Merge pull request #12 from StefanBratanov/java_bindings_improvements

Java bindings improvements

bindings/java/Makefile

@@ -1,7 +1,9 @@
 INCLUDE_DIRS = ../../src ../../blst/bindings
 
+LIBRARY_FOLDER=src/main/resources/ethereum/ckzg4844/lib
+
 ifeq ($(OS),Windows_NT)
-	CLANG_EXECUTABLE=gcc
+	CLANG_EXECUTABLE=clang
 	GRADLE_COMMAND=gradlew
 	CLANG_FLAGS=-shared
 	JNI_INCLUDE_FOLDER=win32
@@ -32,9 +34,9 @@ endif
 all: build test
 
 build:
-	${CLANG_EXECUTABLE} ${CLANG_FLAGS} -O -Wall ${addprefix -I,${INCLUDE_DIRS}} -I"${JAVA_HOME}/include" -I"${JAVA_HOME}/include/${JNI_INCLUDE_FOLDER}" -o src/main/resources/lib/${LIBRARY_RESOURCE} c_kzg_4844_jni.c c_kzg_4844.o ../../lib/libblst.a
+	mkdir -p ${LIBRARY_FOLDER}
+	${CLANG_EXECUTABLE} ${CLANG_FLAGS} -O -Wall ${addprefix -I,${INCLUDE_DIRS}} -I"${JAVA_HOME}/include" -I"${JAVA_HOME}/include/${JNI_INCLUDE_FOLDER}" -o ${LIBRARY_FOLDER}/${LIBRARY_RESOURCE} c_kzg_4844_jni.c c_kzg_4844.o ../../lib/libblst.a
 
 test:
 	${GRADLE_COMMAND} clean test
 
-

bindings/java/README.md

@@ -2,15 +2,15 @@
 
 ## Prerequisites
 
-* Follow the instructions in the [README.md](../../README.md) to install blst and build the C-KZG code.
+* Follow the instructions in the [README.md](../../README.md) to install blst and build the C-KZG library.
-* `JAVA_HOME` environment variable is set to a JDK with an `include` folder containing a jni.h file.
+* `JAVA_HOME` environment variable is set to a JDK with an `include` folder containing a `jni.h` file.
 
 ## Build
 ```bash
 make build
 ```
 
-This will install the library in the `src/main/resources/lib` folder according to your OS
+This will install the library in the `src/main/resources/ethereum/ckzg4844/lib` folder with a name according to your OS
 
