MemoryFileProvider

app/CMakeLists.txt

@@ -5,6 +5,8 @@ project(DroidFS)
 option(GOCRYPTFS "build libgocryptfs" ON)
 option(CRYFS "build libcryfs" ON)
 
+add_library(memfile SHARED src/main/native/memfile.cpp)
+
 if (GOCRYPTFS)
 	add_library(gocryptfs SHARED IMPORTED)
 	set_target_properties(

app/src/main/AndroidManifest.xml

@@ -68,8 +68,14 @@
         </receiver>
 
         <provider
-            android:name=".content_providers.RestrictedFileProvider"
+            android:name=".content_providers.MemoryFileProvider"
-            android:authorities="${applicationId}.temporary_provider"
+            android:authorities="${applicationId}.memory_provider"
+            android:exported="true"
+            android:writePermission="${applicationId}.WRITE_TEMPORARY_STORAGE" />
+
+        <provider
+            android:name=".content_providers.DiskFileProvider"
+            android:authorities="${applicationId}.disk_provider"
             android:exported="true"
             android:writePermission="${applicationId}.WRITE_TEMPORARY_STORAGE" />
     </application>

app/src/main/java/sushi/hardcore/droidfs/FileShare.kt

@@ -0,0 +1,93 @@
+package sushi.hardcore.droidfs
+
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.webkit.MimeTypeMap
+import sushi.hardcore.droidfs.content_providers.DiskFileProvider
+import sushi.hardcore.droidfs.content_providers.MemoryFileProvider
+import sushi.hardcore.droidfs.content_providers.TemporaryFileProvider
+import sushi.hardcore.droidfs.filesystems.EncryptedVolume
+import sushi.hardcore.droidfs.util.Version
+import java.io.File
+
+class FileShare(private val encryptedVolume: EncryptedVolume, private val context: Context) {
+
+    companion object {
+        private const val content_type_all = "*/*"
+        fun getContentType(filename: String, previousContentType: String?): String {
+            if (content_type_all != previousContentType) {
+                var contentType = MimeTypeMap.getSingleton()
+                    .getMimeTypeFromExtension(File(filename).extension)
+                if (contentType == null) {
+                    contentType = content_type_all
+                }
+                if (previousContentType == null) {
+                    return contentType
+                } else if (previousContentType != contentType) {
+                    return content_type_all
+                }
+            }
+            return previousContentType
+        }
+    }
+
+    private val fileProvider: TemporaryFileProvider<*>
+
+    init {
+        var provider: MemoryFileProvider? = null
+        System.getProperty("os.version")?.let {
+            if (Version(it) >= Version("3.17")) {
+                provider = MemoryFileProvider()
+            }
+        }
+        fileProvider = provider ?: DiskFileProvider()
+    }
+
+    private fun exportFile(path: String, size: Long, previousContentType: String? = null): Pair<Uri?, String?> {
+        val fileName = File(path).name
+        val uri = fileProvider.newFile(fileName, size)
+        if (uri != null) {
+            if (encryptedVolume.exportFile(context, path, uri)) {
+                return Pair(uri, getContentType(fileName, previousContentType))
+            }
+        }
+        return Pair(null, null)
+    }
+
+    fun share(files: List<Pair<String, Long>>): Pair<Intent?, String?> {
+        var contentType: String? = null
+        val uris = ArrayList<Uri>(files.size)
+        for ((path, size) in files) {
+            val result = exportFile(path, size, contentType)
+            contentType = if (result.first == null) {
+                return Pair(null, path)
+            } else {
+                uris.add(result.first!!)
+                result.second
+            }
+        }
+        return Pair(Intent().apply {
+            type = contentType
+            if (uris.size == 1) {
+                action = Intent.ACTION_SEND
+                putExtra(Intent.EXTRA_STREAM, uris[0])
+            } else {
+                action = Intent.ACTION_SEND_MULTIPLE
+                putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris)
+            }
+        }, null)
+    }
+
+    fun openWith(path: String, size: Long): Intent? {
+        val result = exportFile(path, size)
+        return if (result.first != null) {
+            Intent(Intent.ACTION_VIEW).apply {
+                addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+                setDataAndType(result.first, result.second)
+            }
+        } else {
+            null
+        }
+    }
+}

