Digital object repositories, models, protocol, apparatus, methods and software and data structures, relating thereto

• US 20060041661A1
• Filed: 07/02/2004
• Published: 02/23/2006
• Est. Priority Date: 07/02/2004
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Banks, David Murray, Erikson, John S.
• Granted Patent: US 7,702,725 B2
• Time in Patent Office: Days
• US Class Current: 709/225
• CPC Class Codes: G06F 16/9024 Graphs; Linked lists G06F16/9027 takes precedence
• CPC Class Codes: G06F 16/9566 URL specific, e.g. using aliases, detecting broken or misspelled links
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries

Abstract

A method of providing internet access to a data object repository comprising managing data objects hosted by said repository using a generalised repository directed graph data model having object nodes and resources, said resources comprising at least one of (i) a literal; (ii) actual resource data; and/or (iii) a URI directing a request for resources to an address; wherein said object nodes comprise higher level abstractions of data objects; wherein all object nodes and resources are named, as well as all arcs between object nodes and other object nodes or resources, said arcs modelling properties of said nodes; wherein each said directed graph has a graph interface which represents data as a directed graph of nodes and resources; and wherein said graph interface is capable of enabling access to data represented by said directed graph by traversal of said directed graph using http:GET.

Claims

1. A method of providing internet access to a data object repository comprising managing data objects hosted by said repository using a generalised repository directed graph data model having object nodes and resources, said resources comprising at least one of:

(i) a literal;

(ii) actual resource data; and

/or

(iii) a URI directing a request for resources to an address;

wherein said object nodes comprise higher level abstractions of data objects;

wherein all object nodes and resources are named, as well as all arcs between object nodes and other object nodes or resources, said arcs modelling properties of said nodes;

wherein each said directed graph has a graph interface which represents data as a directed graph of nodes and resources; and

wherein said graph interface is capable of enabling access to data represented by said directed graph by traversal of said directed graph using http;

GET.

2. A method according to claim 1 wherein said graph interface also supports http:

POST for mutation of said graph.

3. A method according to claim 1 wherein said directed graph spans data hosted in a plurality of repositories, there being at least one object node and/or resource of said directed graph stored in a first data object repository and at least one object node and/or resource of said directed graph stored in a second, different, data object repository.

4. A method according to claim 1 wherein said directed graph model organisation of said data objects is the native data organisation model of said repository, or at least of one of said repositories.

5. A method according to claim 1 wherein in a network where said repository, or at least one of said repositories has a native data organisation model that is not a directed graph model capable of being traversed by http:

GET in accordance with claim 1, said method comprising wrapping said native data organisation model in an API which does expose a directed graph data structure in accordance with claim 1, thereby providing web browser access to data hosted by said repository or said at least one repository.

6. A method according to claim 1 wherein in a network where said repository, or at least one of said repositories has a native data organisation model that is not a directed graph model capable of being traversed by http:

GET in accordance with claim 1, said method comprising providing said repository with an additional data model, in addition to said native data organisational model, said additional data model comprising a directed graph data model in accordance with claim 1, thereby providing an alternative, additional, method of querying data in said repository, or in said at least one repository.

7. A method according to claim 1 comprising defining the interaction of said graph interface with GET or POST requests using on-the-wire protocols, rather than using a language-specific API.

9. A method according to claim 1 further comprising:

managing said directed graph model using a first computer entity, and storing said data objects represented by said directed graph in at least one of;

(i) memory of said first computer entity;

(ii) memory of second computer entity, distinct from said first computer entity;

(iii) a distributed memory, at least one node representing a digital object held in memory of one computer entity, and at least a second node representing a digital object held in memory of a second computer entity; and

/or

(iv) a distributed memory according to (iii) above, and wherein said one computer entity comprises said first computer entity.

