Network redirector

Abstract: An improved method and system for client-side caching that transparently caches suitable network files for offline use. A cache mechanism in a network redirector transparently intercepts requests to access server files, and if the requested file is locally cached, satisfies the request from the cache when possible. Otherwise the cache mechanism creates a local cache file and satisfies the request from the server, and also fills in a sparse cached file as reads for data in ranges that are missing in the cached file are requested and received from the server. A background process also fills in local files that are sparse, using the existing handle of already open server files, or opening, reading from and closing other server files. Security is also provided by maintaining security information received from the server for files that are in the cache, and using that security information to determine access to the file when offline.

Abstract: A system and method that automatically and transparently handle client-side caching of network file data, independent of any remote file handling protocol. A protocol-independent client-side caching mechanism is inserted as a service that handles file-related requests directed to a network, and attempts to satisfy the requests via a client-side caching persistent store. By way of pre-process and post-process calls on a file create request, the caching mechanism creates file-related data structures, and overwrites the information in those structures that a buffering service uses to call back to a network redirector, whereby the client-side caching mechanism inserts itself into the communication flow between the network redirector and the buffering service. Once in the flow of communication, network-directed file read and write requests may be transparently handled by the client-side caching mechanism when appropriate, yet the redirector may be instructed to communicate with the server when needed to satisfy the request.

Abstract: A pipeline I/O mechanism in a network redirector that breaks up large files into sections, and sends write (or read) requests for each section in a pipeline fashion to a network file server, without waiting for a response for a previously-sent section. The pipeline I/O mechanism tracks the returned status of each section for which a request was made, so that success or failure of the request is determined as a whole. The pipeline I/O system and method dramatically increase the performance of network remote I/O operations, particularly with file write operations directed to a file on a network file server.

Abstract: A system and method that automatically and transparently handle client-side caching of network file data, independent of any remote file handling protocol. A protocol-independent client-side caching mechanism is inserted as a service that handles file-related requests directed to a network, and attempts to satisfy the requests via a client-side caching persistent store. By way of pre-process and post-process calls on a file create request, the caching mechanism creates file-related data structures, and overwrites the information in those structures that a buffering service uses to call back toa network redirector, whereby the client-side caching mechanism inserts itself into the communication flow between the network redirector and the buffering service. Once in the flow of communication,network-directed file read and write requests may be transparently handled by the client-side caching mechanism when appropriate, yet the redirector may be instructed to communicate with the server when needed to satisfy the request.