Make TunnelManager the point of asynchronicity

Signed-off-by: Samuel Holland <samuel@sholland.org>

6 files changed, 125 insertions, 154 deletions

diff --git a/app/src/main/java/com/wireguard/android/Application.java b/app/src/main/java/com/wireguard/android/Application.java
index c0fb046a..e8d0d7db 100644
--- a/app/src/main/java/com/wireguard/android/Application.java
+++ b/app/src/main/java/com/wireguard/android/Application.java
@@ -81,17 +81,15 @@ public class Application extends android.app.Application {
 
         @ApplicationScope
         @Provides
-        public static Backend getBackend(final AsyncWorker asyncWorker,
-                                         @ApplicationContext final Context context,
+        public static Backend getBackend(@ApplicationContext final Context context,
                                          final RootShell rootShell) {
-            return new WgQuickBackend(asyncWorker, context, rootShell);
+            return new WgQuickBackend(context, rootShell);
         }
 
         @ApplicationScope
         @Provides
-        public static ConfigStore getConfigStore(final AsyncWorker asyncWorker,
-                                                 @ApplicationContext final Context context) {
-            return new FileConfigStore(asyncWorker, context);
+        public static ConfigStore getConfigStore(@ApplicationContext final Context context) {
+            return new FileConfigStore(context);
         }
 
 
diff --git a/app/src/main/java/com/wireguard/android/backend/Backend.java b/app/src/main/java/com/wireguard/android/backend/Backend.java
index fc174be1..fb71a3d3 100644
--- a/app/src/main/java/com/wireguard/android/backend/Backend.java
+++ b/app/src/main/java/com/wireguard/android/backend/Backend.java
@@ -7,61 +7,53 @@ import com.wireguard.config.Config;
 
 import java.util.Set;
 
-import java9.util.concurrent.CompletionStage;
-
 /**
  * Interface for implementations of the WireGuard secure network tunnel.
  */
 
 public interface Backend {
     /**
-     * Update the volatile configuration of a running tunnel, asynchronously, and return the
-     * resulting configuration. If the tunnel is not up, return the configuration that would result
-     * (if known), or else simply return the given configuration.
+     * Update the volatile configuration of a running tunnel and return the resulting configuration.
+     * If the tunnel is not up, return the configuration that would result (if known), or else
+     * simply return the given configuration.
      *
      * @param tunnel The tunnel to apply the configuration to.
      * @param config The new configuration for this tunnel.
-     * @return A future completed when the configuration of the tunnel has been updated, and the new
-     * volatile configuration has been determined. This future will always be completed on the main
-     * thread.
+     * @return The updated configuration of the tunnel.
      */
-    CompletionStage<Config> applyConfig(Tunnel tunnel, Config config);
+    Config applyConfig(Tunnel tunnel, Config config) throws Exception;
 
     /**
      * Enumerate the names of currently-running tunnels.
      *
-     * @return A future completed when the set of running tunnel names is available. This future
-     * will always be completed on the main thread.
+     * @return The set of running tunnel names.
      */
-    CompletionStage<Set<String>> enumerate();
+    Set<String> enumerate() throws Exception;
 
     /**
-     * Get the actual state of a tunnel, asynchronously.
+     * Get the actual state of a tunnel.
      *
      * @param tunnel The tunnel to examine the state of.
-     * @return A future completed when the state of the tunnel has been determined. This future will
-     * always be completed on the main thread.
+     * @return The state of the tunnel.
      */
-    CompletionStage<State> getState(Tunnel tunnel);
+    State getState(Tunnel tunnel) throws Exception;
 
     /**
-     * Get statistics about traffic and errors on this tunnel, asynchronously. If the tunnel is not
-     * running, the statistics object will be filled with zero values.
+     * Get statistics about traffic and errors on this tunnel. If the tunnel is not running, the
+     * statistics object will be filled with zero values.
      *
      * @param tunnel The tunnel to retrieve statistics for.
-     * @return A future completed when statistics for the tunnel are available. This future will
-     * always be completed on the main thread.
+     * @return The statistics for the tunnel.
      */
-    CompletionStage<Statistics> getStatistics(Tunnel tunnel);
+    Statistics getStatistics(Tunnel tunnel) throws Exception;
 
