www.oasis-open.org
SCA C++, C and COBOL
Bryan Aupperle ([email protected])
David Haney ([email protected])
13 Dec. 2007
Specification Status
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C and C++ specification
development proceeding in OASIS



Based on work started in Open SOA
(OSOA)
Now proceeding in the SCA-C-C++ TC
COBOL specification remains under
OSOA

SCA-C-C++ TC work will influence
SCA-C-C++ TC Work

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Updated conformance statements
Definition of a conformance test suite
Formal definition of C/C++ Annotations
Updated C++ -> WSDL, WSDL -> C++
Mapping
Incorporation of SCA Policy
SCDL for C++

interface.cpp
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header – C++ header file describing the interface
class – (optional) Class defining the interface
callbackHeader – (optional) C++ header describing the
callback interface
callbackClass – (optional) Class defining the callback
interface
remotable – (optional) Indicates whether the service can be
called from a remote system
implementation.cpp
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library – Shared library defining the service factory
path – (optional) Path to search for the library
header – C++ header file describing the implementation
class – (optional) Class defining the implementation
scope – (optional) Specifies the lifetime and reuse options for
an implementation instance
C++ APIs
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ComponentContext

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Primary interface for accessing SCA defined
components.
Component Meta Information

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Service Lookup


getCurrent(), getURI(), getProperties(),
getDataFactory()
getService(), getServices()
Service References


getServiceReference(), getServiceReferences()
getSelfReference()
C++ APIs (cont)
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ServiceReference

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Interface for interacting with service
instances
Conversational interface
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getConversationID(), setConversationID()
Asynchronous interface
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getCallbackID(), setCallbackID()
getCallback(), setCallback()
C++ WSDL Mapping

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Defines a translation from a C++ class interface
to a WSDL
Uses comment annotations to control the
conversion
Defines mapping rules for:
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primitive types
C++ Standard Library types
SDO
classes, structs, arrays, enums
Defines a mapping from a WSDL to a C++ class
interface
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
Currently defers to the OMG WSDL to C++ Mapping
Alternative mappings are being reviewed.
C++ Example

Interface SCDL
<service name=“LoanService”>
<interface.cpp header=“LoanService.h”/>
</service>

Implementation SCDL
<component name=“LoanServiceImpl”>
<implementation.cpp library=“loan”
header=“LoanServiceImpl.h”/>
</component>
C++ Example (cont)

LoanService Interface
class LoanService {
public:
virtual bool approveLoan(
unsigned long customerNumber,
unsigned long loanAmount) = 0;
};
C++ Example (cont)

LoanServiceImpl Interface
class LoanServiceImpl
: public LoanService {
public:
virtual bool approveLoan(
unsigned long customerNumber,
unsigned long loanAmount) {
// …
}
};
C++ Example (cont)

SCA Application
int main(void) {
ComponentContextPtr context =
ComponentContext::getCurrent();
LoanService* service =
(LoanService*)
context->getService(“LoanService”);
bool result = service->approveLoan(12345, 100);
return 0;
}
SCDL for C
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Interface defined by a set of functions
interface.c
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header – header file describing the interface
callbackHeader – (optional) header file describing the
callback interface
remotable – (optional) Indicates whether the service can be
called from a remote system
implementation.c



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module – binary executable for the component
implementation
library – (optional) indicates whether the service is
implemented as a library or a program
location – (optional) location of the module
scope – (optional) Specifies the lifetime and reuse options for
an implementation instance
C APIs
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Synchronous Programming
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Asynchronous Programming
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SCALocate(), SCALocateMultiple() – get handle(s) to services
SCAInvoke() – invokes an operation of a service
SCAProperty<PropertyType>() – get the value of a property
SCAGetFaultMessage(), SCASetFaultMessage() – get or set a
fault message for a service operation
SCAGetCallback() – get handle of callback instance
SCACallback() – invoke a callback operation
SCASetCallback() – set a callback function for a reference
SCASetCallbackID(), SCAGetCallbackID() – get or set the callback
ID for a service instance
Conversation Services
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SCAGetConversationID(), SCASetConversationID() – get or set a
user provided conversation ID
SCAEndConversation() – end a conversation
C Example

Interface SCDL
<service name="LoanService">
<interface.c header="LoanService.h"/>
</service>

Implementation SCDL
<component name="LoanService">
<implementation.c module="loan"/>
</component>
C Example (cont)

LoanService Interface
char approveLoan(
long customerNumber,
long loanAmount);

LoanService Implementation
char approveLoan(
long customerNumber,
long loanAmount)
{
…
}
C Example (cont)

SCA Application
void clientFunction()
{
…
SCALocate(L”customerService”, &serviceToken,
&compCode, &reason);
SCAInvoke(serviceToken, L“getCreditRating”,
sizeof(custNum), (void *)&custNum,
sizeof(rating), (void *)&rating,
&compCode, &reason);
}
SCDL for COBOL
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interface.cobol
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copybook – copybook file describing the interface
callbackCopybook – (optional) copybook file that describing
the callback interface
location – (optional) location of library containing the
copybook files
remotable – (optional) Indicates whether the service can be
called from a remote system
implementation.cobol
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

program –binary executable for the component
implementation
location – (optional) location of library containing the binary
executable
scope – (optional) Specifies the lifetime and reuse options for
an implementation instance
COBOL APIs
Same functions as in C

