* Add static long Pointer.getDirectBufferAddress(Buffer) method fo…

…r convenience (pull #629)
bytedeco · Oct 27, 2022 · 7fc94e3 · 7fc94e3
1 parent 45a6a4b
commit 7fc94e3
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diff --git a/src/main/java/org/bytedeco/javacpp/Pointer.java b/src/main/java/org/bytedeco/javacpp/Pointer.java
@@ -33,6 +33,7 @@
 import java.util.Iterator;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.bytedeco.javacpp.annotation.Name;
+import org.bytedeco.javacpp.annotation.Raw;
 import org.bytedeco.javacpp.tools.Generator;
 import org.bytedeco.javacpp.tools.Logger;
 
@@ -589,6 +590,10 @@ public static long maxPhysicalBytes() {
     /** Returns the amount of physical memory that is free according to the operating system, or 0 if unknown. */
     @Name("JavaCPP_availablePhysicalBytes") public static native long availablePhysicalBytes();
 
+    /** Returns the starting address of the memory region referenced by the given direct {@link java.nio.Buffer}.
+     * An alternative to allocating a new Pointer object if all you need is the memory address. */
+    @Name("JavaCPP_getDirectBufferAddress") protected static native long getDirectBufferAddress(@Raw(withEnv = true) Buffer b);
+
     /** The native address of this Pointer, which can be an array. */
     protected long address = 0;
     /** The index of the element of a native array that should be accessed. */

diff --git a/src/main/java/org/bytedeco/javacpp/tools/Generator.java b/src/main/java/org/bytedeco/javacpp/tools/Generator.java
@@ -664,6 +664,10 @@ boolean classes(boolean handleExceptions, boolean defineAdapters, boolean conver
             out.println("    return size;");
             out.println("}");
             out.println();
+            out.println("static inline jlong JavaCPP_getDirectBufferAddress(JNIEnv *env, jclass cls, jobject obj) {");
+            out.println("    return (jlong)env->GetDirectBufferAddress(obj);");
+            out.println("}");
+            out.println();
             out.println("static inline jint JavaCPP_totalProcessors() {");
             out.println("    jint total = 0;");
             out.println("#ifdef __linux__");

diff --git a/src/test/java/org/bytedeco/javacpp/BufferTest.java b/src/test/java/org/bytedeco/javacpp/BufferTest.java
@@ -101,6 +101,7 @@ public ByteBuffer call(ByteBuffer buffer) {
         BytePointer pointer = new BytePointer(arrayBuffer);
         ByteBuffer directBuffer = pointer.asBuffer();
         assertEquals(pointer.address(), new BytePointer(directBuffer).address());
+        assertEquals(pointer.address(), Pointer.getDirectBufferAddress(directBuffer));
 
         assertTrue(directBuffer.compareTo(arrayBuffer) == 0);
         assertEquals(arrayBuffer.position(), directBuffer.position());
@@ -123,6 +124,7 @@ public ByteBuffer call(ByteBuffer buffer) {
         ShortPointer pointer = new ShortPointer(arrayBuffer);
         ShortBuffer directBuffer = pointer.asBuffer();
         assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), new ShortPointer(directBuffer).address());
+        assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), Pointer.getDirectBufferAddress(directBuffer));
 
         assertTrue(directBuffer.compareTo(arrayBuffer) == 0);
         assertEquals(arrayBuffer.limit() - arrayBuffer.position(), directBuffer.limit());
@@ -144,6 +146,7 @@ public ByteBuffer call(ByteBuffer buffer) {
         IntPointer pointer = new IntPointer(arrayBuffer);
         IntBuffer directBuffer = pointer.asBuffer();
         assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), new IntPointer(directBuffer).address());
+        assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), Pointer.getDirectBufferAddress(directBuffer));
 
         assertTrue(directBuffer.compareTo(arrayBuffer) == 0);
         assertEquals(arrayBuffer.limit() - arrayBuffer.position(), directBuffer.limit());
@@ -165,6 +168,7 @@ public ByteBuffer call(ByteBuffer buffer) {
         LongPointer pointer = new LongPointer(arrayBuffer);
         LongBuffer directBuffer = pointer.asBuffer();
         assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), new LongPointer(directBuffer).address());
+        assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), Pointer.getDirectBufferAddress(directBuffer));
 
         assertTrue(directBuffer.compareTo(arrayBuffer) == 0);
         assertEquals(arrayBuffer.limit() - arrayBuffer.position(), directBuffer.limit());
@@ -186,6 +190,7 @@ public ByteBuffer call(ByteBuffer buffer) {
         FloatPointer pointer = new FloatPointer(arrayBuffer);
         FloatBuffer directBuffer = pointer.asBuffer();
         assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), new FloatPointer(directBuffer).address());
+        assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), Pointer.getDirectBufferAddress(directBuffer));
 
         assertTrue(directBuffer.compareTo(arrayBuffer) == 0);
         assertEquals(arrayBuffer.limit() - arrayBuffer.position(), directBuffer.limit());
@@ -207,6 +212,7 @@ public ByteBuffer call(ByteBuffer buffer) {
         DoublePointer pointer = new DoublePointer(arrayBuffer);
         DoubleBuffer directBuffer = pointer.asBuffer();
         assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), new DoublePointer(directBuffer).address());
+        assertEquals(pointer.address() + pointer.position() * pointer.sizeof(), Pointer.getDirectBufferAddress(directBuffer));
 
         assertTrue(directBuffer.compareTo(arrayBuffer) == 0);
         assertEquals(arrayBuffer.limit() - arrayBuffer.position(), directBuffer.limit());