app/src/main/java/sushi/hardcore/droidfs/MemFile.kt

@@ -0,0 +1,22 @@
+package sushi.hardcore.droidfs
+
+import android.os.ParcelFileDescriptor
+
+class MemFile private constructor(private val fd: Int) {
+    companion object {
+        private external fun createMemFile(name: String, size: Long): Int
+        init {
+            System.loadLibrary("memfile")
+        }
+
+        fun create(name: String, size: Long): MemFile? {
+            val fd = createMemFile(name, size)
+            return if (fd > 0) MemFile(fd) else null
+        }
+    }
+
+    private external fun close(fd: Int)
+
+    fun getParcelFileDescriptor(): ParcelFileDescriptor = ParcelFileDescriptor.fromFd(fd)
+    fun close() = close(fd)
+}

app/src/main/java/sushi/hardcore/droidfs/VolumeManagerApp.kt

@@ -6,7 +6,8 @@ import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.ProcessLifecycleOwner
 import androidx.preference.PreferenceManager
-import sushi.hardcore.droidfs.content_providers.RestrictedFileProvider
+import sushi.hardcore.droidfs.content_providers.MemoryFileProvider
+import sushi.hardcore.droidfs.content_providers.DiskFileProvider
 
 class VolumeManagerApp : Application(), DefaultLifecycleObserver {
     companion object {
@@ -45,7 +46,8 @@ class VolumeManagerApp : Application(), DefaultLifecycleObserver {
             if (!usfKeepOpen) {
                 volumeManager.closeAll()
             }
-            RestrictedFileProvider.wipeAll(applicationContext)
+            DiskFileProvider.wipe()
+            MemoryFileProvider.wipe()
         }
     }
 }

app/src/main/java/sushi/hardcore/droidfs/content_providers/DiskFileProvider.kt

@@ -0,0 +1,68 @@
+package sushi.hardcore.droidfs.content_providers
+
+import android.net.Uri
+import android.os.ParcelFileDescriptor
+import sushi.hardcore.droidfs.BuildConfig
+import sushi.hardcore.droidfs.util.Wiper
+import java.io.File
+import java.util.UUID
+
+class DiskFileProvider: TemporaryFileProvider<File>() {
+    companion object {
+        private const val AUTHORITY = BuildConfig.APPLICATION_ID + ".disk_provider"
+        private val CONTENT_URI: Uri = Uri.parse("content://$AUTHORITY")
+        const val TEMPORARY_FILES_DIR_NAME = "temp"
+
+        private lateinit var tempFilesDir: File
+
+        private var files = HashMap<Uri, TemporaryFileProvider<File>.SharedFile>()
+
+        fun wipe() {
+            for (i in files.values) {
+                Wiper.wipe(i.file)
+            }
+            files.clear()
+            tempFilesDir.listFiles()?.let {
+                for (file in it) {
+                    Wiper.wipe(file)
+                }
+            }
+        }
+    }
+
+    override fun onCreate(): Boolean {
+        context?.let {
+            tempFilesDir = File(it.cacheDir, TEMPORARY_FILES_DIR_NAME)
+            return tempFilesDir.mkdirs()
+        }
+        return false
+    }
+
+    override fun getFile(uri: Uri): SharedFile? = files[uri]
+
+    override fun newFile(name: String, size: Long): Uri? {
+        val uuid = UUID.randomUUID().toString()
+        val file = File(tempFilesDir, uuid)
+        return if (file.createNewFile()) {
+            Uri.withAppendedPath(CONTENT_URI, uuid).also {
+                files[it] = SharedFile(name, size, file)
+            }
+        } else {
+            null
+        }
+    }
+
+    override fun delete(uri: Uri, givenSelection: String?, givenSelectionArgs: Array<String>?): Int {
+        return if (files.remove(uri)?.file?.also { Wiper.wipe(it) } == null) 0 else 1
+    }
+
+    override fun openFile(uri: Uri, mode: String): ParcelFileDescriptor? {
+        return if (("w" in mode && callingPackage == BuildConfig.APPLICATION_ID) || "w" !in mode) {
+            files[uri]?.file?.let {
+                return ParcelFileDescriptor.open(it, ParcelFileDescriptor.parseMode(mode))
+            }
+        } else {
+            throw SecurityException("Read-only access")
+        }
+    }
+}

