Framework for object-oriented interface to record file data

• US 6,018,743 A
• Filed: 10/04/1996
• Issued: 01/25/2000
• Est. Priority Date: 10/04/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Xu, Jian J.
• Primary Examiner(s): Von Buhr, Maria N.
• Application Number:
  US08/726,108
• Time in Patent Office: 1,208 Days
• Field of Search: 707/103, 707/100, 707/101, 707/104
• US Class Current: 1/1
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 9/4493 Object persistence
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

An object-oriented framework provides an interface for use with object oriented data management systems to provide multiple types of object-oriented data access to record-oriented data files, and can utilize multiple record file adapters to provide OOP applications with access to multiple types of record-oriented data files. The framework thereby permits API programmers to easily create OOP applications that manipulate data in record file data storage. Thus, the framework accesses data stored in record file data structures through a dual two-way interface with persistent object data management services.

Claims

1. A method of operating a computer system that provides an object-oriented programming environment, having one or more datastores that contain record-oriented data files, and communicating with one or more users executing object-oriented application programs for manipulation of persistent data objects corresponding to the data files, the method comprising the steps of:

(a) receiving a request for manipulation of a persistent data object from one of at least two incompatible persistent object service systems utilizing different data protocols and class hierarchies;

(b) associating each persistent data object with a data file by

(1) associating each instance of a persistent data object with a persistent object identifier;

(2) associating each instance of the persistent data object with only one data file in a datastore, such that each instance of an attribute of the data object is mapped to one associated data file, and

(3) defining within each persistent object identifier a data identifier that is associated with either a record number or a key within the data file associated with the persistent object identifier; and

(c) instructing the datastore to alter the information within a selected data file through the associated instance of the persistent data object.

2. A method as defined in claim 1, wherein the step of instructing the datastore to alter a data file comprises communicating with the datastore through an adapter object that is adapted for the record format of the datastore.

3. A method as defined in claim 2, wherein the step of instructing the datastore further comprises selecting the adapter object from among a predetermined set of adapter objects, each of which is adapted for a different record format.

4. A method as defined in claim 3, wherein the adapter object is selected by a schema mapper object.

5. A method as defined in claim 1, wherein the persistent object identifier designates the data protocol to be used.

6. A method as defined in claim 1, wherein the step of receiving a request comprises receiving a request from a first one of the persistent object service systems at a first data object and receiving a request from a second one of the persistent object service systems at a second data object.

7. A method as defined in claim 6, wherein the first data object comprises a persistent data service object and the second data object comprises a datastore manager object.

8. A computer system comprising:

a central processing unit;

a user interface;

one or more datastores that contain record-oriented data files; and

a main memory having an operating system that provides an object-oriented programming environment containing a framework that maintains a Persistent Object Service object that receives requests for manipulation of a persistent data object corresponding to the data files from one of at least two incompatible persistent object service systems utilizing different data protocols and class hierarchies, such that the Persistent Object Service object satisfies the request by performing steps comprising;

(a) associating each persistent data object with a data file by

(1) associating each instance of a persistent data object with a Persistent Identifier object,

(2) associating each instance of the persistent data object with only one data file in a datastore, such that each instance of an attribute of the persistent data object is mapped to one associated data file, and

(3) defining within each Persistent Identifier object a data identifier that is associated with either a record number or a key within the data file associated with the Persistent Identifier object; and

(b) instructing the datastore to alter the information within a selected data file through the associated instance of the persistent data object.

9. A computer system as defined in claim 8, wherein the step of instructing the datastore to alter a data file comprises communicating with the datastore through a framework Adapter object that is adapted for the record format of the datastore.

10. A computer system as defined in claim 9, wherein the step of instructing the datastore further comprises selecting the Adapter object from among a predetermined set of framework Adapter objects, each of which is adapted for a different record format.

11. A computer system as defined in claim 10, wherein the Adapter object is selected by a framework Schema Mapper object.