15. A method of providing network access to digital objects stored on a plurality of digital object repositories comprising, in addition to whatever native data structure each repository may have for its hosted digital objects, providing each repository with a common parallel data structure comprising a directed graph of nodes and resources, and ensuring that said parallel directed graph data structures support simple http GET requests to provide traversal of said directed graph data structures for read operations, thereby providing a user with access to said plurality of repositories via a web browser, and wherein said common parallel data structure directed graph comprises resource nodes and object nodes, said resource nodes comprising bit stream data representing a resource, or a URI;

and said object nodes comprising higher level abstractions of data objects;

said nodes being typed, and all said nodes being named, and all arcs between nodes being named, said arcs representing properties of node type—

node value pairs; and

wherein said repository which hosts data objects nodes and resource nodes of a said directed graph has a repository interface, said repository interface responding to a http;

GetCabilities( ) request, or other equivalent request, by returning details of the capabilities of said repository, including details of which data-model-specific interfaces are implemented by said repository and their bindings, which method is performed upon a data object repository having a pre-existing data structure and content management system that is not organised in accordance with claim 1, said method further comprising creating an additional alternative data structure and associated content management structure that is in accordance with claim 1, thereby providing an alternative, additional, way of querying or interacting with said data objects.

16. A method according to claim 15 comprising performing a method of providing network access to digital objects stored on a plurality of digital object repositories comprising, in addition to whatever native data structure each repository may have for its hosted digital objects, providing each repository with a common parallel data structure comprising a directed graph of nodes and resources, and ensuring that said parallel directed graph data structures support simple http GET requests to provide traversal of said directed graph data structures for read operations, thereby providing a user with access to said plurality of repositories via a web browser, and wherein said common parallel data structure directed graph comprises resource nodes and object nodes, said resource nodes comprising bit stream data representing a resource, or a URI;

and said object nodes comprising higher level abstractions of data objects;

said nodes being typed, and all said nodes being named, and all arcs between nodes being named, said arcs representing properties of node type—

node value pairs; and

wherein said repository which hosts data objects nodes and resource nodes of a said directed graph has a repository interface, said repository interface responding to a http;

GetCabilities( ) request, or other equivalent request, by returning details of the capabilities of said repository, including details of which data-model-specific interfaces are implemented by said repository and their bindings further comprising distributing nodes of said directed graph model over a plurality of repositories upon a plurality of data object repositories so as to enable said plurality of repositories to be read/write accessible using a common protocol, thereby providing interoperability for a user.

8. A method according to claim 8 comprising using an [RFC2616]—

compliant request string to make the request of said target node, the request including the nodal operation to perform, and the arguments of the nodal operation.

10. A method of providing network access to digital objects stored on a plurality of digital object repositories comprising, in addition to whatever native data structure each repository may have for its hosted digital objects, providing each repository with a common parallel data structure comprising a directed graph of nodes and resources, and ensuring that said parallel directed graph data structures support simple http GET requests to provide traversal of said directed graph data structures for read operations, thereby providing a user with access to said plurality of repositories via a web browser.

11. A method according to claim 10 wherein said common parallel data structure directed graph comprises resource nodes and object nodes, said resource nodes comprising bit stream data representing a resource, or a URI;

and said object nodes comprising higher level abstractions of data objects;

said nodes being typed, and all said nodes being named, and all arcs between nodes being named, said arcs representing properties of node type—

node value pairs; and

wherein said repository which hosts data objects nodes and resource nodes of a said directed graph has a repository interface, said repository interface responding to a http;

GetCabilities( ) request, or other equivalent request, by returning details of the capabilities of said repository, including details of which data-model-specific interfaces are implemented by said repository and their bindings.

12. A method according to claim 11 wherein content of a node is viewed using a http GET query expression.

13. A method according to claim 11 wherein content of a node is altered using a http POST expression.

14. A method according to claim 11 comprising distributing nodes of said directed graph model over a plurality of repositories.

