add configurable default and maximum values for query workflow instances

nflow-engine/src/main/java/com/nitorcreations/nflow/engine/internal/dao/WorkflowInstanceDao.java

@@ -26,6 +26,7 @@
 
 import org.apache.commons.lang3.mutable.MutableInt;
 import org.joda.time.DateTime;
+import org.springframework.core.env.Environment;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.DuplicateKeyException;
 import org.springframework.jdbc.core.JdbcTemplate;
@@ -61,6 +62,8 @@ public class WorkflowInstanceDao {
   private JdbcTemplate jdbc;
   private NamedParameterJdbcTemplate namedJdbc;
   ExecutorDao executorInfo;
+  private long workflowInstanceQueryMaxResults;
+  private long workflowInstanceQueryMaxResultsDefault;
 
   /**
    * Use setter injection because having the dataSource in constructor may not work
@@ -78,6 +81,12 @@ public void setExecutorDao(ExecutorDao executorDao) {
     this.executorInfo = executorDao;
   }
 
+  @Inject
+  public void setEnvironment(Environment env) {
+    workflowInstanceQueryMaxResults = env.getRequiredProperty("nflow.workflow.instance.query.max.results", Long.class);
+    workflowInstanceQueryMaxResultsDefault = env.getRequiredProperty("nflow.workflow.instance.query.max.results.default", Long.class);
+  }
+
   public int insertWorkflowInstance(WorkflowInstance instance) {
     try {
       return insertWorkflowInstanceImpl(instance);
@@ -234,10 +243,8 @@ public List<WorkflowInstance> queryWorkflowInstances(QueryWorkflowInstances quer
     if (!isEmpty(conditions)) {
       sql += " where " + collectionToDelimitedString(conditions, " and ");
     }
-    if (query.maxResults < Long.MAX_VALUE) {
-      sql += " limit :limit";
-      params.addValue("limit", query.maxResults);
-    }
+    sql += " limit :limit";
+    params.addValue("limit", getMaxResults(query.maxResults));
     List<WorkflowInstance> ret = namedJdbc.query(sql, params, new WorkflowInstanceRowMapper());
     for (WorkflowInstance instance : ret) {
       fillState(instance);
@@ -250,6 +257,16 @@ public List<WorkflowInstance> queryWorkflowInstances(QueryWorkflowInstances quer
     return ret;
   }
 
+  private long getMaxResults(Long maxResults) {
+    if (maxResults == null) {
+      return workflowInstanceQueryMaxResultsDefault;
+    }
+    if (maxResults.longValue() > workflowInstanceQueryMaxResults) {
+      return workflowInstanceQueryMaxResults;
+    }
+    return maxResults.longValue();
+  }
+
   private void fillActions(WorkflowInstance instance, boolean includeStateVariables) {
     Map<Integer, Map<String, String>> actionStates = includeStateVariables ? fetchActionStateVariables(instance) :
       EMPTY_ACTION_STATE_MAP;

nflow-engine/src/main/java/com/nitorcreations/nflow/engine/workflow/instance/QueryWorkflowInstances.java

@@ -51,12 +51,13 @@ public class QueryWorkflowInstances {
   public final boolean includeActionStateVariables;
 
   /**
-   * The maximum number of instances to be returned by the query.
+   * The maximum number of instances to be returned by the query. If null, uses
+   * default value configured for the nFlow engine. The maximum value may also
+   * be limited by nFlow engine configuration.
    */
-  public final long maxResults;
+  public final Long maxResults;
 
   QueryWorkflowInstances(Builder builder) {
-    super();
     this.ids = new ArrayList<>(builder.ids);
     this.types = new ArrayList<>(builder.types);
     this.states = new ArrayList<>(builder.states);
@@ -80,7 +81,7 @@ public static class Builder {
     boolean includeActions;
     boolean includeCurrentStateVariables;
     boolean includeActionStateVariables;
-    long maxResults = Long.MAX_VALUE;
+    Long maxResults;
 
     /**
      * Create a workflow instance query builder.
@@ -173,7 +174,7 @@ public Builder setIncludeActionStateVariables(boolean includeActionStateVariable
      * @param maxResults
      * @return this.
      */
-    public Builder setMaxResults(long maxResults) {
+    public Builder setMaxResults(Long maxResults) {
       this.maxResults = maxResults;
       return this;
     }

nflow-engine/src/main/resources/nflow-engine.properties

@@ -8,6 +8,9 @@ nflow.transition.delay.waiterror.ms=7200000
 
 nflow.max.state.retries=3
 
+nflow.workflow.instance.query.max.results=10000
+nflow.workflow.instance.query.max.results.default=100
+
 nflow.db.user=nflow
 nflow.db.password=nflow
 

nflow-engine/src/test/resources/junit.properties

@@ -1,5 +1,8 @@
 nflow.executor.group=junit
 
+nflow.workflow.instance.query.max.results=10000
+nflow.workflow.instance.query.max.results.default=100
+
 nflow.db.h2.driver=org.h2.jdbcx.JdbcDataSource
 nflow.db.h2.url=jdbc:h2:mem:test;TRACE_LEVEL_FILE=4
 nflow.db.h2.user=sa

nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/WorkflowInstanceResource.java

@@ -140,7 +140,7 @@ public Collection<ListWorkflowInstanceResponse> listWorkflowInstances(
         .setBusinessKey(businessKey).setExternalId(externalId)
         .setIncludeCurrentStateVariables(includes.contains(currentStateVariables)).setIncludeActions(includes.contains(actions))
         .setIncludeActionStateVariables(includes.contains(actionStateVariables))
-        .setMaxResults(maxResults == null ? Long.MAX_VALUE : maxResults.longValue()).build();
+        .setMaxResults(maxResults).build();
     Collection<WorkflowInstance> instances = workflowInstances.listWorkflowInstances(q);
     List<ListWorkflowInstanceResponse> resp = new ArrayList<>();
     for (WorkflowInstance instance : instances) {