Scheduler : fix #2105 (#2270)

Also-by: Markus Rathgeb <maggu2810@gmail.com>
Signed-off-by: Karel Goderis <karel.goderis@me.com>

bundles/core/org.eclipse.smarthome.core.test/src/test/java/org/eclipse/smarthome/core/scheduler/CronExpressionTest.java

@@ -13,7 +13,6 @@
 import java.util.Calendar;
 import java.util.Date;
 
-import org.eclipse.smarthome.core.scheduler.CronExpression;
 import org.junit.Test;
 
 public class CronExpressionTest {
@@ -63,4 +62,22 @@ public void getFinalTimeCheck() throws ParseException {
 
  assertEquals(checkDate, nextDate);
  }
+
+ @Test
+ public void runForever() throws ParseException, InterruptedException {
+
+ final CronExpression expression;
+ expression = new CronExpression("* * * * * ?");
+
+ Date nextDate = expression.getTimeAfter(Calendar.getInstance().getTime());
+ int counter = 1;
+
+ while (nextDate != null && counter <= 150) {
+ System.out.println("value " + counter + " is " + nextDate);
+ nextDate = expression.getTimeAfter(nextDate);
+ counter++;
+ }
+
+ }
+
 }

bundles/core/org.eclipse.smarthome.core/src/main/java/org/eclipse/smarthome/core/scheduler/AbstractExpression.java

@@ -29,7 +29,7 @@ public abstract class AbstractExpression<E extends AbstractExpressionPart> imple
 
  private final Logger logger = LoggerFactory.getLogger(this.getClass().getName());
 
- private int minimumCandidates = 10;
+ private int minimumCandidates = 1;
  private int maximumCandidates = 100;
 
  private String expression;
@@ -207,22 +207,49 @@ protected void prune() {
 
  @Override
  public Date getTimeAfter(Date afterTime) {
- if (getCandidates().isEmpty()) {
+
+ Date currentStartDate = getStartDate();
+
+ if (hasFloatingStartDate()) {
+ try {
+ clearCandidates();
+ setStartDate(afterTime);
+ } catch (IllegalArgumentException | ParseException e) {
+ logger.error("An exception occurred while setting the start date : '{}'", e.getMessage());
+ }
+ } else if (getCandidates().isEmpty()) {
  try {
  setStartDate(afterTime);
- parseExpression(expression);
  } catch (ParseException e) {
- logger.error("An exception occurred while parsing the expression : '{}'", e.getMessage());
+ logger.error("An exception occurred while setting the start date : '{}'", e.getMessage());
  }
  }
 
  if (!getCandidates().isEmpty()) {
-
- Collections.sort(getCandidates());
-
- for (Date candidate : getCandidates()) {
- if (candidate.after(afterTime)) {
- return candidate;
+ if (getCandidates().size() == 1) {
+ return getCandidates().get(0);
+ } else {
+ while (getCandidates().size() > 1) {
+
+ Collections.sort(getCandidates());
+
+ Date newStartDate = null;
+
+ try {
+
+ for (Date candidate : getCandidates()) {
+ newStartDate = candidate;
+ if (candidate.after(afterTime)) {
+ setStartDate(currentStartDate);
+ return candidate;
+ }
+ }
+
+ clearCandidates();
+ setStartDate(newStartDate);
+ } catch (IllegalArgumentException | ParseException e) {
+ logger.error("An exception occurred while parsing the expression : '{}'", e.getMessage());
+ }
  }
  }
  }
@@ -232,6 +259,9 @@ public Date getTimeAfter(Date afterTime) {
 
  @Override
  public Date getFinalFireTime() {
+
+ Date currentStartDate = getStartDate();
+
  if (getCandidates().isEmpty()) {
  try {
  parseExpression(getExpression());
@@ -240,11 +270,36 @@ public Date getFinalFireTime() {
  }
  }
 
- if (getCandidates().isEmpty()) {
- return null;
+ Date lastCandidate = null;
+
+ if (!getCandidates().isEmpty()) {
+ if (getCandidates().size() == 1) {
+ lastCandidate = getCandidates().get(0);
+ } else {
+
+ while (getCandidates().size() == maximumCandidates) {
+ Collections.sort(getCandidates());
+ lastCandidate = getCandidates().get(getCandidates().size() - 1);
+ try {
+ clearCandidates();
+ setStartDate(lastCandidate);
+ } catch (IllegalArgumentException | ParseException e) {
+ logger.error("An exception occurred while parsing the expression : '{}'", e.getMessage());
+ }
+
+ }
+
+ lastCandidate = getCandidates().get(getCandidates().size() - 1);
+
+ try {
+ setStartDate(currentStartDate);
+ } catch (IllegalArgumentException | ParseException e) {
+ logger.error("An exception occurred while setting the start date : '{}'", e.getMessage());
+ }
+ }
  }
 