17. A virtual, distributed, data object repository spanning a plurality of physical data repositories, comprising a first memory unit in a first repository, a second memory unit in a second repository, and a first control processor associated with the first repository, and a second control processor associated with a second repository;

said first repository being capable of providing access to said first and second data memory units;

said first processor managing data objects and metadata relating to data objects stored in said virtual repository according to a directed graph model of said data objects, said directed graph having resource, leaf, nodes comprising at least one of, (i) bit stream data streams;

(ii) literals;

(iii) a URI directing a query to one of (i) or (ii), and object nodes comprising aggregations representing a higher level abstraction of data objects; and

wherein properties of object nodes are represented by arcs connecting the object nodes to other object nodes or to leaf nodes; and

wherein said directed graph has nodes hosted by said first repository and at least one node hosted by said second repository, said first control processor, managing said directed graph, being adapted to cause queries relating to nodes hosted on said first repository to be directed to such nodes on the first repository, and to cause queries relating to the node or nodes hosted on said second repository to be directed to said second repository node(s).

18. A virtual data object repository according to claim 17 wherein said first and second control processors are adapted to expose data objects hosted on them to the Internet via respective directed graph interfaces which can be:

(i) traversed using simple http;

GET; and

/or (ii) mutated using simple http;

POST.

19. A virtual data object repository according to claim 17 wherein said directed graph interfaces are defined using on-the-wire protocols, as opposed to language-specific API'"'"'s.

20. A network comprising:

a first digital object repository having a first control processor, first memory for storing digital objects, and first digital object management software accessible by said first control processor, said first digital object management software being adapted to represent digital objects stored in said first memory to establish a first native structure for organising and managing read and write access to said first digital objects;

a second digital object repository having a second control processor, second memory for storing digital objects, and second digital object management software accessible by said second control processor, said second digital object management software being adapted to represent digital objects stored in said second memory to establish a second native data structure for organising and managing read and write access to said second digital objects;

said first and second repositories being accessible by a network-connected user;

said first digital object management software being of a different kind to said second digital object management software and representing said first digital objects in a different native data structure to the way that said second digital object management software represents said second digital objects in said second data structure, said first digital object management software requiring a first, different, read and/or write interaction instruction from said user to perform read and/or write operations than a second read and/or write interaction instruction required by said second digital object management software; and

wherein

said first control processor has first mapping software runable on it, said first mapping software mapping said first digital objects to a first directed graph data structure and being adapted to create first directed graph metadata and to provide read out/or write access to said first digital objects via traversal and/or mutation of said first directed graph data structure using an on-the-wire protocol request language such that network communication relating to first digital objects outside of said first repository is effectible using said first directed graph data structure and said on-the-wire protocol; and

wherein said second control processor has second mapping software runable on it, said second mapping software mapping said second digital objects to a second directed graph data structure and being adapted to create second directed graph metadata and to provide read and/or write access to said second digital objects via traversal and/or mutation of said second directed graph data structure using the same said on-the-wire protocol request language as is interactable with said first directed graph data structure, such that network communication relating to said second digital objects outside of said second repository is effectible using said on-the-wire protocol;

thereby enabling said user to read and/or write in relation to said first and second digital objects provided that they have the capability of using said on-the-wire protocol.

21. A network according to claim 20 wherein said on-the-wire protocol is from the group:

(i) http;

(ii) ftp;

or

(iii) another protocol.

22. A network according to claim 20 wherein said first and second mapping software support at least one of:

(i) http GET operations relating to nodes or resources managed by the first and second directed graph data structures; and

/or (ii) http POST operations relating to nodes or resources managed by the first and second directed graph data structures.

23. A network according to claim 20 wherein at least one data object or resource hosted in said first repository is associated with a node or resource of said second directed graph;

said second directed graph representing nodes that are distributed over said first and second repositories.

24. A network according to claim 20 wherein said first native data structure and said different said second native data structure are accessible for read and/or write operations of digital objects hosted by said first and second repositories using said, different, first and second interaction instructions respectively, there being two pathways to interact with said first and second digital objects:

a first pathway via the first and second native data structures and a second pathway via the first and second directed graph data structures.