     /**
-     * Set the state of a tunnel, asynchronously.
+     * Set the state of a tunnel.
      *
      * @param tunnel The tunnel to control the state of.
      * @param state  The new state for this tunnel. Must be {@code UP}, {@code DOWN}, or
      *               {@code TOGGLE}.
-     * @return A future completed when the state of the tunnel has changed, containing the new state
-     * of the tunnel. This future will always be completed on the main thread.
+     * @return The updated state of the tunnel.
      */
-    CompletionStage<State> setState(Tunnel tunnel, State state);
+    State setState(Tunnel tunnel, State state) throws Exception;
 }
diff --git a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
index 656cfa9c..6703f735 100644
--- a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
+++ b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
@@ -6,7 +6,6 @@ import android.util.Log;
 import com.wireguard.android.model.Tunnel;
 import com.wireguard.android.model.Tunnel.State;
 import com.wireguard.android.model.Tunnel.Statistics;
-import com.wireguard.android.util.AsyncWorker;
 import com.wireguard.android.util.RootShell;
 import com.wireguard.config.Config;
 
@@ -17,25 +16,20 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 
-import java9.util.concurrent.CompletableFuture;
-import java9.util.concurrent.CompletionStage;
 import java9.util.stream.Collectors;
 import java9.util.stream.Stream;
 
 /**
- * Created by samuel on 12/19/17.
+ * WireGuard backend that uses {@code wg-quick} to implement tunnel configuration.
  */
 
 public final class WgQuickBackend implements Backend {
     private static final String TAG = WgQuickBackend.class.getSimpleName();
 
-    private final AsyncWorker asyncWorker;
     private final Context context;
     private final RootShell rootShell;
 
-    public WgQuickBackend(final AsyncWorker asyncWorker, final Context context,
-                          final RootShell rootShell) {
-        this.asyncWorker = asyncWorker;
+    public WgQuickBackend(final Context context, final RootShell rootShell) {
         this.context = context;
         this.rootShell = rootShell;
     }
@@ -49,47 +43,47 @@ public final class WgQuickBackend implements Backend {
     }
 
     @Override
-    public CompletionStage<Config> applyConfig(final Tunnel tunnel, final Config config) {
+    public Config applyConfig(final Tunnel tunnel, final Config config) {
         if (tunnel.getState() == State.UP)
-            return CompletableFuture.failedFuture(new UnsupportedOperationException("stub"));
-        return CompletableFuture.completedFuture(config);
+            throw new UnsupportedOperationException("Not implemented");
+        return config;
     }
 
     @Override
-    public CompletionStage<Set<String>> enumerate() {
-        return asyncWorker.supplyAsync(() -> {
-            final List<String> output = new LinkedList<>();
-            // Don't throw an exception here or nothing will show up in the UI.
-            if (rootShell.run(output, "wg show interfaces") != 0 || output.isEmpty())
-                return Collections.emptySet();
-            // wg puts all interface names on the same line. Split them into separate elements.
-            return Stream.of(output.get(0).split(" "))
-                    .collect(Collectors.toUnmodifiableSet());
-        });
+    public Set<String> enumerate() {
+        final List<String> output = new LinkedList<>();
+        // Don't throw an exception here or nothing will show up in the UI.
+        if (rootShell.run(output, "wg show interfaces") != 0 || output.isEmpty())
+            return Collections.emptySet();
+        // wg puts all interface names on the same line. Split them into separate elements.
+        return Stream.of(output.get(0).split(" ")).collect(Collectors.toUnmodifiableSet());
     }
 