app/src/main/java/sushi/hardcore/droidfs/content_providers/ExternalProvider.kt

@@ -1,124 +0,0 @@
-package sushi.hardcore.droidfs.content_providers
-
-import android.content.Context
-import android.content.Intent
-import android.net.Uri
-import android.webkit.MimeTypeMap
-import androidx.appcompat.app.AppCompatActivity
-import androidx.lifecycle.lifecycleScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.launch
-import sushi.hardcore.droidfs.LoadingTask
-import sushi.hardcore.droidfs.R
-import sushi.hardcore.droidfs.Theme
-import sushi.hardcore.droidfs.filesystems.EncryptedVolume
-import sushi.hardcore.droidfs.widgets.CustomAlertDialogBuilder
-import java.io.File
-
-object ExternalProvider {
-    private const val content_type_all = "*/*"
-    private var storedFiles = HashSet<Uri>()
-    private fun getContentType(filename: String, previous_content_type: String?): String {
-        if (content_type_all != previous_content_type) {
-            var contentType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(File(filename).extension)
-            if (contentType == null) {
-                contentType = content_type_all
-            }
-            if (previous_content_type == null) {
-                return contentType
-            } else if (previous_content_type != contentType) {
-                return content_type_all
-            }
-        }
-        return previous_content_type
-    }
-
-    private fun exportFile(context: Context, encryptedVolume: EncryptedVolume, file_path: String, previous_content_type: String?): Pair<Uri?, String?> {
-        val fileName = File(file_path).name
-        val tmpFileUri = RestrictedFileProvider.newFile(fileName)
-        if (tmpFileUri != null){
-            storedFiles.add(tmpFileUri)
-            if (encryptedVolume.exportFile(context, file_path, tmpFileUri)) {
-                return Pair(tmpFileUri, getContentType(fileName, previous_content_type))
-            }
-        }
-        return Pair(null, null)
-    }
-
-    fun share(activity: AppCompatActivity, theme: Theme, encryptedVolume: EncryptedVolume, file_paths: List<String>) {
-        var contentType: String? = null
-        val uris = ArrayList<Uri>(file_paths.size)
-        object : LoadingTask<String?>(activity, theme, R.string.loading_msg_export) {
-            override suspend fun doTask(): String? {
-                for (path in file_paths) {
-                    val result = exportFile(activity, encryptedVolume, path, contentType)
-                    contentType = if (result.first != null) {
-                        uris.add(result.first!!)
-                        result.second
-                    } else {
-                        return path
-                    }
-                }
-                return null
-            }
-        }.startTask(activity.lifecycleScope) { failedItem ->
-            if (failedItem == null) {
-                val shareIntent = Intent()
-                shareIntent.type = contentType
-                if (uris.size == 1) {
-                    shareIntent.action = Intent.ACTION_SEND
-                    shareIntent.putExtra(Intent.EXTRA_STREAM, uris[0])
-                } else {
-                    shareIntent.action = Intent.ACTION_SEND_MULTIPLE
-                    shareIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris)
-                }
-                activity.startActivity(Intent.createChooser(shareIntent, activity.getString(R.string.share_chooser)))
-            } else {
-                CustomAlertDialogBuilder(activity, theme)
-                    .setTitle(R.string.error)
-                    .setMessage(activity.getString(R.string.export_failed, failedItem))
-                    .setPositiveButton(R.string.ok, null)
-                    .show()
-            }
-        }
-    }
-
-    fun open(activity: AppCompatActivity, theme: Theme, encryptedVolume: EncryptedVolume, file_path: String) {
-        object : LoadingTask<Intent?>(activity, theme, R.string.loading_msg_export) {
-            override suspend fun doTask(): Intent? {
-                val result = exportFile(activity, encryptedVolume, file_path, null)
-                return if (result.first != null) {
-                    Intent(Intent.ACTION_VIEW).apply {
-                        addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
-                        setDataAndType(result.first, result.second)
-                    }
-                } else {
-                    null
-                }
-            }
-        }.startTask(activity.lifecycleScope) { openIntent ->
-            if (openIntent == null) {
-                CustomAlertDialogBuilder(activity, theme)
-                    .setTitle(R.string.error)
-                    .setMessage(activity.getString(R.string.export_failed, file_path))
-                    .setPositiveButton(R.string.ok, null)
-                    .show()
-            } else {
-                activity.startActivity(openIntent)
-            }
-        }
-    }
-
-    fun removeFilesAsync(context: Context) = GlobalScope.launch(Dispatchers.IO) {
-        val success = HashSet<Uri>(storedFiles.size)
-        for (uri in storedFiles) {
-            if (context.contentResolver.delete(uri, null, null) == 1) {
-                success.add(uri)
-            }
-        }
-        for (uri in success) {
-            storedFiles.remove(uri)
-        }
-    }
-}

