Inline Edit: Acquire content and type in one request

BinaryResult can return X-FYI-Content-Type header with the
real content type. Use this inside of FileContentUtil to
send back the actual type in one request.

By using a single request the server only needs to load
object data into memory once, to determine type and to
stream the content to the client.

Move base64 decoding into RestApi. The format is very
predictable from the server and can be applied to any
REST API call made from the browser.

Change-Id: I3b6c83efd0eb76148a3ac3e50cd2e3e4c37f08c5

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/edit/ChangeEditIT.java

@@ -59,6 +59,7 @@ import com.google.inject.Inject;
 import org.apache.commons.codec.binary.Base64;
 import org.apache.commons.codec.binary.StringUtils;
 import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.joda.time.DateTime;
@@ -194,10 +195,10 @@ public class ChangeEditIT extends AbstractDaemonTest {
     Date beforeRebase = edit.getEditCommit().getCommitterIdent().getWhen();
     modifier.rebaseEdit(edit, current);
     edit = editUtil.byChange(change).get();
-    assertByteArray(fileUtil.getContent(edit.getChange().getProject(), edit
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.getChange().getProject()),
-        .getRevision().get(), FILE_NAME), CONTENT_NEW);
+        ObjectId.fromString(edit.getRevision().get()), FILE_NAME), CONTENT_NEW);
-    assertByteArray(fileUtil.getContent(edit.getChange().getProject(), edit
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.getChange().getProject()),
-        .getRevision().get(), FILE_NAME2), CONTENT_NEW2);
+        ObjectId.fromString(edit.getRevision().get()), FILE_NAME2), CONTENT_NEW2);
     assertThat(edit.getBasePatchSet().getPatchSetId()).isEqualTo(
         current.getPatchSetId());
     Date afterRebase = edit.getEditCommit().getCommitterIdent().getWhen();
@@ -218,10 +219,10 @@ public class ChangeEditIT extends AbstractDaemonTest {
     RestResponse r = adminSession.post(urlRebase());
     assertThat(r.getStatusCode()).isEqualTo(SC_NO_CONTENT);
     edit = editUtil.byChange(change).get();
-    assertByteArray(fileUtil.getContent(edit.getChange().getProject(), edit
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.getChange().getProject()),
-        .getRevision().get(), FILE_NAME), CONTENT_NEW);
+        ObjectId.fromString(edit.getRevision().get()), FILE_NAME), CONTENT_NEW);
-    assertByteArray(fileUtil.getContent(edit.getChange().getProject(), edit
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.getChange().getProject()),
-        .getRevision().get(), FILE_NAME2), CONTENT_NEW2);
+        ObjectId.fromString(edit.getRevision().get()), FILE_NAME2), CONTENT_NEW2);
     assertThat(edit.getBasePatchSet().getPatchSetId()).isEqualTo(
         current.getPatchSetId());
     Date afterRebase = edit.getEditCommit().getCommitterIdent().getWhen();
@@ -235,9 +236,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(modifier.modifyFile(edit.get(), FILE_NAME, RestSession.newRawInput(CONTENT_NEW)))
         .isEqualTo(RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_NEW);
-            .getRevision().get(), FILE_NAME), CONTENT_NEW);
     editUtil.delete(edit.get());
     edit = editUtil.byChange(change);
     assertThat(edit.isPresent()).isFalse();
@@ -364,8 +364,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
         RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
     try {
-      fileUtil.getContent(edit.get().getChange().getProject(),
+      fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-          edit.get().getRevision().get(), FILE_NAME);
+          ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME);
       fail("ResourceNotFoundException expected");
     } catch (ResourceNotFoundException rnfe) {
     }
@@ -377,8 +377,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(r.getStatusCode()).isEqualTo(SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
     try {
-      fileUtil.getContent(edit.get().getChange().getProject(),
+      fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-          edit.get().getRevision().get(), FILE_NAME);
+          ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME);
       fail("ResourceNotFoundException expected");
     } catch (ResourceNotFoundException rnfe) {
     }
@@ -397,8 +397,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
         SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
     try {
-      fileUtil.getContent(edit.get().getChange().getProject(),
+      fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-          edit.get().getRevision().get(), FILE_NAME);
+          ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME);
       fail("ResourceNotFoundException expected");
     } catch (ResourceNotFoundException rnfe) {
     }
@@ -412,9 +412,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(modifier.restoreFile(edit.get(), FILE_NAME)).isEqualTo(
         RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change2);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_OLD);
-            .getRevision().get(), FILE_NAME), CONTENT_OLD);
   }
 
   @Test
@@ -424,9 +423,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(adminSession.post(urlEdit2(), in).getStatusCode()).isEqualTo(
         SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change2);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_OLD);
-            .getRevision().get(), FILE_NAME), CONTENT_OLD);
   }
 
   @Test
@@ -436,15 +434,13 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(modifier.modifyFile(edit.get(), FILE_NAME, RestSession.newRawInput(CONTENT_NEW)))
         .isEqualTo(RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_NEW);
-            .getRevision().get(), FILE_NAME), CONTENT_NEW);
     assertThat(modifier.modifyFile(edit.get(), FILE_NAME, RestSession.newRawInput(CONTENT_NEW2)))
         .isEqualTo(RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_NEW2);
-            .getRevision().get(), FILE_NAME), CONTENT_NEW2);
   }
 
