Add support for XXHash algos (#966)

Author: DmitriyMusatkin

NOTICE

@@ -1,3 +1,30 @@
 AWS Crt Java
 Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved. 
 SPDX-License-Identifier: Apache-2.0.
+
+** XXHash - https://xxhash.com/
+Copyright (c) 2012-2021 Yann Collet
+All rights reserved.
+
+BSD 2-Clause License (https://www.opensource.org/licenses/bsd-license.php)
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -298,3 +298,6 @@ To debug native code with VSCode or CLion or any other IDE:
 3. Set the parameters to be the ones used by the ```mvn``` script, as per above
 4. Set the working directory to the `aws-crt-java` directory
 5. On windows, you will need to manually load the PDB via the Modules window in Visual Studio, as it is not embedded in the JAR. It will be in the ```target/cmake-build/lib/windows/<arch>``` folder.
+
+## Attribution
+This library exposes native XXHash implementation (https://github.com/Cyan4973/xxHash) through JNI interface.

crt/aws-checksums

@@ -0,0 +1,189 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package software.amazon.awssdk.crt.checksums;
+import software.amazon.awssdk.crt.CrtResource;
+
+public class XXHash extends CrtResource {
+    
+    private XXHash(long nativeHandle) {
+        acquireNativeHandle(nativeHandle);
+    }
+
+    /**
+     * Determines whether a resource releases its dependencies at the same time the native handle is released or if it waits.
+     * Resources that wait are responsible for calling releaseReferences() manually.
+     */
+    @Override
+    protected boolean canReleaseReferencesImmediately() { return true; }
+
+    /**
+     * Releases the instance's reference to the underlying native key pair
+     */
+    @Override
+    protected void releaseNativeHandle() {
+        if (!isNull()) {
+            xxHashRelease(getNativeHandle());
+        }
+    }
+
+    /**
+     * Create new streaming XXHash64.
+     * @param seed seed to use for the hash
+     * @return new XXHash instance
+     */
+    static public XXHash newXXHash64(long seed) {
+        long nativeHandle = xxHash64Create(seed);
+        return new XXHash(nativeHandle);
+    }
+
+
+    /**
+     * Create new streaming XXHash64.
+     * @return new XXHash instance
+     */
+    static public XXHash newXXHash64() {
+        long nativeHandle = xxHash64Create(0);
+        return new XXHash(nativeHandle);
+    }
+
+    /**
+     * Create new streaming XXHash3_64.
+     * @param seed seed to use for the hash
+     * @return new XXHash instance
+     */
+    static public XXHash newXXHash3_64(long seed) {
+        long nativeHandle = xxHash364Create(seed);
+        return new XXHash(nativeHandle);
+    }
+
+    /**
+     * Create new streaming XXHash3_64.
+     * @return new XXHash instance
+     */
+    static public XXHash newXXHash3_64() {
+        long nativeHandle = xxHash364Create(0);
+        if (nativeHandle != 0) {
+            return new XXHash(nativeHandle);
+        }
+
+        return null;
+    }
+
+    /**
+     * Create new streaming XXHash3_128.
+     * @param seed seed to use for the hash
+     * @return new XXHash instance
+     */
+    static public XXHash newXXHash3_128(long seed) {
+        long nativeHandle = xxHash3128Create(seed);
+        if (nativeHandle != 0) {
+            return new XXHash(nativeHandle);
+        }
+
+        return null;
+    }
+
+    /**
+     * Create new streaming XXHash3_128.
+     * @return new XXHash instance
+     */
+    static public XXHash newXXHash3_128() {
+        long nativeHandle = xxHash3128Create(0);
+        if (nativeHandle != 0) {
+            return new XXHash(nativeHandle);
+        }
+
+        return null;
+    }
+
+    /**
+     * Update xxhash state from input
+     * @param input input to update with
+     */
+    public void update(byte[] input) {
+        xxHashUpdate(getNativeHandle(), input);
+    }
+
+    /**
+     * Return digest for the current state of hash.
+     * @return hash as bytes in big endian
+     */
+    public byte[] digest() {
+        return xxHashFinalize(getNativeHandle());
+    }
+
+    /**
+     * Oneshot compute XXHash64.
+     * @param input input input to hash
+     * @param seed seed
+     * @return xxhash64 hash
+     */
+    static public byte[] computeXXHash64(byte[] input, long seed) {
+        return xxHash64Compute(input, seed);
+    }
+
+    /**
+     * Oneshot compute XXHash64.
+     * @param input input input to hash
+     * @return xxhash64 hash
+     */
+    static public byte[] computeXXHash64(byte[] input) {
+        return xxHash64Compute(input, 0);
+    }
+
+
+    /**
+     * Oneshot compute XXHash3_64.
+     * @param input input input to hash
+     * @param seed seed
+     * @return xxhash64 hash
+     */
+    static public byte[] computeXXHash3_64(byte[] input, long seed) {
+        return xxHash364Compute(input, seed);
+    }
+
+    /**
+     * Oneshot compute XXHash3_64.
+     * @param input input input to hash
+     * @return xxhash64 hash
+     */
+    static public byte[] computeXXHash3_64(byte[] input) {
+        return xxHash364Compute(input, 0);
+    }
+
+    /**
+     * Oneshot compute XXHash3_128.
+     * @param input input input to hash
+     * @param seed seed
+     * @return xxhash64 hash
+     */
+    static public byte[] computeXXHash3_128(byte[] input, long seed) {
+        return xxHash3128Compute(input, seed);
+    }
+
+    /**
+     * Oneshot compute XXHash3_128.
+     * @param input input input to hash
+     * @return xxhash64 hash
+     */
+    static public byte[] computeXXHash3_128(byte[] input) {
+        return xxHash3128Compute(input, 0);
+    }
+
+    /*******************************************************************************
+     * native methods
+     ******************************************************************************/
+    private static native byte[] xxHash64Compute(byte[] input, long seed);
+    private static native byte[] xxHash364Compute(byte[] input, long seed);
+    private static native byte[] xxHash3128Compute(byte[] input, long seed);
+
+    private static native long xxHash64Create(long seed);
+    private static native long xxHash364Create(long seed);
+    private static native long xxHash3128Create(long seed);
+    private static native void xxHashRelease(long xxhash);
+
+    private static native void xxHashUpdate(long xxhash, byte[] input);
+    private static native byte[] xxHashFinalize(long xxhash);
+}