basedatabase.java

开源的axion的数据库代码

                if (rsel instanceof AggregateFunction) {
                    throw new AxionException("use of aggregate function in expression is not allowed.");
                } 
                leaf.setRight(rsel);
            }
        } else if(node instanceof InWhereNode) {
            InWhereNode in = (InWhereNode)node;
            if(null != in.getLeft()) {
                in.setLeft(resolveSelectable(in.getLeft(),tables));
            }
        } else {
            throw new AxionException("Unrecognized WhereNode " + node);
        }
    }

    public Selectable resolveSelectable(Selectable selectable, TableIdentifier[] tables) throws AxionException {
        if(selectable instanceof ColumnIdentifier) {
            return resolveColumn((ColumnIdentifier)selectable,tables);
        } else if(selectable instanceof FunctionIdentifier) {
            return resolveFunctionIdentifier((FunctionIdentifier)selectable,tables);
        } else if(selectable instanceof ConcreteFunction) {
            return selectable;
        } else if(selectable instanceof BindVariable) {
            BindVariable bvar = (BindVariable)selectable;
            if(!bvar.isBound()) {
                throw new AxionException("Unbound variable found.");
            } else {
                return selectable;
            }
        } else if(selectable instanceof Literal) {
            return selectable;
        } else if(selectable instanceof  ExpressionIdentifier) { // rahul added for evaluating expression 
            return resolveExpression((ExpressionIdentifier)selectable,tables);
        } else if (selectable instanceof WhereNode) {
            resolveWhereNode((WhereNode)selectable, tables);
            return (selectable);
        } else {
            throw new AxionException("Couldn't resolve Selectable " + selectable);
        }
    }

    public void checkpoint() throws AxionException {
        Iterator tables = _tables.values().iterator();
        while(tables.hasNext()) {
            Table table = (Table)(tables.next());
            table.checkpoint();
        }
    }

    public void createSequence(Sequence seq) throws AxionException {
        if (seq != null) {
            DatabaseSequenceEvent e = new DatabaseSequenceEvent(seq);
            Iterator i = getDatabaseModificationListeners().iterator();
            while (i.hasNext()) {
                DatabaseModificationListener cur = (DatabaseModificationListener)i.next();
                cur.sequenceAdded(e);
            }            
            _sequences.put(seq.getName(), seq);
            seq.addSequenceModificationListener((SequenceModificationListener)_seqUpd);
        }
    }

    public void dropSequence(String name) {
        String uName = name.toUpperCase();
        if (getSequence(uName) != null) {
            _sequences.remove(uName);
        }
    }

    public Sequence getSequence(String name) {
        Sequence result = null;
        if (name != null) {
            result = (Sequence)_sequences.get(name.toUpperCase());
        }
        return result;
    }
    
    public TransactionManager getTransactionManager() {
        return _transactionManager;
    }

    public void addDatabaseModificationListener(DatabaseModificationListener l) {
        _listeners.add(l);
    }

    public List getDatabaseModificationListeners() {
        return _listeners;
    }

    //--------------------------------------------------------------- Protected
    
    protected Iterator getSequences() {
        return _sequences.values().iterator();
    }

    protected int getSequenceCount() {
        return _sequences.size();
    }
    
    protected Iterator getTables() {
        return _tables.values().iterator();
    }

    protected void loadProperties(Properties props) throws AxionException {
        Enumeration enum = props.propertyNames();
        while(enum.hasMoreElements()) {
            String key = (String)(enum.nextElement());
            if(key.startsWith("type.")) {
                addDataType(key.substring("type.".length()),props.getProperty(key));
            } else if(key.startsWith("function.")) {
                addFunction(key.substring("function.".length()),props.getProperty(key));
            } else if(key.startsWith("index.")) {
                addIndexType(key.substring("index.".length()),props.getProperty(key));
            } else if(key.equals("readonly")) {
                String val = props.getProperty(key);
                if("yes".equalsIgnoreCase(val) || "true".equalsIgnoreCase(val) || "on".equalsIgnoreCase(val)) {
                    _readOnly = true;
                } else {
                    _readOnly = false;
                }
            } else {
                _log.warn("Unrecognized property \"" + key + "\".");
            }
        }
    }

    /** Callers should treat the returned Properties as immutable. */
    protected static synchronized Properties getBaseProperties() {
        if(null == _props) {
            _props = new Properties();
            // lets try the class loader that loaded me
            ClassLoader classLoader = BaseDatabase.class.getClassLoader();
            InputStream in = classLoader.getResourceAsStream("axiondb.properties");
            
            if(null == in) {
                _log.debug( "Couldn't find axiondb.properties via my system classloader, trying the context class loader" );
                
