blob/java: listBlobbifiedRanges java bindings

bindings/java/fdbJNI.cpp

@@ -976,6 +976,40 @@ JNIEXPORT jlong JNICALL Java_com_apple_foundationdb_FDBDatabase_Database_1unblob
 	return (jlong)f;
 }
 
+JNIEXPORT jlong JNICALL Java_com_apple_foundationdb_FDBDatabase_Database_1listBlobbifiedRanges(JNIEnv* jenv,
+                                                                                               jobject,
+                                                                                               jlong dbPtr,
+                                                                                               jbyteArray beginKeyBytes,
+                                                                                               jbyteArray endKeyBytes,
+                                                                                               jint rangeLimit) {
+	if (!dbPtr || !beginKeyBytes || !endKeyBytes) {
+		throwParamNotNull(jenv);
+		return 0;
+	}
+	FDBDatabase* tr = (FDBDatabase*)dbPtr;
+
+	uint8_t* startKey = (uint8_t*)jenv->GetByteArrayElements(beginKeyBytes, JNI_NULL);
+	if (!startKey) {
+		if (!jenv->ExceptionOccurred())
+			throwRuntimeEx(jenv, "Error getting handle to native resources");
+		return 0;
+	}
+
+	uint8_t* endKey = (uint8_t*)jenv->GetByteArrayElements(endKeyBytes, JNI_NULL);
+	if (!endKey) {
+		jenv->ReleaseByteArrayElements(beginKeyBytes, (jbyte*)startKey, JNI_ABORT);
+		if (!jenv->ExceptionOccurred())
+			throwRuntimeEx(jenv, "Error getting handle to native resources");
+		return 0;
+	}
+
+	FDBFuture* f = fdb_database_list_blobbified_ranges(
+	    tr, startKey, jenv->GetArrayLength(beginKeyBytes), endKey, jenv->GetArrayLength(endKeyBytes), rangeLimit);
+	jenv->ReleaseByteArrayElements(beginKeyBytes, (jbyte*)startKey, JNI_ABORT);
+	jenv->ReleaseByteArrayElements(endKeyBytes, (jbyte*)endKey, JNI_ABORT);
+	return (jlong)f;
+}
+
 JNIEXPORT jboolean JNICALL Java_com_apple_foundationdb_FDB_Error_1predicate(JNIEnv* jenv,
                                                                             jobject,
                                                                             jint predicate,

bindings/java/src/main/com/apple/foundationdb/Database.java

@@ -252,6 +252,32 @@ public interface Database extends AutoCloseable, TransactionContext {
 	 */
 	CompletableFuture<Boolean> unblobbifyRange(byte[] beginKey, byte[] endKey, Executor e);
 
+	/**
+	 * Runs {@link #listBlobbifiedRanges(Function)} on the default executor.
+	 *
+	 * @param beginKey start of the key range
+	 * @param endKey end of the key range
+	 * @param rangeLimit batch size
+	 * @param e the {@link Executor} to use for asynchronous callbacks
+
+	 * @return a future with the list of blobbified ranges.
+	 */
+	 default CompletableFuture<KeyRangeArrayResult> listBlobbifiedRanges(byte[] beginKey, byte[] endKey, int rangeLimit) {
+		return listBlobbifiedRanges(beginKey, endKey, rangeLimit, getExecutor());
+	 }
+
+	/**
+	 * Lists blobbified ranges in the database. There may be more if result.size() == rangeLimit.
+	 *
+	 * @param beginKey start of the key range
+	 * @param endKey end of the key range
+	 * @param rangeLimit batch size
+	 * @param e the {@link Executor} to use for asynchronous callbacks
+
+	 * @return a future with the list of blobbified ranges.
+	 */
+	 CompletableFuture<KeyRangeArrayResult> listBlobbifiedRanges(byte[] beginKey, byte[] endKey, int rangeLimit, Executor e);
+
 	/**
 	 * Runs a read-only transactional function against this {@code Database} with retry logic.
 	 *  {@link Function#apply(Object) apply(ReadTransaction)} will be called on the

bindings/java/src/main/com/apple/foundationdb/FDBDatabase.java

@@ -240,6 +240,16 @@ class FDBDatabase extends NativeObjectWrapper implements Database, OptionConsume
 		}
 	}
 
+	@Override
+	public CompletableFuture<KeyRangeArrayResult> listBlobbifiedRanges(byte[] beginKey, byte[] endKey, int rangeLimit, Executor e) {
+		pointerReadLock.lock();
+		try {
+			return new FutureKeyRangeArray(Database_listBlobbifiedRanges(getPtr(), beginKey, endKey, rangeLimit), e);
+		} finally {
+			pointerReadLock.unlock();
+		}
+	}
+
 	@Override
 	public Executor getExecutor() {
 		return executor;
@@ -259,4 +269,5 @@ class FDBDatabase extends NativeObjectWrapper implements Database, OptionConsume
 	private native long Database_waitPurgeGranulesComplete(long cPtr, byte[] purgeKey);
 	private native long Database_blobbifyRange(long cPtr, byte[] beginKey, byte[] endKey);
 	private native long Database_unblobbifyRange(long cPtr, byte[] beginKey, byte[] endKey);
+	private native long Database_listBlobbifiedRanges(long cPtr, byte[] beginKey, byte[] endKey, int rangeLimit);
 }