/**
   * @param projectId
   * @param changePackage
   * @param projectHistory
   * @param newVersion
   * @param newProjectState
   * @throws FatalESException
   */
  private void trySave(
      ProjectId projectId,
      AbstractChangePackage changePackage,
      final ProjectHistory projectHistory,
      Version newVersion,
      final Project newProjectState)
      throws FatalESException {
    getResourceHelper()
        .createResourceForProject(
            newProjectState, newVersion.getPrimarySpec(), projectHistory.getProjectId());
    getResourceHelper()
        .createResourceForChangePackage(changePackage, newVersion.getPrimarySpec(), projectId);
    if (FileBasedChangePackage.class.isInstance(changePackage)) {
      try {
        /* move the temporary file to the project folder */
        final URI uri = changePackage.eResource().getURI();
        final URI normalizedUri =
            changePackage.eResource().getResourceSet().getURIConverter().normalize(uri);
        final String filePath = normalizedUri.toFileString() + ".1"; // $NON-NLS-1$
        FileBasedChangePackage.class.cast(changePackage).move(filePath);
        ModelUtil.saveResource(changePackage.eResource(), ModelUtil.getResourceLogger());
      } catch (final IOException ex) {
        throw new FatalESException(StorageException.NOSAVE, ex);
      }
    }

    getResourceHelper().createResourceForVersion(newVersion, projectHistory.getProjectId());

    newVersion.setProjectStateResource(newProjectState.eResource());
    newVersion.setChangeResource(changePackage.eResource());
  }
  private PrimaryVersionSpec resolvePagedUpdateVersionSpec(
      ProjectHistory projectHistory, PagedUpdateVersionSpec baseVersion) {

    int changes = 0;
    PrimaryVersionSpec resolvedSpec = baseVersion.getBaseVersionSpec();
    int maxChanges = baseVersion.getMaxChanges();

    int i = resolvedSpec.getIdentifier();

    AbstractChangePackage cp = projectHistory.getVersions().get(i).getChanges();

    if (i == projectHistory.getVersions().size() - 1) {
      return projectHistory.getVersions().get(i).getPrimarySpec();
    }

    do {
      cp = projectHistory.getVersions().get(++i).getChanges();
    } while (cp == null && i < projectHistory.getVersions().size());

    // pull at least one change package
    if (cp.leafSize() > maxChanges) {
      maxChanges = cp.leafSize();
    }

    while (changes < maxChanges && i < projectHistory.getVersions().size()) {
      resolvedSpec = projectHistory.getVersions().get(i).getPrimarySpec();
      final Version version = projectHistory.getVersions().get(i);
      final AbstractChangePackage changePackage = version.getChanges();

      if (changePackage != null) {
        final int size = changePackage.leafSize();
        if (changes + size >= maxChanges) {
          resolvedSpec = projectHistory.getVersions().get(i).getPrimarySpec();
          break;
        }
        changes += size;
      }
      i += 1;
    }

    return resolvedSpec;
  }
  /**
   * Returns all changes within the specified version range for a given project.
   *
   * @param projectId the ID of a project
   * @param source the source version
   * @param target the target version (inclusive)
   * @return a list of change packages containing all the changes for the specified version range
   * @throws InvalidVersionSpecException if an invalid version has been specified
   * @throws ESException in case of failure
   */
  @ESMethod(MethodId.GETCHANGES)
  public List<AbstractChangePackage> getChanges(
      ProjectId projectId, VersionSpec source, VersionSpec target)
      throws InvalidVersionSpecException, ESException {

    sanityCheckObjects(projectId, source, target);
    final PrimaryVersionSpec resolvedSource = resolveVersionSpec(projectId, source);
    final PrimaryVersionSpec resolvedTarget = resolveVersionSpec(projectId, target);
    // if target and source are equal return empty list
    if (resolvedSource.getIdentifier() == resolvedTarget.getIdentifier()) {
      return new ArrayList<AbstractChangePackage>();
    }

    synchronized (getMonitor()) {
      final boolean updateForward = resolvedTarget.getIdentifier() > resolvedSource.getIdentifier();

      // Example: if you want the changes to get from version 5 to 7, you
      // need the changes contained in version 6
      // and 7. The reason is that each version holds the changes which
      // occurred from the predecessor to the
      // version itself. Version 5 holds the changes to get from version 4
      // to 5 and therefore is irrelevant.
      // For that reason the first version is removed, since getVersions
      // always sorts ascending order.
      final List<Version> versions = getVersions(projectId, resolvedSource, resolvedTarget);
      if (versions.size() > 1) {
        versions.remove(0);
      }

      List<AbstractChangePackage> result = new ArrayList<AbstractChangePackage>();
      for (final Version version : versions) {
        final AbstractChangePackage changes = version.getChanges();
        if (changes != null) {
          changes.setLogMessage(ModelUtil.clone(version.getLogMessage()));
          result.add(changes);
        }
      }