25. A network according to claim 20 wherein said first and second mapping software has a function which responds to an http GetCapabilities (node) request, or equivalent request, by returning the capabilities of the requested node.

26. A network according to claim 25 wherein said first and second digital object management mapping software reacts to an unspecified http GetCapabilities( ) request, or equivalent request, by returning the capabilities of the first and second repositories, as represented by the first and second directed graphs.

27. Software, optionally encoded upon a data carrier, which when run on a control processor of a digital object repository having a directed graph data structure is adapted to permit traversal and/or mutation of the data structure using an on-the-wire protocol.

28. Software, optionally encoded upon a data carrier, which when run on a control processor of a digital object repository having a directed graph data structure is adapted to permit traversal and/or mutation of the data structure using http protocol.

29. Directed Graph Digital Object Management Software which, when run on a control processor of a digital objected repository, is adapted to provide for the organisation of digital objects as a directed graph of nodes and resources and to enable traversal and/or mutation of said nodes and resources by a user connected to said repository using an on-the-wire protocol from the group:

(i) http;

(ii) ftp;

or

(iii) another on-the-wire protocol.

30. A method of providing network access to a plurality of digital object repositories comprising organising the digital objects of the repositories in a directed graph data structure and providing a digital object management system which supports access for read of said digital objects via a web browser by interacting with said digital object management system via one of:

(i) a transport protocol;

or

(ii) http GET requests.

31. A virtual digital object repository distributed over a plurality of physical digital object repositories each having a repository control processor and repository memory, said virtual repository comprising a directed graph data structure of nodes and resources representing digital objects contained in said virtual repository, said directed graph data structure being hosted and managed by a managing control processor, said nodes and resources being distributed over the memory of a plurality of physical repositories.

32. A data structure comprising a directed graph of nodes and resources representing data, and an interface to said directed graph, said interface mapping at least one of traversal and mutation of nodes and resources to http GET and/or http POST.

33. A method of producing an interoperable network of digital object repositories comprising:

decomposing existing data models, or data, of existing digital object repositories into directed graphs; and

providing interfaces to said directed graphs that are mapped onto http GET and POST methods in order to provide for traversal and mutation of said directed graphs.

34. A digital object repository having a control processor and associated accessible memory, and digital object management software runable on said control processor;

said digital object management system being adapted to organise digital objects in said repository as a directed graph of nodes and resources, and being adapted to provide traversal and/or mutation of said graph by a remote user via simple on-the-wire protocol requests, said digital object management system providing an interface to communicate with said directed graph at two levels of operation;

(i) repository level operations, and (ii) node level operations, said node level operations interacting with specific identified nodes, and said repo level operations relating to higher level operations applicable to more than an identified node and/or to repository metadata.

35. A method of querying a digital object repository managing a plurality of resources, comprising bit stream data, via a digital object management system, the digital object management system using a directed graph to organise said resources and metadata relating to said resources as reference, leaf nodes, and object nodes, with properties of nodes represented by arcs between object nodes and either object nodes or reference nodes;

said method comprising providing a binding of a query expression to an internet transport protocol in order to traverse said directed graph.

36. Client machine software adapted, when run on a control processor of a client machine, to bind (i) a read and/or write query expression intended for receipt by, or response by, a repository having a data structure managed by a digital object management system which represents a data structure as a direct graph of named nodes and arcs, to (ii) an internet transport protocol so as to enable said protocol to mediate interactions with said directed graph data structure to enable traversal of said directed graph data structure.

37. A method of providing API language-independent interoperability with digital object repositories comprising using a directed graph data model to represent resources and metadata managed by said repositories, and providing traversal and/or mutation of directed graphs using query expressions bound to an internet transport protocol.

38. A method of providing interoperability of existing digital object repositories having diverse Content Management Systems (CMS) requirements comprising providing them with a common digital object management system comprising a directed graph data model data structure which exposes nodal interfaces that are accessible using an on-the-wire protocol.