   @Test
@@ -454,16 +450,14 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(adminSession.putRaw(urlEditFile(), in.content).getStatusCode())
         .isEqualTo(SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_NEW);
-            .getRevision().get(), FILE_NAME), CONTENT_NEW);
     in.content = RestSession.newRawInput(CONTENT_NEW2);
     assertThat(adminSession.putRaw(urlEditFile(), in.content).getStatusCode())
         .isEqualTo(SC_NO_CONTENT);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_NEW2);
-            .getRevision().get(), FILE_NAME), CONTENT_NEW2);
   }
 
   @Test
@@ -474,9 +468,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(adminSession.putRaw(urlEditFile(), in.content).getStatusCode())
         .isEqualTo(SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_NEW);
-            .getRevision().get(), FILE_NAME), CONTENT_NEW);
   }
 
   @Test
@@ -485,9 +478,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(adminSession.put(urlEditFile()).getStatusCode()).isEqualTo(
         SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), "".getBytes());
-            .getRevision().get(), FILE_NAME), "".getBytes());
   }
 
   @Test
@@ -495,9 +487,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(adminSession.post(urlEdit()).getStatusCode()).isEqualTo(
         SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME), CONTENT_OLD);
-            .getRevision().get(), FILE_NAME), CONTENT_OLD);
   }
 
   @Test
@@ -536,8 +527,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
         SC_NO_CONTENT);
     Optional<ChangeEdit> edit = editUtil.byChange(change);
     try {
-      fileUtil.getContent(edit.get().getChange().getProject(),
+      fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-          edit.get().getRevision().get(), FILE_NAME);
+          ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME);
       fail("ResourceNotFoundException expected");
     } catch (ResourceNotFoundException rnfe) {
     }
@@ -552,9 +543,8 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(modifier.modifyFile(edit.get(), FILE_NAME2, RestSession.newRawInput(CONTENT_NEW)))
         .isEqualTo(RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME2), CONTENT_NEW);
-            .getRevision().get(), FILE_NAME2), CONTENT_NEW);
   }
 
   @Test
@@ -564,15 +554,13 @@ public class ChangeEditIT extends AbstractDaemonTest {
     assertThat(modifier.modifyFile(edit.get(), FILE_NAME2, RestSession.newRawInput(CONTENT_NEW)))
         .isEqualTo(RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME2), CONTENT_NEW);
-            .getRevision().get(), FILE_NAME2), CONTENT_NEW);
     assertThat(modifier.modifyFile(edit.get(), FILE_NAME2, RestSession.newRawInput(CONTENT_NEW2)))
         .isEqualTo(RefUpdate.Result.FORCED);
     edit = editUtil.byChange(change);
-    assertByteArray(
+    assertByteArray(fileUtil.getContent(projectCache.get(edit.get().getChange().getProject()),
-        fileUtil.getContent(edit.get().getChange().getProject(), edit.get()
+        ObjectId.fromString(edit.get().getRevision().get()), FILE_NAME2), CONTENT_NEW2);
-            .getRevision().get(), FILE_NAME2), CONTENT_NEW2);
   }
 
   @Test

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/FileTextBox.java

@@ -16,6 +16,9 @@ package com.google.gerrit.client.change;
 
 import com.google.gerrit.client.changes.ChangeFileApi;
 import com.google.gerrit.client.rpc.GerritCallback;
+import com.google.gerrit.client.rpc.HttpCallback;
+import com.google.gerrit.client.rpc.HttpResponse;
+import com.google.gerrit.client.rpc.NativeString;
 import com.google.gerrit.client.rpc.RestApi;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gwt.event.dom.client.BlurEvent;
@@ -51,10 +54,10 @@ class FileTextBox extends NpTextBox {
   }
 
   private void loadFileContent() {
-    ChangeFileApi.getContent(id, getText(), new GerritCallback<String>() {
+    ChangeFileApi.getContent(id, getText(), new HttpCallback<NativeString>() {
       @Override
-      public void onSuccess(String result) {
+      public void onSuccess(HttpResponse<NativeString> result) {
-        textArea.setText(result);
+        textArea.setText(result.getResult().asString());
       }
 
       @Override
@@ -62,7 +65,7 @@ class FileTextBox extends NpTextBox {
         if (RestApi.isNotFound(caught)) {
           // that means that the file doesn't exist in the repository
         } else {
-          super.onFailure(caught);
+          GerritCallback.showFailure(caught);
         }
       }
     });

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeFileApi.java

@@ -16,6 +16,7 @@ package com.google.gerrit.client.changes;
 