app/src/main/java/sushi/hardcore/droidfs/content_providers/MemoryFileProvider.kt

@@ -0,0 +1,48 @@
+package sushi.hardcore.droidfs.content_providers
+
+import android.net.Uri
+import android.os.ParcelFileDescriptor
+import sushi.hardcore.droidfs.BuildConfig
+import sushi.hardcore.droidfs.MemFile
+import java.io.FileInputStream
+import java.util.UUID
+
+class MemoryFileProvider: TemporaryFileProvider<MemFile>() {
+    companion object {
+        private const val AUTHORITY = BuildConfig.APPLICATION_ID + ".memory_provider"
+        private val BASE_URI: Uri = Uri.parse("content://$AUTHORITY")
+
+        private var files = HashMap<Uri, TemporaryFileProvider<MemFile>.SharedFile>()
+
+        fun wipe() {
+            for (i in files.values) {
+                i.file.close()
+            }
+            files.clear()
+        }
+    }
+
+    override fun onCreate(): Boolean = true
+
+    override fun getFile(uri: Uri): SharedFile? = files[uri]
+
+    override fun newFile(name: String, size: Long): Uri? {
+        val uuid = UUID.randomUUID().toString()
+        return Uri.withAppendedPath(BASE_URI, uuid).also {
+            files[it] = SharedFile(name, size, MemFile.create(uuid, size) ?: return null)
+        }
+    }
+
+    override fun delete(uri: Uri, selection: String?, selectionArgs: Array<out String>?): Int {
+        return if (files.remove(uri)?.file?.close() == null) 0 else 1
+    }
+
+    override fun openFile(uri: Uri, mode: String): ParcelFileDescriptor? {
+        return files[uri]?.file?.getParcelFileDescriptor()?.also {
+            FileInputStream(it.fileDescriptor).apply {
+                channel.position(0)
+                close()
+            }
+        }
+    }
+}

app/src/main/java/sushi/hardcore/droidfs/content_providers/RestrictedFileProvider.kt