      // if source is after target in time
      if (!updateForward) {
        // reverse list and change packages
        final List<AbstractChangePackage> resultReverse = new ArrayList<AbstractChangePackage>();
        for (final AbstractChangePackage changePackage : result) {

          final ChangePackage changePackageReverse =
              VersioningFactory.eINSTANCE.createChangePackage();
          final ESCloseableIterable<AbstractOperation> reversedOperations =
              changePackage.reversedOperations();
          final ArrayList<AbstractOperation> copiedReversedOperations =
              new ArrayList<AbstractOperation>();
          try {
            for (final AbstractOperation op : reversedOperations.iterable()) {
              copiedReversedOperations.add(op.reverse());
            }
          } finally {
            reversedOperations.close();
          }

          for (final AbstractOperation reversedOperation : copiedReversedOperations) {
            changePackageReverse.add(reversedOperation);
          }

          // copy again log message
          // reverse() created a new change package without copying
          // existent attributes
          changePackageReverse.setLogMessage(ModelUtil.clone(changePackage.getLogMessage()));
          resultReverse.add(changePackageReverse);
        }

        Collections.reverse(resultReverse);
        result = resultReverse;
      }

      return result;
    }
  }
  private PrimaryVersionSpec internalCreateVersion(
      ProjectId projectId,
      PrimaryVersionSpec baseVersionSpec,
      AbstractChangePackage changePackage,
      BranchVersionSpec targetBranch,
      PrimaryVersionSpec sourceVersion,
      LogMessage logMessage,
      final ACUser user)
      throws ESException {
    synchronized (getMonitor()) {
      final long currentTimeMillis = System.currentTimeMillis();
      final ProjectHistory projectHistory =
          getSubInterface(ProjectSubInterfaceImpl.class).getProject(projectId);

      // Find branch
      final BranchInfo baseBranch = getBranchInfo(projectHistory, baseVersionSpec);
      final Version baseVersion = getVersion(projectHistory, baseVersionSpec);

      if (baseVersion == null || baseBranch == null) {
        throw new InvalidVersionSpecException(
            Messages.VersionSubInterfaceImpl_InvalidBranchOrVersion);
      }

      // defined here fore scoping reasons
      Version newVersion = null;
      BranchInfo newBranch = null;

      // copy project and apply changes
      final Project newProjectState =
          ((ProjectImpl) getSubInterface(ProjectSubInterfaceImpl.class).getProject(baseVersion))
              .copy();
      changePackage.apply(newProjectState);

      // regular commit
      if (isRegularCommit(targetBranch, baseVersion)) {

        newVersion =
            performRegularCommit(
                baseVersionSpec,
                logMessage,
                user,
                projectHistory,
                baseBranch,
                baseVersion,
                newProjectState);

        // case for new branch creation
      } else if (isNewBranchCommit(targetBranch, projectHistory)) {
        checkNewBranchCommitPreRequisites(targetBranch.getBranch());
        // when branch does NOT exist, create new branch
        newVersion = createVersion(projectHistory, newProjectState, logMessage, user, baseVersion);
        newBranch =
            createNewBranch(
                projectHistory,
                baseVersion.getPrimarySpec(),
                newVersion.getPrimarySpec(),
                targetBranch);
        newVersion.setAncestorVersion(baseVersion);

      } else {
        // This point only can be reached with invalid input
        throw new IllegalStateException(
            Messages.VersionSubInterfaceImpl_TargetBranchCombination_Invalid);
      }

      if (sourceVersion != null) {
        newVersion.getMergedFromVersion().add(getVersion(projectHistory, sourceVersion));
      }

      // try to save
      try {
        try {
          trySave(projectId, changePackage, projectHistory, newVersion, newProjectState);
        } catch (final FatalESException e) {
          // try to roll back. removing version is necessary in all cases
          rollback(projectHistory, baseBranch, baseVersion, newVersion, newBranch, e);
        }

        // if ancestor isn't null, a new branch was created. In this
        // case we want to keep the old base project
        // state
        if (newVersion.getAncestorVersion() == null && baseVersion.getProjectState() != null) {
          // delete projectstate from last revision depending on
          // persistence policy
          deleteOldProjectStateAccordingToOptions(projectId, baseVersion);
        }

        save(baseVersion);
        save(projectHistory);

      } catch (final FatalESException e) {
        // roll back failed
        EMFStoreController.getInstance().shutdown(e);
        throw new ESException(Messages.VersionSubInterfaceImpl_ShuttingServerDown);
      }

      ModelUtil.logInfo(
          Messages.VersionSubInterfaceImpl_TotalTimeForCommit
              + (System.currentTimeMillis() - currentTimeMillis));
      return newVersion.getPrimarySpec();
    }
  }