Bug 575699 - Simplify/avoid creation of EnumerationsI20210908-1800

Change-Id: I8baac46b7b34a270b0e5d72d426534bd92eee7c0
Signed-off-by: Hannes Wellmann <wellmann.hannes1@gmx.net>
Reviewed-on: https://git.eclipse.org/r/c/equinox/rt.equinox.p2/+/184748
Tested-by: Equinox Bot <equinox-bot@eclipse.org>
Tested-by: Alexander Kurtakov <akurtako@redhat.com>
Reviewed-by: Alexander Kurtakov <akurtako@redhat.com>

7 files changed, 16 insertions, 42 deletions

diff --git a/bundles/org.eclipse.equinox.p2.core/META-INF/MANIFEST.MF b/bundles/org.eclipse.equinox.p2.core/META-INF/MANIFEST.MF
index 19cf0c2f6..fdd4ec76f 100644
--- a/bundles/org.eclipse.equinox.p2.core/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.equinox.p2.core/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.equinox.p2.core;singleton:=true
-Bundle-Version: 2.8.0.qualifier
+Bundle-Version: 2.8.100.qualifier
 Bundle-ClassPath: .
 Bundle-Activator: org.eclipse.equinox.internal.p2.core.Activator
 Bundle-Vendor: %providerName
diff --git a/bundles/org.eclipse.equinox.p2.core/pom.xml b/bundles/org.eclipse.equinox.p2.core/pom.xml
index e1ca1fe6d..57357f7af 100644
--- a/bundles/org.eclipse.equinox.p2.core/pom.xml
+++ b/bundles/org.eclipse.equinox.p2.core/pom.xml
@@ -9,6 +9,6 @@
   </parent>
   <groupId>org.eclipse.equinox</groupId>
   <artifactId>org.eclipse.equinox.p2.core</artifactId>
-  <version>2.8.0-SNAPSHOT</version>
+  <version>2.8.100-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
 </project>
diff --git a/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/FileUtils.java b/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/FileUtils.java
index f97d822e7..1c48c0742 100644
--- a/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/FileUtils.java
+++ b/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/FileUtils.java
@@ -25,8 +25,7 @@ public class FileUtils {
 	private static File[] untarFile(File source, File outputDir) throws IOException, TarException {
 		List<File> untarredFiles = new ArrayList<>();
 		try (TarFile tarFile = new TarFile(source)) {
-			for (Enumeration<TarEntry> e = tarFile.entries(); e.hasMoreElements();) {
-				TarEntry entry = e.nextElement();
+			for (TarEntry entry : tarFile.entries()) {
 				try (InputStream input = tarFile.getInputStream(entry)) {
 					File outFile = createSubPathFile(outputDir, entry.getName());
 					outFile = outFile.getCanonicalFile(); //bug 266844
diff --git a/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/TarFile.java b/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/TarFile.java
index 567be31af..e8ccb6cd0 100644
--- a/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/TarFile.java
+++ b/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/p2/core/helpers/TarFile.java
@@ -14,7 +14,8 @@
 package org.eclipse.equinox.internal.p2.core.helpers;
 
 import java.io.*;
-import java.util.Enumeration;
+import java.util.Objects;
+import java.util.stream.Stream;
 import java.util.zip.GZIPInputStream;
 
 /**
@@ -23,9 +24,7 @@ import java.util.zip.GZIPInputStream;
 public class TarFile implements Closeable {
 	private File file;
 	private TarInputStream entryEnumerationStream;
-	private TarEntry curEntry;
 	private TarInputStream entryStream;
-
 	private InputStream internalEntryStream;
 
 	/**
@@ -54,7 +53,6 @@ public class TarFile implements Closeable {
 			in.close();
 			throw ex;
 		}
-		curEntry = entryEnumerationStream.getNextEntry();
 	}
 
 	/**
@@ -74,26 +72,15 @@ public class TarFile implements Closeable {
 	 *
 	 * @return enumeration of all files in the archive
 	 */
-	public Enumeration<TarEntry> entries() {
-		return new Enumeration<>() {
-			@Override
-			public boolean hasMoreElements() {
-				return (curEntry != null);
-			}
-
-			@Override
-			public TarEntry nextElement() {
-				TarEntry oldEntry = curEntry;
-				try {
-					curEntry = entryEnumerationStream.getNextEntry();
-				} catch (TarException e) {
-					curEntry = null;
-				} catch (IOException e) {
-					curEntry = null;
-				}
-				return oldEntry;
+	public Iterable<TarEntry> entries() throws TarException, IOException {
+		TarEntry first = entryEnumerationStream.getNextEntry(); // throws if stream is empty
+		return Stream.iterate(first, Objects::nonNull, e -> {
+			try {
+				return entryEnumerationStream.getNextEntry();
+			} catch (TarException | IOException e1) {
+				return null;
 			}
-		};
+		})::iterator;
 	}
 
 	/**
diff --git a/bundles/org.eclipse.equinox.p2.engine/META-INF/MANIFEST.MF b/bundles/org.eclipse.equinox.p2.engine/META-INF/MANIFEST.MF
index 83eacd2af..72d1dac18 100644
--- a/bundles/org.eclipse.equinox.p2.engine/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.equinox.p2.engine/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.equinox.p2.engine;singleton:=true
-Bundle-Version: 2.7.100.qualifier
+Bundle-Version: 2.7.200.qualifier
 Bundle-Activator: org.eclipse.equinox.internal.p2.engine.EngineActivator
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/bundles/org.eclipse.equinox.p2.engine/pom.xml b/bundles/org.eclipse.equinox.p2.engine/pom.xml
index 45e469344..d96856da2 100644
--- a/bundles/org.eclipse.equinox.p2.engine/pom.xml
+++ b/bundles/org.eclipse.equinox.p2.engine/pom.xml
@@ -9,6 +9,6 @@
   </parent>
   <groupId>org.eclipse.equinox</groupId>
   <artifactId>org.eclipse.equinox.p2.engine</artifactId>
-  <version>2.7.100-SNAPSHOT</version>
+  <version>2.7.200-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
 </project>
diff --git a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/spi/Memento.java b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/spi/Memento.java
index cab39fdfe..eb82f08d8 100644
--- a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/spi/Memento.java
+++ b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/spi/Memento.java
@@ -51,19 +51,7 @@ public final class Memento {
 	}
 
 	public Enumeration<String> getKeys() {
-		return new Enumeration<>() {
-			Iterator<String> keysIterator = mementoMap.keySet().iterator();
-
-			@Override
-			public boolean hasMoreElements() {
-				return keysIterator.hasNext();
-			}
-
-			@Override
-			public String nextElement() {
-				return keysIterator.next();
-			}
-		};
+		return Collections.enumeration(mementoMap.keySet());
 	}
 
 	private static void validateValue(Object value) {