add cpc-go cross-serde

Author: QasimKhan5d

src/test/java/org/apache/datasketches/common/TestUtil.java

@@ -47,6 +47,7 @@ public final class TestUtil  {
    */
   public static final String GENERATE_JAVA_FILES = "generate_java_files";
   public static final String CHECK_CPP_FILES = "check_cpp_files";
+  public static final String CHECK_GO_FILES = "check_go_files";
   public static final String CHECK_CPP_HISTORICAL_FILES = "check_cpp_historical_files";
 
   /**
@@ -59,6 +60,11 @@ public final class TestUtil  {
    */
   public static final Path cppPath = createPath("serialization_test_data/cpp_generated_files");
 
+  /**
+   * The full target Path for Go serialized sketches to be tested by Java.
+   */
+  public static final Path goPath = createPath("serialization_test_data/go_generated_files");
+
   private static Path createPath(final String projectLocalDir) {
     try {
       return Files.createDirectories(Paths.get(userDir, projectLocalDir));

src/test/java/org/apache/datasketches/cpc/CpcSketchCrossLanguageTest.java

@@ -20,8 +20,10 @@
 package org.apache.datasketches.cpc;
 
 import static org.apache.datasketches.common.TestUtil.CHECK_CPP_FILES;
+import static org.apache.datasketches.common.TestUtil.CHECK_GO_FILES;
 import static org.apache.datasketches.common.TestUtil.GENERATE_JAVA_FILES;
 import static org.apache.datasketches.common.TestUtil.cppPath;
+import static org.apache.datasketches.common.TestUtil.goPath;
 import static org.apache.datasketches.common.TestUtil.javaPath;
 import static org.testng.Assert.assertEquals;
 
@@ -78,4 +80,17 @@ public void allFlavors() throws IOException {
     }
   }
 
+  @Test(groups = {CHECK_GO_FILES})
+  public void checkAllFlavorsGo() throws IOException {
+    final int[] nArr = {0, 100, 200, 2000, 20000};
+    final Flavor[] flavorArr = {Flavor.EMPTY, Flavor.SPARSE, Flavor.HYBRID, Flavor.PINNED, Flavor.SLIDING};
+    int flavorIdx = 0;
+    for (int n: nArr) {
+      final byte[] bytes = Files.readAllBytes(goPath.resolve("cpc_n" + n + "_go.sk"));
+      final CpcSketch sketch = CpcSketch.heapify(Memory.wrap(bytes));
+      assertEquals(sketch.getFlavor(), flavorArr[flavorIdx++]);
+      assertEquals(sketch.getEstimate(), n, n * 0.02);
+    }
+  }
+
 }