 import com.google.gerrit.client.VoidResult;
 import com.google.gerrit.client.rpc.GerritCallback;
+import com.google.gerrit.client.rpc.HttpCallback;
 import com.google.gerrit.client.rpc.NativeString;
 import com.google.gerrit.client.rpc.RestApi;
 import com.google.gerrit.reviewdb.client.Change;
@@ -29,52 +30,10 @@ import com.google.gwt.user.client.rpc.AsyncCallback;
  * files in a change.
  */
 public class ChangeFileApi {
-  static abstract class CallbackWrapper<I, O> implements AsyncCallback<I> {
-    protected AsyncCallback<O> wrapped;
-
-    public CallbackWrapper(AsyncCallback<O> callback) {
-      wrapped = callback;
-    }
-
-    @Override
-    public abstract void onSuccess(I result);
-
-    @Override
-    public void onFailure(Throwable caught) {
-      wrapped.onFailure(caught);
-    }
-  }
-
-  private static CallbackWrapper<NativeString, String> wrapper(
-      AsyncCallback<String> cb) {
-    return new CallbackWrapper<NativeString, String>(cb) {
-      @Override
-      public void onSuccess(NativeString b64) {
-        if (b64 != null) {
-          wrapped.onSuccess(b64decode(b64.asString()));
-        }
-      }
-    };
-  }
-
   /** Get the contents of a File in a PatchSet or change edit. */
   public static void getContent(PatchSet.Id id, String filename,
-      AsyncCallback<String> cb) {
+      HttpCallback<NativeString> cb) {
-    contentEditOrPs(id, filename).get(wrapper(cb));
+    contentEditOrPs(id, filename).get(cb);
-  }
-
-  /** Get the content type of a File in a PatchSet or change edit. */
-  public static void getContentType(PatchSet.Id id, String filename,
-      AsyncCallback<String> cb) {
-    contentTypeEditOrPs(id, filename).get(
-        new CallbackWrapper<NativeString, String>(cb) {
-          @Override
-          public void onSuccess(NativeString str) {
-            if (str != null) {
-              wrapped.onSuccess(str.asString());
-            }
-          }
-        });
   }
 
   /**
@@ -82,11 +41,11 @@ public class ChangeFileApi {
    * edit.
    **/
   public static void getContentOrMessage(PatchSet.Id id, String path,
-      AsyncCallback<String> cb) {
+      HttpCallback<NativeString> cb) {
     RestApi api = (Patch.COMMIT_MSG.equals(path) && id.get() == 0)
         ? messageEdit(id)
         : contentEditOrPs(id, path);
-    api.get(wrapper(cb));
+    api.get(cb);
   }
 
   /** Put contents into a File in a change edit. */
@@ -141,18 +100,10 @@ public class ChangeFileApi {
     return ChangeApi.change(id.getParentKey().get()).view("edit:message");
   }
 
-  private static RestApi contentTypeEditOrPs(PatchSet.Id id, String filename) {
-    return id.get() == 0
-        ? contentEdit(id.getParentKey(), filename).view("type")
-        : ChangeApi.revision(id).view("files").id(filename).view("type");
-  }
-
   private static RestApi contentEdit(Change.Id id, String filename) {
     return ChangeApi.edit(id.get()).id(filename);
   }
 
-  private static native String b64decode(String a) /*-{ return window.atob(a); }-*/;
-
   private static class Input extends JavaScriptObject {
     final native void restore_path(String p) /*-{ if(p)this.restore_path=p; }-*/;
 

gerrit-gwtui/src/main/java/com/google/gerrit/client/editor/EditScreen.java

@@ -25,6 +25,9 @@ import com.google.gerrit.client.diff.FileInfo;
 import com.google.gerrit.client.diff.Header;
 import com.google.gerrit.client.rpc.CallbackGroup;
 import com.google.gerrit.client.rpc.GerritCallback;
+import com.google.gerrit.client.rpc.HttpCallback;
+import com.google.gerrit.client.rpc.HttpResponse;
+import com.google.gerrit.client.rpc.NativeString;
 import com.google.gerrit.client.rpc.ScreenLoadCallback;
 import com.google.gerrit.client.ui.Screen;
 import com.google.gerrit.common.PageLinks;
@@ -68,7 +71,7 @@ public class EditScreen extends Screen {
   private final String path;
   private DiffPreferences prefs;
   private CodeMirror cm;
-  private String type;
+  private HttpResponse<NativeString> content;
 
   @UiField Element header;
   @UiField Element project;
@@ -116,20 +119,6 @@ public class EditScreen extends Screen {
       }
     }));
 
-    if (prefs.syntaxHighlighting() && !Patch.COMMIT_MSG.equals(path)) {
-      final AsyncCallback<Void> modeInjectorCb = group.addEmpty();
-      ChangeFileApi.getContentType(revision, path,
-          cmGroup.add(new GerritCallback<String>() {
-            @Override
-            public void onSuccess(String result) {
-              ModeInfo mode = ModeInfo.findMode(result, path);
-              type = mode != null ? mode.mime() : null;
-              injectMode(result, modeInjectorCb);
-            }
-          }));
-    }
-    cmGroup.done();
-
     ChangeApi.detail(revision.getParentKey().get(),
         group.add(new GerritCallback<ChangeInfo>() {
           @Override
@@ -140,12 +129,34 @@ public class EditScreen extends Screen {
         }));
 
     ChangeFileApi.getContentOrMessage(revision, path,
-        group.addFinal(new ScreenLoadCallback<String>(this) {
+        cmGroup.add(new HttpCallback<NativeString>() {
+          final AsyncCallback<Void> modeCallback = group.addEmpty();
+
           @Override
-          protected void preDisplay(String content) {
+          public void onSuccess(HttpResponse<NativeString> fc) {
-            initEditor(content);
+            content = fc;
+            if (prefs.syntaxHighlighting()) {
+              injectMode(fc.getContentType(), modeCallback);
+            } else {
+              modeCallback.onSuccess(null);
+            }
+          }
+
+          @Override
+          public void onFailure(Throwable e) {
+            GerritCallback.showFailure(e);
           }
         }));
+
+    group.addListener(new ScreenLoadCallback<Void>(this) {
+      @Override
+      protected void preDisplay(Void result) {
+        initEditor(content);
+        content = null;
+      }
+    });
+    cmGroup.done();
+    group.done();
   }
 
