ReceiveCommits: Use ImmutableList for the list of CreateRequests
This list is never updated, hence it can be immutable. Before this
change it was either mutable or immutable depending on whether
selectNewAndReplacedChangesFromMagicBranch returned a mutable or
immutable list. By making the list always be immutable we fix the
MixedMutabilityReturnType error prone pattern for the
selectNewAndReplacedChangesFromMagicBranch method.
Bug: Issue 15071
Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I045de0342baf35a94a395bcdb542787f18290db4
diff --git a/java/com/google/gerrit/server/git/receive/ReceiveCommits.java b/java/com/google/gerrit/server/git/receive/ReceiveCommits.java
index f4c7a92..c68ea29 100644
--- a/java/com/google/gerrit/server/git/receive/ReceiveCommits.java
+++ b/java/com/google/gerrit/server/git/receive/ReceiveCommits.java
@@ -781,7 +781,7 @@
Task newProgress = progress.beginSubTask("new", UNKNOWN);
Task replaceProgress = progress.beginSubTask("updated", UNKNOWN);
- List<CreateRequest> newChanges = Collections.emptyList();
+ ImmutableList<CreateRequest> newChanges = ImmutableList.of();
try {
if (magicBranch != null && magicBranch.cmd.getResult() == NOT_ATTEMPTED) {
try {
@@ -1009,7 +1009,8 @@
addMessage(changeFormatter.changeUpdated(input));
}
- private void insertChangesAndPatchSets(List<CreateRequest> newChanges, Task replaceProgress) {
+ private void insertChangesAndPatchSets(
+ ImmutableList<CreateRequest> newChanges, Task replaceProgress) {
try (TraceTimer traceTimer =
newTimer(
"insertChangesAndPatchSets", Metadata.builder().resourceCount(newChanges.size()))) {
@@ -2248,7 +2249,7 @@
}
}
- private void warnAboutMissingChangeId(List<CreateRequest> newChanges) {
+ private void warnAboutMissingChangeId(ImmutableList<CreateRequest> newChanges) {
for (CreateRequest create : newChanges) {
try {
receivePack.getRevWalk().parseBody(create.commit);
@@ -2265,7 +2266,7 @@
}
}
- private List<CreateRequest> selectNewAndReplacedChangesFromMagicBranch(Task newProgress)
+ private ImmutableList<CreateRequest> selectNewAndReplacedChangesFromMagicBranch(Task newProgress)
throws IOException {
try (TraceTimer traceTimer = newTimer("selectNewAndReplacedChangesFromMagicBranch")) {
logger.atFine().log("Finding new and replaced changes");
@@ -2280,7 +2281,7 @@
try {
RevCommit start = setUpWalkForSelectingChanges();
if (start == null) {
- return Collections.emptyList();
+ return ImmutableList.of();
}
LinkedHashMap<RevCommit, ChangeLookup> pending = new LinkedHashMap<>();
@@ -2358,7 +2359,7 @@
reject(
magicBranch.cmd,
"the number of pushed changes in a batch exceeds the max limit " + maxBatchChanges);
- return Collections.emptyList();
+ return ImmutableList.of();
}
if (commitAlreadyTracked) {
@@ -2391,7 +2392,7 @@
if (!validationResult.isValid()) {
// Not a change the user can propose? Abort as early as possible.
logger.atFine().log("Aborting early due to invalid commit");
- return Collections.emptyList();
+ return ImmutableList.of();
}
// Don't allow merges to be uploaded in commit chain via all-not-in-target
@@ -2428,7 +2429,7 @@
if (newChangeIds.contains(p.changeKey)) {
logger.atFine().log("Multiple commits with Change-Id %s", p.changeKey);
reject(magicBranch.cmd, SAME_CHANGE_ID_IN_MULTIPLE_CHANGES);
- return Collections.emptyList();
+ return ImmutableList.of();
}
List<ChangeData> changes = p.destChanges;
@@ -2444,7 +2445,7 @@
// this error message as Change-Id should be unique per branch.
//
reject(magicBranch.cmd, p.changeKey.get() + " has duplicates");
- return Collections.emptyList();
+ return ImmutableList.of();
}
if (changes.size() == 1) {
@@ -2469,13 +2470,13 @@
magicBranch.cmd, false, changes.get(0).change(), p.commit)) {
continue;
}
- return Collections.emptyList();
+ return ImmutableList.of();
}
if (changes.isEmpty()) {
if (!isValidChangeId(p.changeKey.get())) {
reject(magicBranch.cmd, "invalid Change-Id");
- return Collections.emptyList();
+ return ImmutableList.of();
}
// In case the change look up from the index failed,
@@ -2483,7 +2484,7 @@
if (foundInExistingPatchSets(receivePackRefCache.patchSetIdsFromObjectId(p.commit))) {
if (pending.size() == 1) {
reject(magicBranch.cmd, "commit(s) already exists (as current patchset)");
- return Collections.emptyList();
+ return ImmutableList.of();
}
itr.remove();
continue;
@@ -2503,11 +2504,11 @@
if (newChanges.isEmpty() && replaceByChange.isEmpty()) {
reject(magicBranch.cmd, "no new changes");
- return Collections.emptyList();
+ return ImmutableList.of();
}
if (!newChanges.isEmpty() && magicBranch.edit) {
reject(magicBranch.cmd, "edit is not supported for new changes");
- return newChanges;
+ return ImmutableList.copyOf(newChanges);
}
SortedSetMultimap<ObjectId, String> groups = groupCollector.getGroups();
@@ -2524,7 +2525,7 @@
update.groups = ImmutableList.copyOf((groups.get(update.commit)));
}
logger.atFine().log("Finished updating groups from GroupCollector");
- return newChanges;
+ return ImmutableList.copyOf(newChanges);
}
}
@@ -2827,7 +2828,7 @@
}
}
- private void preparePatchSetsForReplace(List<CreateRequest> newChanges) {
+ private void preparePatchSetsForReplace(ImmutableList<CreateRequest> newChanges) {
try (TraceTimer traceTimer =
newTimer(
"preparePatchSetsForReplace", Metadata.builder().resourceCount(newChanges.size()))) {
