Class PreprocessorContext

src/org/apache/pig/tools/parameters/PreprocessorContext.java:52–392

import org.apache.pig.validator.PigCommandFilter;

public class PreprocessorContext {

    private int tableinitsize = 10;
    private Deque<Map<String,String>> param_val_stack;

    private PigContext pigContext;

    public Map<String, String> getParamVal() {
        Map <String, String> ret = new Hashtable <String, String>(tableinitsize);

        //stack (deque) iterates LIFO
        for (Map <String, String> map : param_val_stack ) {
            for (Map.Entry<String, String> entry : map.entrySet()) {
                if( ! ret.containsKey(entry.getKey()) ) {
                    ret.put(entry.getKey(), entry.getValue());
                }
            }
        }
        return ret;
    }

    private final Log log = LogFactory.getLog(getClass());

    /**
     * @param limit - max number of parameters. Passing
     *                smaller number only impacts performance
     */
    public PreprocessorContext(int limit) {
        tableinitsize = limit;
        param_val_stack = new ArrayDeque<Map<String,String>> ();
        param_val_stack.push(new Hashtable<String, String> (tableinitsize));
    }

    public void setPigContext(PigContext context) {
        this.pigContext = context;
    }

    /**
     * This method generates parameter value by running specified command
     *
     * @param key - parameter name
     * @param val - string containing command to be executed
     */
    public  void processShellCmd(String key, String val)  throws ParameterSubstitutionException, FrontendException {
        processShellCmd(key, val, true);
    }

    /**
     * This method generates value for the specified key by
     * performing substitution if needed within the value first.
     *
     * @param key - parameter name
     * @param val - value supplied for the key
     */
    public  void processOrdLine(String key, String val)  throws ParameterSubstitutionException {
        processOrdLine(key, val, true);
    }