@@ -1,194 +0,0 @@
-package sushi.hardcore.droidfs.content_providers
-
-import android.content.ContentProvider
-import android.content.ContentValues
-import android.content.Context
-import android.database.Cursor
-import android.database.MatrixCursor
-import android.database.sqlite.SQLiteDatabase
-import android.database.sqlite.SQLiteOpenHelper
-import android.net.Uri
-import android.os.ParcelFileDescriptor
-import android.provider.MediaStore
-import sushi.hardcore.droidfs.BuildConfig
-import sushi.hardcore.droidfs.util.SQLUtil.appendSelectionArgs
-import sushi.hardcore.droidfs.util.SQLUtil.concatenateWhere
-import sushi.hardcore.droidfs.util.Wiper
-import java.io.File
-import java.util.UUID
-import java.util.regex.Pattern
-
-class RestrictedFileProvider: ContentProvider() {
-    companion object {
-        private const val DB_NAME = "temporary_files.db"
-        private const val TABLE_FILES = "files"
-        private const val DB_VERSION = 3
-        private var dbHelper: RestrictedDatabaseHelper? = null
-        private const val AUTHORITY = BuildConfig.APPLICATION_ID + ".temporary_provider"
-        private val CONTENT_URI: Uri = Uri.parse("content://$AUTHORITY")
-        const val TEMPORARY_FILES_DIR_NAME = "temp"
-        private val UUID_PATTERN = Pattern.compile("[a-fA-F0-9-]+")
-
-        private lateinit var tempFilesDir: File
-
-        internal class TemporaryFileColumns {
-            companion object {
-                const val COLUMN_UUID = "uuid"
-                const val COLUMN_NAME = "name"
-            }
-        }
-
-        internal class RestrictedDatabaseHelper(context: Context?): SQLiteOpenHelper(context, DB_NAME, null, DB_VERSION) {
-            override fun onCreate(db: SQLiteDatabase) {
-                db.execSQL(
-                    "CREATE TABLE IF NOT EXISTS " + TABLE_FILES + " (" +
-                            TemporaryFileColumns.COLUMN_UUID + " TEXT PRIMARY KEY, " +
-                            TemporaryFileColumns.COLUMN_NAME + " TEXT" +
-                            ");"
-                )
-            }
-
-            override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
-                if (oldVersion == 1) {
-                    db.execSQL("DROP TABLE IF EXISTS files")
-                    db.execSQL(
-                        "CREATE TABLE IF NOT EXISTS " + TABLE_FILES + " (" +
-                                TemporaryFileColumns.COLUMN_UUID + " TEXT PRIMARY KEY, " +
-                                TemporaryFileColumns.COLUMN_NAME + " TEXT" +
-                                ");"
-                    )
-                }
-            }
-        }
-
-        fun newFile(fileName: String): Uri? {
-            val uuid = UUID.randomUUID().toString()
-            val file = File(tempFilesDir, uuid)
-            return if (file.createNewFile()){
-                val contentValues = ContentValues()
-                contentValues.put(TemporaryFileColumns.COLUMN_UUID, uuid)
-                contentValues.put(TemporaryFileColumns.COLUMN_NAME, fileName)
-                if (dbHelper?.writableDatabase?.insert(TABLE_FILES, null, contentValues)?.toInt() != -1){
-                    Uri.withAppendedPath(CONTENT_URI, uuid)
-                } else {
-                    null
-                }
-            } else {
-                null
-            }
-        }
-
-        fun wipeAll(context: Context) {
-            tempFilesDir.listFiles()?.let{
-                for (file in it) {
-                    Wiper.wipe(file)
-                }
-            }
-            dbHelper?.close()
-            context.deleteDatabase(DB_NAME)
-        }
-
-        private fun isValidUUID(uuid: String): Boolean {
-            return UUID_PATTERN.matcher(uuid).matches()
-        }
-
-        private fun getUuidFromUri(uri: Uri): String? {
-            val uuid = uri.lastPathSegment
-            if (uuid != null) {
-                if (isValidUUID(uuid)) {
-                    return uuid
-                }
-            }
-            return null
-        }
-
-        private fun getFileFromUUID(uuid: String): File? {
-            if (isValidUUID(uuid)){
-                return File(tempFilesDir, uuid)
-            }
-            return null
-        }
-
-        private fun getFileFromUri(uri: Uri): File? {
-            getUuidFromUri(uri)?.let {
-                return getFileFromUUID(it)
-            }
-            return null
-        }
-    }
-
-    override fun onCreate(): Boolean {
-        context?.let {
-            dbHelper = RestrictedDatabaseHelper(it)
-            tempFilesDir = File(it.cacheDir, TEMPORARY_FILES_DIR_NAME)
-            return tempFilesDir.mkdirs()
-        }
-        return false
-    }
-
-    override fun insert(uri: Uri, values: ContentValues?): Uri? {
-        throw RuntimeException("Operation not supported")
-    }
-
-    override fun update(uri: Uri, values: ContentValues?, selection: String?, selectionArgs: Array<String>?): Int {
-        throw RuntimeException("Operation not supported")
-    }
-
-    override fun query(uri: Uri, projection: Array<String>?, selection: String?, selectionArgs: Array<String>?, sortOrder: String?): Cursor? {
-        var resultCursor: MatrixCursor? = null
-        val temporaryFile = getFileFromUri(uri)
-        temporaryFile?.let{
-            val fileName = dbHelper?.readableDatabase?.query(TABLE_FILES, arrayOf(TemporaryFileColumns.COLUMN_NAME), TemporaryFileColumns.COLUMN_UUID + "=?", arrayOf(uri.lastPathSegment), null, null, null)
-            fileName?.let{
-                if (fileName.moveToNext()) {
-                    resultCursor = MatrixCursor(
-                        arrayOf(
-                            MediaStore.MediaColumns.DISPLAY_NAME,
-                            MediaStore.MediaColumns.SIZE
-                        )
-                    )
-                    resultCursor!!.newRow()
-                        .add(fileName.getString(0))
-                        .add(temporaryFile.length())
-                }
-                fileName.close()
-            }
-        }
-        return resultCursor
-    }
-
-    override fun delete(uri: Uri, givenSelection: String?, givenSelectionArgs: Array<String>?): Int {
-        val uuid = getUuidFromUri(uri)
-        uuid?.let{
-            val selection = concatenateWhere(givenSelection ?: "" , TemporaryFileColumns.COLUMN_UUID + "=?")
-            val selectionArgs = appendSelectionArgs(givenSelectionArgs, arrayOf(it))
-
-            val files = dbHelper?.readableDatabase?.query(TABLE_FILES, arrayOf(TemporaryFileColumns.COLUMN_UUID), selection, selectionArgs, null, null, null)
-            if (files != null) {
-                while (files.moveToNext()) {
-                    getFileFromUUID(files.getString(0))?.let { file ->
-                        Wiper.wipe(file)
-                    }
-                }
-                files.close()
-                return dbHelper?.writableDatabase?.delete(TABLE_FILES, selection, selectionArgs) ?: 0
-            }
-        }
-        return 0
-    }
-
-    override fun getType(uri: Uri): String {
-        return "application/octet-stream"
-    }
-
-    override fun openFile(uri: Uri, mode: String): ParcelFileDescriptor? {
-        if (("w" in mode && callingPackage == BuildConfig.APPLICATION_ID) || "w" !in mode) {
-            getFileFromUri(uri)?.let{
-                return ParcelFileDescriptor.open(it, ParcelFileDescriptor.parseMode(mode))
-            }
-        } else {
-            throw SecurityException("Read-only access")
-        }
-        return null
-    }
-}

