Interpretive object-oriented facility which can access pre-compiled classes

• US 5,307,499 A
• Filed: 05/20/1993
• Issued: 04/26/1994
• Est. Priority Date: 11/30/1990
• Status: Expired due to Term

• Current Assignee: Singapore Computer Systems Limited (Singapore Telecommunications Limited)
• Original Assignee: Singapore Computer Systems Limited (Singapore Telecommunications Limited)
• Inventors: Yin, Fong K.
• Primary Examiner(s): Kriess, Kevin A.
• Application Number:
  US08/065,457
• Time in Patent Office: 341 Days
• Field of Search: 395/650, 395/700
• US Class Current: 717/139
• CPC Class Codes: G06F 8/30 Creation or generation of source code
• CPC Class Codes: G06F 8/41 Compilation
• CPC Class Codes: G06F 8/42 Syntactic analysis
• CPC Class Codes: G06F 9/4488 Object-oriented
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching

Abstract

An object-oriented technology is provided which is capable of operating interpretively to allow prompt and easy prototyping and debugging using a compiled class library, and which is also capable of operating after compilation, thereby providing excellent performance. A software facility allows direct access to class attributes and direct invocation of class methods defined in pre-compiled classes in a class library in an interpretive mode. When this facility is used with or embedded within an application development environment, it allows an application builder to interactively build prototypes as well as production quality applications rapidly. When the facility is integrated with an object-oriented database, it allows interactive query and data manipulation using pre-complied classes.

Claims

1. A method implemented by a computer system to cause said computer system to execute an object-oriented source code of an object-oriented language, comprising the steps of:

writing a plurality of classes using object-oriented source code of said object-oriented language;

scanning said class library containing said compiled classes to determine class definition information;

using said class definition information to produce object manipulation functions that allow said computer system to access the methods and attributes of said compiled classes to manipulate the objects of said compiled classes;

using said class definition information to produce dispatch tables containing addresses to said object manipulation functions;

interpreting a source code written using said object-oriented language, said source code including statements seeking access to one or more of said compiled classes within said class library; and

invoking previously written object entry functions which provide entry into said dispatch tables to activate said object manipulation functions during said step of said computer system interpreting said source code, at references within said source code to said compiled classes, thereby causing said computer system to use said object-oriented source code to access said compiled classes.

2. A method as in claim 1 wherein said step of scanning said class library includes a step of selecting one or more compiled classes from said class library so that only said selected one or more compiled classes can be accessed by said computer system during said step of interpreting said object-oriented source code.

3. A method as in claim 1 wherein said step of producing object manipulation functions comprises the steps of:

generating object manipulation function source code, in said object-oriented language, using said class definition information;

translating said object manipulation function source code into translated object manipulation function source code, written in a non-object-oriented language; and

compiling said translated object manipulation function source code into object manipulation functions object code.

4. A method as in claim 3 which further comprises the step of patching said translated object manipulation function source code that, upon execution by said computer system, return an instance of a class, thereby causing said execution by said computer system of said translated object manipulation function to return information comprising a pointer to said instance, the class to which said instance belongs, and an indication of how the memory for said descriptor is to be freed.

5. A method as in claim 1 wherein said step of producing said dispatch tables comprises the steps of:

generating dispatch tables source code, in said object-oriented language, using said class definition information;

translating said dispatch tables source code into a translated dispatch tables source code, in a non-object-oriented language; and

compiling said translated dispatch tables source code into dispatch tables object code.

6. A method implemented by a computer system to cause said computer system to execute an object-oriented source code of an object-oriented language, said computer system including a class library containing a plurality of compiled classes which have been compiled from classes written using source code of said object-oriented language, comprising the steps of:

scanning said class library containing said compiled classes to determine class definition information;

using said class definition information to produce object manipulation functions that access the methods and attributes of said compiled classed to manipulate the objects of said compiled classes;

using said class definition information to produce dispatch tables containing addresses to said object manipulation functions;

interpreting a source code written using said object-oriented language, said source code including statements seeking access to one or more of said compiled classes within said class library; and

invoking previously written object entry functions which provide entry into the dispatch tables to activate the object manipulation functions during said step of interpreting said source code, at references within said source code to said compiled classes, thereby causing said computer system to use said object-oriented source code to access said compiled classes.

7. A method as in claim 6 wherein said step of scanning said class library includes the step of selecting one or more classes from said class library so that only said selected one or more compiled classes can be accessed by said computer system during said step of interpreting said object-oriented source code.