   @Override
@@ -223,12 +234,12 @@ public class EditScreen extends Screen {
     Gerrit.display(PageLinks.toChangeInEditMode(revision.getParentKey()));
   }
 
-  private void initEditor(String content) {
+  private void initEditor(HttpResponse<NativeString> file) {
     ModeInfo mode = prefs.syntaxHighlighting()
-        ? ModeInfo.findMode(type, path)
+        ? ModeInfo.findMode(file.getContentType(), path)
         : null;
     cm = CodeMirror.create(editor, Configuration.create()
-        .set("value", content)
+        .set("value", file.getResult().asString())
         .set("readOnly", false)
         .set("cursorBlinkRate", 0)
         .set("cursorHeight", 0.85)

gerrit-gwtui/src/main/java/com/google/gerrit/client/rpc/CallbackGroup.java

@@ -42,8 +42,8 @@ import java.util.Set;
  * processing it.
  */
 public class CallbackGroup {
-  private final List<CallbackImpl<?>> callbacks;
+  private final List<CallbackGlue> callbacks;
-  private final Set<CallbackImpl<?>> remaining;
+  private final Set<CallbackGlue> remaining;
   private boolean finalAdded;
 
   private boolean failed;
@@ -76,6 +76,27 @@ public class CallbackGroup {
     return handleAdd(cb);
   }
 
+  public <T> HttpCallback<T> add(HttpCallback<T> cb) {
+    checkFinalAdded();
+    if (failed) {
+      cb.onFailure(failedThrowable);
+      return new HttpCallback<T>() {
+        @Override
+        public void onSuccess(HttpResponse<T> result) {
+        }
+
+        @Override
+        public void onFailure(Throwable caught) {
+        }
+      };
+    }
+
+    HttpCallbackImpl<T> w = new HttpCallbackImpl<>(cb);
+    callbacks.add(w);
+    remaining.add(w);
+    return w;
+  }
+
   public <T> Callback<T> addFinal(final AsyncCallback<T> cb) {
     checkFinalAdded();
     finalAdded = true;
@@ -84,7 +105,7 @@ public class CallbackGroup {
 
   public void done() {
     finalAdded = true;
-    applyAllSuccess();
+    apply();
   }
 
   public void addListener(AsyncCallback<Void> cb) {
@@ -99,20 +120,31 @@ public class CallbackGroup {
     addListener(group.<Void> addEmpty());
   }
 
-  private void applyAllSuccess() {
+  private void success(CallbackGlue cb) {
-    if (!failed && finalAdded && remaining.isEmpty()) {
+    remaining.remove(cb);
-      for (CallbackImpl<?> cb : callbacks) {
+    apply();
-        cb.applySuccess();
-      }
-      callbacks.clear();
-    }
   }
 
-  private void applyAllFailed() {
+  private <T> void failure(CallbackGlue w, Throwable caught) {
-    if (failed && finalAdded && remaining.isEmpty()) {
+    if (!failed) {
-      for (CallbackImpl<?> cb : callbacks) {
+      failed = true;
+      failedThrowable = caught;
+    }
+    remaining.remove(w);
+    apply();
+  }
+
+  private void apply() {
+    if (finalAdded && remaining.isEmpty()) {
+      if (failed) {
+        for (CallbackGlue cb : callbacks) {
           cb.applyFailed();
         }
+      } else {
+        for (CallbackGlue cb : callbacks) {
+          cb.applySuccess();
+        }
+      }
       callbacks.clear();
     }
   }
@@ -139,7 +171,12 @@ public class CallbackGroup {
       extends AsyncCallback<T>, com.google.gwtjsonrpc.common.AsyncCallback<T> {
   }
 
-  private class CallbackImpl<T> implements Callback<T> {
+  private interface CallbackGlue {
+    void applySuccess();
+    void applyFailed();
+  }
+
+  private class CallbackImpl<T> implements Callback<T>, CallbackGlue {
     AsyncCallback<T> delegate;
     T result;
 
@@ -150,21 +187,16 @@ public class CallbackGroup {
     @Override
     public void onSuccess(T value) {
       this.result = value;
-      remaining.remove(this);
+      success(this);
-      CallbackGroup.this.applyAllSuccess();
     }
 
     @Override
     public void onFailure(Throwable caught) {
-      if (!failed) {
+      failure(this, caught);
-        failed = true;
-        failedThrowable = caught;
-      }
-      remaining.remove(this);
-      CallbackGroup.this.applyAllFailed();
     }
 
-    void applySuccess() {
+    @Override
+    public void applySuccess() {
       AsyncCallback<T> cb = delegate;
       if (cb != null) {
         delegate = null;
@@ -173,7 +205,8 @@ public class CallbackGroup {
       }
     }
 
