Proposal: Opening/Closing Mechanism for Zip Files

resources/bundles/org.eclipse.core.filesystem/plugin.xml

@@ -16,4 +16,11 @@
          <run class="org.eclipse.core.internal.filesystem.NullFileSystem"/>
       </filesystem>
    </extension>
+   <extension
+         id="org.eclipse.core.filesystem.zip"
+         point="org.eclipse.core.filesystem.filesystems">
+      <filesystem scheme="zip">
+         <run class="org.eclipse.core.internal.filesystem.zip.ZipFileSystem"/>
+      </filesystem>
+   </extension>
 </plugin>

resources/bundles/org.eclipse.core.filesystem/src/org/eclipse/core/filesystem/ZipFileUtil.java

@@ -0,0 +1,103 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Vector Informatik GmbH and others.
+ *
+ * This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License 2.0 which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors: Vector Informatik GmbH - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.core.filesystem;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.util.zip.ZipInputStream;
+import org.eclipse.core.internal.filesystem.zip.ZipFileStore;
+import org.eclipse.core.runtime.CoreException;
+
+/**
+ * Utility class for zip files.
+ *
+ * @since 1.11
+ */
+public class ZipFileUtil {
+
+
+	public static boolean isInsideOpenZipFile(IFileStore store) {
+		return store instanceof ZipFileStore;
+	}
+
+	public static boolean isInsideOpenZipFile(URI locationURI) {
+		IFileStore store;
+		try {
+			if (locationURI != null) {
+				store = EFS.getStore(locationURI);
+			} else {
+				return false;
+			}
+		} catch (CoreException e) {
+			return false;
+		}
+		return isInsideOpenZipFile(store);
+	}
+
+	/**
+	 * Determines if the given {@link IFileStore} represents an open ZIP file.
+	 * This can be used to check if operations on a ZIP file should be allowed or handled differently.
+	 *
+	 * @param store The file store to check.
+	 * @return true if the store is an instance of {@link ZipFileStore}, false otherwise.
+	 */
+	public static boolean isOpenZipFile(IFileStore store) {
+		if (isInsideOpenZipFile(store)) {
+			ZipFileStore zipStore = (ZipFileStore) store;
+			return zipStore.getPath().isEmpty(); //if path is empty its the root
+		}
+		return false;
+	}
+
+	/**
+	 * @see ZipFileUtil#isOpenZipFile(IFileStore)
+	 */
+	public static boolean isOpenZipFile(URI locationURI) {
+		IFileStore store;
+		try {
+			store = EFS.getStore(locationURI);
+		} catch (CoreException e) {
+			return false;
+		}
+		return isOpenZipFile(store);
+	}
+
+	public static boolean isNested(URI fileURI) {
+		if (fileURI.getScheme().contains("zip")) { //$NON-NLS-1$
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Checks if the provided {@link InputStream} represents a ZIP archive
+	 * by attempting to open it as a ZIP archive.
+	 * This method throws {@link IOException} if the stream does not represent a valid ZIP archive.
+	 *
+	 * @param fis The {@link InputStream} of the file to check.
+	 * @throws IOException If the stream does not represent a valid ZIP archive
+	 *                     or an I/O error occurs during reading from the stream.
+	 */
+	public static void canZipFileBeOpened(InputStream fis) throws IOException {
+		// Use ZipInputStream to try reading the InputStream as a ZIP file
+		try (ZipInputStream zipStream = new ZipInputStream(fis)) {
+			// Attempt to read the first entry from the zip stream
+			if (zipStream.getNextEntry() == null) {
+				// If there are no entries, then it might not be a ZIP file or it's empty
+				throw new IOException();
+			}
+			// Successfully reading an entry implies it's likely a valid ZIP file
+		}
+	}
+}

resources/bundles/org.eclipse.core.filesystem/src/org/eclipse/core/internal/filesystem/zip/ZipEntryFileVisitor.java

@@ -0,0 +1,49 @@
+package org.eclipse.core.internal.filesystem.zip;
+
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.zip.ZipEntry;
+
+public class ZipEntryFileVisitor extends SimpleFileVisitor<Path> {
+	private final Path zipRoot;
+	private final List<ZipEntry> entryList;
+
+	public ZipEntryFileVisitor(Path zipRoot) {
+		this.zipRoot = zipRoot;
+		this.entryList = new ArrayList<>();
+	}
+
+	@Override
+	public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+		String entryName = zipRoot.relativize(file).toString();
+		if (!Files.isDirectory(file)) {
+			ZipEntry zipEntry = new ZipEntry(entryName);
+			zipEntry.setSize(attrs.size());
+			zipEntry.setTime(attrs.lastModifiedTime().toMillis());
+			zipEntry.setMethod(ZipEntry.DEFLATED);
+			entryList.add(zipEntry);
+		} else {
+			entryList.add(new ZipEntry(entryName + "/")); //$NON-NLS-1$
+		}
+		return FileVisitResult.CONTINUE;
+	}
+
+	@Override
+	public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
+		if (!dir.equals(zipRoot)) {
+			String dirName = zipRoot.relativize(dir).toString() + "/"; //$NON-NLS-1$
+			entryList.add(new ZipEntry(dirName));
+			return FileVisitResult.SKIP_SUBTREE; // Skip the subdirectories
+		}
+		return FileVisitResult.CONTINUE;
+	}
+
+	public List<ZipEntry> getEntries() {
+		return entryList;
+	}
+}