     @Override
-    public CompletionStage<State> getState(final Tunnel tunnel) {
+    public State getState(final Tunnel tunnel) {
         Log.v(TAG, "Requested state for tunnel " + tunnel.getName());
-        return enumerate().thenApply(set -> set.contains(tunnel.getName()) ? State.UP : State.DOWN);
+        return enumerate().contains(tunnel.getName()) ? State.UP : State.DOWN;
     }
 
     @Override
-    public CompletionStage<Statistics> getStatistics(final Tunnel tunnel) {
-        return CompletableFuture.completedFuture(new Statistics());
+    public Statistics getStatistics(final Tunnel tunnel) {
+        return new Statistics();
     }
 
     @Override
-    public CompletionStage<State> setState(final Tunnel tunnel, final State state) {
+    public State setState(final Tunnel tunnel, final State state) throws IOException {
         Log.v(TAG, "Requested state change to " + state + " for tunnel " + tunnel.getName());
-        return tunnel.getStateAsync().thenCompose(currentState -> asyncWorker.supplyAsync(() -> {
-            final String stateName = resolveState(currentState, state).name().toLowerCase();
-            final File file = new File(context.getFilesDir(), tunnel.getName() + ".conf");
-            final String path = file.getAbsolutePath();
+        final State originalState = getState(tunnel);
+        final State resolvedState = resolveState(originalState, state);
+        if (resolvedState == State.UP) {
             // FIXME: Assumes file layout from FileConfigStore. Use a temporary file.
-            if (rootShell.run(null, String.format("wg-quick %s '%s'", stateName, path)) != 0)
+            final File file = new File(context.getFilesDir(), tunnel.getName() + ".conf");
+            if (rootShell.run(null, String.format("wg-quick up '%s'", file.getAbsolutePath())) != 0)
+                throw new IOException("wg-quick failed");
+        } else {
+            if (rootShell.run(null, String.format("wg-quick down '%s'", tunnel.getName())) != 0)
                 throw new IOException("wg-quick failed");
-            return tunnel;
-        })).thenCompose(this::getState);
+        }
+        return getState(tunnel);
     }
 }
diff --git a/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java b/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java
index 19bb6bf5..c1f5b4e3 100644
--- a/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java
+++ b/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java
@@ -4,8 +4,6 @@ import com.wireguard.config.Config;
 
 import java.util.Set;
 
-import java9.util.concurrent.CompletionStage;
-
 /**
  * Interface for persistent storage providers for WireGuard configurations.
  */
@@ -17,39 +15,32 @@ public interface ConfigStore {
      *
      * @param name   The name of the tunnel to create.
      * @param config Configuration for the new tunnel.
-     * @return A future completed when the tunnel and its configuration have been saved to
-     * persistent storage. This future encapsulates the configuration that was actually saved to
-     * persistent storage. This future will always be completed on the main thread.
+     * @return The configuration that was actually saved to persistent storage.
      */
-    CompletionStage<Config> create(final String name, final Config config);
+    Config create(final String name, final Config config) throws Exception;
 
     /**
      * Delete a persistent tunnel.
      *
      * @param name The name of the tunnel to delete.
-     * @return A future completed when the tunnel and its configuration have been deleted. This
-     * future will always be completed on the main thread.
      */
-    CompletionStage<Void> delete(final String name);
+    void delete(final String name) throws Exception;
 
     /**
      * Enumerate the names of tunnels present in persistent storage.
      *
-     * @return A future completed when the set of present tunnel names is available. This future
-     * will always be completed on the main thread.
+     * @return The set of present tunnel names.
      */
-    CompletionStage<Set<String>> enumerate();
+    Set<String> enumerate() throws Exception;
 
     /**
      * Load the configuration for the tunnel given by {@code name}.
      *
      * @param name The identifier for the configuration in persistent storage (i.e. the name of the
      *             tunnel).
-     * @return A future completed when an in-memory representation of the configuration is
-     * available. This future encapsulates the configuration loaded from persistent storage. This
-     * future will always be completed on the main thread.
+     * @return An in-memory representation of the configuration loaded from persistent storage.
      */
-    CompletionStage<Config> load(final String name);
+    Config load(final String name) throws Exception;
 
