Examples with SyncToken com.zimbra.cs.service.util.SyncToken used on opensource projects

Example 1 with SyncToken

use of com.zimbra.cs.service.util.SyncToken in project zm-mailbox by Zimbra.

the class WaitSetRequest method parseAddUpdateAccounts.

/**
     * @param allowedAccountIds NULL means "all allowed" (admin)
     */
static List<WaitSetAccount> parseAddUpdateAccounts(ZimbraSoapContext zsc, Element elt, Set<MailItem.Type> defaultInterest) throws ServiceException {
    List<WaitSetAccount> toRet = new ArrayList<WaitSetAccount>();
    if (elt != null) {
        for (Iterator<Element> iter = elt.elementIterator(MailConstants.E_A); iter.hasNext(); ) {
            Element a = iter.next();
            String id;
            String name = a.getAttribute(MailConstants.A_NAME, null);
            if (name != null) {
                Account acct = Provisioning.getInstance().get(AccountBy.name, name);
                if (acct != null) {
                    id = acct.getId();
                } else {
                    WaitSetError err = new WaitSetError(name, WaitSetError.Type.NO_SUCH_ACCOUNT);
                    continue;
                }
            } else {
                id = a.getAttribute(MailConstants.A_ID);
            }
            WaitSetMgr.checkRightForAdditionalAccount(id, zsc);
            String tokenStr = a.getAttribute(MailConstants.A_TOKEN, null);
            SyncToken token = tokenStr != null ? new SyncToken(tokenStr) : null;
            Set<MailItem.Type> interests = parseInterestStr(a.getAttribute(MailConstants.A_TYPES, null), defaultInterest);
            toRet.add(new WaitSetAccount(id, token, interests));
        }
    }
    return toRet;
}

Example 2 with SyncToken

use of com.zimbra.cs.service.util.SyncToken in project zm-mailbox by Zimbra.

the class SyncTest method testPaginatedSync.

