org.nhindirect.policy

Interface Compiler

All Known Implementing Classes:

StackMachineCompiler

public interface Compiler

The compiler is the second step of the execution process after a lexicon has been parse into a PolicyExpression tree. The compiler consumes the parsed expressions and generates an ordered vector of Opcode objects that are specific to a particular ExecutionEngine. The resulting vector is then fed to the engine to evaluate the boolean result of the expression.

By default, the compile operation throws a PolicyRequiredException exception if a required attribute is missing in the provided certificate. This halts the evaluation process immediately at the point the first missing required field is encountered. However, there are use cases, such as a policy validation tool, where a generating a complete list of missing fields may be useful. In addition, it may desired to process the certificate through the execution engine even though it is known that required fields are missing. Obviously this is not the most efficient operating mode when executing inside of an environment where the only result of interest is the simple binary decision of policy compliance.
To enable the ability to retrieve a list of all known missing fields (or other compilation errors), the compiler supports a report mode that can be enabled by calling the setReportModeEnabled(boolean) method. When reporting mode is turned on, the compiler will no longer throw an exception when a required attribute is missing. After compilation is complete, a collection of all compilation issues can be retrieved by calling the getCompilationReport() method.

Since:

1.0

Author:

Greg Meyer

Method Summary

Modifier and Type	Method and Description
Vector<Opcode>	compile(X509Certificate cert, PolicyExpression expression) Compiles the given certificate and a parsed PolicyExpression tree in a series of executables Opcode objects.
Collection<String>	getCompilationReport() Gets a collection of compilation issues.
boolean	isReportModeEnabled() Indicates whether or not the compiler is in report mode.
void	setReportModeEnabled(boolean reportMode) Sets or removes the compiler from report mode.

Method Detail

compile

Vector<Opcode> compile(X509Certificate cert,
                       PolicyExpression expression)
                throws PolicyProcessException

Compiles the given certificate and a parsed PolicyExpression tree in a series of executables Opcode objects.

Implementations should be thread same meaning multiple expressions can be compiled concurrently with the same compiler.

Parameters:

cert - The certificate that will be evaluated for policy compliance.

expression - The parsed expression tree.

Returns:

A vector of Opcode objects that are fed into an ExecutionEngine for final evaluation of policy compliance.

Throws:

PolicyProcessException - Thrown if a required certificate attribute does not exist in the given certification. However, this exception is suppressed if the compiler is placed into report model.

setReportModeEnabled

void setReportModeEnabled(boolean reportMode)

Sets or removes the compiler from report mode. When in report mode, the compiler will not fail if required attributes are missing from the certificate.

Parameters:

reportMode - true if the compiler is to be set into report mode. false otherwise

isReportModeEnabled

boolean isReportModeEnabled()

Indicates whether or not the compiler is in report mode.

Returns:

true if the compiler is in report mode. false otherwise

getCompilationReport

Collection<String> getCompilationReport()

Gets a collection of compilation issues. This report can only be generated if the compiler is in report mode.

The collection is reset each time a compilation occurs. For concurrent compilation, the generated report is specific to the thread that compilation process was executed on.

Returns:

A collection of compilation issues. If no issues were found or the compiler was not in report mode, then an empty collection is returned.