app/src/main/java/sushi/hardcore/droidfs/content_providers/TemporaryFileProvider.kt

@@ -0,0 +1,36 @@
+package sushi.hardcore.droidfs.content_providers
+
+import android.content.ContentProvider
+import android.content.ContentValues
+import android.database.Cursor
+import android.database.MatrixCursor
+import android.net.Uri
+import android.provider.OpenableColumns
+import android.webkit.MimeTypeMap
+import java.io.File
+
+abstract class TemporaryFileProvider<T>: ContentProvider() {
+    protected inner class SharedFile(val name: String, val size: Long, val file: T)
+
+    protected abstract fun getFile(uri: Uri): SharedFile?
+    abstract fun newFile(name: String, size: Long): Uri?
+
+    override fun query(uri: Uri, projection: Array<String>?, selection: String?, selectionArgs: Array<String>?, sortOrder: String?): Cursor? {
+        val file = getFile(uri) ?: return null
+        return MatrixCursor(arrayOf(OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE), 1).apply {
+            addRow(arrayOf(file.name, file.size))
+        }
+    }
+
+    override fun insert(uri: Uri, values: ContentValues?): Uri? {
+        throw UnsupportedOperationException("Operation not supported")
+    }
+
+    override fun update(uri: Uri, values: ContentValues?, selection: String?, selectionArgs: Array<String>?): Int {
+        throw UnsupportedOperationException("Operation not supported")
+    }
+
+    override fun getType(uri: Uri): String = getFile(uri)?.name?.let {
+        MimeTypeMap.getSingleton().getMimeTypeFromExtension(File(it).extension)
+    } ?: "application/octet-stream"
+}