12. A computer system as defined in claim 8, wherein the Persistent Identifier object designates the data protocol to be used.

13. A computer system as defined in claim 8, wherein the step of receiving a request comprises receiving a request from a first one of the persistent object service systems at a first framework data object and receiving a request from a second one of the persistent object service systems at a second framework data object.

14. A computer system as defined in claim 13, wherein the first data object comprises a framework Persistent Data Service object and the second data object comprises a framework DataStore Manager object.

15. A program product for use in a computer system having an object-oriented programming environment, the program product comprising:

(a) a signal bearing media; and

(b) a sequence of instructions on the signal bearing media that are executable by the computer system, the sequence providing an object-oriented application program that instantiates objects needed for execution of the application program such that the computer system performs the steps of;

(1) generating a Persistent Identification object that is adapted to identify an access path to a particular record data file contained within a datastore in accordance with a datastore name, a data file identifier, and a schema mapper;

(2) generating a Persistent Data Service object that performs Level 2 data access operations with a client process by interfacing with a POSSOM persistent object service system and a DataStore Manager object and is adapted to interface with record data files;

(3) generating the DataStore Manager object to which the Persistent Data Service object interfaces such that the generated DataStore Manager object provides Level 3 data access operations and is adapted to interface with a CODA persistent object service system and with record data files;

(4) generating a Schema Mapper object that receives a mapping indicator that specifies the manner in which the Persistent Identification object is to be mapped to the associated record, and

(5) generating a Record File Adapter object that provides a mapping between the DataStore Manager object and a datastore procedure adapted for a predetermined type of datastore.

16. A program product as defined in claim 15, wherein the signal bearing media comprises recordable media.

17. A program product as defined in claim 15, wherein the signal bearing media comprises transmission media.

18. A computer system that provides access to record files in datastore from an object oriented user interface, the computer system providing an object-oriented programming environment having a framework that includes:

a Persistent Data Service object that receives Level 2 data access requests from the user interface for data access operations on persistent data objects associated with record files and generates datastore operations on the associated record files; and

a DataStore Manager that receives Level 2 and Level 3 data access requests directly from the user interface and Level 2 data access requests from the Persistent Data Service object, such that the DataStore Manager provides direct access to a Record File Adapter object adapted to communicate with a predetermined record file system.

19. A computer system as defined in claim 18, wherein the framework further includes a Persistent Object Service object that causes the computer system to perform the steps of:

(a) associating each persistent data object with a data file by

(1) associating each instance of a persistent data object with a persistent object identifier,

(2) associating each instance of the persistent data object with only one data file in datastore, such that each instance of an attribute of the data object is mapped to one associated data file, and

(3) defining within each persistent object identifier a data identifier that is associated with either a record number or a key within the data file associated with the persistent object identifier; and

(b) instructing the datastore to alter the information within a selected data file through the associated instance of the persistent data object.

20. A computer system as defined in claim 19, wherein the step of instructing the datastore to alter a data file comprises communicating with the datastore through a Record File Adapter object that is adapted for the record format of the datastore.

21. A computer system as defined in claim 20, wherein the step of instructing the datastore further comprises selecting the Record File Adapter object from among a predetermined set of objects, each of which is adapted for a different record format.

22. A computer system as defined in claim 21, wherein the Record File Adapter object is selected by a Schema Mapper object.

23. A computer system as defined in claim 19, wherein the persistent object systems utilize different data protocols.

24. A computer system as defined in claim 23, wherein the persistent object identifier designates the data protocol to be used.

25. A computer system as defined in claim 19, wherein the step of receiving a request comprises receiving a request from a first one of the persistent object service systems at a first data object and receiving a request from a second one of the persistent object service systems at a second data object.

26. A computer system as defined in claim 25, wherein the first data object comprises the Persistent Data Service object and the second data object comprises the DataStore Manager object.