Class loading using java data cartridges

• US 8,959,106 B2
• Filed: 04/19/2011
• Issued: 02/17/2015
• Est. Priority Date: 12/28/2009
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: de Castro Alves, Alexandre, Srinivasan, Anand
• Primary Examiner(s): Spieler, William
• Application Number:
  US13/089,556
• Publication Number:
  US 20110196891A1
• Time in Patent Office: 1,400 Days
• Field of Search: 707/769, 719/310
• US Class Current: 707/768
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57

Abstract

Techniques for loading Java classes referenced in a continuous query. In one set of embodiments, the Java classes can be loaded based on a class space defined for an application considered to be in scope for the query. In another set of embodiments, the Java classes can be loaded based on a server class space that includes all exported classes visible to the event processing system executing the query.

Claims

1. A method comprising:

receiving, by a computer system, executable instructions for a first query that an invocation of a first method, expressed in a first programming language;

receiving, by the computer system, executable instructions for a second query that includes an expression that specifies an invocation of a second method expressed in a second programming language that differs from the first programming language; and

executing, by the computer system, the executable instructions for the first and second queries in the context of an application;

wherein a first repository contains metadata specifying a compile-time component for a first programmatic class that includes the first method;

wherein a second repository, separate from the first repository, contains metadata specifying a compile-time component for a second programmatic class that includes the second method;

reading, during a compilation process, context information specified in the metadata contained in the first repository; and

passing, by a runtime engine, following the compilation process, the context information in the invocation of the first method.

2. The method of claim 1 wherein the application is associated with an application class space including programmatic classes defined in the application'"'"'s internal classpath and programmatic classes imported by the application, and wherein loading the first programmatic class according to the application class space mode comprises searching for the first programmatic class in the application class space.

3. The method of claim 2 wherein the programmatic classes imported by the application are defined in a manifest file associated with the application.

4. The method of claim 1 wherein loading the first programmatic class comprises:

identifying all exported programmatic classes in the computer system; and

loading the first programmatic class by searching for the first programmatic class among the exported programmatic classes.

5. The method of claim of claim 4 wherein the exported programmatic classes include one or more programmatic classes that are defined by other applications and are not User Defined Functions (UDFs).

6. The method of claim 1 wherein the executing comprises determining whether to load the first and second programmatic classes according to an application class space mode or according to a server class space mode;

and wherein determining whether to load the first programmatic class according to the application class space mode or according to the server class space mode comprises searching for a header entry in a manifest file associated with the application.

7. The method of claim 1, wherein the first and second programming languages provide functions that a native query processing language in which the first and second queries are expressed does not provide.

8. The method of claim 1, further comprising:

a locator passing, to a semantic analyzer, a first handle to the first repository;

the locator passing, to the semantic analyzer, a second handle to the second repository that is included within a data cartridge that is registered with an event processing system;

the semantic analyzer interacting with the first repository through a particular interface using the first handle to retrieve, from the first repository, the metadata specifying the compile-time component for the first programmatic class; and

the semantic analyzer interacting with the second repository through the particular interface using the second handle to retrieve, from the second repository, the metadata specifying the compile-time component for the second programmatic class.

9. The method of claim 1, wherein the metadata contained in the first repository specifies a first coordinate system;

and wherein the metadata contained in the second repository specified a second coordinate system that differs from the first coordinate system.

10. The method of claim 1, wherein the context information specifies a spatial coordinate system.

11. A method comprising:

receiving, by a computer system, executable instructions for a first query that (a) is continuously executable relative to stream-specified events as those events are received by the computer system and (b) includes an expression that specifies both (i) an invocation of a compile method that is expressed in a programming language other than a native query processing language and (ii) an invocation of a second method, also expressed in the programming language, relative to a first object returned by the compile method, said first object being an instance of a first programmatic class;

receiving, by the computer system, executable instructions for a second query that includes an expression that specifies an invocation of a third method relative to a second object, said second object being an instance of a second programmatic class that differs from the first programmatic class; and

executing, by the computer system, the executable instructions for the first and second queries in the context of an application, wherein the executing comprises determining whether to load the first and second programmatic classes according to an application class space mode or according to a server class space mode;

wherein a first repository contains metadata specifying a compile-time component for the first programmatic class;

wherein a second repository, separate from the first repository, contains metadata specifying a compile-time component for the second programmatic class; and

wherein loading the first programmatic class according to the application class space mode comprises;

in response to determining that the first programmatic class is referenced solely by a local name in the query, (1) attempting, in a first attempt, to load the first programmatic class by searching for the local name in an unnamed package of the application class space;