-    void applyFailed() {
+    @Override
+    public void applyFailed() {
       AsyncCallback<T> cb = delegate;
       if (cb != null) {
         delegate = null;
@@ -182,4 +215,44 @@ public class CallbackGroup {
       }
     }
   }
+
+  private class HttpCallbackImpl<T> implements HttpCallback<T>, CallbackGlue {
+    private HttpCallback<T> delegate;
+    private HttpResponse<T> result;
+
+    HttpCallbackImpl(HttpCallback<T> delegate) {
+      this.delegate = delegate;
+    }
+
+    @Override
+    public void onSuccess(HttpResponse<T> result) {
+      this.result = result;
+      success(this);
+    }
+
+    @Override
+    public void onFailure(Throwable caught) {
+      failure(this, caught);
+    }
+
+    @Override
+    public void applySuccess() {
+      HttpCallback<T> cb = delegate;
+      if (cb != null) {
+        delegate = null;
+        cb.onSuccess(result);
+        result = null;
+      }
+    }
+
+    @Override
+    public void applyFailed() {
+      HttpCallback<T> cb = delegate;
+      if (cb != null) {
+        delegate = null;
+        result = null;
+        cb.onFailure(failedThrowable);
+      }
+    }
+  }
 }

gerrit-gwtui/src/main/java/com/google/gerrit/client/rpc/GerritCallback.java

@@ -23,7 +23,6 @@ import com.google.gerrit.common.errors.NoSuchAccountException;
 import com.google.gerrit.common.errors.NoSuchEntityException;
 import com.google.gerrit.common.errors.NoSuchGroupException;
 import com.google.gerrit.common.errors.NotSignedInException;
-import com.google.gwt.core.client.GWT;
 import com.google.gwt.user.client.rpc.InvocationException;
 import com.google.gwtjsonrpc.client.RemoteJsonException;
 import com.google.gwtjsonrpc.client.ServerUnavailableException;
@@ -35,6 +34,10 @@ public abstract class GerritCallback<T> implements
     com.google.gwt.user.client.rpc.AsyncCallback<T> {
   @Override
   public void onFailure(final Throwable caught) {
+    showFailure(caught);
+  }
+
+  public static void showFailure(Throwable caught) {
     if (isNotSignedIn(caught) || isInvalidXSRF(caught)) {
       new NotSignedInDialog().center();
 
@@ -70,7 +73,6 @@ public abstract class GerritCallback<T> implements
       new ErrorDialog(RpcConstants.C.errorServerUnavailable()).center();
 
     } else {
-      GWT.log(getClass().getName() + " caught " + caught, caught);
       new ErrorDialog(caught).center();
     }
   }

gerrit-gwtui/src/main/java/com/google/gerrit/client/rpc/HttpCallback.java

@@ -0,0 +1,21 @@
+// Copyright (C) 2015 The Android Open Source Project
+//
+// 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.google.gerrit.client.rpc;
+
+/** AsyncCallback supplied with HTTP response headers. */
+public interface HttpCallback<T> {
+  void onSuccess(HttpResponse<T> result);
+  void onFailure(Throwable caught);
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/rpc/HttpResponse.java

@@ -0,0 +1,56 @@
+// Copyright (C) 2015 The Android Open Source Project
+//
+// 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.google.gerrit.client.rpc;
+
+import com.google.gwt.http.client.Response;
+
+/** Wraps decoded server reply with HTTP headers. */
+public class HttpResponse<T> {
+  private final Response httpResponse;
+  private final String contentType;
+  private final T result;
+
+  HttpResponse(Response httpResponse, String contentType, T result) {
+    this.httpResponse = httpResponse;
+    this.contentType = contentType;
+    this.result = result;
+  }
+
+  /** HTTP status code, always in the 2xx family. */
+  public int getStatusCode() {
+    return httpResponse.getStatusCode();
+  }
+
+  /**
+   * Content type supplied by the server.
+   *
+   * This helper simplifies the common {@code getHeader("Content-Type")} case.
+   */
+  public String getContentType() {
+    return contentType;
+  }
+
+  /** Lookup an arbitrary reply header. */
+  public String getHeader(String header) {
+    if ("Content-Type".equals(header)) {
+      return contentType;
+    }
+    return httpResponse.getHeader(header);
+  }
+
+  public T getResult() {
+    return result;
+  }
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/rpc/RestApi.java

@@ -104,21 +104,21 @@ public class RestApi {
     }
   }
 
-  private static class HttpCallback<T extends JavaScriptObject>
+  private static class HttpImpl<T extends JavaScriptObject>
       implements RequestCallback {
     private final boolean background;
-    private final AsyncCallback<T> cb;
+    private final HttpCallback<T> cb;
 
-    HttpCallback(boolean bg, AsyncCallback<T> cb) {
+    HttpImpl(boolean bg, HttpCallback<T> cb) {
       this.background = bg;
       this.cb = cb;
     }
 
     @Override
-    public void onResponseReceived(Request req, Response res) {
+    public void onResponseReceived(Request req, final Response res) {
       int status = res.getStatusCode();
       if (status == Response.SC_NO_CONTENT) {
-        cb.onSuccess(null);
+        cb.onSuccess(new HttpResponse<T>(res, null, null));
         if (!background) {
           RpcStatus.INSTANCE.onRpcComplete();
         }
@@ -126,12 +126,12 @@ public class RestApi {
       } else if (200 <= status && status < 300) {
         long start = System.currentTimeMillis();
         final T data;
-        if (isTextBody(res)) {
+        final String type;
-          data = NativeString.wrap(res.getText()).cast();
+        if (isJsonBody(res)) {
-        } else if (isJsonBody(res)) {
           try {
             // javac generics bug
             data = RestApi.<T> cast(parseJson(res));
+            type = JSON_TYPE;
           } catch (JSONException e) {
             if (!background) {
               RpcStatus.INSTANCE.onRpcComplete();
@@ -140,6 +140,12 @@ public class RestApi {
                 "Invalid JSON: " + e.getMessage()));
             return;
           }
+        } else if (isEncodedBase64(res)) {
+          data = NativeString.wrap(decodeBase64(res.getText())).cast();
+          type = simpleType(res.getHeader("X-FYI-Content-Type"));
+        } else if (isTextBody(res)) {
+          data = NativeString.wrap(res.getText()).cast();
+          type = TEXT_TYPE;
         } else {
           if (!background) {
             RpcStatus.INSTANCE.onRpcComplete();
@@ -154,7 +160,7 @@ public class RestApi {
           @Override
           public void execute() {
             try {
-              cb.onSuccess(data);
+              cb.onSuccess(new HttpResponse<>(res, type, data));
             } finally {
               if (!background) {
                 RpcStatus.INSTANCE.onRpcComplete();
@@ -318,21 +324,24 @@ public class RestApi {
   }
 
