Add ByteBuffersTest

Signed-off-by: Fredy Wijaya <fredyw@google.com>

mobile/library/java/io/envoyproxy/envoymobile/engine/BUILD

@@ -30,6 +30,7 @@ android_library(
 java_library(
     name = "envoy_base_engine_lib",
     srcs = [
+        "ByteBuffers.java",
         "EnvoyConfiguration.java",
         "EnvoyEngine.java",
         "EnvoyEngineImpl.java",

mobile/library/java/io/envoyproxy/envoymobile/engine/ByteBuffers.java

@@ -0,0 +1,17 @@
+package io.envoyproxy.envoymobile.engine;
+
+import java.nio.ByteBuffer;
+
+public class ByteBuffers {
+  /**
+   * Copies the specified `ByteBuffer` into a new `ByteBuffer`. The `ByteBuffer` created will
+   * be backed by `byte[]`.
+   */
+  public static ByteBuffer copy(ByteBuffer byteBuffer) {
+    byte[] bytes = new byte[byteBuffer.capacity()];
+    byteBuffer.get(bytes);
+    return ByteBuffer.wrap(bytes);
+  }
+
+  private ByteBuffers() {}
+}

mobile/library/java/io/envoyproxy/envoymobile/engine/JvmCallbackContext.java

@@ -1,7 +1,6 @@
 package io.envoyproxy.envoymobile.engine;
 
 import java.nio.ByteBuffer;
-import java.util.List;
 import java.util.Map;
 
 import io.envoyproxy.envoymobile.engine.types.EnvoyHTTPCallbacks;
@@ -76,9 +75,7 @@ public Object onResponseTrailers(long trailerCount, long[] streamIntel) {
   public Object onResponseData(ByteBuffer data, boolean endStream, long[] streamIntel) {
     // Create a copy of the `data` because the `data` uses direct `ByteBuffer` and the `data` will
     // be destroyed after calling this callback.
-    byte[] bytes = new byte[data.capacity()];
-    data.get(bytes);
-    ByteBuffer copiedData = ByteBuffer.wrap(bytes);
+    ByteBuffer copiedData = ByteBuffers.copy(data);
     callbacks.getExecutor().execute(new Runnable() {
       public void run() {
         callbacks.onData(copiedData, endStream, new EnvoyStreamIntelImpl(streamIntel));

mobile/library/java/io/envoyproxy/envoymobile/engine/JvmFilterContext.java

@@ -66,8 +66,11 @@ public Object onRequestHeaders(long headerCount, boolean endStream, long[] strea
    * @return Object[],   pair of HTTP filter status and optional modified data.
    */
   public Object onRequestData(ByteBuffer data, boolean endStream, long[] streamIntel) {
+    // Create a copy of the `data` because the `data` uses direct `ByteBuffer` and the `data` will
+    // be destroyed after calling this callback.
+    ByteBuffer copiedData = ByteBuffers.copy(data);
     return toJniFilterDataStatus(
-        filter.onRequestData(data, endStream, new EnvoyStreamIntelImpl(streamIntel)));
+        filter.onRequestData(copiedData, endStream, new EnvoyStreamIntelImpl(streamIntel)));
   }
 
   /**
@@ -108,8 +111,11 @@ public Object onResponseHeaders(long headerCount, boolean endStream, long[] stre
    * @return Object[],   pair of HTTP filter status and optional modified data.
    */
   public Object onResponseData(ByteBuffer data, boolean endStream, long[] streamIntel) {
+    // Create a copy of the `data` because the `data` uses direct `ByteBuffer` and the `data` will
+    // be destroyed after calling this callback.
+    ByteBuffer copiedData = ByteBuffers.copy(data);
     return toJniFilterDataStatus(
-        filter.onResponseData(data, endStream, new EnvoyStreamIntelImpl(streamIntel)));
+        filter.onResponseData(copiedData, endStream, new EnvoyStreamIntelImpl(streamIntel)));
   }
 
