Refactored EstimateIterationsResult and added tests

api/src/main/java/io/jsonwebtoken/security/EstimateIterationsResult.java

@@ -1,44 +1,60 @@
 package io.jsonwebtoken.security;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 public class EstimateIterationsResult {
-    private int iterations;
-    private List<Integer> workFactors;
-    private List<Long> durations;
+    private int estimatedIterations;
+    private List<Result> results;
+
+    private boolean estimateSet;
 
     public EstimateIterationsResult() {
-        this.workFactors = new ArrayList<>();
-        this.durations = new ArrayList<>();
+        this.results = new ArrayList<>();
     }
 
     public EstimateIterationsResult(int numSamples) {
-        this.workFactors = new ArrayList<>(numSamples);
-        this.durations = new ArrayList<>(numSamples);
+        this.results = new ArrayList<>(numSamples);
     }
 
-    public int getIterations() {
-        return iterations;
+    public int getEstimatedIterations() {
+        return estimatedIterations;
     }
 
-    public void setIterations(int iterations) {
-        this.iterations = iterations;
+    public synchronized void setEstimatedIterations(int estimatedIterations) {
+        if (estimateSet) {
+            throw new UnsupportedOperationException("Estimated iterations already set and can only be set once.");
+        }
+        estimateSet = true;
+        this.estimatedIterations = estimatedIterations;
     }
 
-    public List<Integer> getWorkFactors() {
-        return workFactors;
+    public void addResult(int workFactor, long duration) {
+        this.results.add(new Result(workFactor, duration));
     }
 
-    public void setWorkFactors(List<Integer> workFactors) {
-        this.workFactors = workFactors;
+    public List<Result> getResults() {
+        return Collections.unmodifiableList(results);
     }
 
-    public List<Long> getDurations() {
-        return durations;
+    public static final class Result {
+        private int workFactor;
+        private long duration;
+
+        private Result(){}
+
+        public Result(int workFactor, long duration) {
+            this.workFactor = workFactor;
+            this.duration = duration;
         }
 
-    public void setDurations(List<Long> durations) {
-        this.durations = durations;
+        public int getWorkFactor() {
+            return workFactor;
+        }
+
+        public long getDuration() {
+            return duration;
+        }
     }
 }

api/src/test/groovy/io/jsonwebtoken/security/EstimateIterationsResultTest.groovy

@@ -0,0 +1,42 @@
+package io.jsonwebtoken.security
+
+import org.junit.Test
+import org.junit.runner.RunWith
+import static org.junit.Assert.*
+import org.powermock.modules.junit4.PowerMockRunner
+
+@RunWith(PowerMockRunner)
+class EstimateIterationsResultTest {
+
+    // for coverage
+    @Test
+    void testConstructor() {
+        new EstimateIterationsResult()
+        new EstimateIterationsResult(10)
+    }
+
+    @Test
+    void testImmutable() {
+        EstimateIterationsResult r = new EstimateIterationsResult()
+        r.addResult(1, 1)
+        try {
+            def result = r.getResults()
+            result.add(new EstimateIterationsResult.Result(2, 2))
+            fail()
+        } catch (Exception e) {
+            assertTrue e instanceof UnsupportedOperationException
+        }
+    }
+
+    @Test
+    void testSetEstimateOnlyOnce() {
+        EstimateIterationsResult r = new EstimateIterationsResult()
+        r.setEstimatedIterations(1);
+        try {
+            r.setEstimatedIterations(1)
+            fail()
+        } catch (UnsupportedOperationException e) {
+            assertEquals "Estimated iterations already set and can only be set once.", e.message
+        }
+    }
+}

impl/src/main/java/io/jsonwebtoken/impl/security/KeyAlgorithmsBridge.java

@@ -188,9 +188,7 @@ public final class KeyAlgorithmsBridge {
             if (collectSample) {
                 // For each attempt, the x axis is the workFactor, and the y axis is how long it took to compute:
                 points.add(new Point(workFactor, duration));
-                ret.getDurations().add(duration);
-                ret.getWorkFactors().add(workFactor);
-                //System.out.println("Collected point: workFactor=" + workFactor + ", duration=" + duration + " ms, %achieved=" + durationPercentAchieved);
+                ret.addResult(workFactor, duration);
             } else {
                 minWorkFactor = Math.max(minWorkFactor, workFactor);
                 //System.out.println("      Excluding sample: workFactor=" + workFactor + ", duration=" + duration + " ms, %achieved=" + durationPercentAchieved);
@@ -232,7 +230,7 @@ public final class KeyAlgorithmsBridge {
         }
         double average = sumX / points.size();
         //ensure our average is at least as much as the smallest work factor that got us closest to desiredMillis:
-        ret.setIterations((int) Math.max(average, minWorkFactor));
+        ret.setEstimatedIterations((int) Math.max(average, minWorkFactor));
         return ret;
     }