Simplify the files in the jni folder into one and move the resulting file to the parent folder

Author: sungshik

src/main/java/engineering/swat/watch/impl/mac/NativeLibrary.java

@@ -0,0 +1,103 @@
+/*
+ * BSD 2-Clause License
+ *
+ * Copyright (c) 2023, Swat.engineering
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package engineering.swat.watch.impl.mac;
+
+import static java.nio.file.attribute.PosixFilePermission.*;
+
+import java.nio.file.Files;
+import java.nio.file.StandardOpenOption;
+import java.nio.file.attribute.FileAttribute;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.util.Set;
+
+public class NativeLibrary {
+
+    public static native long start(String path, NativeEventHandler handler);
+    public static native void stop(long watchId);
+
+    private static boolean isMac() {
+        var os = System.getProperty("os.name");
+        return os != null && (os.toLowerCase().contains("mac") || os.toLowerCase().contains("darwin"));
+    }
+
+    private static boolean isAarch64() {
+        var arch = System.getProperty("os.arch");
+        return arch != null && arch.toLowerCase().equals("aarch64");
+    }
+
+    private static volatile boolean loaded = false;
+    public static void load() {
+        if (loaded) {
+            return;
+        }
+        try {
+            if (!isMac()) {
+                throw new IllegalStateException("We should not be loading FileSystemEvents api on non mac machines");
+            }
+            String path = "/engineering/swat/watch/jni/";
+            if (isAarch64()) {
+                path += "macos-aarch64/";
+            }
+            else {
+                path += "macos-x64/";
+            }
+            path += "librust_fsevents_jni.dylib";
+
+            loadLibrary(path);
+        } finally {
+            loaded = true;
+        }
+    }
+
+    private static FileAttribute<Set<PosixFilePermission>> PRIVATE_FILE = PosixFilePermissions.asFileAttribute(Set.of(OWNER_READ, OWNER_WRITE , OWNER_EXECUTE));
+
+    private static void loadLibrary(String path) {
+        try {
+            var localFile = NativeLibrary.class.getResource(path);
+            if (localFile != null && localFile.getProtocol().equals("file")) {
+                System.load(localFile.getPath());
+                return;
+            }
+            // in most cases the file is inside of a jar
+            // so we have to copy it out and load that file instead
+            var localCopy = Files.createTempFile("watch", ".dylib"/*  , PRIVATE_FILE*/);
+            localCopy.toFile().deleteOnExit();
+            try (var libStream = NativeLibrary.class.getResourceAsStream(path)) {
+                if (libStream != null) {
+                    try (var writer = Files.newOutputStream(localCopy, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE)) {
+                        libStream.transferTo(writer);
+                    }
+                    System.load(localCopy.toString());
+                }
+            }
+        }
+        catch (Throwable e) {
+            throw new IllegalStateException("We could not load: " + path, e);
+        }
+    }
+}