/**
     * Test Paginations.
     * 1. Modified paged , delete paged (del cutoff modseq <  modified cutoff mod Seq)
     * 2. All modified , delete paged.
     * 3. Modified paged , delete paged (del cutoff modseq >  modified cutoff mod Seq)
     * 4. Modified paged , all deletes.
     * 5. Modified and delete unpaged.
     * @throws Exception
     */
@Test
public void testPaginatedSync() throws Exception {
    Account acct = Provisioning.getInstance().get(Key.AccountBy.name, "test@zimbra.com");
    Mailbox mbox = MailboxManager.getInstance().getMailboxByAccount(acct);
    mbox.beginTrackingSync();
    SyncRequest request = new SyncRequest();
    request.setFolderId("2");
    Map<String, Object> context = new HashMap<String, Object>();
    context.put(SoapEngine.ZIMBRA_CONTEXT, new ZimbraSoapContext(AuthProvider.getAuthToken(acct), acct.getId(), SoapProtocol.Soap12, SoapProtocol.Soap12));
    Element response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    SyncResponse syncRes = JaxbUtil.elementToJaxb(response);
    Set<Integer> itemsDeleted = new HashSet<Integer>();
    Set<Integer> itemsAddedOrModified = new HashSet<Integer>();
    String token = syncRes.getToken();
    int msgId1 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId2 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId3 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId4 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId5 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId6 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    itemsAddedOrModified.add(msgId1);
    itemsAddedOrModified.add(msgId2);
    itemsAddedOrModified.add(msgId3);
    itemsAddedOrModified.add(msgId4);
    itemsAddedOrModified.add(msgId5);
    itemsAddedOrModified.add(msgId6);
    request = new SyncRequest();
    request.setChangeLimit(100);
    request.setFolderId("2");
    request.setToken(token);
    response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    syncRes = JaxbUtil.elementToJaxb(response);
    List<Object> listObj = syncRes.getItems();
    removeItemsFromList(itemsAddedOrModified, listObj);
    Assert.assertTrue(itemsAddedOrModified.isEmpty());
    token = syncRes.getToken();
    // Modified paged , delete paged (del cutoff modseq < modified cutoff mod Seq);
    mbox.move(null, msgId1, Type.MESSAGE, 5);
    mbox.move(null, msgId2, Type.MESSAGE, 5);
    mbox.delete(null, msgId3, Type.MESSAGE);
    mbox.alterTag(null, new int[] { msgId5, msgId6, msgId4 }, MailItem.Type.MESSAGE, Flag.FlagInfo.UNREAD, true, null);
    itemsDeleted.add(msgId1);
    itemsDeleted.add(msgId2);
    itemsDeleted.add(msgId3);
    itemsAddedOrModified.add(msgId4);
    itemsAddedOrModified.add(msgId5);
    itemsAddedOrModified.add(msgId6);
    request = new SyncRequest();
    request.setToken(token);
    request.setFolderId("2");
    request.setChangeLimit(2);
    request.setDeleteLimit(2);
    response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    syncRes = JaxbUtil.elementToJaxb(response);
    token = syncRes.getToken();
    //Expected 2 deletes and 2 added message. and hasMore=true
    SyncDeletedInfo sdi1 = syncRes.getDeleted();
    String[] deletes = sdi1.getIds().split(",");
    Assert.assertEquals(2, deletes.length);
    removeDeleteFromList(itemsDeleted, deletes);
    //pending to sync.
    Assert.assertEquals(1, itemsDeleted.size());
    listObj = syncRes.getItems();
    Assert.assertEquals(2, listObj.size());
    removeItemsFromList(itemsAddedOrModified, listObj);
    //pending to sync.
    Assert.assertEquals(1, itemsAddedOrModified.size());
    Assert.assertTrue(syncRes.getMore());
    SyncToken syncToken = new SyncToken(token);
    int lastChange = syncToken.getChangeId();
    int lastDel = syncToken.getDeleteModSeq();
    Assert.assertTrue(lastDel < lastChange);
    // Test3: previous interrupted sync. All modified and delete paged.
    mbox.move(null, msgId5, Type.MESSAGE, 5);
    mbox.delete(null, msgId4, Type.MESSAGE);
    itemsDeleted.add(msgId4);
    itemsDeleted.add(msgId5);
    request = new SyncRequest();
    request.setToken(token);
    request.setFolderId("2");
    request.setDeleteLimit(2);
    request.setChangeLimit(2);
    response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    syncRes = JaxbUtil.elementToJaxb(response);
    token = syncRes.getToken();
    //Expected all modified and 2 deleted message. and hasMore=true
    SyncDeletedInfo sdi2 = syncRes.getDeleted();
    deletes = sdi2.getIds().split(",");
    Assert.assertEquals(2, deletes.length);
    removeDeleteFromList(itemsDeleted, deletes);
    //pending to sync.
    Assert.assertEquals(1, itemsDeleted.size());
    listObj = syncRes.getItems();
    Assert.assertEquals(1, listObj.size());
    removeItemsFromList(itemsAddedOrModified, listObj);
    //All synced.
    Assert.assertEquals(0, itemsAddedOrModified.size());
    Assert.assertTrue(syncRes.getMore());
    syncToken = new SyncToken(token);
    lastChange = syncToken.getChangeId();
    lastDel = syncToken.getDeleteModSeq();
    Assert.assertTrue(lastDel < lastChange);
