Class TimeShift

src/query/expression/TimeShift.java:24–144

import java.util.concurrent.TimeUnit;

public class TimeShift implements Expression {
  /**
   * in place modify of TsdbResult array to increase timestamps by timeshift
   *
   * @param data_query
   * @param results
   * @param params
   * @return
   */
  @Override
  public DataPoints[] evaluate(TSQuery data_query, List<DataPoints[]> results, List<String> params) {
    //not 100% sure what to do here -> do I need to think of the case where I have no data points
    if (results == null || results.isEmpty()) {
      return new DataPoints[]{};
    }
    if (params == null || params.isEmpty()) {
      throw new IllegalArgumentException("Need amount of timeshift to perform timeshift");
    }

    String param = params.get(0);
    if (param == null || param.length() == 0) {
      throw new IllegalArgumentException("Invalid timeshift='" + param + "'");
    }

    param = param.trim();

    long timeshift = -1;
    if (param.startsWith("'") && param.endsWith("'")) {
      timeshift = parseParam(param);
    } else {
      throw new RuntimeException("Invalid timeshift parameter: eg '10min'");
    }

    if (timeshift <= 0) {
      throw new RuntimeException("timeshift <= 0");
    }

    return performShift(results.get(0), timeshift);
  }

  private static Boolean timeshiftIsInt(final long timeshift) {
    return (timeshift == Math.floor(timeshift)) &&
        !Double.isInfinite(timeshift);
  }

  DataPoints[] performShift(DataPoints[] inputPoints, long timeshift) {
    DataPoints[] outputPoints = new DataPoints[inputPoints.length];
    for (int n = 0; n < inputPoints.length; n++) {
      outputPoints[n] = shift(inputPoints[n], timeshift);
    }
    return outputPoints;
  }

  long parseParam(String param) {
    char[] chars = param.toCharArray();
    int tuIndex = 0;
    for (int c = 1; c < chars.length; c++) {
      if (Character.isDigit(chars[c])) {