Backport to branch(3) : Relax visibility of Coordinator's methods for use by other ScalarDB components

core/src/main/java/com/scalar/db/transaction/consensuscommit/Coordinator.java

@@ -79,24 +79,40 @@ public Coordinator(DistributedStorage storage, ConsensusCommitConfig config) {
     keyManipulator = new CoordinatorGroupCommitKeyManipulator();
   }
 
+  /**
+   * Gets the coordinator state by ID. If the ID is a full ID for the coordinator group commit, it
+   * will look up the state using the parent ID and the child ID. Otherwise, it will look up the
+   * state only by ID.
+   *
+   * @param id the ID of the coordinator state
+   * @return the coordinator state
+   * @throws CoordinatorException if the coordinator state cannot be retrieved
+   */
   public Optional<Coordinator.State> getState(String id) throws CoordinatorException {
     if (keyManipulator.isFullKey(id)) {
       return getStateForGroupCommit(id);
     }
 
-    Get get = createGetWith(id);
-    return get(get);
+    return getStateInternal(id);
   }
 
+  /**
+   * Gets the coordinator state for a group commit by ID. It first looks up the state using the
+   * parent ID and then checks if the child ID is contained in the state. If the child ID is not
+   * found, it will look up the state using the full ID.
+   *
+   * @param fullId the full ID for the coordinator group commit
+   * @return the coordinator state
+   * @throws CoordinatorException if the coordinator state cannot be retrieved
+   */
   @VisibleForTesting
   Optional<Coordinator.State> getStateForGroupCommit(String fullId) throws CoordinatorException {
     // Scan with the parent ID for a normal group that contains multiple transactions.
     Keys<String, String, String> idForGroupCommit = keyManipulator.keysFromFullKey(fullId);
 
     String parentId = idForGroupCommit.parentKey;
     String childId = idForGroupCommit.childKey;
-    Get get = createGetWith(parentId);
-    Optional<State> state = get(get);
+    Optional<State> state = getStateByParentId(parentId);
     // The current implementation is optimized for cases where most transactions are
     // group-committed. It first looks up a transaction state using the parent ID with a single read
     // operation. If no matching transaction state is found (i.e., the transaction was delayed and
@@ -113,7 +129,41 @@ Optional<Coordinator.State> getStateForGroupCommit(String fullId) throws Coordin
       return stateContainingTargetTxId;
     }
 
-    return get(createGetWith(fullId));
+    return getStateByFullId(fullId);
+  }
+
+  private Optional<Coordinator.State> getStateInternal(String id) throws CoordinatorException {
+    Get get = createGetWith(id);
+    return get(get);
+  }
+
+  /**
+   * Gets the coordinator state by the parent ID for the coordinator group commit. Note: The scope
+   * of this method has public visibility, but is intended for internal use. Also, the method only
+   * calls {@link #getStateInternal(String)} with the parent ID, but it exists as a separate method
+   * for clarifying this specific use case.
+   *
+   * @param parentId the parent ID of the coordinator state for the coordinator group commit
+   * @return the coordinator state
+   * @throws CoordinatorException if the coordinator state cannot be retrieved
+   */
+  public Optional<Coordinator.State> getStateByParentId(String parentId)
+      throws CoordinatorException {
+    return getStateInternal(parentId);
+  }
+
+  /**
+   * Gets the coordinator state by the full ID for the coordinator group commit. Note: The scope of
+   * this method has public visibility, but is intended for internal use. Also, the method only
+   * calls {@link #getStateInternal(String)} with the parent ID, but it exists as a separate method
+   * for clarifying this specific use case.
+   *
+   * @param fullId the parent ID of the coordinator state for the coordinator group commit
+   * @return the coordinator state
+   * @throws CoordinatorException if the coordinator state cannot be retrieved
+   */
+  public Optional<Coordinator.State> getStateByFullId(String fullId) throws CoordinatorException {
+    return getStateInternal(fullId);
   }
 
   public void putState(Coordinator.State state) throws CoordinatorException {
@@ -339,6 +389,10 @@ public State(String id, TransactionState state) {
       this(id, state, System.currentTimeMillis());
     }
 
+    public State(String id, List<String> childIds, TransactionState state) {
+      this(id, childIds, state, System.currentTimeMillis());
+    }
+
     @VisibleForTesting
     State(String id, List<String> childIds, TransactionState state, long createdAt) {
       this.id = checkNotNull(id);
@@ -374,8 +428,9 @@ public long getCreatedAt() {
       return createdAt;
     }
 