    Assert.assertTrue(syncRes.getMore());
    // Test3: previous interrupted sync. modified and delete paged.(del cutoff modseq > modified cutoff mod Seq)
    int msgId7 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId8 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId9 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    mbox.alterTag(null, new int[] { msgId9 }, MailItem.Type.MESSAGE, Flag.FlagInfo.UNREAD, true, null);
    mbox.delete(null, msgId6, Type.MESSAGE);
    itemsAddedOrModified.add(msgId7);
    itemsAddedOrModified.add(msgId8);
    itemsAddedOrModified.add(msgId9);
    itemsDeleted.add(msgId6);
    request = new SyncRequest();
    request.setToken(token);
    request.setFolderId("2");
    request.setChangeLimit(2);
    request.setDeleteLimit(1);
    response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    syncRes = JaxbUtil.elementToJaxb(response);
    token = syncRes.getToken();
    //Expected 1 deletes and 2 added message. and hasMore=true
    SyncDeletedInfo sdi3 = syncRes.getDeleted();
    deletes = sdi3.getIds().split(",");
    Assert.assertEquals(1, deletes.length);
    removeDeleteFromList(itemsDeleted, deletes);
    //pending to sync.
    Assert.assertEquals(1, itemsDeleted.size());
    listObj = syncRes.getItems();
    Assert.assertEquals(2, listObj.size());
    removeItemsFromList(itemsAddedOrModified, listObj);
    //pending to sync.
    Assert.assertEquals(1, itemsAddedOrModified.size());
    Assert.assertTrue(syncRes.getMore());
    syncToken = new SyncToken(token);
    lastChange = syncToken.getChangeId();
    lastDel = syncToken.getDeleteModSeq();
    Assert.assertTrue(lastDel > lastChange);
    Assert.assertTrue(syncRes.getMore());
    // Test4: previous interrupted sync. Modified paged and All Deletes.
    int msgId10 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId11 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    int msgId12 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    mbox.alterTag(null, new int[] { msgId9 }, MailItem.Type.MESSAGE, Flag.FlagInfo.UNREAD, true, null);
    mbox.delete(null, msgId9, Type.MESSAGE);
    itemsAddedOrModified.add(msgId10);
    itemsAddedOrModified.add(msgId11);
    itemsAddedOrModified.add(msgId12);
    itemsAddedOrModified.remove(msgId9);
    itemsDeleted.add(msgId9);
    request = new SyncRequest();
    request.setToken(token);
    request.setFolderId("2");
    request.setDeleteLimit(2);
    request.setChangeLimit(2);
    response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    syncRes = JaxbUtil.elementToJaxb(response);
    token = syncRes.getToken();
    //Expected 2 deletes and 2 added message. and hasMore=true.
    //trick: deleted the remaining to sync modified message from last sync.
    SyncDeletedInfo sdi4 = syncRes.getDeleted();
    deletes = sdi4.getIds().split(",");
    Assert.assertEquals(2, deletes.length);
    removeDeleteFromList(itemsDeleted, deletes);
    //All synced.
    Assert.assertEquals(0, itemsDeleted.size());
    listObj = syncRes.getItems();
    Assert.assertEquals(2, listObj.size());
    removeItemsFromList(itemsAddedOrModified, listObj);
    //pending to sync.
    Assert.assertEquals(1, itemsAddedOrModified.size());
    Assert.assertTrue(syncRes.getMore());
    syncToken = new SyncToken(token);
    lastChange = syncToken.getChangeId();
    lastDel = syncToken.getDeleteModSeq();
    Assert.assertTrue(lastDel == mbox.getLastChangeID());
    Assert.assertTrue(syncRes.getMore());
    //Test5: All deletes and all Modified.
    int msgId13 = mbox.addMessage(null, MailboxTestUtil.generateMessage("test subject"), MailboxTest.STANDARD_DELIVERY_OPTIONS, null).getId();
    mbox.alterTag(null, new int[] { msgId11 }, MailItem.Type.MESSAGE, Flag.FlagInfo.UNREAD, true, null);
    mbox.delete(null, msgId10, Type.MESSAGE);
    itemsAddedOrModified.add(msgId13);
    itemsAddedOrModified.add(msgId11);
    itemsDeleted.add(msgId10);
    request = new SyncRequest();
    request.setToken(token);
    request.setFolderId("2");
    request.setDeleteLimit(0);
    request.setChangeLimit(10);
    response = new Sync().handle(JaxbUtil.jaxbToElement(request), context);
    syncRes = JaxbUtil.elementToJaxb(response);
    token = syncRes.getToken();
    //Expected 2 deletes and 2 added message. and hasMore=true.
    //trick: deleted the remaining to sync modified message from last sync.
    SyncDeletedInfo sdi5 = syncRes.getDeleted();
    deletes = sdi5.getIds().split(",");
    Assert.assertEquals(1, deletes.length);
    removeDeleteFromList(itemsDeleted, deletes);
    // All synced.
    Assert.assertEquals(0, itemsDeleted.size());
    listObj = syncRes.getItems();
    Assert.assertEquals(3, listObj.size());
    removeItemsFromList(itemsAddedOrModified, listObj);
    //All synced.
    Assert.assertEquals(0, itemsAddedOrModified.size());
    syncToken = new SyncToken(token);
    lastChange = syncToken.getChangeId();
    lastDel = syncToken.getDeleteModSeq();
    Assert.assertEquals(lastChange, mbox.getLastChangeID());
    Assert.assertTrue(lastDel == -1);
    Assert.assertNull(syncRes.getMore());
}

