Added chaotic stress test for InternalFlatFileRealm

 - broke out common functionality in to `FlatFileStressBase`

integrationtests/src/test/java/org/neo4j/auth/FlatFileChaoticStressIT.java

@@ -0,0 +1,274 @@
+/*
+ * Copyright (c) 2002-2016 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.auth;
+
+import org.junit.Rule;
+
+import java.io.IOException;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.stream.IntStream;
+
+import org.neo4j.io.fs.FileSystemAbstraction;
+import org.neo4j.kernel.api.exceptions.InvalidArgumentsException;
+import org.neo4j.test.rule.fs.EphemeralFileSystemRule;
+
+public class FlatFileChaoticStressIT extends FlatFileStressBase
+{
+    @Rule
+    public EphemeralFileSystemRule fsRule = new EphemeralFileSystemRule();
+
+    @Override
+    FileSystemAbstraction getFileSystem()
+    {
+        return fsRule.get();
+    }
+
+    @Override
+    ExecutorService setupWorkload( int n )
+    {
+        ExecutorService service = Executors.newFixedThreadPool( n );
+        Set<String> usernames = makeWithPrefix( "user", n );
+        Set<String> roleNames = makeWithPrefix( "role", n );
+        for ( int i = 0; i < n; i++ )
+        {
+            service.submit( new ChaoticAdmin( i, usernames, roleNames ) );
+        }
+        return service;
+    }
+
+    private Set<String> makeWithPrefix( String prefix, int n )
+    {
+        Set<String> set = new LinkedHashSet<>(  );
+        IntStream.range( 0, n ).forEach( i -> set.add( prefix + i ) );
+        return set;
+    }
+
+    private class ChaoticAdmin extends IrrationalAdmin
+    {
+        private final int number;
+        private final String[] usernames;
+        private final String[] roleNames;
+
+        ChaoticAdmin( int number, Set<String> usernames, Set<String> roleNames )
+        {
+            super();
+            this.number = number;
+            this.usernames = usernames.toArray( new String[ usernames.size() ] );
+            this.roleNames = roleNames.toArray( new String[ roleNames.size() ] );
+            setActions(
+                    this::createUser,
+                    this::deleteUser,
+                    this::changePassword,
+                    this::suspend,
+                    this::activate,
+                    this::createRole,
+                    this::deleteRole,
+                    this::assignRole,
+                    this::unAssignRole
+                );
+        }
+
+        @Override
+        public String toString()
+        {
+            return "ChaoticAdmin " + number;
+        }
+
+        // __________ ACTIONS ___________
+
+        private void createUser()
+        {
+            String username = randomUser();
+            String password = deviousPassword();
+            try
+            {
+                flatFileRealm.newUser( username, password, false );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void deleteUser()
+        {
+            String username = randomUser();
+            try
+            {
+                flatFileRealm.deleteUser( username );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void changePassword()
+        {
+            String username = randomUser();
+            String password = deviousPassword();
+            try
+            {
+                flatFileRealm.setUserPassword( username, password, false );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void suspend()
+        {
+            String username = randomUser();
+            try
+            {
+                flatFileRealm.suspendUser( username );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void activate()
+        {
+            String username = randomUser();
+            try
+            {
+                flatFileRealm.activateUser( username, false );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void createRole()
+        {
+            String username = randomUser();
+            String roleName = randomRole();
+            try
+            {
+                flatFileRealm.newRole( roleName, username );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void deleteRole()
+        {
+            String roleName = randomRole();
+            try
+            {
+                flatFileRealm.deleteRole( roleName );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void assignRole()
+        {
+            String username = randomUser();
+            String roleName = randomRole();
+            try
+            {
+                flatFileRealm.addRoleToUser( roleName, username );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        private void unAssignRole()
+        {
+            String username = randomUser();
+            String roleName = randomRole();
+            try
+            {
+                flatFileRealm.removeRoleFromUser( roleName, username );
+            }
+            catch ( IOException e )
+            {
+                errors.add( e );
+            }
+            catch ( InvalidArgumentsException e )
+            {
+                // ignore
+            }
+        }
+
+        // ______________ HELPERS ______________
+
+        private String deviousPassword()
+        {
+            return random.nextBoolean() ? "123" : "321";
+        }
+
+        private String randomUser()
+        {
+            return usernames[ random.nextInt( usernames.length ) ];
+        }
+
+        private String randomRole()
+        {
+            return roleNames[ random.nextInt( roleNames.length ) ];
+        }
+    }
+}