protected static LocalSymbolTableImports readLocalSymbolTable()

in src/com/amazon/ion/impl/LocalSymbolTable.java [219:330]
93 lines of code
18 McCabe index (conditional complexity)

    protected static LocalSymbolTableImports readLocalSymbolTable(IonReader reader,
                                                                  IonCatalog catalog,
                                                                  boolean isOnStruct,
                                                                  List<String> symbolsListOut,
                                                                  SymbolTable currentSymbolTable)
    {
        if (! isOnStruct)
        {
            reader.next();
        }

        assert reader.getType() == IonType.STRUCT
            : "invalid symbol table image passed in reader " +
              reader.getType() + " encountered when a struct was expected";

        assert ION_SYMBOL_TABLE.equals(reader.getTypeAnnotations()[0])
            : "local symbol tables must be annotated by " + ION_SYMBOL_TABLE;

        reader.stepIn();

        List<SymbolTable> importsList = new ArrayList<SymbolTable>();
        importsList.add(reader.getSymbolTable().getSystemSymbolTable());

        IonType fieldType;
        boolean foundImportList = false;
        boolean foundLocalSymbolList = false;
        boolean isAppend = false;
        while ((fieldType = reader.next()) != null)
        {
            if (reader.isNullValue()) continue;

            SymbolToken symTok = reader.getFieldNameSymbol();
            int sid = symTok.getSid();
            if (sid == SymbolTable.UNKNOWN_SYMBOL_ID)
            {
                // This is a user-defined IonReader or a pure DOM, fall
                // back to text
                final String fieldName = reader.getFieldName();
                sid = getSidForSymbolTableField(fieldName);
            }

            // TODO amzn/ion-java/issues/36 Switching over SIDs doesn't cover the case
            //      where the relevant field names are defined by a prev LST;
            //      the prev LST could have 'symbols' defined locally with a
            //      different SID!
            switch (sid)
            {
                case SYMBOLS_SID:
                {
                    // As per the Spec, other field types are treated as
                    // empty lists
                    if(foundLocalSymbolList){
                        throw new IonException("Multiple symbol fields found within a single local symbol table.");
                    }
                    foundLocalSymbolList = true;
                    if (fieldType == IonType.LIST)
                    {
                        reader.stepIn();
                        IonType type;
                        while ((type = reader.next()) != null)
                        {
                            final String text;
                            if (type == IonType.STRING)
                            {
                                text = reader.stringValue();
                            }
                            else
                            {
                                text = null;
                            }

                            symbolsListOut.add(text);
                        }
                        reader.stepOut();
                    }
                    break;
                }
                case IMPORTS_SID:
                {
                    if(foundImportList){
                        throw new IonException("Multiple imports fields found within a single local symbol table.");
                    }
                    foundImportList = true;
                    if (fieldType == IonType.LIST)
                    {
                        prepImportsList(importsList, reader, catalog);
                    }
                    else if (fieldType == IonType.SYMBOL && ION_SYMBOL_TABLE.equals(reader.stringValue()))
                    {
                        isAppend = true;
                    }
                    break;
                }
                default:
                {
                    // As per the Spec, any other field is ignored
                    break;
                }
            }
        }
        reader.stepOut();
        if (isAppend && currentSymbolTable.isLocalTable()) {
            // Because the current symbol table is a local symbol table (i.e. not the system symbol table), it can
            // be appended in-place.
            LocalSymbolTable currentLocalSymbolTable = (LocalSymbolTable) currentSymbolTable;
            for (String newSymbol : symbolsListOut) {
                currentLocalSymbolTable.putSymbol(newSymbol);
            }
            return null;
        }
        return new LocalSymbolTableImports(importsList);
    }