     /**
      * Save the configuration for an existing tunnel given by {@code name}.
@@ -57,9 +48,7 @@ public interface ConfigStore {
      * @param name   The identifier for the configuration in persistent storage (i.e. the name of
      *               the tunnel).
      * @param config An updated configuration object for the tunnel.
-     * @return A future completed when the configuration has been saved to persistent storage. This
-     * future encapsulates the configuration that was actually saved to persistent storage. This
-     * future will always be completed on the main thread.
+     * @return The configuration that was actually saved to persistent storage.
      */
-    CompletionStage<Config> save(final String name, final Config config);
+    Config save(final String name, final Config config) throws Exception;
 }
diff --git a/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java b/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java
index 099bc0d3..30b2fba8 100644
--- a/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java
+++ b/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java
@@ -4,7 +4,6 @@ import android.content.Context;
 import android.util.Log;
 
 import com.wireguard.android.Application.ApplicationContext;
-import com.wireguard.android.util.AsyncWorker;
 import com.wireguard.config.Config;
 
 import java.io.File;
@@ -14,56 +13,48 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Set;
 
-import java9.util.concurrent.CompletionStage;
 import java9.util.stream.Collectors;
 import java9.util.stream.Stream;
 
 /**
- * Created by samuel on 12/28/17.
+ * Configuration store that uses a {@code wg-quick}-style file for each configured tunnel.
  */
 
 public final class FileConfigStore implements ConfigStore {
     private static final String TAG = FileConfigStore.class.getSimpleName();
 
-    private final AsyncWorker asyncWorker;
     private final Context context;
 
-    public FileConfigStore(final AsyncWorker asyncWorker,
-                           @ApplicationContext final Context context) {
-        this.asyncWorker = asyncWorker;
+    public FileConfigStore(@ApplicationContext final Context context) {
         this.context = context;
     }
 
     @Override
-    public CompletionStage<Config> create(final String name, final Config config) {
-        return asyncWorker.supplyAsync(() -> {
-            final File file = fileFor(name);
-            if (!file.createNewFile()) {
-                final String message = "Configuration file " + file.getName() + " already exists";
-                throw new IllegalStateException(message);
-            }
-            try (FileOutputStream stream = new FileOutputStream(file, false)) {
-                stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
-                return config;
-            }
-        });
+    public Config create(final String name, final Config config) throws IOException {
+        final File file = fileFor(name);
+        if (!file.createNewFile()) {
+            final String message = "Configuration file " + file.getName() + " already exists";
+            throw new IllegalStateException(message);
+        }
+        try (FileOutputStream stream = new FileOutputStream(file, false)) {
+            stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
+            return config;
+        }
     }
 
     @Override
-    public CompletionStage<Void> delete(final String name) {
-        return asyncWorker.runAsync(() -> {
-            final File file = fileFor(name);
-            if (!file.delete())
-                throw new IOException("Cannot delete configuration file " + file.getName());
-        });
+    public void delete(final String name) throws IOException {
+        final File file = fileFor(name);
+        if (!file.delete())
+            throw new IOException("Cannot delete configuration file " + file.getName());
     }
 
     @Override
-    public CompletionStage<Set<String>> enumerate() {
-        return asyncWorker.supplyAsync(() -> Stream.of(context.fileList())
+    public Set<String> enumerate() {
+        return Stream.of(context.fileList())
                 .filter(name -> name.endsWith(".conf"))
                 .map(name -> name.substring(0, name.length() - ".conf".length()))
-                .collect(Collectors.toUnmodifiableSet()));
+                .collect(Collectors.toUnmodifiableSet());
     }
 
     private File fileFor(final String name) {
@@ -71,28 +62,23 @@ public final class FileConfigStore implements ConfigStore {
     }
 
     @Override
-    public CompletionStage<Config> load(final String name) {
-        return asyncWorker.supplyAsync(() -> {
-            try (FileInputStream stream = new FileInputStream(fileFor(name))) {
-                return Config.from(stream);
-            }
-        });
+    public Config load(final String name) throws IOException {
+        try (FileInputStream stream = new FileInputStream(fileFor(name))) {
+            return Config.from(stream);
+        }
     }
 