Example 3 with SyncToken

use of com.zimbra.cs.service.util.SyncToken in project zm-mailbox by Zimbra.

the class MailboxUpgrade method migrateHighestIndexed.

private static void migrateHighestIndexed(Mailbox mbox) throws ServiceException {
    DbConnection conn = DbPool.getConnection(mbox);
    PreparedStatement stmt;
    ResultSet rs;
    try {
        // fetch highest_indexed
        String highestIndexed = null;
        stmt = conn.prepareStatement("SELECT highest_indexed FROM " + DbMailbox.qualifyZimbraTableName(mbox, "mailbox") + " WHERE id = ?");
        stmt.setInt(1, mbox.getId());
        rs = stmt.executeQuery();
        if (rs.next()) {
            highestIndexed = rs.getString(1);
        }
        rs.close();
        stmt.close();
        if (Strings.isNullOrEmpty(highestIndexed)) {
            return;
        }
        SyncToken token;
        try {
            token = new SyncToken(highestIndexed);
        } catch (ServiceException e) {
            return;
        }
        // update index_id where mod_content/mod_metadata > highest_indexed
        stmt = conn.prepareStatement("UPDATE " + DbMailItem.getMailItemTableName(mbox) + " SET index_id = 0 WHERE " + DbMailItem.IN_THIS_MAILBOX_AND + "mod_content > ? AND mod_metadata > ? AND index_id IS NOT NULL");
        int pos = DbMailItem.setMailboxId(stmt, mbox, 1);
        stmt.setInt(pos++, token.getChangeId());
        stmt.setInt(pos++, token.getChangeId());
        stmt.executeUpdate();
        stmt.close();
        // clear highest_indexed
        stmt = conn.prepareStatement("UPDATE " + DbMailbox.qualifyZimbraTableName(mbox, "mailbox") + " SET highest_indexed = NULL WHERE id = ?");
        stmt.setInt(1, mbox.getId());
        stmt.executeUpdate();
        stmt.close();
        conn.commit();
    } catch (SQLException e) {
        conn.rollback();
        throw ServiceException.FAILURE("Failed to migrate highest_indexed", e);
    } finally {
        conn.closeQuietly();
    }
}

Example 4 with SyncToken

use of com.zimbra.cs.service.util.SyncToken in project zm-mailbox by Zimbra.

the class Sync method handle.