- return getCandidates().get(getCandidates().size() - 1);
+ return lastCandidate;
  }
 
  /**
@@ -275,6 +330,10 @@ protected void setCandidates(ArrayList<Date> candidates) {
  this.candidates = candidates;
  }
 
+ protected void clearCandidates() {
+ this.candidates = null;
+ }
+
  public ArrayList<E> getExpressionParts() {
  return expressionParts;
  }

bundles/core/org.eclipse.smarthome.core/src/main/java/org/eclipse/smarthome/core/scheduler/CronExpression.java

@@ -169,7 +169,7 @@ public CronExpression(final String expression, final Date startTime) throws Pars
  * @throws ParseException if the string expression cannot be parsed into a valid <code>CronExpression</code>.
  */
  public CronExpression(final String expression, final Date startTime, final TimeZone zone) throws ParseException {
- super(expression, " \t", startTime, zone, 10);
+ super(expression, " \t", startTime, zone, 0);
  }
 
  @Override
@@ -1193,4 +1193,9 @@ public ArrayList<Date> apply(Date startDate, ArrayList<Date> candidates) {
  return candidates;
  }
  }
+
+ @Override
+ public boolean hasFloatingStartDate() {
+ return true;
+ }
 }

bundles/core/org.eclipse.smarthome.core/src/main/java/org/eclipse/smarthome/core/scheduler/DateExpression.java

@@ -174,4 +174,9 @@ public int order() {
  }
  }
 
+ @Override
+ public boolean hasFloatingStartDate() {
+ return false;
+ }
+
 }

bundles/core/org.eclipse.smarthome.core/src/main/java/org/eclipse/smarthome/core/scheduler/Expression.java

@@ -43,7 +43,7 @@ public interface Expression {
  /**
  * Returns the final time that the <code>Expression</code> will match.
  *
- * @return the last date the expression will fire
+ * @return the last date the expression will fire, or null when the final time can not be calculated
  */
  Date getFinalFireTime();
 
@@ -81,17 +81,25 @@ public interface Expression {
  /**
  * Returns the start date of the expression.
  *
- * @return the start date.
+ * @return the start date, as from which the expression will be evaluated
  */
 
  Date getStartDate();
 
  /**
- * Sets the start date of the rule.
+ * Sets the start date of the rule
  *
  * @param startTime the start date to set
  * @throws ParseException when the expression can not be parsed correctly after the start date was set
  */
  void setStartDate(Date startTime) throws ParseException;
 
+ /**
+ * Indicates whether the expression does not need an explicit start date in order to be evaluated. 'infinite' style
+ * expression types, e.g. without an explicit start date part of their definition, like cron, should return true
+ *
+ * @return true, if the start date does not matter for evaluating the expression
+ */
+ boolean hasFloatingStartDate();
+
 }

bundles/core/org.eclipse.smarthome.core/src/main/java/org/eclipse/smarthome/core/scheduler/RecurrenceExpression.java

@@ -326,7 +326,7 @@
  * arrive at "every other year". Then, "BYMONTH=1" would be applied
  * to arrive at "every January, every other year". Then, "BYDAY=SU"
  * would be applied to arrive at "every Sunday in January, every
- * other year".  Then, "BYHOUR=8,9" would be applied to arrive at
+ * other year". Then, "BYHOUR=8,9" would be applied to arrive at
  * "every Sunday in January at 8 AM and 9 AM, every other year".
  * Then, "BYMINUTE=30" would be applied to arrive at "every Sunday in
  * January at 8:30 AM and 9:30 AM, every other year". Then, lacking
@@ -551,23 +551,8 @@ public final Date getFinalFireTime() {
  if (!(isUntil || isCount)) {
  return null;
  } else {
-
- if (getCandidates().isEmpty()) {
- try {
- parseExpression(getExpression());
- } catch (ParseException e) {
- logger.error("An exception occurred while parsing the expression : '{}'", e.getMessage());
- }
- }
-
- if (!getCandidates().isEmpty()) {
-
- Collections.sort(getCandidates());
-
- return getCandidates().get(getCandidates().size() - 1);
- }
+ return super.getFinalFireTime();
  }
- return null;
  }
 
  @Override
@@ -1847,4 +1832,9 @@ public int order() {
  }
  }
 
+ @Override
+ public boolean hasFloatingStartDate() {
+ return false;
+ }
+
 }