 ## Test
 ```bash

bindings/java/build.gradle

@@ -7,7 +7,12 @@ repositories {
 }
 
 dependencies {
-    testImplementation("org.junit.jupiter:junit-jupiter:5.9.1")
+
+    def junitVersion = "5.9.1"
+
+    testImplementation("org.junit.jupiter:junit-jupiter:${junitVersion}")
+    testImplementation("org.junit.jupiter:junit-jupiter-params:${junitVersion}")
+
 }
 
 test {

bindings/java/c_kzg_4844_jni.c

@@ -22,7 +22,7 @@ void throw_exception(JNIEnv *env, const char *message)
   (*env)->ThrowNew(env, Exception, message);
 }
 
-JNIEXPORT void JNICALL Java_CKzg4844JNI_loadTrustedSetup(JNIEnv *env, jclass thisCls, jstring file)
+JNIEXPORT void JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_loadTrustedSetup(JNIEnv *env, jclass thisCls, jstring file)
 {
   if (settings != NULL)
   {
@@ -61,7 +61,7 @@ JNIEXPORT void JNICALL Java_CKzg4844JNI_loadTrustedSetup(JNIEnv *env, jclass thi
   (*env)->ReleaseStringUTFChars(env, file, file_native);
 }
 
-JNIEXPORT void JNICALL Java_CKzg4844JNI_freeTrustedSetup(JNIEnv *env, jclass thisCls)
+JNIEXPORT void JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_freeTrustedSetup(JNIEnv *env, jclass thisCls)
 {
   if (settings == NULL)
   {
@@ -72,7 +72,7 @@ JNIEXPORT void JNICALL Java_CKzg4844JNI_freeTrustedSetup(JNIEnv *env, jclass thi
   reset_trusted_setup();
 }
 
-JNIEXPORT jbyteArray JNICALL Java_CKzg4844JNI_computeAggregateKzgProof(JNIEnv *env, jclass thisCls, jbyteArray blobs, jlong count)
+JNIEXPORT jbyteArray JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_computeAggregateKzgProof(JNIEnv *env, jclass thisCls, jbyteArray blobs, jlong count)
 {
   if (settings == NULL)
   {
@@ -104,7 +104,7 @@ JNIEXPORT jbyteArray JNICALL Java_CKzg4844JNI_computeAggregateKzgProof(JNIEnv *e
   return proof;
 }
 
-JNIEXPORT jboolean JNICALL Java_CKzg4844JNI_verifyAggregateKzgProof(JNIEnv *env, jclass thisCls, jbyteArray blobs, jbyteArray commitments, jlong count, jbyteArray proof)
+JNIEXPORT jboolean JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_verifyAggregateKzgProof(JNIEnv *env, jclass thisCls, jbyteArray blobs, jbyteArray commitments, jlong count, jbyteArray proof)
 {
   if (settings == NULL)
   {
@@ -163,7 +163,7 @@ JNIEXPORT jboolean JNICALL Java_CKzg4844JNI_verifyAggregateKzgProof(JNIEnv *env,
   return (jboolean)out;
 }
 
-JNIEXPORT jbyteArray JNICALL Java_CKzg4844JNI_blobToKzgCommitment(JNIEnv *env, jclass thisCls, jbyteArray blob)
+JNIEXPORT jbyteArray JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_blobToKzgCommitment(JNIEnv *env, jclass thisCls, jbyteArray blob)
 {
   if (settings == NULL)
   {
@@ -186,7 +186,7 @@ JNIEXPORT jbyteArray JNICALL Java_CKzg4844JNI_blobToKzgCommitment(JNIEnv *env, j
   return commitment;
 }
 
-JNIEXPORT jboolean JNICALL Java_CKzg4844JNI_verifyKzgProof(JNIEnv *env, jclass thisCls, jbyteArray commitment, jbyteArray z, jbyteArray y, jbyteArray proof)
+JNIEXPORT jboolean JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_verifyKzgProof(JNIEnv *env, jclass thisCls, jbyteArray commitment, jbyteArray z, jbyteArray y, jbyteArray proof)
 {
   if (settings == NULL)
   {

bindings/java/c_kzg_4844_jni.h

@@ -1,59 +1,54 @@
 /* DO NOT EDIT THIS FILE - it is machine generated */
 #include <jni.h>
-/* Header for class CKzg4844JNI */
+/* Header for class ethereum_ckzg4844_CKzg4844JNI */
 
-#ifndef _Included_CKzg4844JNI
+#ifndef _Included_ethereum_ckzg4844_CKzg4844JNI
-#define _Included_CKzg4844JNI
+#define _Included_ethereum_ckzg4844_CKzg4844JNI
 #ifdef __cplusplus
-extern "C" {
+extern "C"
+{
 #endif
-/*
+  /*
- * Class:     CKzg4844JNI
+   * Class:     ethereum_ckzg4844_CKzg4844JNI
- * Method:    loadTrustedSetup
+   * Method:    loadTrustedSetup
- * Signature: (Ljava/lang/String;)V
+   * Signature: (Ljava/lang/String;)V
- */
+   */
-JNIEXPORT void JNICALL Java_CKzg4844JNI_loadTrustedSetup
+  JNIEXPORT void JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_loadTrustedSetup(JNIEnv *, jclass, jstring);
-  (JNIEnv *, jclass, jstring);
 
-/*
+  /*
- * Class:     CKzg4844JNI
+   * Class:     ethereum_ckzg4844_CKzg4844JNI
- * Method:    freeTrustedSetup
+   * Method:    freeTrustedSetup
- * Signature: ()V
+   * Signature: ()V