8. A method as in claim 6 wherein said step of producing object manipulation functions comprises the steps of:

generating object manipulation function source code, in said object-oriented language, using said class definition information;

translating said object manipulation function source code into translated object manipulation function source code, written in a non-object-oriented language; and

compiling said translated object manipulation function source code into object manipulation functions object code.

9. A method as in claim 8 which further comprises the step of patching said translated object manipulation function source code that, upon execution by said computer system, return an instance of a class, thereby causing said execution by said computer system of said translated object manipulation function to return information comprising a pointer to said instance, the class to which said instance belongs, and an indication of how the memory for said descriptor is to be freed.

10. A method as in claim 6 wherein said step of producing said dispatch tables comprises the steps of:

generating dispatch tables source code, in said object-oriented language, using said class definition information;

translating said dispatch tables source code into a translated dispatch tables source code, in a non-object-oriented language; and

compiling said translated dispatch tables source code into dispatch tables object code.

11. A method implemented by a computer system to cause said computer system to execute an interactive database query of an object-oriented database comprising the steps of:

writing a plurality of classes using an object-oriented code of an object-oriented language;

compiling said plurality of classes written using said object-oriented language to create a class library of compiled classes;

scanning said class library containing said compiled classes to determine class definition information;

using said class definition information to produce object manipulation functions that access the methods and attributes of said compiled classes to manipulate the objects of said compiled classes;

using said class definition information to produce dispatch tables containing addresses to said object manipulation functions;

preprocessing a database query written using an object-oriented database query language into a source code of an object-oriented language, said source code including statements seeking access to one or more of said compiled classes within said class library;

interpreting said source code; and

invoking previously written object entry functions which provide entry into said dispatch tables to activate said object manipulation functions during said step of interpreting said source code, at references within said source code of said compiled classes, thereby causing said computer system to use said source code to access said compiled classes.

12. A method as in claim 11 wherein said step of scanning said class library includes the step of selecting one or more compiled classes from said class library so that only said selected one or more compiled classes can be accessed by said computer system during said step of interpreting said object-oriented source code.

13. A method as in claim 11 wherein said step of producing object manipulation functions comprises the steps of:

generating object manipulation function source code, in said object-oriented language, using said class definition information;

translating said object manipulation function source code into translated object manipulation function source code, written in a non-object-oriented language; and

compiling said translated object manipulation function source code into object manipulation functions object code.

14. A method as in claim 13 which further comprises the step patching said translated object manipulation function source code that, upon execution by said computer system, return an instance of a class, thereby causing said execution by said computer system of said translated object manipulation function to return information comprising a pointer to said instance, the class to which the instance belongs, and an indication of how the memory for said descriptor is to be free.

15. A method as in claim 11 wherein said step of producing said dispatch tables comprises the steps of:

generating dispatch tables source code, in said object-oriented language, using said class definition information;

translating said dispatch tables source code into a translated dispatch tables source code, in a non-object-oriented language; and

compiling said translated dispatch tables function source code into dispatch tables object code.

16. A method implemented by a computer system to cause said computer system to execute an interactive database query of an object-oriented database, said computer system including a class library containing a plurality of compiled classes which have been compiled from classes written using source code of said object-oriented language, comprising the steps of:

scanning said class library containing said compiled classes to determine class definition information;

using class definition information to produce object manipulation functions that access the methods and attributes of said compiled classes to manipulate the objects of said compiled classes;

using said class definition information to produce dispatch tables containing addresses to said object manipulation functions;

preprocessing a database query written using an object-oriented database query language into a source code of an object-oriented language, said source code including statements seeking access to one or more of said compiled classes within said class library;

interpreting said source code; and

invoking previously written object entry functions which provide entry into said dispatch tables to activate said object manipulation functions during said step of interpreting said source code, at reference within said source code, as executed by said computer system to said compiled classes, thereby causing said source code to access said compiled classes.

17. A method as in claim 16 wherein said step of scanning said class library includes the step of selecting one or more compiled classes from said class library so that only said selected one or more compiled classes can be accessed by said object-oriented source code.

18. A method as in claim 16 wherein said step of producing object manipulation functions comprises the steps of:

generating object manipulation function source code, in said object-oriented language, using said class definition information;

translating said object manipulation function source code into translated object manipulation function source code, written in a non-object-oriented language; and

compiling said translated object manipulation function source code into object manipulation functions object code.

19. A method as in claim 18 which further comprises the step of patching said translated object manipulation function source code that, upon execution by said computer system, return an instance of a class, thereby causing said execution by said computer system of said translated object manipulation function to return information comprising a pointer to said instance, the class to which said instance belongs, and an indication of how the memory for said descriptor is to be freed.