                // lets try the context class loader
                classLoader = Thread.currentThread().getContextClassLoader();
                in = classLoader.getResourceAsStream("axiondb.properties");
            }
            if(null != in) {
                try {
                    _props.load(in);
                } catch(Exception e) {
                    _log.error("Exception while loading properties from CLASSPATH axiondb.properties",e); // PROPOGATE UP!?!
                }
                try { in.close(); } catch(Exception e) { }
            } else {
                _log.warn("Could not find axiondb.properties on the classpath.");
            }
        }
        return _props;
    }

    protected abstract Table createSystemTable(String name);

    //----------------------------------------------------------------- Private

    /**
     * Should get called by subclasses in constructors
     */
    protected void createMetaDataTables() throws AxionException {
        Table columns = null;
        {
            columns = createSystemTable("AXION_COLUMNS");
            columns.addColumn(new Column("TABLE_CAT",new StringType()));
            columns.addColumn(new Column("TABLE_SCHEM",new StringType()));
            columns.addColumn(new Column("TABLE_NAME",new StringType()));
            columns.addColumn(new Column("COLUMN_NAME",new StringType()));
            columns.addColumn(new Column("DATA_TYPE",new ShortType()));
            columns.addColumn(new Column("TYPE_NAME",new StringType()));
            columns.addColumn(new Column("COLUMN_SIZE",new IntegerType()));
            columns.addColumn(new Column("BUFFER_LENGTH",new IntegerType()));
            columns.addColumn(new Column("DECIMAL_DIGITS",new IntegerType()));
            columns.addColumn(new Column("NUM_PREC_RADIX",new IntegerType()));
            columns.addColumn(new Column("NULLABLE",new IntegerType()));
            columns.addColumn(new Column("REMARKS",new StringType()));
            columns.addColumn(new Column("COLUMN_DEF",new StringType()));
            columns.addColumn(new Column("SQL_DATA_TYPE",new IntegerType()));
            columns.addColumn(new Column("SQL_DATETIME_SUB",new IntegerType()));
            columns.addColumn(new Column("CHAR_OCTET_LENGTH",new IntegerType()));
            columns.addColumn(new Column("ORDINAL_POSITION",new IntegerType()));
            columns.addColumn(new Column("IS_NULLABLE",new StringType())); // yes, StringType "NO", "YES", ""
        }
        addDatabaseModificationListener(_colUpd);
        addTable(columns);

        Table tables  = null;
        AxionTablesMetaTableUpdater updTables = new AxionTablesMetaTableUpdater(this);
        {
            tables = createSystemTable("AXION_TABLES");
            tables.addColumn(new Column("TABLE_CAT", new StringType()));
            tables.addColumn(new Column("TABLE_SCHEM", new StringType()));
            tables.addColumn(new Column("TABLE_NAME", new StringType()));
            tables.addColumn(new Column("TABLE_TYPE", new StringType()));
            tables.addColumn(new Column("REMARKS", new StringType()));
            // bootstrap AXION_COLUMNS into AXION_TABLES
            Row row = updTables.createRowForAddedTable(columns);
            tables.addRow(row);
        }
        addDatabaseModificationListener(updTables);
        addTable(tables);

        {
            Table tableTypes = createSystemTable("AXION_TABLE_TYPES");
            tableTypes.addColumn(new Column("TABLE_TYPE",new StringType()));
            String[] types = new String[] { Table.REGULAR_TABLE_TYPE,
                                            Table.SYSTEM_TABLE_TYPE };
            for (int i = 0; i < types.length; i++) {
                SimpleRow row = new SimpleRow(1);
                row.set(0, types[i]);
                tableTypes.addRow(row);
            }
            addTable(tableTypes);
        }

        {
            Table catalogs = createSystemTable("AXION_CATALOGS");
            catalogs.addColumn(new Column("TABLE_CAT",new StringType()));
            {
                SimpleRow row = new SimpleRow(1);
                row.set(0,"");
                catalogs.addRow(row);
            }
            addTable(catalogs);
        }

        {
            Table schemata = createSystemTable("AXION_SCHEMATA");
            schemata.addColumn(new Column("TABLE_CAT",new StringType()));
            schemata.addColumn(new Column("TABLE_SCHEM",new StringType()));
            {
                SimpleRow row = new SimpleRow(2);
                row.set(0,"");
                row.set(1,"");
                schemata.addRow(row);
            }
            addTable(schemata);
        }

        {
            // XXX FIX ME XXX
            // these are a bit hacked
            Table types = createSystemTable("AXION_TYPES");
            types.addColumn(new Column("TYPE_NAME",new StringType()));
            types.addColumn(new Column("DATA_TYPE",new ShortType()));