- */
+   */
-JNIEXPORT void JNICALL Java_CKzg4844JNI_freeTrustedSetup
+  JNIEXPORT void JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_freeTrustedSetup(JNIEnv *, jclass);
-  (JNIEnv *, jclass);
 
-/*
+  /*
- * Class:     CKzg4844JNI
+   * Class:     ethereum_ckzg4844_CKzg4844JNI
- * Method:    computeAggregateKzgProof
+   * Method:    computeAggregateKzgProof
- * Signature: ([BJ)[B
+   * Signature: ([BJ)[B
- */
+   */
-JNIEXPORT jbyteArray JNICALL Java_CKzg4844JNI_computeAggregateKzgProof
+  JNIEXPORT jbyteArray JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_computeAggregateKzgProof(JNIEnv *, jclass, jbyteArray, jlong);
-  (JNIEnv *, jclass, jbyteArray, jlong);
 
-/*
+  /*
- * Class:     CKzg4844JNI
+   * Class:     ethereum_ckzg4844_CKzg4844JNI
- * Method:    verifyAggregateKzgProof
+   * Method:    verifyAggregateKzgProof
- * Signature: ([B[BJ[B)Z
+   * Signature: ([B[BJ[B)Z
- */
+   */
-JNIEXPORT jboolean JNICALL Java_CKzg4844JNI_verifyAggregateKzgProof
+  JNIEXPORT jboolean JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_verifyAggregateKzgProof(JNIEnv *, jclass, jbyteArray, jbyteArray, jlong, jbyteArray);
-  (JNIEnv *, jclass, jbyteArray, jbyteArray, jlong, jbyteArray);
 
-/*
+  /*
- * Class:     CKzg4844JNI
+   * Class:     ethereum_ckzg4844_CKzg4844JNI
- * Method:    blobToKzgCommitment
+   * Method:    blobToKzgCommitment
- * Signature: ([B)[B
+   * Signature: ([B)[B
- */
+   */
-JNIEXPORT jbyteArray JNICALL Java_CKzg4844JNI_blobToKzgCommitment
+  JNIEXPORT jbyteArray JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_blobToKzgCommitment(JNIEnv *, jclass, jbyteArray);
-  (JNIEnv *, jclass, jbyteArray);
 
-/*
+  /*
- * Class:     CKzg4844JNI
+   * Class:     ethereum_ckzg4844_CKzg4844JNI
- * Method:    verifyKzgProof
+   * Method:    verifyKzgProof
- * Signature: ([B[B[B[B)Z
+   * Signature: ([B[B[B[B)Z
- */
+   */
-JNIEXPORT jboolean JNICALL Java_CKzg4844JNI_verifyKzgProof
+  JNIEXPORT jboolean JNICALL Java_ethereum_ckzg4844_CKzg4844JNI_verifyKzgProof(JNIEnv *, jclass, jbyteArray, jbyteArray, jbyteArray, jbyteArray);
-  (JNIEnv *, jclass, jbyteArray, jbyteArray, jbyteArray, jbyteArray);
 
 #ifdef __cplusplus
 }

bindings/java/src/main/java/ethereum/ckzg4844/CKzg4844JNI.java

@@ -1,3 +1,5 @@
+package ethereum.ckzg4844;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
@@ -39,17 +41,60 @@ public class CKzg4844JNI {
   public static int BYTES_PER_FIELD_ELEMENT = 32;
   public static int BYTES_PER_BLOB = FIELD_ELEMENTS_PER_BLOB * BYTES_PER_FIELD_ELEMENT;
 
+  /**
+   * Loads the trusted setup from a file. Once loaded, the same setup will be used for all the
+   * native calls. To load a new setup, free the current one by calling {@link #freeTrustedSetup()}
+   * and then load the new one. If no trusted setup has been loaded, all the native calls will throw
+   * an exception.
+   *
+   * @param file a path to a trusted setup file
+   */
   public static native void loadTrustedSetup(String file);
 
+  /**
+   * Free the current trusted setup. This method will throw an exception if no trusted setup has
+   * been loaded.
+   */
   public static native void freeTrustedSetup();
 
+  /**
+   * Calculates aggregated proof for the given blobs
+   *
+   * @param blobs blobs as flattened bytes
+   * @param count the count of the blobs
+   * @return the aggregated proof
+   */
   public static native byte[] computeAggregateKzgProof(byte[] blobs, long count);
 
+  /**
+   * Verify aggregated proof and commitments for the given blobs
+   *
+   * @param blobs       blobs as flattened bytes
+   * @param commitments commitments as flattened bytes
+   * @param count       the count of the blobs (should be same as the count of the commitments)
+   * @param proof       the proof that needs verifying
+   * @return true if the proof is valid and false otherwise
+   */
   public static native boolean verifyAggregateKzgProof(byte[] blobs, byte[] commitments, long count,
       byte[] proof);
 
+  /**
+   * Calculates commitment for a given blob
+   *
+   * @param blob blob bytes
+   * @return the commitment
+   */
   public static native byte[] blobToKzgCommitment(byte[] blob);
 