(2) in response to determining that the first attempt has failed, attempting, in a second attempt, to load the first programmatic class by searching for the local name in the application'"'"'s internal classpath, regardless of package; and

(3) in response to determining that the second attempt has failed, attempting, in a third attempt, to the load the first programmatic class by searching for entries in the manifest file that, in conjunction with the local name, are useable for identifying the first programmatic class.

12. A system comprising:

a first repository containing metadata specifying a compile-time component for a first programmatic class that includes a first method;

a second repository, separate from the first repository, containing metadata specifying a compile-time component for a second programmatic class that includes a second method; and

a processor configured to;

read, during a compilation process, context information specified in the metadata contained in the first repository;

receive executable instructions for a first query that includes an expression that specifies an invocation of the first method expressed in a first programming language;

receive executable instructions for a second query that includes an expression that specifies an invocation of the second method expressed in a second programming language that differs from the first programming language;

execute the executable instructions for the first and second queries in the context of an application; and

pass, by a runtime engine, following the compilation process, the context information in the invocation of the first method.

13. The system of claim 12 wherein the application is associated with an application class space including programmatic classes defined in the application'"'"'s internal classpath and programmatic classes imported by the application, and wherein loading the first programmatic class according to an application class space mode comprises searching for the first programmatic class in the application class space.

14. The system of claim 12 wherein loading the first programmatic class according to a server class mode comprises:

identifying all exported programmatic classes in the computer system; and

loading the first programmatic class by searching for the first programmatic class among the exported programmatic classes.

15. A non-transitory computer-readable storage medium having stored thereon instructions executable by a processor, the instructions comprising:

instructions that cause the processor to read, during a compilation process, context information specified in metadata contained in a first repository containing metadata specifying a compile-time component for a first programmatic class that includes a first method expressed in a first programming language;

instructions that cause the processor to receive executable instructions for a first query that includes an expression that specifies an invocation of the first method;

instructions that cause the processor to receive executable instructions for a second query that includes an expression that specifies an invocation of a second method expressed in a second programming language that differs from the first programming language; and

instructions that cause the processor to execute the executable instructions for the first and second queries in the context of an application; and

instructions that cause the processor to pass, by a runtime engine, following the compilation process, the context information in the invocation of the first method;

wherein a second repository, separate from the first repository, contains metadata specifying a compile-time component for a second programmatic class that includes the second method.

16. The non-transitory computer-readable storage medium of claim 15 wherein the application is associated with an application class space including programmatic classes defined in the application'"'"'s internal classpath and programmatic classes imported by the application, and wherein loading the first programmatic class according to an application class space mode comprises searching for the first programmatic class in the application class space.

17. The non-transitory computer-readable storage medium of claim 15 wherein loading the first programmatic class according to a server class mode comprises:

identifying all exported programmatic classes in the computer system; and

loading the first programmatic class by searching for the first programmatic class among the exported programmatic classes.

18. A method comprising:

receiving, by a computer system, executable instructions for a first query that an invocation of a first method, expressed in a first programming language;

receiving, by the computer system, executable instructions for a second query that includes an expression that specifies an invocation of a second method expressed in a second programming language that differs from the first programming language; and

executing, by the computer system, the executable instructions for the first and second queries in the context of an application;

wherein a first repository contains metadata specifying a compile-time component for a first programmatic class that includes the first method;

wherein a second repository, separate from the first repository, contains metadata specifying a compile-time component for a second programmatic class that includes the second method;

reading information specified in the metadata contained in the first repository; and

performing, based on the information specified in the metadata contained in the first repository, type checking relative to the first query.

19. The method of claim 18, further comprising:

reading information specified in the metadata contained in the second repository;

performing, based on the information specified in the metadata contained in the second repository, type checking relative to the second query;

wherein the information specified in the metadata contained in the first repository differs from the information specified in the metadata contained in the second repository.