Lp 10190 support gzip (#318)

* accepted encodgin gzip

* Leanplum feature flag

* fixed feature flag

* Update AndroidSDKCore/src/main/java/com/leanplum/internal/Util.java

Co-Authored-By: hrishileanplum <[email protected]>

* cleanup code

* useragent gzip support added

* support gzip response parsing

* test cases added

* test cases

* cleanup

* comment

* trim logic

Author: hrishileanplum

AndroidSDKCore/src/main/java/com/leanplum/internal/Constants.java

@@ -38,6 +38,7 @@ public class Constants {
   public static int NETWORK_TIMEOUT_SECONDS_FOR_DOWNLOADS = 10;
   public static String LEANPLUM_VERSION = BuildConfig.SDK_VERSION + '.' + BuildConfig.BUILD_NUMBER;
   public static String CLIENT = "android";
+  public static String LEANPLUM_SUPPORTED_ENCODING = "gzip";
 
   static final String LEANPLUM_PACKAGE_IDENTIFIER = BuildConfig.LEANPLUM_PACKAGE_IDENTIFIER;
   static final String INVALID_MAC_ADDRESS = "02:00:00:00:00:00";

AndroidSDKCore/src/main/java/com/leanplum/internal/Util.java

@@ -81,6 +81,7 @@
 import java.util.UUID;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
+import java.util.zip.GZIPInputStream;
 
 import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLSocketFactory;
@@ -553,10 +554,18 @@ static HttpURLConnection createHttpUrlConnection(
     urlConnection.setUseCaches(false);
     urlConnection.setInstanceFollowRedirects(true);
     Context context = Leanplum.getContext();
+
+    /*
+      Must include `Accept-Encoding: gzip` in the header
+      Must include the phrase `gzip` in the `User-Agent` header
+      https://cloud.google.com/appengine/kb/
+    */
+
     urlConnection.setRequestProperty("User-Agent",
         getApplicationName(context) + "/" + getVersionName() + "/" + RequestOld.appId() + "/" +
             Constants.CLIENT + "/" + Constants.LEANPLUM_VERSION + "/" + getSystemName() + "/" +
-            getSystemVersion() + "/" + Constants.LEANPLUM_PACKAGE_IDENTIFIER);
+            getSystemVersion() + "/" + Constants.LEANPLUM_SUPPORTED_ENCODING + "/" + Constants.LEANPLUM_PACKAGE_IDENTIFIER);
+    urlConnection.setRequestProperty("Accept-Encoding", Constants.LEANPLUM_SUPPORTED_ENCODING);
     return urlConnection;
   }
 
@@ -660,7 +669,12 @@ public static void saveResponse(URLConnection op, OutputStream outputStream) thr
   private static String getResponse(HttpURLConnection op) throws IOException {
     InputStream inputStream;
     if (op.getResponseCode() < 400) {
-      inputStream = op.getInputStream();
+      String contentHeader = op.getHeaderField("content-encoding");
+      if (contentHeader != null && contentHeader.trim().equalsIgnoreCase(Constants.LEANPLUM_SUPPORTED_ENCODING)) {
+        inputStream = new GZIPInputStream(op.getInputStream());
+      } else {
+        inputStream = op.getInputStream();
+      }
     } else {
       inputStream = op.getErrorStream();
     }

AndroidSDKTests/src/test/java/com/leanplum/internal/UtilTest.java

@@ -0,0 +1,71 @@
+package com.leanplum.internal;
+
+import com.leanplum.__setup.LeanplumTestApp;
+import com.leanplum._whitebox.utilities.ResponseHelper;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PowerMockIgnore;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import java.net.HttpURLConnection;
+
+import static junit.framework.Assert.assertNotNull;
+import static org.powermock.api.mockito.PowerMockito.mock;
+import static org.powermock.api.mockito.PowerMockito.when;
+
+/**
+ * Tests for {@link Util} class.
+ *
+ * @author Hrishi Amravatkar
+ */
+@RunWith(RobolectricTestRunner.class)
+@Config(
+    sdk = 16,
+    application = LeanplumTestApp.class
+)
+@PowerMockIgnore({
+    "org.mockito.*",
+    "org.robolectric.*",
+    "org.json.*",
+    "org.powermock.*",
+    "android.*"
+})
+@PrepareForTest({Util.class})
+public class UtilTest {
+
+  /**
+   * Runs before every test case.
+   */
+  @Before
+  public void setUp() {
+  }
+
+
+  /**
+   * Test for {@link Util#getJsonResponse(HttpURLConnection op)} that returns no gzip unmarshalled data.
+   */
+  @Test
+  public void getNonGzipEncodedResponseWithNoContentEncodingTest() throws Exception {
+    HttpURLConnection mockHttpUrlConnection = mock(HttpURLConnection.class);
+    when(mockHttpUrlConnection.getInputStream()).thenReturn(ResponseHelper.class.getResourceAsStream("/responses/simple_start_response.json"));
+    when(mockHttpUrlConnection.getResponseCode()).thenReturn(200);
+    assertNotNull(Util.getJsonResponse(mockHttpUrlConnection));
+  }
+
+  /**
+   * Test for {@link Util#getJsonResponse(HttpURLConnection op)} that returns gzip unmarshalled data.
+   */
+  @Test
+  public void getGzipEncodedResponseWithContentEndingTest() throws Exception {
+    HttpURLConnection mockHttpUrlConnection = mock(HttpURLConnection.class);
+    when(mockHttpUrlConnection.getInputStream()).thenReturn(ResponseHelper.class.getResourceAsStream("/responses/simple_start_response.json.gz"));
+    when(mockHttpUrlConnection.getResponseCode()).thenReturn(200);
+    when(mockHttpUrlConnection.getHeaderField("content-encoding")).thenReturn("gzip");
+    assertNotNull(Util.getJsonResponse(mockHttpUrlConnection));
+  }
+
+}