+  /**
+   * Verify the proof by point evaluation for the given commitment
+   *
+   * @param commitment commitment bytes
+   * @param z          Z
+   * @param y          Y
+   * @param proof      the proof that needs verifying
+   * @return true if the proof is valid and false otherwise
+   */
   public static native boolean verifyKzgProof(byte[] commitment, byte[] z, byte[] y, byte[] proof);
 
 }

bindings/java/src/test/java/ethereum/ckzg4844/CKzg4844JNITest.java

@@ -1,3 +1,5 @@
+package ethereum.ckzg4844;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -6,9 +8,13 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.Random;
+import java.util.stream.IntStream;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
-public class CKZg4844JNITest {
+public class CKzg4844JNITest {
 
   private final Random random = new Random();
 
@@ -26,7 +32,6 @@ public class CKZg4844JNITest {
     assertEquals(CKzg4844JNI.BYTES_PER_COMMITMENT, commitment.length);
     assertEquals(CKzg4844JNI.BYTES_PER_COMMITMENT, commitment2.length);
 
-    // flatten blobs and commitments
     final byte[] blobs = flatten(blob, blob2);
     final byte[] commitments = flatten(commitment, commitment2);
 
@@ -36,7 +41,7 @@ public class CKZg4844JNITest {
 
     assertTrue(CKzg4844JNI.verifyAggregateKzgProof(blobs, commitments, 2, proof));
 
-    final byte[] fakeProof = createRandomProof();
+    final byte[] fakeProof = createRandomProof(2);
     assertFalse(CKzg4844JNI.verifyAggregateKzgProof(blobs, commitments, 2, fakeProof));
 
     CKzg4844JNI.freeTrustedSetup();
@@ -61,6 +66,36 @@ public class CKZg4844JNITest {
 
   }
 
+  @Disabled("Use for manually testing performance.")
+  @ParameterizedTest
+  @ValueSource(ints = {1, 10, 100, 1000})
+  public void testPerformance(final int count) {
+
+    loadTrustedSetup();
+
+    final byte[] blobs = createRandomBlobs(count);
+    final byte[] commitments = getCommitmentsForBlobs(blobs, count);
+
+    long startTime = System.currentTimeMillis();
+    final byte[] proof = CKzg4844JNI.computeAggregateKzgProof(blobs, count);
+    long endTime = System.currentTimeMillis();
+
+    System.out.printf("Computing aggregate proof for %d blobs took %d milliseconds%n", count,
+        endTime - startTime);
+
+    startTime = System.currentTimeMillis();
+    boolean proofValidity = CKzg4844JNI.verifyAggregateKzgProof(blobs, commitments, count, proof);
+    endTime = System.currentTimeMillis();
+
+    assertTrue(proofValidity);
+
+    System.out.printf("Verifying aggregate proof for %d blobs took %d milliseconds%n", count,
+        endTime - startTime);
+
+    CKzg4844JNI.freeTrustedSetup();
+
+  }
+
   @Test
   public void throwsIfMethodIsUsedWithoutLoadingTrustedSetup() {
 
@@ -82,6 +117,7 @@ public class CKZg4844JNITest {
         exception.getMessage());
 
     CKzg4844JNI.freeTrustedSetup();
+
   }
 
   @Test
@@ -108,12 +144,27 @@ public class CKZg4844JNITest {
     return blob;
   }
 
-  private byte[] createRandomProof() {
+  private byte[] createRandomBlobs(final int count) {
-    final byte[] blob = createRandomBlob();
+    final byte[][] blobs = IntStream.range(0, count).mapToObj(__ -> createRandomBlob())
-    return CKzg4844JNI.computeAggregateKzgProof(blob, 1);
+        .toArray(byte[][]::new);
+    return flatten(blobs);
   }
 
-  private byte[] flatten(byte[]... bytes) {
+  private byte[] createRandomProof(final int count) {
+    return CKzg4844JNI.computeAggregateKzgProof(createRandomBlobs(count), count);
+  }
+
+  private byte[] getCommitmentsForBlobs(final byte[] blobs, final int count) {
+    final byte[][] commitments = new byte[count][];
+    IntStream.range(0, count).forEach(i -> {
+      final byte[] blob = Arrays.copyOfRange(blobs, i * CKzg4844JNI.BYTES_PER_BLOB,
+          (i + 1) * CKzg4844JNI.BYTES_PER_BLOB);
+      commitments[i] = CKzg4844JNI.blobToKzgCommitment(blob);
+    });
+    return flatten(commitments);
+  }
+
+  private byte[] flatten(final byte[]... bytes) {
     final int capacity = Arrays.stream(bytes).mapToInt(b -> b.length).sum();
     final ByteBuffer buffer = ByteBuffer.allocate(capacity);
     Arrays.stream(bytes).forEach(buffer::put);