app/src/main/java/sushi/hardcore/droidfs/explorers/BaseExplorerActivity.kt

@@ -26,10 +26,12 @@ import kotlinx.coroutines.*
 import sushi.hardcore.droidfs.*
 import sushi.hardcore.droidfs.adapters.ExplorerElementAdapter
 import sushi.hardcore.droidfs.adapters.OpenAsDialogAdapter
-import sushi.hardcore.droidfs.content_providers.ExternalProvider
+import sushi.hardcore.droidfs.content_providers.MemoryFileProvider
+import sushi.hardcore.droidfs.content_providers.DiskFileProvider
 import sushi.hardcore.droidfs.file_operations.FileOperationService
 import sushi.hardcore.droidfs.file_operations.OperationFile
 import sushi.hardcore.droidfs.file_operations.TaskResult
+import sushi.hardcore.droidfs.FileShare
 import sushi.hardcore.droidfs.file_viewers.*
 import sushi.hardcore.droidfs.filesystems.EncryptedVolume
 import sushi.hardcore.droidfs.filesystems.Stat
@@ -69,6 +71,9 @@ open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listene
     private lateinit var numberOfFilesText: TextView
     private lateinit var numberOfFoldersText: TextView
     private lateinit var totalSizeText: TextView
+    protected val fileShare by lazy {
+        FileShare(encryptedVolume, this)
+    }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -187,12 +192,27 @@ open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listene
         startActivity(intent)
     }
 
-    private fun openWithExternalApp(fullPath: String) {
+    private fun openWithExternalApp(path: String, size: Long) {
         app.isStartingExternalApp = true
-        ExternalProvider.open(this, theme, encryptedVolume, fullPath)
+        object : LoadingTask<Intent?>(this, theme, R.string.loading_msg_export) {
+            override suspend fun doTask(): Intent? {
+                return fileShare.openWith(path, size)
+            }
+        }.startTask(lifecycleScope) { openIntent ->
+            if (openIntent == null) {
+                CustomAlertDialogBuilder(this, theme)
+                    .setTitle(R.string.error)
+                    .setMessage(getString(R.string.export_failed, path))
+                    .setPositiveButton(R.string.ok, null)
+                    .show()
+            } else {
+                startActivity(openIntent)
+            }
+        }
     }
 
-    private fun showOpenAsDialog(path: String) {
+    private fun showOpenAsDialog(explorerElement: ExplorerElement) {
+        val path = explorerElement.fullPath
         val adapter = OpenAsDialogAdapter(this, usf_open)
         CustomAlertDialogBuilder(this, theme)
             .setSingleChoiceItems(adapter, -1) { dialog, which ->
@@ -203,7 +223,7 @@ open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listene
                     "pdf" -> startFileViewer(PdfViewer::class.java, path)
                     "text" -> startFileViewer(TextEditor::class.java, path)
                     "external" -> if (usf_open) {
-                        openWithExternalApp(path)
+                        openWithExternalApp(path, explorerElement.stat.size)
                     }
                 }
                 dialog.dismiss()
@@ -250,7 +270,7 @@ open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listene
                 FileTypes.isAudio(fullPath) -> {
                     startFileViewer(AudioPlayer::class.java, fullPath)
                 }
-                else -> showOpenAsDialog(fullPath)
+                else -> showOpenAsDialog(explorerElements[position])
             }
         }
         invalidateOptionsMenu()
@@ -575,22 +595,13 @@ open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listene
                 true
             }
             R.id.open_as -> {
-                showOpenAsDialog(
+                showOpenAsDialog(explorerElements[explorerAdapter.selectedItems.first()])
-                    PathUtils.pathJoin(
-                        currentDirectoryPath,
-                        explorerElements[explorerAdapter.selectedItems.first()].name
-                    )
-                )
                 true
             }
             R.id.external_open -> {
                 if (usf_open){
-                    openWithExternalApp(
+                    val explorerElement = explorerElements[explorerAdapter.selectedItems.first()]
-                        PathUtils.pathJoin(
+                    openWithExternalApp(explorerElement.fullPath, explorerElement.stat.size)
-                            currentDirectoryPath,
-                            explorerElements[explorerAdapter.selectedItems.first()].name
-                        )
-                    )
                     unselectAll()
                 }
                 true
@@ -617,7 +628,8 @@ open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listene
     override fun onResume() {
         super.onResume()
         if (app.isStartingExternalApp) {
-            ExternalProvider.removeFilesAsync(this)
+            MemoryFileProvider.wipe()
+            DiskFileProvider.wipe()
         }
         if (encryptedVolume.isClosed()) {
             finish()