-    @VisibleForTesting
-    List<String> getChildIds() {
+    @SuppressFBWarnings("EI_EXPOSE_REP")
+    @Nonnull
+    public List<String> getChildIds() {
       return childIds;
     }
 

core/src/test/java/com/scalar/db/transaction/consensuscommit/CoordinatorTest.java

@@ -102,6 +102,73 @@ public void getState_TransactionIdGivenAndExceptionThrownInGet_ShouldThrowCoordi
     assertThatThrownBy(() -> coordinator.getState(id)).isInstanceOf(CoordinatorException.class);
   }
 
+  @Test
+  public void getStateByParentId_GroupCommitParentIdGiven_ShouldReturnStateUsingItParent()
+      throws ExecutionException, CoordinatorException {
+    // Arrange
+    CoordinatorGroupCommitKeyManipulator keyManipulator =
+        new CoordinatorGroupCommitKeyManipulator();
+    String parentId = keyManipulator.generateParentKey();
+    String childIdsStr =
+        String.join(
+            ",",
+            UUID.randomUUID().toString(),
+            UUID.randomUUID().toString(),
+            UUID.randomUUID().toString());
+
+    Result result = mock(Result.class);
+    when(result.getValue(Attribute.ID))
+        .thenReturn(Optional.of(new TextValue(Attribute.ID, parentId)));
+    when(result.getValue(Attribute.CHILD_IDS))
+        .thenReturn(Optional.of(new TextValue(Attribute.CHILD_IDS, childIdsStr)));
+    when(result.getValue(Attribute.STATE))
+        .thenReturn(Optional.of(new IntValue(Attribute.STATE, TransactionState.ABORTED.get())));
+    when(result.getValue(Attribute.CREATED_AT))
+        .thenReturn(Optional.of(new BigIntValue(Attribute.CREATED_AT, ANY_TIME_1)));
+    when(storage.get(any(Get.class))).thenReturn(Optional.of(result));
+
+    // Act
+    Optional<Coordinator.State> state = coordinator.getStateByParentId(parentId);
+
+    // Assert
+    assertThat(state.get().getId()).isEqualTo(parentId);
+    assertThat(state.get().getChildIds()).isEqualTo(Arrays.asList(childIdsStr.split(",")));
+    assertThat(state.get().getChildIdsAsString()).isEqualTo(childIdsStr);
+    Assertions.assertThat(state.get().getState()).isEqualTo(TransactionState.ABORTED);
+    assertThat(state.get().getCreatedAt()).isEqualTo(ANY_TIME_1);
+  }
+
+  @Test
+  public void getStateByFullId_GroupCommitFullIdGiven_ShouldReturnStateUsingItParent()
+      throws ExecutionException, CoordinatorException {
+    // Arrange
+    CoordinatorGroupCommitKeyManipulator keyManipulator =
+        new CoordinatorGroupCommitKeyManipulator();
+    String fullId =
+        keyManipulator.fullKey(keyManipulator.generateParentKey(), UUID.randomUUID().toString());
+
+    Result result = mock(Result.class);
+    when(result.getValue(Attribute.ID))
+        .thenReturn(Optional.of(new TextValue(Attribute.ID, fullId)));
+    when(result.getValue(Attribute.CHILD_IDS))
+        .thenReturn(Optional.of(new TextValue(Attribute.CHILD_IDS, EMPTY_CHILD_IDS)));
+    when(result.getValue(Attribute.STATE))
+        .thenReturn(Optional.of(new IntValue(Attribute.STATE, TransactionState.ABORTED.get())));
+    when(result.getValue(Attribute.CREATED_AT))
+        .thenReturn(Optional.of(new BigIntValue(Attribute.CREATED_AT, ANY_TIME_1)));
+    when(storage.get(any(Get.class))).thenReturn(Optional.of(result));
+
+    // Act
+    Optional<Coordinator.State> state = coordinator.getStateByFullId(fullId);
+
+    // Assert
+    assertThat(state.get().getId()).isEqualTo(fullId);
+    assertThat(state.get().getChildIds()).isEmpty();
+    assertThat(state.get().getChildIdsAsString()).isEmpty();
+    Assertions.assertThat(state.get().getState()).isEqualTo(TransactionState.ABORTED);
+    assertThat(state.get().getCreatedAt()).isEqualTo(ANY_TIME_1);
+  }
+
   @Test
   public void putState_StateGiven_ShouldPutWithCorrectValues()
       throws ExecutionException, CoordinatorException {