Android: Add specialized content provider implementation of DoFileSearch

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/main/MainPresenter.java

@@ -130,8 +130,8 @@ public final class MainPresenter
 
     boolean recursive = BooleanSetting.MAIN_RECURSIVE_ISO_PATHS.getBooleanGlobal();
     String[] childNames = ContentHandler.getChildNames(uri, recursive);
-    if (Arrays.stream(childNames).noneMatch((name) ->
-            FileBrowserHelper.GAME_EXTENSIONS.contains(FileBrowserHelper.getExtension(name))))
+    if (Arrays.stream(childNames).noneMatch((name) -> FileBrowserHelper.GAME_EXTENSIONS.contains(
+            FileBrowserHelper.getExtension(name, false))))
     {
       AlertDialog.Builder builder = new AlertDialog.Builder(mContext, R.style.DolphinDialogBase);
       builder.setMessage(mContext.getString(R.string.wrong_file_extension_in_directory,

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/ContentHandler.java

@@ -15,7 +15,9 @@ import org.dolphinemu.dolphinemu.DolphinApplication;
 
 import java.io.FileNotFoundException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
+import java.util.function.Predicate;
 
 /*
   We use a lot of "catch (Exception e)" in this class. This is for two reasons:
@@ -184,34 +186,94 @@ public class ContentHandler
   public static String[] getChildNames(@NonNull Uri uri, boolean recursive)
   {
     ArrayList<String> result = new ArrayList<>();
-    getChildNames(uri, DocumentsContract.getDocumentId(treeToDocument(uri)), recursive, result);
+
+    ForEachChildCallback callback = new ForEachChildCallback()
+    {
+      @Override
+      public void run(String displayName, String documentId, boolean isDirectory)
+      {
+        if (recursive && isDirectory)
+        {
+          forEachChild(uri, documentId, this);
+        }
+        else
+        {
+          result.add(displayName);
+        }
+      }
+    };
+
+    forEachChild(uri, DocumentsContract.getDocumentId(treeToDocument(uri)), callback);
+
     return result.toArray(new String[0]);
   }
 
-  private static void getChildNames(@NonNull Uri uri, @NonNull String documentId, boolean recursive,
-          List<String> resultOut)
+  @NonNull @Keep
+  public static String[] doFileSearch(@NonNull String directory, @NonNull String[] extensions,
+          boolean recursive)
+  {
+    ArrayList<String> result = new ArrayList<>();
+
+    try
+    {
+      Uri uri = unmangle(directory);
+      String documentId = DocumentsContract.getDocumentId(treeToDocument(uri));
+      boolean acceptAll = extensions.length == 0;
+      Predicate<String> extensionCheck = (displayName) ->
+      {
+        String extension = FileBrowserHelper.getExtension(displayName, true);
+        return extension != null && Arrays.stream(extensions).anyMatch(extension::equalsIgnoreCase);
+      };
+      doFileSearch(uri, directory, documentId, recursive, result, acceptAll, extensionCheck);
+    }
+    catch (Exception ignored)
+    {
+    }
+
+    return result.toArray(new String[0]);
+  }
+
+  private static void doFileSearch(@NonNull Uri baseUri, @NonNull String path,
+          @NonNull String documentId, boolean recursive, @NonNull List<String> resultOut,
+          boolean acceptAll, @NonNull Predicate<String> extensionCheck)
+  {
+    forEachChild(baseUri, documentId, (displayName, childDocumentId, isDirectory) ->
+    {
+      String childPath = path + '/' + displayName;
+      if (acceptAll || (!isDirectory && extensionCheck.test(displayName)))
+      {
+        resultOut.add(childPath);
+      }
+      if (recursive && isDirectory)
+      {
+        doFileSearch(baseUri, childPath, childDocumentId, recursive, resultOut, acceptAll,
+                extensionCheck);
+      }
+    });
+  }
+
+  private interface ForEachChildCallback
+  {
+    void run(String displayName, String documentId, boolean isDirectory);
+  }
+
+  private static void forEachChild(@NonNull Uri uri, @NonNull String documentId,
+          @NonNull ForEachChildCallback callback)
   {
     try
     {
       Uri childrenUri = DocumentsContract.buildChildDocumentsUriUsingTree(uri, documentId);
 