app/src/main/java/sushi/hardcore/droidfs/explorers/ExplorerActivity.kt

@@ -17,7 +17,6 @@ import sushi.hardcore.droidfs.LoadingTask
 import sushi.hardcore.droidfs.MainActivity
 import sushi.hardcore.droidfs.R
 import sushi.hardcore.droidfs.adapters.IconTextDialogAdapter
-import sushi.hardcore.droidfs.content_providers.ExternalProvider
 import sushi.hardcore.droidfs.file_operations.OperationFile
 import sushi.hardcore.droidfs.filesystems.Stat
 import sushi.hardcore.droidfs.util.PathUtils
@@ -386,12 +385,27 @@ class ExplorerActivity : BaseExplorerActivity() {
                 true
             }
             R.id.share -> {
-                val paths: MutableList<String> = ArrayList()
-                for (i in explorerAdapter.selectedItems) {
-                    paths.add(explorerElements[i].fullPath)
-                }
                 app.isStartingExternalApp = true
-                ExternalProvider.share(this, theme, encryptedVolume, paths)
+                val files = explorerAdapter.selectedItems.map { i ->
+                    explorerElements[i].let {
+                        Pair(it.fullPath, it.stat.size)
+                    }
+                }
+                object : LoadingTask<Pair<Intent?, String?>>(this, theme, R.string.loading_msg_export) {
+                    override suspend fun doTask(): Pair<Intent?, String?> {
+                        return fileShare.share(files)
+                    }
+                }.startTask(lifecycleScope) { (intent, failedItem) ->
+                    if (intent == null) {
+                        CustomAlertDialogBuilder(this, theme)
+                            .setTitle(R.string.error)
+                            .setMessage(getString(R.string.export_failed, failedItem))
+                            .setPositiveButton(R.string.ok, null)
+                            .show()
+                    } else {
+                        startActivity(Intent.createChooser(intent, getString(R.string.share_chooser)))
+                    }
+                }
                 unselectAll()
                 true
             }

app/src/main/java/sushi/hardcore/droidfs/util/Version.kt

@@ -0,0 +1,27 @@
+package sushi.hardcore.droidfs.util
+
+import java.lang.Integer.max
+
+class Version(inputVersion: String) : Comparable<Version> {
+    private var version: String
+
+    init {
+        val regex = "[0-9]+(\\.[0-9]+)*".toRegex()
+        val match = regex.find(inputVersion) ?: throw IllegalArgumentException("Invalid version format")
+        version = match.value
+    }
+
+    fun split() = version.split(".").toTypedArray()
+
+    override fun compareTo(other: Version) =
+        (split() to other.split()).let { (split, otherSplit) ->
+            val length = max(split.size, otherSplit.size)
+            for (i in 0 until length) {
+                val part = if (i < split.size) split[i].toInt() else 0
+                val otherPart = if (i < otherSplit.size) otherSplit[i].toInt() else 0
+                if (part < otherPart) return -1
+                if (part > otherPart) return 1
+            }
+            0
+        }
+}

app/src/main/native/memfile.cpp

@@ -0,0 +1,24 @@
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <jni.h>
+
+extern "C"
+JNIEXPORT jint JNICALL
+Java_sushi_hardcore_droidfs_MemFile_00024Companion_createMemFile(JNIEnv *env, jobject thiz, jstring jname,
+                                                  jlong size) {
+    const char* name = env->GetStringUTFChars(jname, nullptr);
+    int fd = syscall(SYS_memfd_create, name, MFD_CLOEXEC);
+    if (fd < 0) return fd;
+    if (ftruncate64(fd, size) == -1) {
+        close(fd);
+        return -1;
+    }
+    return fd;
+}
+
+extern "C"
+JNIEXPORT void JNICALL
+Java_sushi_hardcore_droidfs_MemFile_close(JNIEnv *env, jobject thiz, jint fd) {
+    close(fd);
+}