     @Override
-    public CompletionStage<Config> save(final String name, final Config config) {
+    public Config save(final String name, final Config config) throws IOException {
         Log.d(TAG, "Requested save config for tunnel " + name);
-        return asyncWorker.supplyAsync(() -> {
-            final File file = fileFor(name);
-            if (!file.isFile()) {
-                final String message = "Configuration file " + file.getName() + " not found";
-                throw new IllegalStateException(message);
-            }
-            try (FileOutputStream stream = new FileOutputStream(file, false)) {
-                Log.d(TAG, "Writing out config for tunnel " + name);
-                stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
-                return config;
-            }
-        });
+        final File file = fileFor(name);
+        if (!file.isFile()) {
+            final String message = "Configuration file " + file.getName() + " not found";
+            throw new IllegalStateException(message);
+        }
+        try (FileOutputStream stream = new FileOutputStream(file, false)) {
+            stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
+            return config;
+        }
     }
 }
diff --git a/app/src/main/java/com/wireguard/android/model/TunnelManager.java b/app/src/main/java/com/wireguard/android/model/TunnelManager.java
index 22bf1190..e802c152 100644
--- a/app/src/main/java/com/wireguard/android/model/TunnelManager.java
+++ b/app/src/main/java/com/wireguard/android/model/TunnelManager.java
@@ -1,12 +1,14 @@
 package com.wireguard.android.model;
 
 import android.content.SharedPreferences;
+import android.support.annotation.NonNull;
 
 import com.wireguard.android.Application.ApplicationScope;
 import com.wireguard.android.backend.Backend;
 import com.wireguard.android.configStore.ConfigStore;
 import com.wireguard.android.model.Tunnel.State;
 import com.wireguard.android.model.Tunnel.Statistics;
+import com.wireguard.android.util.AsyncWorker;
 import com.wireguard.android.util.ExceptionLoggers;
 import com.wireguard.android.util.ObservableKeyedList;
 import com.wireguard.android.util.ObservableSortedKeyedArrayList;
@@ -38,6 +40,7 @@ public final class TunnelManager {
     private static final String KEY_RUNNING_TUNNELS = "enabled_configs";
     private static final String TAG = TunnelManager.class.getSimpleName();
 
+    private final AsyncWorker asyncWorker;
     private final Backend backend;
     private final ConfigStore configStore;
     private final SharedPreferences preferences;
@@ -45,45 +48,55 @@ public final class TunnelManager {
             new ObservableSortedKeyedArrayList<>(COMPARATOR);
 
     @Inject
-    public TunnelManager(final Backend backend, final ConfigStore configStore,
-                         final SharedPreferences preferences) {
+    public TunnelManager(final AsyncWorker asyncWorker, final Backend backend,
+                         final ConfigStore configStore, final SharedPreferences preferences) {
+        this.asyncWorker = asyncWorker;
         this.backend = backend;
         this.configStore = configStore;
         this.preferences = preferences;
     }
 
-    private Tunnel add(final String name, final Config config, final State state) {
+    private Tunnel addToList(final String name, final Config config, final State state) {
         final Tunnel tunnel = new Tunnel(this, name, config, state);
         tunnels.add(tunnel);
         return tunnel;
     }
 
-    public CompletionStage<Tunnel> create(final String name, final Config config) {
+    public CompletionStage<Tunnel> create(@NonNull final String name, final Config config) {
         if (!Tunnel.isNameValid(name))
             return CompletableFuture.failedFuture(new IllegalArgumentException("Invalid name"));
         if (tunnels.containsKey(name)) {
             final String message = "Tunnel " + name + " already exists";
             return CompletableFuture.failedFuture(new IllegalArgumentException(message));
         }
-        return configStore.create(name, config).thenApply(cfg -> add(name, cfg, State.DOWN));
+        return asyncWorker.supplyAsync(() -> configStore.create(name, config))
+                .thenApply(savedConfig -> addToList(name, savedConfig, State.DOWN));
     }
 
