Abstract: A media server system and method are disclosed for playback of digital media. For playback, header information associated with a complex asset is received. The header information comprises information for initializing a decoder (56) for playback of the complex asset. Artificial headers (54) for the complex asset are then created using the header information. A digital packet stream for the complex asset is received and passed decoder (56) for playback. During playback, artificial headers (54) are injected as appropriate for initializing the decoder (56) for playback of the complex asset. In one implementation, the complex asset can be a clip asset (100), a parallel asset (102), a sequential asset (106) or a composite asset (110).

Abstract: A system and method for resource recovery in a distributed system uses a resource audit service to monitor the status of a client that receives a resource from a service that allocates the resource. The allocating service registers a callback with the resource audit service identifying the client. The resource audit service subsequently monitors the status of the client. When the resource audit service determines that the client has failed, the resource audit service performs the callback to the allocating service indicating the failure of the client. Upon receiving the callback, the allocating service is able to recover the resource from the client.

Abstract: A media server system and method are disclosed for playback of digital media. For playback, header information associated with a complex asset is received. The header information comprises information for initializing a decoder (56) for playback of the complex asset. Artificial headers (54) for the complex asset are then created using the header information. A digital packet stream for the complex asset is received and passed decoder (56) for playback. During playback, artificial headers (54) are injected as appropriate for initializing the decoder (56) for playback of the complex asset. In one implementation, the complex asset can be a clip asset (100), a parallel asset (102), a sequential asset (106) or a composite asset (110).

Abstract: A media server system and method are disclosed for playback of digital media. For playback, header information associated with a complex asset is received. The header information comprises information for initializing a decoder (56) for playback of the complex asset. Artificial headers (54) for the complex asset are then created using the header information. A digital packet stream for the complex asset is received and passed decoder (56) for playback. During playback, artificial headers (54) are injected as appropriate for initializing the decoder (56) for playback of the complex asset. In one implementation, the complex asset can be a clip asset (100), a parallel asset (102), a sequential asset (106) or a composite asset (110).

Abstract: A system for recovering resources, wherein the system includes a plurality of allocating services that each allocate resources to clients and a resource audit service in communication with each of the plurality of allocating services. When one of the plurality of allocating services allocates a resource to a client, the one of the plurality of allocating services sends a registration to the resource audit service identifying the client as a recipient of the resource. The resource audit service monitors status of the clients thereby freeing the plurality of allocating services from individually monitoring the status of the clients to which resources have been allocated. When one of the clients fails, the resource audit service sends a failure notification to each of the plurality of allocating services that have allocated a resource to the failed client, thereby allowing each of the plurality of allocating services to recover the resource that had been allocated to the failed client.

Abstract: A system and method for resource recovery in a distributed system uses a resource audit service to monitor the status of a client that receives a resource from a service that allocates the resource. The allocating service registers a callback with the resource audit service identifying the client. The resource audit service subsequently monitors the status of the client. When the resource audit service determines that the client has failed, the resource audit service performs the callback to the allocating service indicating the failure of the client. Upon receiving the callback, the allocating service is able to recover the resource from the client.

Abstract: A method, apparatus, and computer-usable medium for compressing data in a file system utilizing the concept of "holes". A mapping table in a file system maps the logical blocks of a file to actual physical blocks on disk where the data is stored. Blocks may be arranged in units of a cluster, and the file may be compressed cluster-by-cluster. Holes are used within a cluster to indicate not only that a cluster has been compressed, but also the compression algorithm used. Different clusters within a file may be compressed with different compression algorithms. A unit of data is compressed, with the result that the file occupies fewer physical blocks than it has logical blocks. The mapping table is updated to indicate that for a given unit of data compressed, fewer physical blocks are needed. Certain logical blocks belonging to this unit of data are not mapped to physical blocks but are mapped to a hole.

Abstract: An extensible set of auxiliary services for objects in an object-oriented system. Every object in an object-oriented system is implemented by an associated object manager. Each object manager in the present invention has an associated object manager identifier that identifies the object manager. Each object manager in the system can optionally provide various auxiliary services for objects that the object manager implements. These auxiliary services are objects implemented by the object manager itself, or by another object manager. For a particular type of auxiliary service, different object managers may provide different auxiliary services. For example, two object managers may provide two different freeze-melt services. For each type of auxiliary service type, there is a well-known context in which auxiliary services of that type are associated with names. For each type of auxiliary service, there is also a well-known function that transforms an object manager identifier into a name.

Abstract: A secure naming model for objects in an object-oriented system, wherein names are bound to objects within context objects. The context objects are implemented by name servers, and clients request that a context object "resolve" the name for the object. The name server that implements the context returns a duplicate of the desired object. If a name resolution involves more than one name server, an assurance of security is provided by the first name server to the second name server.

Abstract: In this disclosure an architecture for extensible file systems is described. Also disclosed is an implementation of the architecture. The architecture enables the extension of file system functionality by stacking (or composing) new file systems (layers) on top of existing file systems. The implementor of a new layer has the option of keeping the files exported by the new layer coherent with files of the underlying layer, as well as the option of sharing the same cached memory with the files of the underlying layer. A flexible framework is also disclosed for arranging the file systems' name spaces. Composing of new layers on top of existing ones can be done statically (at compile/configuration time) or dynamically (at boot/run time). In addition, the file system layers can reside in the same address space or in different address spaces, and be implemented on a local computer node or on a remote computer node.

Abstract: A method is disclosed for a method to dynamically link a new program image and related library programs into an executable application program image. The method provides for producing a linked list of the required programs by giving the linker an argument representing the designated program image and a naming context which contains data on the associated library programs which are to be linked together. The linker finds all of the required programs, and links them together. The parent maps the program images into the designated addresses thereby completing the linking of the executable application program. In finding the required programs, the linker first checks the image cache to see if the new program and its related library programs is already linked and cached because it was executed before.

Abstract: A method and apparatus are described for a caching file server ("CFS") system which permits end user client programs on a local node of a distributed computer system, to issue requests to read/write data to a remote file and to query/set attributes of the remote file, and to have these requests serviced by the CFS in a way which minimizes the caching resources used as well as minimizes the related network communications. The CFS establishes CFS file programs to interface with the client programs, and sets up a common CFS cache for the file attributes, which cache is kept current via a communications link to a file program in a file server at the remote node containing the file, wherein the file program automatically updates the common CFS cache whenever any attributes change. The CFS also caches the results of bind operations in order to further minimize network calls and redundant cache usage.

Abstract: The present invention is a method and apparatus for efficiently using existing cache memory in a virtual memory computer system for servicing different demands for such memory. Moreover, the method and apparatus of the present invention, provides a way for authenticating untrusted virtual memory managers (VMMs) and untrusted pagers, which use and supply such caching services. The method and apparatus for authenticating the VMM and pagers can be practiced in an object oriented programming environment or in a non-object oriented environment.

Abstract: A method and apparatus for client programs adapted for use in an object oriented, distributed computing system, to have the ability to communicate and use references to objects in a way which improves the benefits of software caching are disclosed. A mechanism is described whereby a network object handle (an augmented object handle) can be used to reference both a server and a local cache manager. When the augmented object handle is transmitted it is automatically updated to use a local cache manager in its target environment (i.e. on the same machine on which the receiving client program resides) if possible.