   public <T extends JavaScriptObject> void get(AsyncCallback<T> cb) {
+    get(wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void get(HttpCallback<T> cb) {
     send(GET, cb);
   }
 
   public <T extends JavaScriptObject> void delete(AsyncCallback<T> cb) {
+    delete(wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void delete(HttpCallback<T> cb) {
     send(DELETE, cb);
   }
 
-  public <T extends JavaScriptObject> void delete(JavaScriptObject content,
+  private <T extends JavaScriptObject> void send(Method method,
-      AsyncCallback<T> cb) {
+      HttpCallback<T> cb) {
-    sendJSON(DELETE, content, cb);
+    HttpImpl<T> httpCallback = new HttpImpl<>(background, cb);
-  }
-
-  private <T extends JavaScriptObject> void send(
-      Method method, AsyncCallback<T> cb) {
-    HttpCallback<T> httpCallback = new HttpCallback<>(background, cb);
     try {
       if (!background) {
         RpcStatus.INSTANCE.onRpcStart();
@@ -346,33 +355,59 @@ public class RestApi {
   public <T extends JavaScriptObject> void post(
       JavaScriptObject content,
       AsyncCallback<T> cb) {
+    post(content, wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void post(
+      JavaScriptObject content,
+      HttpCallback<T> cb) {
     sendJSON(POST, content, cb);
   }
 
   public <T extends JavaScriptObject> void post(String content,
       AsyncCallback<T> cb) {
+    post(content, wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void post(String content,
+      HttpCallback<T> cb) {
     sendRaw(POST, content, cb);
   }
 
   public <T extends JavaScriptObject> void put(AsyncCallback<T> cb) {
+    put(wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void put(HttpCallback<T> cb) {
     send(PUT, cb);
   }
 
   public <T extends JavaScriptObject> void put(String content,
       AsyncCallback<T> cb) {
+    put(content, wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void put(String content,
+      HttpCallback<T> cb) {
     sendRaw(PUT, content, cb);
   }
 
   public <T extends JavaScriptObject> void put(
       JavaScriptObject content,
       AsyncCallback<T> cb) {
+    put(content, wrap(cb));
+  }
+
+  public <T extends JavaScriptObject> void put(
+      JavaScriptObject content,
+      HttpCallback<T> cb) {
     sendJSON(PUT, content, cb);
   }
 
   private <T extends JavaScriptObject> void sendJSON(
       Method method, JavaScriptObject content,
-      AsyncCallback<T> cb) {
+      HttpCallback<T> cb) {
-    HttpCallback<T> httpCallback = new HttpCallback<>(background, cb);
+    HttpImpl<T> httpCallback = new HttpImpl<>(background, cb);
     try {
       if (!background) {
         RpcStatus.INSTANCE.onRpcStart();
@@ -385,11 +420,15 @@ public class RestApi {
     }
   }
 
-  private static native String str(JavaScriptObject jso) /*-{ return JSON.stringify(jso); }-*/;
+  private static native String str(JavaScriptObject jso)
+  /*-{ return JSON.stringify(jso) }-*/;
+
+  private static native String decodeBase64(String a)
+  /*-{ return $wnd.atob(a) }-*/;
 
   private <T extends JavaScriptObject> void sendRaw(Method method, String body,
-      AsyncCallback<T> cb) {
+      HttpCallback<T> cb) {
-    HttpCallback<T> httpCallback = new HttpCallback<>(background, cb);
+    HttpImpl<T> httpCallback = new HttpImpl<>(background, cb);
     try {
       if (!background) {
         RpcStatus.INSTANCE.onRpcStart();
@@ -422,16 +461,22 @@ public class RestApi {
     return isContentType(res, TEXT_TYPE);
   }
 
+  private static boolean isEncodedBase64(Response res) {
+    return "base64".equals(res.getHeader("X-FYI-Content-Encoding"))
+        && isTextBody(res);
+  }
+
   private static boolean isContentType(Response res, String want) {
     String type = res.getHeader("Content-Type");
-    if (type == null) {
+    return type != null && want.equals(simpleType(type));
-      return false;
   }
+
+  private static String simpleType(String type) {
     int semi = type.indexOf(';');
     if (semi >= 0) {
-      type = type.substring(0, semi).trim();
+      return type.substring(0, semi).trim();
     }
-    return want.equals(type);
+    return type;
   }
 
   private static JSONValue parseJson(Response res)
@@ -464,4 +509,19 @@ public class RestApi {
       throw new JSONException("unsupported JSON type");
     }
   }
+
+  private static <T extends JavaScriptObject> HttpCallback<T> wrap(
+      final AsyncCallback<T> cb) {
+    return new HttpCallback<T>() {
+      @Override
+      public void onSuccess(HttpResponse<T> r) {
+        cb.onSuccess(r.getResult());
+      }
+
+      @Override
+      public void onFailure(Throwable e) {
+        cb.onFailure(e);
+      }
+    };
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeEdits.java