-      final String[] projection = recursive ? new String[]{Document.COLUMN_DISPLAY_NAME,
-              Document.COLUMN_MIME_TYPE, Document.COLUMN_DOCUMENT_ID} :
-              new String[]{Document.COLUMN_DISPLAY_NAME};
+      final String[] projection = new String[]{Document.COLUMN_DISPLAY_NAME,
+              Document.COLUMN_MIME_TYPE, Document.COLUMN_DOCUMENT_ID};
       try (Cursor cursor = getContentResolver().query(childrenUri, projection, null, null, null))
       {
         if (cursor != null)
         {
           while (cursor.moveToNext())
           {
-            if (recursive && Document.MIME_TYPE_DIR.equals(cursor.getString(1)))
-            {
-              getChildNames(uri, cursor.getString(2), recursive, resultOut);
-            }
-            else
-            {
-              resultOut.add(cursor.getString(0));
-            }
+            callback.run(cursor.getString(0), cursor.getString(2),
+                    Document.MIME_TYPE_DIR.equals(cursor.getString(1)));
           }
         }
       }

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/FileBrowserHelper.java

@@ -88,10 +88,10 @@ public final class FileBrowserHelper
 
     String path = uri.getLastPathSegment();
     if (path != null)
-      extension = getExtension(new File(path).getName());
+      extension = getExtension(new File(path).getName(), false);
 
     if (extension == null)
-      extension = getExtension(ContentHandler.getDisplayName(uri));
+      extension = getExtension(ContentHandler.getDisplayName(uri), false);
 
     if (extension != null && validExtensions.contains(extension))
     {
@@ -122,13 +122,15 @@ public final class FileBrowserHelper
   }
 
   @Nullable
-  public static String getExtension(@Nullable String fileName)
+  public static String getExtension(@Nullable String fileName, boolean includeDot)
   {
     if (fileName == null)
       return null;
 
     int dotIndex = fileName.lastIndexOf(".");
-    return dotIndex != -1 ? fileName.substring(dotIndex + 1) : null;
+    if (dotIndex == -1)
+      return null;
+    return fileName.substring(dotIndex + (includeDot ? 0 : 1));
   }
 
   public static String setToSortedDelimitedString(Set<String> set)

Source/Android/jni/AndroidCommon/AndroidCommon.cpp

@@ -44,6 +44,14 @@ std::vector<std::string> JStringArrayToVector(JNIEnv* env, jobjectArray array)
   return result;
 }
 
+jobjectArray JStringArrayFromVector(JNIEnv* env, std::vector<std::string> vector)
+{
+  jobjectArray result = env->NewObjectArray(vector.size(), IDCache::GetStringClass(), nullptr);
+  for (jsize i = 0; i < vector.size(); ++i)
+    env->SetObjectArrayElement(result, i, ToJString(env, vector[i]));
+  return result;
+}
+
 bool IsPathAndroidContent(const std::string& uri)
 {
   return StringBeginsWith(uri, "content://");
@@ -130,6 +138,17 @@ std::vector<std::string> GetAndroidContentChildNames(const std::string& uri)
   return JStringArrayToVector(env, reinterpret_cast<jobjectArray>(children));
 }
 
+std::vector<std::string> DoFileSearchAndroidContent(const std::string& directory,
+                                                    const std::vector<std::string>& extensions,
+                                                    bool recursive)
+{
+  JNIEnv* env = IDCache::GetEnvForThread();
+  jobject result = env->CallStaticObjectMethod(
+      IDCache::GetContentHandlerClass(), IDCache::GetContentHandlerDoFileSearch(),
+      ToJString(env, directory), JStringArrayFromVector(env, extensions), recursive);
+  return JStringArrayToVector(env, reinterpret_cast<jobjectArray>(result));
+}
+
 int GetNetworkIpAddress()
 {
   JNIEnv* env = IDCache::GetEnvForThread();