     CompletionStage<Void> delete(final Tunnel tunnel) {
-        return setTunnelState(tunnel, State.DOWN)
-                .thenCompose(x -> configStore.delete(tunnel.getName()))
-                .thenAccept(x -> remove(tunnel));
+        return asyncWorker.runAsync(() -> {
+            backend.setState(tunnel, State.DOWN);
+            configStore.delete(tunnel.getName());
+        }).thenAccept(x -> {
+            if (tunnel.getName().equals(preferences.getString(KEY_PRIMARY_TUNNEL, null)))
+                preferences.edit().remove(KEY_PRIMARY_TUNNEL).apply();
+            tunnels.remove(tunnel);
+        });
     }
 
     CompletionStage<Config> getTunnelConfig(final Tunnel tunnel) {
-        return configStore.load(tunnel.getName()).thenApply(tunnel::onConfigChanged);
+        return asyncWorker.supplyAsync(() -> configStore.load(tunnel.getName()))
+                .thenApply(tunnel::onConfigChanged);
     }
 
     CompletionStage<State> getTunnelState(final Tunnel tunnel) {
-        return backend.getState(tunnel).thenApply(tunnel::onStateChanged);
+        return asyncWorker.supplyAsync(() -> backend.getState(tunnel))
+                .thenApply(tunnel::onStateChanged);
     }
 
     CompletionStage<Statistics> getTunnelStatistics(final Tunnel tunnel) {
-        return backend.getStatistics(tunnel).thenApply(tunnel::onStatisticsChanged);
+        return asyncWorker.supplyAsync(() -> backend.getStatistics(tunnel))
+                .thenApply(tunnel::onStatisticsChanged);
     }
 
     public ObservableKeyedList<String, Tunnel> getTunnels() {
@@ -91,16 +104,14 @@ public final class TunnelManager {
     }
 
     public void onCreate() {
-        configStore.enumerate().thenAcceptBoth(backend.enumerate(), (names, running) -> {
-            for (final String name : names)
-                add(name, null, running.contains(name) ? State.UP : State.DOWN);
-        }).whenComplete(ExceptionLoggers.E);
+        asyncWorker.supplyAsync(configStore::enumerate)
+                .thenAcceptBoth(asyncWorker.supplyAsync(backend::enumerate), this::onTunnelsLoaded)
+                .whenComplete(ExceptionLoggers.E);
     }
 
-    private void remove(final Tunnel tunnel) {
-        if (tunnel.getName().equals(preferences.getString(KEY_PRIMARY_TUNNEL, null)))
-            preferences.edit().remove(KEY_PRIMARY_TUNNEL).apply();
-        tunnels.remove(tunnel);
+    private void onTunnelsLoaded(final Set<String> present, final Set<String> running) {
+        for (final String name : present)
+            addToList(name, null, running.contains(name) ? State.UP : State.DOWN);
     }
 
     public CompletionStage<Void> restoreState() {
@@ -125,13 +136,14 @@ public final class TunnelManager {
     }
 
     CompletionStage<Config> setTunnelConfig(final Tunnel tunnel, final Config config) {
-        return backend.applyConfig(tunnel, config)
-                .thenCompose(cfg -> configStore.save(tunnel.getName(), cfg))
-                .thenApply(tunnel::onConfigChanged);
+        return asyncWorker.supplyAsync(() -> {
+            final Config appliedConfig = backend.applyConfig(tunnel, config);
+            return configStore.save(tunnel.getName(), appliedConfig);
+        }).thenApply(tunnel::onConfigChanged);
     }
 
     CompletionStage<State> setTunnelState(final Tunnel tunnel, final State state) {
-        return backend.setState(tunnel, state)
+        return asyncWorker.supplyAsync(() -> backend.setState(tunnel, state))
                 .thenApply(tunnel::onStateChanged);
     }
 }