A METHOD FOR MANAGING MULTIPLE FILE STATES FOR REPLICATED FILES

摘要

A server file replication technique is implemented which stores three copies of a replicated file. These three files allow improved conflict resolution for the user. The shadow file is a copy of the last known good version of the file on the server. When the file is initially copied from the server, an extra copy is made to the shadow file. The shadow file is brought to the local machine to improve performance in synchronization and conflict management as well as afford an offline experimence. The shadow file is updated from the server copy any time that a connection exists to the server copy has changed from the version contained in the shadow copy. This is the only time this file is updated. The local copy is the user's working copy. Whatever changes the user has made to the file are stored in the local copy. This local copy is used to update the server (in the case that the user'changes need to be pushed to the server) or to identify conflicts (when both the user's and the server versions have changed.) A rollback file is also stored. This rollback file is a copy made of the local copy if the local copy changes (for example, when conflicts are resolved or the server version is copied to the local copy.) This copy ensures the ability to return the user to the last known copy that the user has seen.