Source/Android/jni/AndroidCommon/AndroidCommon.h

@@ -38,6 +38,10 @@ std::string GetAndroidContentDisplayName(const std::string& uri);
 // Returns the display names of all children of a directory, non-recursively.
 std::vector<std::string> GetAndroidContentChildNames(const std::string& uri);
 
+std::vector<std::string> DoFileSearchAndroidContent(const std::string& directory,
+                                                    const std::vector<std::string>& extensions,
+                                                    bool recursive);
+
 int GetNetworkIpAddress();
 int GetNetworkPrefixLength();
 int GetNetworkGateway();

Source/Android/jni/AndroidCommon/IDCache.cpp

@@ -10,6 +10,8 @@ static constexpr jint JNI_VERSION = JNI_VERSION_1_6;
 
 static JavaVM* s_java_vm;
 
+static jclass s_string_class;
+
 static jclass s_native_library_class;
 static jmethodID s_display_alert_msg;
 static jmethodID s_do_rumble;
@@ -47,6 +49,7 @@ static jmethodID s_content_handler_delete;
 static jmethodID s_content_handler_get_size_and_is_directory;
 static jmethodID s_content_handler_get_display_name;
 static jmethodID s_content_handler_get_child_names;
+static jmethodID s_content_handler_do_file_search;
 
 static jclass s_network_helper_class;
 static jmethodID s_network_helper_get_network_ip_address;
@@ -78,6 +81,11 @@ JNIEnv* GetEnvForThread()
   return owned.env;
 }
 
+jclass GetStringClass()
+{
+  return s_string_class;
+}
+
 jclass GetNativeLibraryClass()
 {
   return s_native_library_class;
@@ -228,6 +236,11 @@ jmethodID GetContentHandlerGetChildNames()
   return s_content_handler_get_child_names;
 }
 
+jmethodID GetContentHandlerDoFileSearch()
+{
+  return s_content_handler_do_file_search;
+}
+
 jclass GetNetworkHelperClass()
 {
   return s_network_helper_class;
@@ -262,6 +275,9 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved)
   if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION) != JNI_OK)
     return JNI_ERR;
 
+  const jclass string_class = env->FindClass("java/lang/String");
+  s_string_class = reinterpret_cast<jclass>(env->NewGlobalRef(string_class));
+
   const jclass native_library_class = env->FindClass("org/dolphinemu/dolphinemu/NativeLibrary");
   s_native_library_class = reinterpret_cast<jclass>(env->NewGlobalRef(native_library_class));
   s_display_alert_msg = env->GetStaticMethodID(s_native_library_class, "displayAlertMsg",
@@ -331,6 +347,9 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved)
       s_content_handler_class, "getDisplayName", "(Ljava/lang/String;)Ljava/lang/String;");
   s_content_handler_get_child_names = env->GetStaticMethodID(
       s_content_handler_class, "getChildNames", "(Ljava/lang/String;Z)[Ljava/lang/String;");
+  s_content_handler_do_file_search =
+      env->GetStaticMethodID(s_content_handler_class, "doFileSearch",
+                             "(Ljava/lang/String;[Ljava/lang/String;Z)[Ljava/lang/String;");
 
   const jclass network_helper_class =
       env->FindClass("org/dolphinemu/dolphinemu/utils/NetworkHelper");

Source/Android/jni/AndroidCommon/IDCache.h

@@ -10,6 +10,8 @@ namespace IDCache
 {
 JNIEnv* GetEnvForThread();
 
+jclass GetStringClass();
+
 jclass GetNativeLibraryClass();
 jmethodID GetDisplayAlertMsg();
 jmethodID GetDoRumble();
@@ -47,6 +49,7 @@ jmethodID GetContentHandlerDelete();
 jmethodID GetContentHandlerGetSizeAndIsDirectory();
 jmethodID GetContentHandlerGetDisplayName();
 jmethodID GetContentHandlerGetChildNames();
+jmethodID GetContentHandlerDoFileSearch();
 
 jclass GetNetworkHelperClass();
 jmethodID GetNetworkHelperGetNetworkIpAddress();