@Override
public Element handle(Element request, Map<String, Object> context) throws ServiceException {
    ZimbraSoapContext zsc = getZimbraSoapContext(context);
    Mailbox mbox = getRequestedMailbox(zsc);
    OperationContext octxt = getOperationContext(zsc, context);
    ItemIdFormatter ifmt = new ItemIdFormatter(zsc);
    SyncRequest syncRequest = JaxbUtil.elementToJaxb(request);
    String token = syncRequest.getToken();
    Element response = zsc.createElement(MailConstants.SYNC_RESPONSE);
    response.addAttribute(MailConstants.A_CHANGE_DATE, System.currentTimeMillis() / 1000);
    // the sync token is of the form "last fully synced change id" (e.g. "32425") or
    // last fully synced change id-last item synced in next change id" (e.g. "32425-99213") or
    // last fully synced change id-last item synced in next change id and last fully synced delete change id" (e.g. "32425-99213:d1231232") or
    // last fully synced change id-last item synced in next change id and 
    // last fully synced delete id-last item synced in next delete id (e.g. "32425-99213:d12312-82134")
    SyncToken syncToken = null;
    int tokenInt = 0;
    if (!StringUtil.isNullOrEmpty(token)) {
        syncToken = new SyncToken(token);
        tokenInt = syncToken.getChangeId();
    }
    if (syncToken == null) {
        syncToken = new SyncToken(0);
    }
    int deleleLimit = syncRequest.getDeleteLimit();
    int changeLimit = syncRequest.getChangeLimit();
    // server can apply delete pagination through debugconfig/localconfig.
    if (deleleLimit <= 0) {
        deleleLimit = DebugConfig.syncMaximumDeleteCount;
    }
    // client specify more than DebugConfig.syncMaximumChangeCount It will use DebugConfig.syncMaximumChangeCount
    if (changeLimit <= 0 || changeLimit > DebugConfig.syncMaximumChangeCount) {
        changeLimit = DebugConfig.syncMaximumChangeCount;
    }
    boolean initialSync = tokenInt <= 0;
    // permit the caller to restrict initial sync only to calendar items with a recurrence after a given date
    long calendarStart = (syncRequest.getCalendarCutoff() != null) ? syncRequest.getCalendarCutoff() : -1;
    int messageSyncStart = (syncRequest.getMsgCutoff() != null) ? syncRequest.getMsgCutoff() : -1;
    // if the sync is constrained to a folder subset, we need to first figure out what can be seen
    Folder root = null;
    ItemId iidFolder = null;
    try {
        iidFolder = new ItemId(request.getAttribute(MailConstants.A_FOLDER, DEFAULT_FOLDER_ID + ""), zsc);
        OperationContext octxtOwner = new OperationContext(mbox);
        root = mbox.getFolderById(octxtOwner, iidFolder.getId());
    } catch (MailServiceException.NoSuchItemException nsie) {
    }
    Set<Folder> visible = octxt.isDelegatedRequest(mbox) ? mbox.getVisibleFolders(octxt) : null;
    FolderNode rootNode = null;
    if (root == null || iidFolder == null) {
        // resolve grantee names of all ACLs on the mailbox
        rootNode = mbox.getFolderTree(octxt, null, true);
    } else {
        // resolve grantee names of all ACLs on all sub-folders of the requested folder
        rootNode = mbox.getFolderTree(octxt, iidFolder, true);
    }
    OperationContextData.addGranteeNames(octxt, rootNode);
    // actually perform the sync
    mbox.lock.lock();
    try {
        mbox.beginTrackingSync();
        if (initialSync) {
            response.addAttribute(MailConstants.A_TOKEN, mbox.getLastChangeID());
            response.addAttribute(MailConstants.A_SIZE, mbox.getSize());
            boolean anyFolders = folderSync(response, octxt, ifmt, mbox, root, visible, calendarStart, messageSyncStart, SyncPhase.INITIAL);
            // if no folders are visible, add an empty "<folder/>" as a hint
            if (!anyFolders) {
                response.addElement(MailConstants.E_FOLDER);
            }
        } else {
            boolean typedDeletes = request.getAttributeBool(MailConstants.A_TYPED_DELETES, false);
            String newToken = deltaSync(response, octxt, ifmt, mbox, syncToken, deleleLimit, changeLimit, typedDeletes, root, visible, messageSyncStart);
            response.addAttribute(MailConstants.A_TOKEN, newToken);
        }
    } finally {
        mbox.lock.release();
    }
    return response;
}

Example 5 with SyncToken

use of com.zimbra.cs.service.util.SyncToken in project zm-mailbox by Zimbra.

the class Sync method deltaSync.

