fix: include input files timestamp into code hash

jadx-core/src/main/java/jadx/api/JadxArgs.java

@@ -1,9 +1,7 @@
 package jadx.api;
 
 import java.io.File;
-import java.math.BigInteger;
 import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EnumSet;
@@ -18,6 +16,7 @@
 import jadx.api.data.ICodeData;
 import jadx.api.impl.AnnotatedCodeWriter;
 import jadx.api.impl.InMemoryCodeCache;
+import jadx.core.utils.files.FileUtils;
 
 public class JadxArgs {
 
@@ -524,16 +523,12 @@ public String makeCodeArgsHash() {
 		String argStr = "args:" + decompilationMode + useImports + showInconsistentCode
 				+ inlineAnonymousClasses + inlineMethods
 				+ deobfuscationOn + deobfuscationMinLength + deobfuscationMaxLength
+				+ parseKotlinMetadata + useKotlinMethodsForVarNames
+				+ insertDebugLines + extractFinally
 				+ debugInfo + useSourceNameAsClassAlias + escapeUnicode + replaceConsts
 				+ respectBytecodeAccModifiers + fsCaseSensitive + renameFlags
 				+ commentsLevel + useDxInput + pluginOptions;
-		try {
-			MessageDigest md = MessageDigest.getInstance("MD5");
-			md.update(argStr.getBytes(StandardCharsets.US_ASCII));
-			return new BigInteger(1, md.digest()).toString(16);
-		} catch (Exception e) {
-			throw new RuntimeException(e);
-		}
+		return FileUtils.md5Sum(argStr.getBytes(StandardCharsets.US_ASCII));
 	}
 
 	@Override
@@ -555,6 +550,8 @@ public String toString() {
 				+ ", useSourceNameAsClassAlias=" + useSourceNameAsClassAlias
 				+ ", parseKotlinMetadata=" + parseKotlinMetadata
 				+ ", useKotlinMethodsForVarNames=" + useKotlinMethodsForVarNames
+				+ ", insertDebugLines=" + insertDebugLines
+				+ ", extractFinally=" + extractFinally
 				+ ", deobfuscationMinLength=" + deobfuscationMinLength
 				+ ", deobfuscationMaxLength=" + deobfuscationMaxLength
 				+ ", escapeUnicode=" + escapeUnicode

jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java

@@ -8,10 +8,12 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.FileVisitOption;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.security.MessageDigest;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
@@ -237,18 +239,19 @@ private static File cutFileName(File file) {
 		return new File(file.getParentFile(), name);
 	}
 
-	private static String bytesToHex(byte[] bytes) {
-		char[] hexArray = "0123456789abcdef".toCharArray();
-		if (bytes == null || bytes.length <= 0) {
-			return null;
+	private static final byte[] HEX_ARRAY = "0123456789abcdef".getBytes(StandardCharsets.US_ASCII);
+
+	public static String bytesToHex(byte[] bytes) {
+		if (bytes == null || bytes.length == 0) {
+			return "";
 		}
-		char[] hexChars = new char[bytes.length * 2];
+		byte[] hexChars = new byte[bytes.length * 2];
 		for (int j = 0; j < bytes.length; j++) {
 			int v = bytes[j] & 0xFF;
-			hexChars[j * 2] = hexArray[v >>> 4];
-			hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+			hexChars[j * 2] = HEX_ARRAY[v >>> 4];
+			hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
 		}
-		return new String(hexChars);
+		return new String(hexChars, StandardCharsets.UTF_8);
 	}
 
 	public static boolean isZipFile(File file) {
@@ -298,4 +301,14 @@ public static List<Path> fileNamesToPaths(List<String> fileNames) {
 	public static List<File> toFiles(List<Path> paths) {
 		return paths.stream().map(Path::toFile).collect(Collectors.toList());
 	}
+
+	public static String md5Sum(byte[] data) {
+		try {
+			MessageDigest md = MessageDigest.getInstance("MD5");
+			md.update(data);
+			return bytesToHex(md.digest());
+		} catch (Exception e) {
+			throw new JadxRuntimeException("Failed to build hash", e);
+		}
+	}
 }

jadx-gui/src/main/java/jadx/gui/utils/codecache/disk/DiskCodeCache.java

@@ -1,5 +1,7 @@
 package jadx.gui.utils.codecache.disk;
 
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -9,8 +11,10 @@
 import java.nio.file.PathMatcher;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.FileTime;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -26,13 +30,14 @@
 import jadx.api.ICodeInfo;
 import jadx.api.JadxArgs;
 import jadx.core.dex.nodes.RootNode;
+import jadx.core.utils.Utils;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 import jadx.core.utils.files.FileUtils;
 
 public class DiskCodeCache implements ICodeCache {
 	private static final Logger LOG = LoggerFactory.getLogger(DiskCodeCache.class);
 
-	private static final int DATA_FORMAT_VERSION = 6;
+	private static final int DATA_FORMAT_VERSION = 7;
 
 	private final Path srcDir;
 	private final Path metaDir;
@@ -58,10 +63,6 @@ public DiskCodeCache(RootNode root, Path baseDir) {
 		}
 	}
 
-	private String buildCodeVersion(JadxArgs args) {
-		return String.format("%d:%s", DATA_FORMAT_VERSION, args.makeCodeArgsHash());
-	}
-
 	private boolean checkCodeVersion() {
 		try {
 			if (!Files.exists(codeVersionFile)) {
@@ -209,6 +210,33 @@ private void writeFile(Path file, String data) {
 		}
 	}
 
+	private String buildCodeVersion(JadxArgs args) {
+		return DATA_FORMAT_VERSION
+				+ ":" + args.makeCodeArgsHash()
+				+ ":" + buildInputsHash(args.getInputFiles());
+	}
+
+	/**
+	 * Hash timestamps of all input files
+	 */
+	private String buildInputsHash(List<File> inputs) {
+		try (ByteArrayOutputStream bout = new ByteArrayOutputStream();
+				DataOutputStream data = new DataOutputStream(bout)) {
+			List<Path> inputPaths = Utils.collectionMap(inputs, File::toPath);
+			List<Path> inputFiles = FileUtils.expandDirs(inputPaths);
+			Collections.sort(inputFiles);
+			data.write(inputs.size());
+			data.write(inputFiles.size());
+			for (Path inputFile : inputFiles) {
+				FileTime modifiedTime = Files.getLastModifiedTime(inputFile);
+				data.writeLong(modifiedTime.toMillis());
+			}
+			return FileUtils.md5Sum(bout.toByteArray());
+		} catch (Exception e) {
+			throw new JadxRuntimeException("Failed to build hash for inputs", e);
+		}
+	}
+
 	private Path getJavaFile(String clsFullName) {
 		return srcDir.resolve(clsFullName.replace('.', File.separatorChar) + ".java");
 	}