Source/Core/Common/FileSearch.cpp

@@ -4,6 +4,7 @@
 
 #include <algorithm>
 #include <functional>
+#include <iterator>
 
 #include "Common/CommonPaths.h"
 #include "Common/FileSearch.h"
@@ -15,6 +16,10 @@
 namespace fs = std::filesystem;
 #define HAS_STD_FILESYSTEM
 #else
+#ifdef ANDROID
+#include "jni/AndroidCommon/AndroidCommon.h"
+#endif
+
 #include <cstring>
 #include "Common/CommonFuncs.h"
 #include "Common/FileUtil.h"
@@ -24,36 +29,30 @@ namespace Common
 {
 #ifndef HAS_STD_FILESYSTEM
 
-static std::vector<std::string>
-FileSearchWithTest(const std::vector<std::string>& directories, bool recursive,
-                   std::function<bool(const File::FSTEntry&)> callback)
+static void FileSearchWithTest(const std::string& directory, bool recursive,
+                               std::vector<std::string>* result_out,
+                               std::function<bool(const File::FSTEntry&)> callback)
 {
-  std::vector<std::string> result;
-  for (const std::string& directory : directories)
-  {
-    File::FSTEntry top = File::ScanDirectoryTree(directory, recursive);
+  File::FSTEntry top = File::ScanDirectoryTree(directory, recursive);
 
-    std::function<void(File::FSTEntry&)> DoEntry;
-    DoEntry = [&](File::FSTEntry& entry) {
-      if (callback(entry))
-        result.push_back(entry.physicalName);
-      for (auto& child : entry.children)
-        DoEntry(child);
-    };
-    for (auto& child : top.children)
+  const std::function<void(File::FSTEntry&)> DoEntry = [&](File::FSTEntry& entry) {
+    if (callback(entry))
+      result_out->push_back(entry.physicalName);
+    for (auto& child : entry.children)
       DoEntry(child);
-  }
-  // remove duplicates
-  std::sort(result.begin(), result.end());
-  result.erase(std::unique(result.begin(), result.end()), result.end());
-  return result;
+  };
+
+  for (auto& child : top.children)
+    DoEntry(child);
 }
 
 std::vector<std::string> DoFileSearch(const std::vector<std::string>& directories,
                                       const std::vector<std::string>& exts, bool recursive)
 {
+  std::vector<std::string> result;
+
   bool accept_all = exts.empty();
-  return FileSearchWithTest(directories, recursive, [&](const File::FSTEntry& entry) {
+  const auto callback = [&exts, accept_all](const File::FSTEntry& entry) {
     if (accept_all)
       return true;
     if (entry.isDirectory)
@@ -63,7 +62,34 @@ std::vector<std::string> DoFileSearch(const std::vector<std::string>& directorie
       return name.length() >= ext.length() &&
              strcasecmp(name.c_str() + name.length() - ext.length(), ext.c_str()) == 0;
     });
-  });
+  };
+
+  for (const std::string& directory : directories)
+  {
+#ifdef ANDROID
+    // While File::ScanDirectoryTree (which is called in FileSearchWithTest) does handle Android
+    // content correctly, having a specialized implementation of DoFileSearch for Android content
+    // provides a much needed performance boost. Also, this specialized implementation will be
+    // required if we in the future replace the use of File::ScanDirectoryTree with std::filesystem.
+    if (IsPathAndroidContent(directory))
+    {
+      const std::vector<std::string> partial_result =
+          DoFileSearchAndroidContent(directory, exts, recursive);
+
+      result.insert(result.end(), std::make_move_iterator(partial_result.begin()),
+                    std::make_move_iterator(partial_result.end()));
+    }
+    else
+#endif
+    {
+      FileSearchWithTest(directory, recursive, &result, callback);
+    }
+  }
+
+  // remove duplicates
+  std::sort(result.begin(), result.end());
+  result.erase(std::unique(result.begin(), result.end()), result.end());
+  return result;
 }
 
 #else