private static String deltaSync(Element response, OperationContext octxt, ItemIdFormatter ifmt, Mailbox mbox, SyncToken syncToken, int deleteLimit, int changeLimit, boolean typedDeletes, Folder root, Set<Folder> visible, int messageSyncStart) throws ServiceException {
    int begin = syncToken.getChangeId();
    int deleteModSeqCutoff = syncToken.getDeleteModSeq();
    deleteModSeqCutoff = deleteModSeqCutoff <= 0 ? begin : deleteModSeqCutoff;
    int mboxLastChangeId = mbox.getLastChangeID();
    SyncToken newSyncToken = new SyncToken(mboxLastChangeId);
    if (begin >= mboxLastChangeId && deleteModSeqCutoff >= mboxLastChangeId) {
        return newSyncToken.toString();
    }
    int changeItemIdCutoff = syncToken.getOffsetInNext();
    int deleteItemIdCutoff = syncToken.getDeleteOffsetInNext();
    // first, fetch deleted items
    TypedIdList tombstones = mbox.getTombstones(deleteModSeqCutoff);
    Element eDeleted = response.addElement(MailConstants.E_DELETED);
    // then, put together the requested folder hierarchy in 2 different flavors
    List<Folder> hierarchy = (root == null || root.getId() == Mailbox.ID_FOLDER_USER_ROOT ? null : root.getSubfolderHierarchy());
    Set<Integer> targetIds = (root != null && root.getId() == Mailbox.ID_FOLDER_USER_ROOT ? null : new HashSet<Integer>(hierarchy == null ? 0 : hierarchy.size()));
    if (hierarchy != null) {
        for (Folder folder : hierarchy) {
            targetIds.add(folder.getId());
        }
    }
    // then, handle created/modified folders
    if (octxt.isDelegatedRequest(mbox)) {
        // first, make sure that something changed...
        if (!mbox.getModifiedFolders(begin).isEmpty() || !Collections.disjoint(tombstones.types(), FOLDER_TYPES)) {
            // special-case the folder hierarchy for delegated delta sync
            boolean anyFolders = folderSync(response, octxt, ifmt, mbox, root, visible, -1, messageSyncStart, SyncPhase.DELTA);
            // if no folders are visible, add an empty "<folder/>" as a hint
            if (!anyFolders) {
                response.addElement(MailConstants.E_FOLDER);
            }
        }
    } else {
        for (Folder folder : mbox.getModifiedFolders(begin)) {
            // no case of "synthetic tombstone" (item falling out of the tree being synced)
            if (targetIds == null || targetIds.contains(folder.getId())) {
                ToXML.encodeFolder(response, ifmt, octxt, folder, Change.ALL_FIELDS);
            } else {
                tombstones.add(folder.getType(), folder.getId(), folder.getUuid(), folder.getModifiedSequence());
            }
        }
    }
    // next, handle created/modified tags
    for (Tag tag : mbox.getModifiedTags(octxt, begin)) {
        ToXML.encodeTag(response, ifmt, octxt, tag, Change.ALL_FIELDS);
    }
    // finally, handle created/modified "other items"
    int itemCount = 0;
    Pair<List<Integer>, TypedIdList> changed = mbox.getModifiedItems(octxt, Math.min(begin, deleteModSeqCutoff), messageSyncStart, MailItem.Type.UNKNOWN, targetIds, deleteModSeqCutoff);
    List<Integer> modified = changed.getFirst();
    // items that have been altered in non-visible folders will be returned as "deleted" in order to handle moves
    if (changed.getSecond() != null) {
        tombstones.addAll(changed.getSecond());
    }
    delta: while (!modified.isEmpty()) {
        List<Integer> batch = modified.subList(0, Math.min(modified.size(), FETCH_BATCH_SIZE));
        for (MailItem item : mbox.getItemById(octxt, batch, MailItem.Type.UNKNOWN)) {
            // detect interrupted sync and resume from the appropriate place
            if ((item.getModifiedSequence() == begin + 1 && item.getId() < changeItemIdCutoff) || item.getModifiedSequence() <= begin) {
                //if interrupted delete and un-interrupted modifications.
                continue;
            }
            // if we've overflowed this sync response, set things up so that a subsequent sync starts from where we're cutting off
            if (itemCount >= changeLimit) {
                response.addAttribute(MailConstants.A_QUERY_MORE, true);
                newSyncToken.setChangeModSeq((item.getModifiedSequence() - 1));
                newSyncToken.setChangeItemId(item.getId());
                newSyncToken.setDeleteModSeq(mboxLastChangeId);
                break delta;
            }
            // For items in the system, if the content has changed since the user last sync'ed
            // (because it was edited or created), just send back the folder ID and saved date --
            // the client will request the whole object out of band -- potentially using the
            // content servlet's "include metadata in headers" hack.
            // If it's just the metadata that changed, send back the set of mutable attributes.
            boolean created = item.getSavedSequence() > begin;
            ToXML.encodeItem(response, ifmt, octxt, item, created ? Change.FOLDER | Change.CONFLICT | Change.DATE | Change.PARENT : MUTABLE_FIELDS);
            itemCount++;
        }
        batch.clear();
    }
    // cleanup: only return a <deleted> element if we're sending back deleted item ids
    if ((deleteLimit > 0 && tombstones.size() > deleteLimit) || deleteItemIdCutoff > 0) {
        PagedDelete pgDel = new PagedDelete(tombstones, typedDeletes);
        pgDel.removeBeforeCutoff(deleteItemIdCutoff, deleteModSeqCutoff);
        if (deleteLimit > 0) {
            pgDel.trimDeletesTillPageLimit(deleteLimit);
        }
        encodePagedDelete(eDeleted, pgDel, newSyncToken, tombstones, typedDeletes);
        if (pgDel.isDeleteOverFlow()) {
            response.addAttribute(MailConstants.A_QUERY_MORE, true);
            response.addAttribute(MailConstants.A_QUERY_MORE, true);
        }
    } else {
        encodeUnpagedDelete(eDeleted, tombstones, typedDeletes);
    }
    return newSyncToken.toString();
}