@@ -52,6 +52,7 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import com.google.inject.assistedinject.Assisted;
 
+import org.eclipse.jgit.lib.ObjectId;
 import org.kohsuke.args4j.Option;
 
 import java.io.IOException;
@@ -433,8 +434,8 @@ public class ChangeEdits implements
         throws ResourceNotFoundException, IOException {
       try {
         return Response.ok(fileContentUtil.getContent(
-              rsrc.getChangeEdit().getChange().getProject(),
+              rsrc.getControl().getProjectControl().getProjectState(),
-              rsrc.getChangeEdit().getRevision().get(),
+              ObjectId.fromString(rsrc.getChangeEdit().getRevision().get()),
               rsrc.getPath()));
       } catch (ResourceNotFoundException rnfe) {
         return Response.none();
@@ -502,8 +503,10 @@ public class ChangeEdits implements
         IOException, ResourceNotFoundException {
       Optional<ChangeEdit> edit = editUtil.byChange(rsrc.getChange());
       if (edit.isPresent()) {
-        return BinaryResult.create(
+        String msg = edit.get().getEditCommit().getFullMessage();
-            edit.get().getEditCommit().getFullMessage()).base64();
+        return BinaryResult.create(msg)
+            .setContentType(FileContentUtil.TEXT_X_GERRIT_COMMIT_MESSAGE)
+            .base64();
       }
       throw new ResourceNotFoundException();
     }

gerrit-server/src/main/java/com/google/gerrit/server/change/FileContentUtil.java

@@ -20,7 +20,6 @@ import com.google.gerrit.common.data.PatchScript.FileMode;
 import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.reviewdb.client.Patch;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.FileTypeRegistry;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.project.ProjectState;
@@ -28,6 +27,7 @@ import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.LargeObjectException;
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.ObjectReader;
@@ -44,6 +44,7 @@ public class FileContentUtil {
   public static final String TEXT_X_GERRIT_COMMIT_MESSAGE = "text/x-gerrit-commit-message";
   private static final String X_GIT_SYMLINK = "x-git/symlink";
   private static final String X_GIT_GITLINK = "x-git/gitlink";
+  private static final int MAX_SIZE = 5 << 20;
 
   private final GitRepositoryManager repoManager;
   private final FileTypeRegistry registry;
@@ -55,28 +56,50 @@ public class FileContentUtil {
     this.registry = ftr;
   }
 
-  public BinaryResult getContent(Project.NameKey project, String revstr,
+  public BinaryResult getContent(ProjectState project, ObjectId revstr,
       String path) throws ResourceNotFoundException, IOException {
-    Repository repo = repoManager.openRepository(project);
+    Repository repo = openRepository(project);
     try {
       RevWalk rw = new RevWalk(repo);
       try {
-        RevCommit commit = rw.parseCommit(repo.resolve(revstr));
+        RevCommit commit = rw.parseCommit(revstr);
-        TreeWalk tw =
+        ObjectReader reader = rw.getObjectReader();
-            TreeWalk.forPath(rw.getObjectReader(), path,
+        TreeWalk tw = TreeWalk.forPath(reader, path, commit.getTree());
-                commit.getTree().getId());
         if (tw == null) {
           throw new ResourceNotFoundException();
         }
-        final ObjectLoader object = repo.open(tw.getObjectId(0));
+
-        @SuppressWarnings("resource")
+        org.eclipse.jgit.lib.FileMode mode = tw.getFileMode(0);
-        BinaryResult result = new BinaryResult() {
+        ObjectId id = tw.getObjectId(0);
-          @Override
+        if (mode == org.eclipse.jgit.lib.FileMode.GITLINK) {
-          public void writeTo(OutputStream os) throws IOException {
+          return BinaryResult.create(id.name())
-            object.copyTo(os);
+              .setContentType(X_GIT_GITLINK)
+              .base64();
         }
-        };
+
-        return result.setContentLength(object.getSize()).base64();
+        final ObjectLoader obj = repo.open(id, OBJ_BLOB);
+        byte[] raw;
+        try {
+          raw = obj.getCachedBytes(MAX_SIZE);
+        } catch (LargeObjectException e) {
+          raw = null;
+        }
+
+        BinaryResult result;
+        if (raw != null) {
+          result = BinaryResult.create(raw);
+        } else {
+          result = asBinaryResult(obj);
+        }
+
+        String type;
+        if (mode == org.eclipse.jgit.lib.FileMode.SYMLINK) {
+          type = X_GIT_SYMLINK;
+        } else {
+          type = registry.getMimeType(path, raw).toString();
+          type = resolveContentType(project, path, FileMode.FILE, type);
+        }
+        return result.setContentType(type).base64();
       } finally {
         rw.release();
       }
@@ -85,10 +108,20 @@ public class FileContentUtil {
     }
   }
 
