Refactor archive reading

Writing archives is no longer included as this is not required for
RoboViz.

This also fixes a regression introduced with 0658dff where zip files
could no longer be read because the file was immediately closed again
through the try-with-resources block.

src/main/java/rv/comm/rcssserver/Logfile.java

@@ -24,6 +24,7 @@
 import java.util.List;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.magmaoffenburg.roboviz.util.ArchiveUtilKt;
 import rv.comm.drawing.commands.Command;
 
 /**
@@ -79,7 +80,12 @@ public Logfile(File file, boolean execDrawCmds) throws Exception
 	 */
 	private void open() throws IOException
 	{
-		br = TarBz2ZipUtil.createBufferedReader(logsrc);
+		try {
+			br = ArchiveUtilKt.createBufferedReader(logsrc);
+		} catch (Exception e) {
+			LOGGER.error("Unable to open file", e);
+			br = null;
+		}
 		if (br != null) {
 			curFrameMsg = br.readLine();
 			if (curFrameMsg != null && curFrameMsg.startsWith("[")) {

src/main/kotlin/org/magmaoffenburg/roboviz/util/ArchiveUtil.kt

@@ -0,0 +1,80 @@
+package org.magmaoffenburg.roboviz.util
+
+import org.apache.commons.compress.archivers.tar.TarArchiveInputStream
+import org.apache.commons.compress.compressors.CompressorStreamFactory
+import java.io.BufferedInputStream
+import java.io.BufferedReader
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileNotFoundException
+import java.io.InputStream
+import java.io.InputStreamReader
+import java.util.zip.ZipFile
+import kotlin.math.max
+
+fun createBufferedReader(file: File): BufferedReader {
+    // Extract suffixes from filename to determine extraction method
+    val suffixes = file.name.lowercase().split('.').let { it.subList(max(0, it.size - 2), it.size) }.map {
+        // Fix a few common shortened suffixes
+        when (it) {
+            "tbz2" -> listOf("tar", "bz2")
+            "tgz" -> listOf("tar", "gz")
+            else -> listOf(it)
+        }
+    }.flatten()
+
+    var inputStream: InputStream = BufferedInputStream(FileInputStream(file))
+    for (suffix in suffixes.asReversed()) {
+        when (suffix) {
+            "bz2" -> inputStream =
+                CompressorStreamFactory().createCompressorInputStream(CompressorStreamFactory.BZIP2, inputStream)
+
+            "gz" -> inputStream =
+                CompressorStreamFactory().createCompressorInputStream(CompressorStreamFactory.GZIP, inputStream)
+
+            "tar" -> {
+                // Only works for the current layout of tar files
+                val tarStream = TarArchiveInputStream(inputStream)
+                var entry = tarStream.nextEntry
+
+                // Choose first file when not able to navigate deeper in the directory structure
+                while (entry != null && entry.isDirectory) {
+                    val entries = entry.directoryEntries
+                    entry = if (entries.isNotEmpty()) {
+                        entries[0]
+                    } else {
+                        // empty directory
+                        tarStream.nextEntry
+                    }
+                }
+
+                // Search for proper file
+                while (entry != null && !entry.name.endsWith("sparkmonitor.log")) {
+                    entry = tarStream.nextEntry
+                }
+
+                if (entry == null) {
+                    throw FileNotFoundException("tar file does not contain logfile")
+                }
+
+                // We have reached the proper position
+                inputStream = tarStream
+                break
+            }
+
+            "zip" -> {
+                val zipFile = ZipFile(file)
+                if (zipFile.size() != 1) {
+                    zipFile.close()
+                    throw UnsupportedOperationException("Only support single entry zip files")
+                }
+                val zipEntry = zipFile.entries().nextElement()
+                inputStream = zipFile.getInputStream(zipEntry)
+                break
+            }
+
+            else -> break
+        }
+    }
+    return BufferedReader(InputStreamReader(inputStream))
+}