Improve EI implementation.

fuzz/src/main/java/edu/berkeley/cs/jqf/fuzz/ei/ExecutionIndex.java

@@ -47,12 +47,14 @@
 public class ExecutionIndex implements Comparable<ExecutionIndex> {
 
     final int[] ei;
+    private final int hash;
 
     public ExecutionIndex(int[] ei) {
         if (ei.length == 0 || ei.length % 2 == 1) {
             throw new IllegalArgumentException("Execution index must have non-zero even elements");
         }
         this.ei = ei;
+        hash = Arrays.hashCode(this.ei);
     }
 
     public ExecutionIndex(Prefix prefix, Suffix suffix) {
@@ -72,11 +74,12 @@ public ExecutionIndex(Prefix prefix, Suffix suffix) {
         for (int i = suffix.offset; i < size; i++) {
             this.ei[i] = suffixEi[i];
         }
+        hash = Arrays.hashCode(this.ei);
     }
 
     @Override
     public int hashCode() {
-        return Arrays.hashCode(ei);
+        return hash;
     }
 
     @Override

fuzz/src/main/java/edu/berkeley/cs/jqf/fuzz/ei/ExecutionIndexingDriver.java

@@ -30,8 +30,10 @@
 package edu.berkeley.cs.jqf.fuzz.ei;
 
 import java.io.File;
+import java.util.Random;
 
 import edu.berkeley.cs.jqf.fuzz.junit.GuidedFuzzing;
+import edu.berkeley.cs.jqf.fuzz.util.IOUtils;
 
 /**
  * Entry point for fuzzing with Execution Indexing.
@@ -61,9 +63,15 @@ public static void main(String[] args) {
         try {
             // Load the guidance
             String title = testClassName+"#"+testMethodName;
-            ZestGuidance guidance = seedFiles != null ?
-                    new ExecutionIndexingGuidance(title, null, outputDirectory, seedFiles) :
-                    new ExecutionIndexingGuidance(title, null, outputDirectory, new File[]{});
+            ExecutionIndexingGuidance guidance;
+
+            if (seedFiles == null) {
+                guidance = new ExecutionIndexingGuidance(title, null, null, outputDirectory, new Random());
+            } else if (seedFiles.length == 1 && seedFiles[0].isDirectory()) {
+                guidance = new ExecutionIndexingGuidance(title, null, null, outputDirectory, seedFiles[0], new Random());
+            } else {
+                guidance = new ExecutionIndexingGuidance(title, null, null, outputDirectory, seedFiles, new Random());
+            }
 
             // Ensure that generators are being traced
             System.setProperty("jqf.traceGenerators", "true");

fuzz/src/main/java/edu/berkeley/cs/jqf/fuzz/ei/ExecutionIndexingGuidance.java

@@ -44,6 +44,7 @@
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
+import com.pholser.junit.quickcheck.random.SourceOfRandomness;
 import edu.berkeley.cs.jqf.fuzz.ei.ExecutionIndex.Prefix;
 import edu.berkeley.cs.jqf.fuzz.ei.ExecutionIndex.Suffix;
 import edu.berkeley.cs.jqf.fuzz.ei.state.AbstractExecutionIndexingState;
@@ -53,6 +54,7 @@
 import edu.berkeley.cs.jqf.fuzz.guidance.Result;
 import edu.berkeley.cs.jqf.fuzz.junit.quickcheck.FuzzStatement;
 import edu.berkeley.cs.jqf.fuzz.util.CoverageFactory;
+import edu.berkeley.cs.jqf.fuzz.util.IOUtils;
 import edu.berkeley.cs.jqf.fuzz.util.ProducerHashMap;
 import edu.berkeley.cs.jqf.instrument.tracing.FastCoverageSnoop;
 import edu.berkeley.cs.jqf.instrument.tracing.SingleSnoop;
@@ -101,9 +103,6 @@ public class ExecutionIndexingGuidance extends ZestGuidance {
     /** Mean number of contiguous bytes to mutate in each mutation. */
     protected final double MEAN_MUTATION_SIZE = 4.0; // Bytes
 
-    /** Probability that a standard mutation sets the byte to just zero instead of a random value. */
-    protected final double MUTATION_ZERO_PROBABILITY = 0.05;
-
     /** Max number of contiguous bytes to splice in from another input during the splicing stage. */
     protected final int MAX_SPLICE_SIZE = 64; // Bytes
 
@@ -148,7 +147,8 @@ public ExecutionIndexingGuidance(String testName, Duration duration, Long trials
      * @throws IOException if the output directory could not be prepared
      */
     public ExecutionIndexingGuidance(String testName, Duration duration, Long trials, File outputDirectory, File seedInputDir, Random sourceOfRandomness) throws IOException {
-        super(testName, duration, trials, outputDirectory, seedInputDir, sourceOfRandomness);
+        this(testName, duration, trials, outputDirectory, IOUtils.resolveInputFileOrDirectory(seedInputDir),
+                sourceOfRandomness);
     }
 
     /**
@@ -158,11 +158,21 @@ public ExecutionIndexingGuidance(String testName, Duration duration, Long trials
      * @param testName the name of test to display on the status screen
      * @param duration the amount of time to run fuzzing for, where
      *                 {@code null} indicates unlimited time.
+     * @param trials   the number of trials for which to run fuzzing, where
+     *                 {@code null} indicates unlimited trials.
      * @param outputDirectory the directory where fuzzing results will be written
+     * @param seedFiles the seed input files to be used as initial inputs
+     * @param sourceOfRandomness      a pseudo-random number generator
      * @throws IOException if the output directory could not be prepared
      */
-    public ExecutionIndexingGuidance(String testName, Duration duration, File outputDirectory, File[] seedFiles) throws IOException {
-        super(testName, duration, outputDirectory, seedFiles);
+    public ExecutionIndexingGuidance(String testName, Duration duration, Long trials, File outputDirectory,
+                                     File[] seedFiles, Random sourceOfRandomness) throws IOException {
+        super(testName, duration, trials, outputDirectory, new File[0], sourceOfRandomness);
+        if (seedFiles != null) {
+            for (File seedFile : seedFiles) {
+                seedInputs.add(new MappedSeedInput(seedFile));
+            }
+        }
     }
 
     /** Returns the banner to be displayed on the status screen */

fuzz/src/main/java/edu/berkeley/cs/jqf/fuzz/ei/ZestGuidance.java

@@ -85,6 +85,9 @@
  */
 public class ZestGuidance implements Guidance {
 
+    /** Probability that a standard mutation sets the byte to just zero instead of a random value. */
+    protected final double MUTATION_ZERO_PROBABILITY = 0.1;
+
     /** A pseudo-random number generator for generating fresh values. */
     protected Random random;
 
@@ -1305,7 +1308,7 @@ public Input fuzz(Random random) {
             int numMutations = sampleGeometric(random, MEAN_MUTATION_COUNT);
             newInput.desc += ",havoc:"+numMutations;
 
-            boolean setToZero = random.nextDouble() < 0.1; // one out of 10 times
+            boolean setToZero = random.nextDouble() < MUTATION_ZERO_PROBABILITY; // one out of 10 times
 
             for (int mutation = 1; mutation <= numMutations; mutation++) {