Fix #547

app/src/main/java/eu/kanade/tachiyomi/util/DiskUtil.kt

@@ -0,0 +1,70 @@
+package eu.kanade.tachiyomi.util
+
+import java.io.File
+import java.security.MessageDigest
+import java.security.NoSuchAlgorithmException
+
+object DiskUtil {
+
+    fun hashKeyForDisk(key: String): String {
+        return try {
+            val bytes = MessageDigest.getInstance("MD5").digest(key.toByteArray())
+            val sb = StringBuilder()
+            bytes.forEach { byte ->
+                sb.append(Integer.toHexString(byte.toInt() and 0xFF or 0x100).substring(1, 3))
+            }
+            sb.toString()
+        } catch (e: NoSuchAlgorithmException) {
+            key.hashCode().toString()
+        }
+    }
+
+    fun getDirectorySize(f: File): Long {
+        var size: Long = 0
+        if (f.isDirectory) {
+            for (file in f.listFiles()) {
+                size += getDirectorySize(file)
+            }
+        } else {
+            size = f.length()
+        }
+        return size
+    }
+
+    /**
+     * Mutate the given filename to make it valid for a FAT filesystem,
+     * replacing any invalid characters with "_". This method doesn't allow private files (starting
+     * with a dot), but you can manually add it later.
+     */
+    fun buildValidFatFilename(origName: String): String {
+        val name = origName.trim('.', ' ')
+        if (name.isNullOrEmpty()) {
+            return "(invalid)"
+        }
+        val sb = StringBuilder(name.length)
+        name.forEach { c ->
+            if (isValidFatFilenameChar(c)) {
+                sb.append(c)
+            } else {
+                sb.append('_')
+            }
+        }
+        // Even though vfat allows 255 UCS-2 chars, we might eventually write to
+        // ext4 through a FUSE layer, so use that limit minus 5 reserved characters.
+        return sb.toString().take(250)
+    }
+
+    /**
+     * Returns true if the given character is a valid filename character, false otherwise.
+     */
+    private fun isValidFatFilenameChar(c: Char): Boolean {
+        if (0x00.toChar() <= c && c <= 0x1f.toChar()) {
+            return false
+        }
+        return when (c) {
+            '"', '*', '/', ':', '<', '>', '?', '\\', '|', 0x7f.toChar() -> false
+            else -> true
+        }
+    }
+}
+

app/src/main/java/eu/kanade/tachiyomi/util/DiskUtils.java

@@ -1,69 +0,0 @@
-package eu.kanade.tachiyomi.util;
-
-import java.io.File;
-import java.io.IOException;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-
-public final class DiskUtils {
-
-    private DiskUtils() {
-        throw new AssertionError();
-    }
-
-    public static String hashKeyForDisk(String key) {
-        String cacheKey;
-        try {
-            final MessageDigest mDigest = MessageDigest.getInstance("MD5");
-            mDigest.update(key.getBytes());
-            cacheKey = bytesToHexString(mDigest.digest());
-        } catch (NoSuchAlgorithmException e) {
-            cacheKey = String.valueOf(key.hashCode());
-        }
-        return cacheKey;
-    }
-
-    private static String bytesToHexString(byte[] bytes) {
-        StringBuilder sb = new StringBuilder();
-        for (int i = 0; i < bytes.length; i++) {
-            String hex = Integer.toHexString(0xFF & bytes[i]);
-            if (hex.length() == 1) {
-                sb.append('0');
-            }
-            sb.append(hex);
-        }
-        return sb.toString();
-    }
-    
-    public static void deleteFiles(File inputFile) {
-        if (inputFile.isDirectory()) {
-            for (File childFile : inputFile.listFiles()) {
-                deleteFiles(childFile);
-            }
-        }
-
-        //noinspection ResultOfMethodCallIgnored
-        inputFile.delete();
-    }
-
-    public static synchronized void createDirectory(File directory) throws IOException {
-        if (!directory.exists() && !directory.mkdirs()) {
-            throw new IOException("Failed creating directory");
-        }
-
-    }
-
-    public static long getDirectorySize(File f) {
-        long size = 0;
-        if (f.isDirectory()) {
-            for (File file : f.listFiles()) {
-                size += getDirectorySize(file);
-            }
-        } else {
-            size=f.length();
-        }
-        return size;
-    }
-
-}
-