20. A method as in claim 16 wherein said step of producing said dispatch tables comprises the steps of:

generating dispatch tables source code, in said object-oriented language, using said class definition information;

translating said dispatch tables source code into a translated dispatch tables source code, in a non-object-oriented language; and

compiling said translated dispatch tables source code into dispatch tables object code.

21. A computer system to execute an object-oriented source code of an object-oriented language comprising:

means for storing a class library comprising one or more classes defined in object code generated from source code of an object-oriented language;

means for storing a to-be-executed code written in source code of said object-oriented language;

means for manipulating said computer system in order to interpret said to-be-executed source code, said means for manipulating comprising;

means for accessing said class library to obtain class definition information;

a first means for using said class definition information to produce object manipulation functions which access the methods and attributes of said classes to manipulate the objects of said classes;

a second means for using said class definition information to produce dispatch tables containing addresses to said object manipulation functions;

means for providing entry into said dispatch tables, to activate said object manipulation functions, thereby accessing said compiled classes of said class library; and

means for interpreting said to-be-executed source code and invoking said means for providing entry at locations within said to-be-executed source code which reference said compiled classes of said class library thereby causing said to-be-executed source code to access said compiled classes in said class library.

22. A computer system as in claim 21 wherein said means for accessing said class library to obtain class definition information comprises means for selecting one or more compiled classes from said class library so that only said selected one or more compiled classes can be accessed by said to-be executed source code.

23. A computer system as in claim 21 wherein said first means for using said class definition information comprises:

a first means for operating said computer system to generated object manipulation function source code, in said object-oriented language, using said class definition information;

a second means for operating said computer systems to translate said object manipulation function source code into translated object manipulation function source code, written in a non-object-oriented language; and

a third means for operating said computer system to compile said translated object manipulation function source code into object manipulation functions object code.

24. A computer system as in claim 21 wherein said second means for operating said computer system comprises:

a first means for using said class definition information to generate dispatch tables source code, in said object-oriented language, using said class definition information;

a second means for translating said dispatch tables source code into a translated dispatch tables source code, in a non-object-oriented language; and

a third means for compiling said translated dispatch tables function source code into dispatch tables object code.

25. A system in claim 21 which further comprises means for causing said computer system to patch said translated object manipulation function source code that, upon execution, return an instance of a class, thereby causing said execution of said translated object manipulation function to return information comprising a pointer to said instance, the class to which said instance belongs, and an indication of how the memory for said descriptor is to be free.

26. A computer system to execute an interactive database query comprising:

means for storing a class library comprising one or more classes defined in object code from source code of an object-oriented language;

means for storing a to-be-executed code written in an object-oriented database query language;

means for manipulating said computer system in order to interpret said to-be-executed source code, said means for manipulating comprising;

means for accessing said class library to obtain class definition information;

a first means for using said class definition information to produce object manipulation functions which access the methods and attributes of said classes to manipulate the objects of said classes;

a second means for using said class definition information to produce dispatch tables containing addresses to said object manipulation functions;

means for providing entry into said dispatch tables to activate said object manipulation functions, thereby accessing said compiled classes of said class library;

means for preprocessing said to-be-executed source code into a source code of an object-oriented language; and

means for interpreting said source code of said object-oriented language and invoking said means for providing entry at locations within said source code which reference said compiled classes of said library thereby causing said source code to access said compiled classes in said class library.

27. A computer system as in claim 26 wherein said means for accessing said class library to obtain class definition information comprises means for selecting one or more compiled classes from said class library so that only said selected one or more compiled classes can be accessed by said to-be executed source code.

28. A computer system as in claim 26 wherein said first means for using said class definition information comprises:

a first means for generating object manipulation function source code, in said object-oriented language, using said class definition information;

a second means for translating said object manipulation function source code into translated object manipulation function source code, written in a non-object-oriented language; and

a third means for compiling said translated object manipulation function source code into object manipulation functions object code.

29. A computer system as in claim 26 wherein said second means for using said class definition information comprises:

a first means for generating dispatch tables source code, in said object-oriented language, using said class definition information;

a second means for translating said dispatch tables source code into a translated dispatch tables source code, in a non-object-oriented language; and

a third means for compiling said translated dispatch tables function source code into dispatch tables object code.

30. A system in claim 28 which further comprises means for causing said computer system to patch said translated object manipulation function source code that, upon execution, return an instance of a class, thereby causing said execution of said translated object manipulation function to return information comprising a pointer to said instance, the class to which said instance belongs, and an indication of how the memory of said descriptor is to be freed.