inPackage: String): Seq[PackageEntry] = {
+    val prefix = PackageNameUtils.packagePrefix(inPackage)
+    for {
+      dirEntry <- findDirEntry(inPackage).toSeq
+      entry <- dirEntry.iterator if entry.isPackage
+    } yield PackageEntryImpl(prefix + entry.name)
+  }
+
+  protected def files(inPackage: String): Seq[FileEntryType] =
+    for {
+      dirEntry <- findDirEntry(inPackage).toSeq
+      entry <- dirEntry.iterator if isRequiredFileType(entry)
+    } yield createFileEntry(entry)
+
+  override private[nsc] def list(inPackage: String): FlatClassPathEntries = {
+    val foundDirEntry = findDirEntry(inPackage)
+
+    foundDirEntry map { dirEntry =>
+      val pkgBuf = collection.mutable.ArrayBuffer.empty[PackageEntry]
+      val fileBuf = collection.mutable.ArrayBuffer.empty[FileEntryType]
+      val prefix = PackageNameUtils.packagePrefix(inPackage)
+
+      for (entry <- dirEntry.iterator) {
+        if (entry.isPackage)
+          pkgBuf += PackageEntryImpl(prefix + entry.name)
+        else if (isRequiredFileType(entry))
+          fileBuf += createFileEntry(entry)
+      }
+      FlatClassPathEntries(pkgBuf, fileBuf)
+    } getOrElse FlatClassPathEntries(Seq.empty, Seq.empty)
+  }
+
+  private def findDirEntry(pkg: String) = {
+    val dirName = s"${FileUtils.dirPath(pkg)}/"
+    archive.allDirs.get(dirName)
+  }
+
+  protected def createFileEntry(file: FileZipArchive#Entry): FileEntryType
+  protected def isRequiredFileType(file: AbstractFile): Boolean
+}