Add extension API to get/set default diff preferences

Change-Id: Ia2c4e9516b16e79a18c7e4d84911ef548eb1d1c5
Signed-off-by: Edwin Kempin <ekempin@google.com>

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/config/DiffPreferencesIT.java

@@ -18,18 +18,20 @@ import static com.google.common.truth.Truth.assertThat;
 import static com.google.gerrit.server.config.ConfigUtil.skipField;
 
 import com.google.gerrit.acceptance.AbstractDaemonTest;
-import com.google.gerrit.acceptance.RestResponse;
+import com.google.gerrit.acceptance.NoHttpd;
 import com.google.gerrit.extensions.client.DiffPreferencesInfo;
 
 import org.junit.Test;
 
 import java.lang.reflect.Field;
 
+@NoHttpd
 public class DiffPreferencesIT extends AbstractDaemonTest {
 
   @Test
   public void getDiffPreferences() throws Exception {
-    DiffPreferencesInfo result = get();
+    DiffPreferencesInfo result =
+        gApi.config().server().getDefaultDiffPreferences();
     assertPrefsEqual(result, DiffPreferencesInfo.defaults());
   }
 
@@ -38,28 +40,16 @@ public class DiffPreferencesIT extends AbstractDaemonTest {
     int newLineLength = DiffPreferencesInfo.defaults().lineLength + 10;
     DiffPreferencesInfo update = new DiffPreferencesInfo();
     update.lineLength = newLineLength;
-    DiffPreferencesInfo result = put(update);
+    DiffPreferencesInfo result =
+        gApi.config().server().setDefaultDiffPreferences(update);
     assertThat(result.lineLength).named("lineLength").isEqualTo(newLineLength);
 
-    result = get();
+    result = gApi.config().server().getDefaultDiffPreferences();
     DiffPreferencesInfo expected = DiffPreferencesInfo.defaults();
     expected.lineLength = newLineLength;
     assertPrefsEqual(result, expected);
   }
 
-  private DiffPreferencesInfo get() throws Exception {
-    RestResponse r = adminRestSession.get("/config/server/preferences.diff");
-    r.assertOK();
-    return newGson().fromJson(r.getReader(), DiffPreferencesInfo.class);
-  }
-
-  private DiffPreferencesInfo put(DiffPreferencesInfo input) throws Exception {
-    RestResponse r = adminRestSession.put(
-        "/config/server/preferences.diff", input);
-    r.assertOK();
-    return newGson().fromJson(r.getReader(), DiffPreferencesInfo.class);
-  }
-
   private void assertPrefsEqual(DiffPreferencesInfo actual,
       DiffPreferencesInfo expected) throws Exception {
     for (Field field : actual.getClass().getDeclaredFields()) {

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/config/Server.java

@@ -14,6 +14,7 @@
 
 package com.google.gerrit.extensions.api.config;
 
+import com.google.gerrit.extensions.client.DiffPreferencesInfo;
 import com.google.gerrit.extensions.restapi.NotImplementedException;
 import com.google.gerrit.extensions.restapi.RestApiException;
 
@@ -23,6 +24,10 @@ public interface Server {
    */
   String getVersion() throws RestApiException;
 
+  DiffPreferencesInfo getDefaultDiffPreferences() throws RestApiException;
+  DiffPreferencesInfo setDefaultDiffPreferences(DiffPreferencesInfo in)
+      throws RestApiException;
+
   /**
    * A default implementation which allows source compatibility
    * when adding new methods to the interface.
@@ -32,5 +37,17 @@ public interface Server {
     public String getVersion() throws RestApiException {
       throw new NotImplementedException();
     }
+
+    @Override
+    public DiffPreferencesInfo getDefaultDiffPreferences()
+        throws RestApiException {
+      throw new NotImplementedException();
+    }
+
+    @Override
+    public DiffPreferencesInfo setDefaultDiffPreferences(DiffPreferencesInfo in)
+        throws RestApiException {
+      throw new NotImplementedException();
+    }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/api/config/ServerImpl.java

@@ -16,13 +16,52 @@ package com.google.gerrit.server.api.config;
 
 import com.google.gerrit.common.Version;
 import com.google.gerrit.extensions.api.config.Server;
+import com.google.gerrit.extensions.client.DiffPreferencesInfo;
 import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.server.config.ConfigResource;
+import com.google.gerrit.server.config.GetDiffPreferences;
+import com.google.gerrit.server.config.SetDiffPreferences;
+import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
+import org.eclipse.jgit.errors.ConfigInvalidException;
+
+import java.io.IOException;
+
 @Singleton
 public class ServerImpl implements Server {
+  private final GetDiffPreferences getDiffPreferences;
+  private final SetDiffPreferences setDiffPreferences;
+
+  @Inject
+  ServerImpl(GetDiffPreferences getDiffPreferences,
+      SetDiffPreferences setDiffPreferences) {
+    this.getDiffPreferences = getDiffPreferences;
+    this.setDiffPreferences = setDiffPreferences;
+  }
+
   @Override
   public String getVersion() throws RestApiException {
     return Version.getVersion();
   }
+
+  @Override
+  public DiffPreferencesInfo getDefaultDiffPreferences()
+      throws RestApiException {
+    try {
+      return getDiffPreferences.apply(new ConfigResource());
+    } catch (IOException | ConfigInvalidException e) {
+      throw new RestApiException("Cannot get default diff preferences", e);
+    }
+  }
+
+  @Override
+  public DiffPreferencesInfo setDefaultDiffPreferences(DiffPreferencesInfo in)
+      throws RestApiException {
+    try {
+      return setDiffPreferences.apply(new ConfigResource(), in);
+    } catch (IOException | ConfigInvalidException e) {
+      throw new RestApiException("Cannot set default diff preferences", e);
+    }
+  }
 }