opendev/gerrit
Code Issues Proposed changes

Add a convenience class for making REST API handlers retryable

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We want to get all callers of BatchUpdate to use the new RetryHelper,
but explicitly passing a lambda to the RetryHelper instance in every
case is going to be a lot of boilerplate. Add some sugar for the most
common case, a REST API handler. Using the RetryingRestModifyView,
converting a handler to be retry-friendly is as simple as adding the
base class and changing a method name (and some minor cleanup like
removing a BatchUpdate.Factory field and twiddling exceptions).

Adding an intervening abstract class requires a tweak to the way
RestApiServlet extracts the input type using reflection. Fortunately,
there is a TypeLiteral method that does exactly what we want.

Change-Id: If2b78f0d556a49972ea9976057dd5f9dc21ec750
This commit is contained in:
Dave Borowitz
2017-04-20 15:07:40 -04:00
parent 5b9e7a8d25
commit 04f8f397d7
3 changed files with 60 additions and 43 deletions
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21
gerrit-server/src/main/java/com/google/gerrit/server/change/PutTopic.java
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@@ -19,7 +19,6 @@ import com.google.gerrit.common.TimeUtil;
import com.google.gerrit.extensions.restapi.DefaultInput;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.extensions.restapi.RestModifyView;
import com.google.gerrit.extensions.webui.UiAction;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.ChangeMessage;
@@ -34,6 +33,8 @@ import com.google.gerrit.server.update.BatchUpdate;
import com.google.gerrit.server.update.BatchUpdateOp;
import com.google.gerrit.server.update.ChangeContext;
import com.google.gerrit.server.update.Context;
import com.google.gerrit.server.update.RetryHelper;
import com.google.gerrit.server.update.RetryingRestModifyView;
import com.google.gerrit.server.update.UpdateException;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
@@ -41,10 +42,10 @@ import com.google.inject.Provider;
import com.google.inject.Singleton;
@Singleton
public class PutTopic implements RestModifyView<ChangeResource, Input>, UiAction<ChangeResource> {
public class PutTopic extends RetryingRestModifyView<ChangeResource, Input, Response<String>>
implements UiAction<ChangeResource> {
private final Provider<ReviewDb> dbProvider;
private final ChangeMessagesUtil cmUtil;
private final BatchUpdate.Factory batchUpdateFactory;
private final TopicEdited topicEdited;
public static class Input {
@@ -55,29 +56,27 @@ public class PutTopic implements RestModifyView<ChangeResource, Input>, UiAction
PutTopic(
Provider<ReviewDb> dbProvider,
ChangeMessagesUtil cmUtil,
BatchUpdate.Factory batchUpdateFactory,
RetryHelper retryHelper,
TopicEdited topicEdited) {
super(retryHelper);
this.dbProvider = dbProvider;
this.cmUtil = cmUtil;
this.batchUpdateFactory = batchUpdateFactory;
this.topicEdited = topicEdited;
}
@Override
public Response<String> apply(ChangeResource req, Input input)
protected Response<String> applyImpl(
BatchUpdate.Factory updateFactory, ChangeResource req, Input input)
throws UpdateException, RestApiException, PermissionBackendException {
req.permissions().check(ChangePermission.EDIT_TOPIC_NAME);
Op op = new Op(input != null ? input : new Input());
try (BatchUpdate u =
batchUpdateFactory.create(
updateFactory.create(
dbProvider.get(), req.getChange().getProject(), req.getUser(), TimeUtil.nowTs())) {
u.addOp(req.getId(), op);
u.execute();
}
return Strings.isNullOrEmpty(op.newTopicName)
? Response.<String>none()
: Response.ok(op.newTopicName);
return Strings.isNullOrEmpty(op.newTopicName) ? Response.none() : Response.ok(op.newTopicName);
}
private class Op implements BatchUpdateOp {