+  private static BinaryResult asBinaryResult(final ObjectLoader obj) {
+    @SuppressWarnings("resource")
+    BinaryResult result = new BinaryResult() {
+      @Override
+      public void writeTo(OutputStream os) throws IOException {
+        obj.copyTo(os);
+      }
+    }.setContentLength(obj.getSize());
+    return result;
+  }
+
   public String getContentType(ProjectState project, ObjectId rev,
       String path) throws ResourceNotFoundException, IOException {
-    Repository repo =
+    Repository repo = openRepository(project);
-        repoManager.openRepository(project.getProject().getNameKey());
     try {
       RevWalk rw = new RevWalk(repo);
       try {
@@ -109,7 +142,7 @@ public class FileContentUtil {
         ObjectLoader blob = reader.open(tw.getObjectId(0), OBJ_BLOB);
         byte[] raw;
         try {
-          raw = blob.getCachedBytes(5 << 20);
+          raw = blob.getCachedBytes(MAX_SIZE);
         } catch (LargeObjectException e) {
           raw = null;
         }
@@ -147,4 +180,9 @@ public class FileContentUtil {
         throw new IllegalStateException("file mode: " + fileMode);
     }
   }
+
+  private Repository openRepository(ProjectState project)
+      throws RepositoryNotFoundException, IOException {
+    return repoManager.openRepository(project.getProject().getNameKey());
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/change/GetContent.java

@@ -24,6 +24,8 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
+import org.eclipse.jgit.lib.ObjectId;
+
 import java.io.IOException;
 
 @Singleton
@@ -44,12 +46,14 @@ public class GetContent implements RestReadView<FileResource> {
       OrmException {
     String path = rsrc.getPatchKey().get();
     if (Patch.COMMIT_MSG.equals(path)) {
-      return BinaryResult.create(
+      String msg = changeUtil.getMessage(rsrc.getRevision().getChange());
-          changeUtil.getMessage(rsrc.getRevision().getChange())).base64();
+      return BinaryResult.create(msg)
+          .setContentType(FileContentUtil.TEXT_X_GERRIT_COMMIT_MESSAGE)
+          .base64();
     }
     return fileContentUtil.getContent(
-        rsrc.getRevision().getControl().getProject().getNameKey(),
+        rsrc.getRevision().getControl().getProjectControl().getProjectState(),
-        rsrc.getRevision().getPatchSet().getRevision().get(),
+        ObjectId.fromString(rsrc.getRevision().getPatchSet().getRevision().get()),
         path);
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/project/BranchResource.java

@@ -41,4 +41,8 @@ public class BranchResource extends ProjectResource {
   public String getRef() {
     return branchInfo.ref;
   }
+
+  public String getRevision() {
+    return branchInfo.revision;
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/project/CommitResource.java

@@ -16,7 +16,6 @@ package com.google.gerrit.server.project;
 
 import com.google.gerrit.extensions.restapi.RestResource;
 import com.google.gerrit.extensions.restapi.RestView;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.inject.TypeLiteral;
 
 import org.eclipse.jgit.revwalk.RevCommit;
@@ -33,8 +32,8 @@ public class CommitResource implements RestResource {
     this.commit = commit;
   }
 
-  public Project.NameKey getProject() {
+  public ProjectControl getProject() {
-    return project.getNameKey();
+    return project.getControl();
   }
 
   public RevCommit getCommit() {

gerrit-server/src/main/java/com/google/gerrit/server/project/FileResource.java

@@ -16,28 +16,29 @@ package com.google.gerrit.server.project;
 
 import com.google.gerrit.extensions.restapi.RestResource;
 import com.google.gerrit.extensions.restapi.RestView;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.inject.TypeLiteral;
 
+import org.eclipse.jgit.lib.ObjectId;
+
 public class FileResource implements RestResource {
   public static final TypeLiteral<RestView<FileResource>> FILE_KIND =
       new TypeLiteral<RestView<FileResource>>() {};
 
-  private final Project.NameKey project;
+  private final ProjectControl project;
-  private final String rev;
+  private final ObjectId rev;
   private final String path;
 
-  public FileResource(Project.NameKey project, String rev, String path) {
+  public FileResource(ProjectControl project, ObjectId rev, String path) {
     this.project = project;
     this.rev = rev;
     this.path = path;
   }
 
-  public Project.NameKey getProject() {
+  public ProjectControl getProject() {
     return project;
   }
 
-  public String getRev() {
+  public ObjectId getRev() {
     return rev;
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/project/FilesCollection.java

@@ -22,6 +22,8 @@ import com.google.gerrit.extensions.restapi.RestView;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
+import org.eclipse.jgit.lib.ObjectId;
+
 @Singleton
 public class FilesCollection implements
     ChildCollection<BranchResource, FileResource> {
@@ -39,7 +41,10 @@ public class FilesCollection implements
 
   @Override
   public FileResource parse(BranchResource parent, IdString id) {
-    return new FileResource(parent.getNameKey(), parent.getRef(), id.get());
+    return new FileResource(
+        parent.getControl(),
+        ObjectId.fromString(parent.getRevision()),
+        id.get());
   }
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/project/FilesInCommitCollection.java

@@ -40,8 +40,7 @@ public class FilesInCommitCollection implements
   @Override
   public FileResource parse(CommitResource parent, IdString id)
       throws ResourceNotFoundException {
-    return new FileResource(parent.getProject(), parent.getCommit().getName(),
+    return new FileResource(parent.getProject(), parent.getCommit(), id.get());
-        id.get());
   }
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/project/GetContent.java

@@ -35,7 +35,9 @@ public class GetContent implements RestReadView<FileResource> {
   @Override
   public BinaryResult apply(FileResource rsrc)
       throws ResourceNotFoundException, IOException {
-    return fileContentUtil.getContent(rsrc.getProject(), rsrc.getRev(),
+    return fileContentUtil.getContent(
+        rsrc.getProject().getProjectState(),
+        rsrc.getRev(),
         rsrc.getPath());
   }
 }