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Synchronous Programming
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SCAProperty is not typed
Program-Based Implementation
Support
Asynchronous Programming
Conversation Services
Implementation as
Program

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Support environments where function is
provided by programs
API
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SCAService() – get name of invoked service
SCAOperation() – get name of invoked
operation
SCAMessageIn() – get input message
SCAMessageOut() – set output message
COBOL Example

LoanService Interface
01
LoanServiceInf.
* @Operation name="LoanApplication"
*
input="CustomerName"
*
output="LoanAmount"
03 LoanApplication.
05 CustomerName
PIC X(255).
05 LoanAmount
PIC 9(4).
COBOL Example (cont)

LoanService Implementation
PROCEDURE DIVISION.
IN-THE-BEGINNING.
PERFORM GET-MY-CONTEXT.
EVALUATE My-Operation
WHEN ApproveLoanOperation
* Get service request
MOVE length of CustomerNumber of ApproveLoan To InputMessageLength
CALL "SCAMessageIn" using by content
SCA-COMPCODE, SCA-REASON, My-Service, My-Operation,
InputMessageLength, CustomerNumber of ApproveLoan
PERFORM CUSTOMER-SERVICE
* Return service response
CALL "SCAMessageOut" using by content
SCA-COMPCODE, SCA-REASON, My-Service, My-Operation,
OutputMessageLength, LoanAmount of ApproveLoan
WHEN OTHER
CONTINUE
END-EVALUATE.
* Return to SCA runtime
GOBACK.
GET-MY-CONTEXT.
CALL "SCAService" using by content
SCA-COMPCODE, SCA-REASON, My-Service.
CALL "SCAOperation" using by content
SCA-COMPCODE, SCA-REASON, My-Operation.
COBOL Example (cont)

SCA Application
PROCEDURE DIVISION.
.
CALL "SCALocate" using by content
SCA-COMPCODE,
SCA-REASON,
CustomerServiceReference,
CustomerServiceToken.
CALL "SCAInvoke" using by content
SCA-COMPCODE,
SCA-REASON,
My-CustomerServiceToken,
CreditRatingOperation,
InputMessagelength,
CustomerNumber,
OutputMessageLength,
Rating.
C & COBOL WSDL Mapping
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Defines a translation between language
structures and WSDL
Defines type mapping rules for:
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Primitive types
Structs or Groups
Variable length strings and unbounded arrays
Defines mapping rules between
operations and functions
Annotations
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Contained in comments, processed by tools
Interface
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Invocation attribute
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OneWay
Remotable
Callback
EndConversation
Implementation
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Scope
Lifecycle
Conversation information
Property
Reference
Open Implementations
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Apache Tuscany Native
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
http://incubator.apache.org/tuscany/sca
-native.html
Implements pre-1.0 C++ specification
Working towards 1.0 compliance
OASIS References

Open CSA Member Section

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SCA-C-C++ Technical Committee

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http://www.oasisopen.org/committees/tc_home.php?wg_abbre
v=opencsa-ms
http://www.oasisopen.org/committees/tc_home.php?wg_abbre
v=sca-c-cpp
SCA-C-C++ Charter

http://www.oasis-open.org/committees/sca-ccpp/charter.php
OSOA References

OSOA SCA Specifications


http://www.osoa.org/display/Main/Servi
ce+Component+Architecture+Specifica
tions
Specifications

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SCA C++ Client and Implementation
SCA C Client and Implementation
SCA COBOL Client and Implementation
Thai
Traditional Chinese
Gracias
Russian
Spanish
Thank
You
English
Merci
French
Obrigado
Brazilian Portuguese
Arabic
Grazie
Danke
Italian
German
Simplified Chinese
Japanese
Backup
C++ APIs (cont)
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Supplemental APIs
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RefCountingPointer
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Defines a reference-counted pointer interface
SCAException
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Provides a hierarchy of exception classes for use
with the SCA API.
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•
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SCANullPointerException
ServiceRuntimeException
ServiceUnavailableException
NoRegisteredCallbackException
ConversationEndedException
MultipleServicesException
C++ Annotations
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Contained in comments, processed by tools
Interface Header File
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@Remotable, @Conversational
@Callback, @OneWay
@EndsConversation
Implementation Header File
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@Scope
@EagerInit
@AllowsPassByReference
@ConversationAttributes
@Property
@Reference
C Annotations
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Contained in comments, processed by tools
Header File
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@Interface
@Operation, @Callback, @OneWay
@Remotable, @Conversational
@EndsConversation
Implementation File
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@Service
@Reference
@Property
@Scope
@Init, @Destroy, @EagerInit
@AllowPassByReference
@ConversationAttributes
COBOL Annotations
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Contained in comments, processed by tools
Interface File
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@Interface
@Operation, @Callback, @OneWay
@Remotable, @Conversational
@EndsConversation
Implementation File
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@Service
@Reference
@Property
@Scope
@Init, @Destroy, @EagerInit
@AllowPassByReference
@ConversationAttributes