android: Implement SAF support & migrate to SDK 31. (#4)

src/common/fs/fs_android.h

@@ -0,0 +1,62 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+#include <vector>
+#include <jni.h>
+
+#define ANDROID_STORAGE_FUNCTIONS(V)                                                               \
+    V(OpenContentUri, int, (const std::string& filepath, OpenMode openmode), open_content_uri,     \
+      "openContentUri", "(Ljava/lang/String;Ljava/lang/String;)I")
+
+#define ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(V)                                                 \
+    V(GetSize, std::uint64_t, get_size, CallStaticLongMethod, "getSize", "(Ljava/lang/String;)J")
+
+namespace Common::FS::Android {
+
+static JavaVM* g_jvm = nullptr;
+static jclass native_library = nullptr;
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature) F(JMethodID)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature) F(JMethodID)
+#define F(JMethodID) static jmethodID JMethodID = nullptr;
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+
+enum class OpenMode {
+    Read,
+    Write,
+    ReadWrite,
+    WriteAppend,
+    WriteTruncate,
+    ReadWriteAppend,
+    ReadWriteTruncate,
+    Never
+};
+
+void RegisterCallbacks(JNIEnv* env, jclass clazz);
+
+void UnRegisterCallbacks();
+
+bool IsContentUri(const std::string& path);
+
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature)               \
+    F(FunctionName, Parameters, ReturnValue)
+#define F(FunctionName, Parameters, ReturnValue) ReturnValue FunctionName Parameters;
+ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(FunctionName, ReturnValue)
+#define F(FunctionName, ReturnValue) ReturnValue FunctionName(const std::string& filepath);
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+#undef F
+#undef FR
+
+} // namespace Common::FS::Android