Added sync

app/src/main/java/eu/faircode/email/Helper.java

@@ -2051,6 +2051,12 @@ public class Helper {
 
     // Files
 
+    static {
+        System.loadLibrary("fairemail");
+    }
+
+    public static native void sync();
+
     static String sanitizeFilename(String name) {
         if (name == null)
             return null;

app/src/main/java/eu/faircode/email/WorkerFts.java

@@ -109,8 +109,10 @@ public class WorkerFts extends Worker {
 
             markIndexed(db, ids);
 
-            if (checkpoints)
+            if (checkpoints) {
                 DB.checkpoint(context);
+                Helper.sync();
+            }
 
             Log.i("FTS indexed=" + indexed);
             return Result.success();

app/src/main/jni/fairemail.cc

@@ -7,6 +7,7 @@
 #include <netinet/tcp.h>
 #include <sys/ioctl.h>
 #include <netdb.h>
+#include <unistd.h>
 
 #include "compact_enc_det/compact_enc_det.h"
 #include "cld_3/src/nnet_language_identifier.h"
@@ -200,3 +201,11 @@ Java_eu_faircode_email_ConnectionHelper_jni_1is_1numeric_1address(
     env->ReleaseStringUTFChars(_ip, ip);
     return numeric;
 }
+
+extern "C"
+JNIEXPORT void JNICALL
+Java_eu_faircode_email_Helper_sync(JNIEnv *env, jclass clazz) {
+    log_android(ANDROID_LOG_DEBUG, "sync");
+    sync();
+    log_android(ANDROID_LOG_DEBUG, "synced");
+}