Drop redundant OpenSlideFFM null checks

These were carried over from the JNI implementation, where they were
needed to prevent segfaults.  With FFM, each of the affected variables is
passed to arena.allocateFrom(), which properly throws a
NullPointerException on null.  That seems more correct than returning a
method-specific sentinel value, since none of these methods should ever
receive null in normal operation.

Signed-off-by: Benjamin Gilbert <[email protected]>

Author: bgilbert

org/openslide/OpenSlideFFM.java

@@ -234,9 +234,6 @@ private static RuntimeException wrapException(Throwable ex) {
             C_POINTER, "openslide_detect_vendor", C_POINTER);
 
     static String openslide_detect_vendor(String filename) {
-        if (filename == null) {
-            return null;
-        }
         MemorySegment ret;
         try (Arena arena = Arena.ofConfined()) {
             ret = (MemorySegment) detect_vendor.invokeExact(
@@ -254,9 +251,6 @@ static String openslide_detect_vendor(String filename) {
             C_POINTER, "openslide_open", C_POINTER);
 
     static OpenSlideRef openslide_open(String filename) {
-        if (filename == null) {
-            return null;
-        }
         MemorySegment ret;
         try (Arena arena = Arena.ofConfined()) {
             ret = (MemorySegment) open.invokeExact(
@@ -390,9 +384,6 @@ static String[] openslide_get_property_names(OpenSlideRef osr) {
             C_POINTER, "openslide_get_property_value", C_POINTER, C_POINTER);
 
     static String openslide_get_property_value(OpenSlideRef osr, String name) {
-        if (name == null) {
-            return null;
-        }
         MemorySegment ret;
         try (Arena arena = Arena.ofConfined(); Ref.ScopedLock l = osr.lock()) {
             ret = (MemorySegment) get_property_value.invokeExact(
@@ -426,9 +417,6 @@ static String[] openslide_get_associated_image_names(OpenSlideRef osr) {
 
     static void openslide_get_associated_image_dimensions(OpenSlideRef osr,
             String name, long dim[]) {
-        if (name == null) {
-            return;
-        }
         try (Arena arena = Arena.ofConfined()) {
             MemorySegment w = arena.allocateFrom(JAVA_LONG, 0);
             MemorySegment h = arena.allocateFrom(JAVA_LONG, 0);
@@ -449,9 +437,6 @@ static void openslide_get_associated_image_dimensions(OpenSlideRef osr,
 
     static void openslide_read_associated_image(OpenSlideRef osr, String name,
             int dest[]) {
-        if (name == null) {
-            return;
-        }
         try (Arena arena = Arena.ofConfined()) {
             MemorySegment buf = arena.allocate(JAVA_INT, dest.length);
             try (Ref.ScopedLock l = osr.lock()) {
@@ -470,9 +455,6 @@ static void openslide_read_associated_image(OpenSlideRef osr, String name,
 
     static long openslide_get_associated_image_icc_profile_size(
             OpenSlideRef osr, String name) {
-        if (name == null) {
-            return -1;
-        }
         try (Arena arena = Arena.ofConfined(); Ref.ScopedLock l = osr.lock()) {
             return (long) get_associated_image_icc_profile_size.invokeExact(
                     osr.getSegment(), arena.allocateFrom(name));
@@ -487,9 +469,6 @@ static long openslide_get_associated_image_icc_profile_size(
 
     static void openslide_read_associated_image_icc_profile(OpenSlideRef osr,
             String name, byte dest[]) {
-        if (name == null) {
-            return;
-        }
         try (Arena arena = Arena.ofConfined()) {
             MemorySegment buf = arena.allocate(JAVA_BYTE, dest.length);
             try (Ref.ScopedLock l = osr.lock()) {