private void mutate()

in hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraStore.java [219:301]
66 lines of code
21 McCabe index (conditional complexity)

    private void mutate(CassandraSessionPool.Session session,
                        BackendAction item) {
        CassandraBackendEntry entry = castBackendEntry(item.entry());

        // Check if the entry has no change
        if (!entry.selfChanged() && entry.subRows().isEmpty()) {
            LOG.warn("The entry will be ignored due to no change: {}", entry);
        }

        CassandraTable table;
        if (!entry.olap()) {
            // Oltp table
            table = this.table(entry.type());
        } else {
            if (entry.type().isIndex()) {
                // Olap index
                table = this.table(this.olapTableName(entry.type()));
            } else {
                // Olap vertex
                table = this.table(this.olapTableName(entry.subId()));
            }
        }

        switch (item.action()) {
            case INSERT:
                // Insert entry
                if (entry.selfChanged()) {
                    table.insert(session, entry.row());
                }
                // Insert sub rows (edges)
                for (CassandraBackendEntry.Row row : entry.subRows()) {
                    this.table(row.type()).insert(session, row);
                }
                break;
            case DELETE:
                // Delete entry
                if (entry.selfChanged()) {
                    table.delete(session, entry.row());
                }
                // Delete sub rows (edges)
                for (CassandraBackendEntry.Row row : entry.subRows()) {
                    this.table(row.type()).delete(session, row);
                }
                break;
            case APPEND:
                // Append entry
                if (entry.selfChanged()) {
                    table.append(session, entry.row());
                }
                // Append sub rows (edges)
                for (CassandraBackendEntry.Row row : entry.subRows()) {
                    this.table(row.type()).append(session, row);
                }
                break;
            case ELIMINATE:
                // Eliminate entry
                if (entry.selfChanged()) {
                    table.eliminate(session, entry.row());
                }
                // Eliminate sub rows (edges)
                for (CassandraBackendEntry.Row row : entry.subRows()) {
                    this.table(row.type()).eliminate(session, row);
                }
                break;
            case UPDATE_IF_PRESENT:
                if (entry.selfChanged()) {
                    // TODO: forward to master-writer node
                    table.updateIfPresent(session, entry.row());
                }
                assert entry.subRows().isEmpty() : entry.subRows();
                break;
            case UPDATE_IF_ABSENT:
                if (entry.selfChanged()) {
                    // TODO: forward to master-writer node
                    table.updateIfAbsent(session, entry.row());
                }
                assert entry.subRows().isEmpty() : entry.subRows();
                break;
            default:
                throw new AssertionError(String.format(
                          "Unsupported mutate action: %s", item.action()));
        }
    }