39. A method according to claim 38 in which the common digital object management system is:

(i) provided in parallel with an existing diverse CMS of the repositories; and

/or

(ii) provided as a wrapper covering the existing diverse CMS so as to respond to queries via the common digital object management system, directed graph, data structure.

40. Software, optionally encoded upon a data carrier, which when running a control processor of a digital object repository, is adapted to interact with at least one of:

(i) digital objects stored in said repository; and

/or

(ii) a Content Management System (CMS) runable upon said control processor, said Content Management System organising and managing said digital objects to create a data structure;

so as to construct an alternative, directed graph, data structure with said digital objects comprising object nodes or reference nodes of said directed graph data structure, and said software also creating an alternative associated digital object management system to provide read/write access to said digital objects via said directed graph data structure and said associated digital object management system;

said software also providing an interface to said directed graph data structure which is capable of interacting with said directed graph data structure and/or said nodes and of being accessed using an on-the-wire protocol.

41. Software according to claim 40 which provides an interface capable of interacting with:

(i) specific nodes; and

/or

(ii) collections of nodes; and

/or

(iii) said directed graph digital object management system at a repository level.

42. A digital object repository comprising:

processing means;

memory means; and

directed graph interface means;

said processor means having access to directed graph digital object management software runable on said processor means, and access to digital objects stored in said memory means, said directed graph digital object management software being adapted, when run on said processor means, to represent digital objects as a directed graph data structure of named nodes and arcs; and

wherein said directed graph interface comprises means for receiving internet transport protocol commands and for converting such commands into instructions for traversing said directed graph data structure to enable internet access to said digital objects.

43. A method of creating a distributed digital object repository comprising, in a first digital object repository having a first control processor and digital objects stored in first memory of said first digital object repository with said first digital objects being represented as nodes of a directed graph data structure managed by a directed graph managing control processor which either comprises said first control processor or is accessible by said first control processor, with read of said digital objects being provided for by traversal of said directed graph data structure mediated by a translation between internet transport protocol commands received by said directed graph managing control processor and a command language adapted to traverse said directed graph data structure;

altering said directed graph data structure to include a node with an address that represents memory that is not in said first memory of said first digital object repository, but is instead outside of the first digital object repository, thereby enabling queries of said first digital object repository to encompass digital objects that are outside of said first digital object repository.

44. A method according to claim 43 comprising informing one of:

(i) said first digital object repository control processor, or

(ii) said directed graph-managing control processor about the existence and/or address of an off-first repository digital object.

45. A method according to claim 43 comprising a second digital object repository informing one of:

(i) said first digital object repository or

(ii) said directed graph-managing control processor, of the existence and address of at least one of its digital objects, stored on its, second, memory, and causing said directed graph data structure to be modified to include a node directing to said at least one digital object of said second repository.

46. A method of augmenting the content of a digital object repository comprising conveying to a repository access-managing system URI details of off-repository digital objects for subsequent inclusion in a directed graph data structure of said repository.

47. A computer entity comprising a memory storing a directed graph having:

resources;

leaf nodes comprising at least one of;

(i) bit stream data streams;

(ii) literals, and (iii) a URI directing a query to one of (i) or (ii); and

object nodes comprising aggregations representing a higher level abstraction of data objects;

and the properties of the object nodes being represented by arcs connecting the object nodes to other object nodes or leaf nodes;

the graph representing/modelling a plurality of resources hosted on a plurality of data repositories within a network;

wherein

traversal of the graph and access to a resource represented by it may be performed using a command within an on-the-wire protocol;

the computing entity further comprising a processor adapted to cause a query relating to a node of the graph representing a resource hosted at a data repository remote from the computer entity to direct the query to the remote entity.

48. A computer entity according to claim 47 wherein the memory of the computer entity further stores a data repository containing at least one resource modelled/represented by the graph.