Add FlatListProof#verify benchmark and make it public

[skip ci]

Author: dmitry-timofeev

exonum-java-binding/benchmarks/pom.xml

@@ -66,6 +66,17 @@ THE POSSIBILITY OF SUCH DAMAGE.
       <version>${jmh.version}</version>
       <scope>provided</scope>
     </dependency>
+
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>com.exonum.binding</groupId>
+      <artifactId>exonum-java-binding-common</artifactId>
+      <version>${project.version}</version>
+    </dependency>
   </dependencies>
 
   <build>
@@ -91,6 +102,7 @@ THE POSSIBILITY OF SUCH DAMAGE.
                   implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                   <mainClass>org.openjdk.jmh.Main</mainClass>
                 </transformer>
+                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
               </transformers>
               <filters>
                 <filter>

exonum-java-binding/benchmarks/src/main/java/com/exonum/binding/bench/FlatListProofBenchmark.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2019 The Exonum Team
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.exonum.binding.bench;
+
+import static com.exonum.binding.common.hash.Hashing.sha256;
+import static com.exonum.binding.common.proofs.list.ListProofEntry.checkHeight;
+import static java.util.Collections.singletonList;
+
+import com.exonum.binding.common.hash.HashCode;
+import com.exonum.binding.common.proofs.list.CheckedListProof;
+import com.exonum.binding.common.proofs.list.FlatListProof;
+import com.exonum.binding.common.proofs.list.ListProofElementEntry;
+import com.exonum.binding.common.proofs.list.ListProofHashedEntry;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Level;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+
+@State(Scope.Benchmark)
+@BenchmarkMode(Mode.Throughput)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+public class FlatListProofBenchmark {
+
+  @Param({"10"})
+  private int height;
+
+  private FlatListProof proof;
+
+  /**
+   * Creates a proof for a single element from a tree of the given height.
+   */
+  @Setup(Level.Trial)
+  public void createProof() {
+    /*
+               o
+              / \
+                 h
+            /
+           o
+          / \
+         o   h
+        / \
+       e   h
+     */
+    checkHeight(height);
+    long size = 1L << height;
+    // Create the element(s)
+    // The value size can also be made configurable, though it is not expected to have
+    // a large effect on anything but the first hashing step.
+    byte[] value = {1};
+    List<ListProofElementEntry> elements = singletonList(
+        ListProofElementEntry.newInstance(0L, value));
+    // Create the hash nodes
+    List<ListProofHashedEntry> hashed = new ArrayList<>(height);
+    for (int h = 0; h < height; h++) {
+      HashCode hash = sha256().hashInt(h);
+      hashed.add(ListProofHashedEntry.newInstance(1L, h, hash));
+    }
+    proof = new FlatListProof(elements, hashed, size);
+  }
+
+  @Benchmark
+  public CheckedListProof<?> verify() {
+    return proof.verify();
+  }
+}

exonum-java-binding/common/src/main/java/com/exonum/binding/common/proofs/list/FlatListProof.java

@@ -45,7 +45,7 @@
  * A flat list proof. It proves that certain elements are present in a proof list
  * of a certain size.
  */
-class FlatListProof {
+public class FlatListProof {
   /*
     Proof lists are represented as BSTs, where all leaf elements are at the same height.
     Here is a tree for a three-element proof list:
@@ -95,14 +95,14 @@ class FlatListProof {
   private final List<ListProofHashedEntry> proof;
   private final long size;
 
-  FlatListProof(List<ListProofElementEntry> elements,
+  public FlatListProof(List<ListProofElementEntry> elements,
       List<ListProofHashedEntry> proof, long size) {
     this.elements = checkNotNull(elements);
     this.proof = checkNotNull(proof);
     this.size = size;
   }
 
-  CheckedListProof<byte[]> verify() {
+  public CheckedListProof<byte[]> verify() {
     // Check the size
     if (size < 0 || MAX_SIZE < size) {
       throw new InvalidProofException(String.format("Invalid size (%s), must be in range [0; 2^56]",

exonum-java-binding/common/src/main/java/com/exonum/binding/common/proofs/list/ListProofElementEntry.java

@@ -22,14 +22,14 @@
  * A value stored in the Merkle tree at its bottom level (at height 0).
  */
 @AutoValue
-abstract class ListProofElementEntry implements ListProofEntry {
+public abstract class ListProofElementEntry implements ListProofEntry {
 
   /**
    * Returns a value of the element stored at this index in the list.
    */
   abstract byte[] getElement();
 
-  static ListProofElementEntry newInstance(long index, byte[] element) {
+  public static ListProofElementEntry newInstance(long index, byte[] element) {
     ListProofEntry.checkIndex(index);
     return new AutoValue_ListProofElementEntry(index, element);
   }

exonum-java-binding/common/src/main/java/com/exonum/binding/common/proofs/list/ListProofEntry.java

@@ -18,7 +18,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 
-interface ListProofEntry {
+public interface ListProofEntry {
 
   /**
    * The maximum height of a list proof tree.

exonum-java-binding/common/src/main/java/com/exonum/binding/common/proofs/list/ListProofHashedEntry.java

@@ -23,7 +23,7 @@
  * A hash of a sub-tree in a Merkle proof tree.
  */
 @AutoValue
-abstract class ListProofHashedEntry implements ListProofEntry {
+public abstract class ListProofHashedEntry implements ListProofEntry {
 
   /**
    * Returns the height of the proof tree node corresponding to this entry.
@@ -37,7 +37,7 @@ abstract class ListProofHashedEntry implements ListProofEntry {
    */
   abstract HashCode getHash();
 
-  static ListProofHashedEntry newInstance(long index, int height, HashCode nodeHash) {
+  public static ListProofHashedEntry newInstance(long index, int height, HashCode nodeHash) {
     ListProofEntry.checkIndex(index);
     ListProofEntry.checkHeight(height);
     return new AutoValue_ListProofHashedEntry(index, height, nodeHash);