WIP: Using JNI+Rust instead of JNA on macOS

.editorconfig

@@ -15,3 +15,6 @@ end_of_line = lf
 [*.java]
 indent_size = 4
 max_line_length = 120
+
+[*.rs]
+indent_size = 4

.github/workflows/build.yaml

@@ -32,6 +32,9 @@ jobs:
           java-version: ${{ matrix.jdk }}
           distribution: 'temurin'
           cache: 'maven'
+      #- uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: ./update-rust-jni-libs.sh -r
+        if: ${{ matrix.os.image == 'macos-latest' }}
 
       - name: test
         run: mvn -B clean test "-Dwatch.mac.backend=${{ matrix.os.mac-backend }}"

.gitignore

@@ -27,4 +27,4 @@ replay_pid*
 
 # release plugin state files
 /pom.xml.releaseBackup
-/release.properties
+/release.properties

pom.xml

@@ -74,13 +74,20 @@
     <checkerframework.version>3.49.5</checkerframework.version>
     <junit.version>5.13.4</junit.version>
     <log4j.version>2.25.1</log4j.version>
-    <jna.version>5.17.0</jna.version>
     <maven.compiler.source>11</maven.compiler.source>
     <maven.compiler.target>11</maven.compiler.target>
     <watch.mac.backend>fsevents</watch.mac.backend>
   </properties>
 
   <build>
+    <resources>
+      <resource>
+        <directory>src/main/resources</directory>
+        <excludes>
+          <exclude>src/main/rust/**/*.*</exclude>
+        </excludes>
+      </resource>
+    </resources>
     <plugins>
       <plugin> <!-- configure java compiler -->
         <groupId>org.apache.maven.plugins</groupId>
@@ -147,6 +154,9 @@
               </excludes>
             </licenseSet>
           </licenseSets>
+          <mapping>
+            <rs>DOUBLESLASH_STYLE</rs> <!-- Use same style for license headers in Rust files as in https://github.com/rust-lang/style-team/blob/main/example/lists.rs -->
+          </mapping>
         </configuration>
         <executions>
           <execution>
@@ -170,6 +180,11 @@
             </goals>
           </execution>
         </executions>
+        <configuration>
+          <excludes>
+            <exclude>src/main/resources/**</exclude>
+          </excludes>
+        </configuration>
       </plugin>
       <plugin> <!-- use a new version of maven  -->
         <groupId>org.apache.maven.plugins</groupId>
@@ -229,16 +244,6 @@
       <version>${log4j.version}</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>net.java.dev.jna</groupId>
-      <artifactId>jna</artifactId>
-      <version>${jna.version}</version>
-    </dependency>
-    <dependency>
-      <groupId>net.java.dev.jna</groupId>
-      <artifactId>jna-platform</artifactId>
-      <version>${jna.version}</version>
-    </dependency>
   </dependencies>
 
   <profiles>

src/main/java/engineering/swat/watch/impl/jdk/JDKPoller.java

@@ -56,6 +56,7 @@
 
 import engineering.swat.watch.DaemonThreadPool;
 import engineering.swat.watch.impl.mac.MacWatchService;
+import engineering.swat.watch.impl.mac.NativeLibrary;
 import engineering.swat.watch.impl.util.SubscriptionKey;
 
 /**
@@ -189,7 +190,7 @@ public Watchable newWatchable(Path path) {
         static final Platform CURRENT = current(); // Assumption: the platform doesn't change
 
         private static Platform current() {
-            if (com.sun.jna.Platform.isMac()) {
+            if (NativeLibrary.isMac()) {
                 var key = "engineering.swat.java-watch.mac";
                 var val = System.getProperty(key);
                 if (val != null) {

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

@@ -26,8 +26,13 @@
  */
 package engineering.swat.watch.impl.mac;
 
+import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
+import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
+import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
+import static java.nio.file.StandardWatchEventKinds.OVERFLOW;
+
+import java.nio.file.Path;
 import java.nio.file.WatchEvent;
-import java.nio.file.WatchEvent.Kind;
 
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -51,5 +56,36 @@
  */
 @FunctionalInterface
 interface NativeEventHandler {
-    <T> void handle(Kind<T> kind, @Nullable T context);
+    <T> void handle(java.nio.file.WatchEvent.Kind<T> kind, @Nullable T context);
+
+    default void handle(int kindOrdinal, String rootPath, String relativePath) {
+        if (kindOrdinal < Kind.values().length) {
+            var kind = Kind.values()[kindOrdinal];
+            switch (kind) {
+                case CREATE:
+                    handle(ENTRY_CREATE, toContext(rootPath, relativePath));
+                    break;
+                case MODIFY:
+                    handle(ENTRY_MODIFY, toContext(rootPath, relativePath));
+                    break;
+                case DELETE:
+                    handle(ENTRY_DELETE, toContext(rootPath, relativePath));
+                    break;
+                case OVERFLOW:
+                    handle(OVERFLOW, null);
+                    break;
+            }
+        }
+    }
+
+    static Path toContext(String rootPath, String relativePath) {
+        return Path.of(rootPath).relativize(Path.of(relativePath));
+    }
+}
+
+enum Kind { // Order of values needs to be consistent with enum `Kind` in Rust
+    OVERFLOW,
+    CREATE,
+    DELETE,
+    MODIFY;
 }