   /**
@@ -138,6 +144,9 @@ public Object onResponseTrailers(long trailerCount, long[] streamIntel) {
    */
   public Object onResumeRequest(long headerCount, ByteBuffer data, long trailerCount,
                                 boolean endStream, long[] streamIntel) {
+    // Create a copy of the `data` because the `data` uses direct `ByteBuffer` and the `data` will
+    // be destroyed after calling this callback.
+    ByteBuffer copiedData = ByteBuffers.copy(data);
     // Headers are optional in this call, and a negative length indicates omission.
     Map<String, List<String>> headers = null;
     if (headerCount >= 0) {
@@ -150,7 +159,7 @@ public Object onResumeRequest(long headerCount, ByteBuffer data, long trailerCou
       assert trailerUtility.validateCount(trailerCount);
       trailers = trailerUtility.retrieveHeaders();
     }
-    return toJniFilterResumeStatus(filter.onResumeRequest(headers, data, trailers, endStream,
+    return toJniFilterResumeStatus(filter.onResumeRequest(headers, copiedData, trailers, endStream,
                                                           new EnvoyStreamIntelImpl(streamIntel)));
   }
 
@@ -166,6 +175,9 @@ public Object onResumeRequest(long headerCount, ByteBuffer data, long trailerCou
    */
   public Object onResumeResponse(long headerCount, ByteBuffer data, long trailerCount,
                                  boolean endStream, long[] streamIntel) {
+    // Create a copy of the `data` because the `data` uses direct `ByteBuffer` and the `data` will
+    // be destroyed after calling this callback.
+    ByteBuffer copiedData = ByteBuffers.copy(data);
     // Headers are optional in this call, and a negative length indicates omission.
     Map<String, List<String>> headers = null;
     if (headerCount >= 0) {
@@ -178,7 +190,7 @@ public Object onResumeResponse(long headerCount, ByteBuffer data, long trailerCo
       assert trailerUtility.validateCount(trailerCount);
       trailers = trailerUtility.retrieveHeaders();
     }
-    return toJniFilterResumeStatus(filter.onResumeResponse(headers, data, trailers, endStream,
+    return toJniFilterResumeStatus(filter.onResumeResponse(headers, copiedData, trailers, endStream,
                                                            new EnvoyStreamIntelImpl(streamIntel)));
   }
 

mobile/test/java/io/envoyproxy/envoymobile/engine/BUILD

@@ -67,3 +67,23 @@ envoy_mobile_android_test(
         "//test/kotlin/io/envoyproxy/envoymobile/mocks:mocks_lib",
     ],
 )
+
+envoy_mobile_android_test(
+    name = "byte_buffers_test",
+    srcs = [
+        "ByteBuffersTest.java",
+    ],
+    associates = ["//library/kotlin/io/envoyproxy/envoymobile:envoy_interfaces_lib"],
+    native_deps = [
+        "//test/jni:libenvoy_jni_with_test_extensions.so",
+    ] + select({
+        "@platforms//os:macos": [
+            "//test/jni:libenvoy_jni_with_test_extensions_jnilib",
+        ],
+        "//conditions:default": [],
+    }),
+    native_lib_name = "envoy_jni_with_test_extensions",
+    deps = [
+        "//library/java/io/envoyproxy/envoymobile/engine:envoy_base_engine_lib",
+    ],
+)

mobile/test/java/io/envoyproxy/envoymobile/engine/ByteBuffersTest.java

@@ -0,0 +1,26 @@
+package io.envoyproxy.envoymobile.engine;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.nio.ByteBuffer;
+
+@RunWith(AndroidJUnit4.class)
+public class ByteBuffersTest {
+  @Test
+  public void testCopy() {
+    ByteBuffer source = ByteBuffer.allocateDirect(3);
+    source.put((byte)1);
+    source.put((byte)2);
+    source.put((byte)3);
+    source.flip();
+
+    ByteBuffer dest = ByteBuffers.copy(source);
+    source.flip();
+    assertThat(dest).isEqualTo(source);
+  }
+}

mobile/test/java/io/envoyproxy/envoymobile/utilities/ByteBuffersTest.java

@@ -0,0 +1,7 @@
+package io.envoyproxy.envoymobile.utilities;
+
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+@RunWith(RobolectricTestRunner.class)
+public class ByteBuffersTest {}