Make SubmitRuleEvaluator usable for testing prolog rules.

For the purpose of testing submit rules the SubmitRuleEvaluator needs
more flexibility like skipping the submit filters and loading prolog
rules from a caller provided input stream.

This change is a preparation for refactoring of the test-submit-rule
command which currently duplicates most of the code for finding and
executing the prolog rules.

Change-Id: I54086590fa5dc5cefdd9c36ca2e8587d374bd988
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java

@@ -42,6 +42,7 @@ import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -168,6 +169,20 @@ public class ProjectState {
     return envFactory.create(pmc);
   }
 
+  /**
+   * Like {@link #newPrologEnvironment()} but instead of reading the rules.pl
+   * read the provided input stream.
+   *
+   * @param name a name of the input stream. Could be any name.
+   * @param in InputStream to read prolog rules from
+   * @throws CompileException
+   */
+  public PrologEnvironment newPrologEnvironment(String name, InputStream in)
+      throws CompileException {
+    PrologMachineCopy pmc = rulesCache.loadMachine(name, in);
+    return envFactory.create(pmc);
+  }
+
   public Project getProject() {
     return config.getProject();
   }