Examples with CodeGenerator org.neo4j.codegen.CodeGenerator used on opensource projects

Example 1 with CodeGenerator

use of org.neo4j.codegen.CodeGenerator in project neo4j by neo4j.

the class ProcedureCompilation method compileFunction.

/**
 * Generates code for a user-defined function.
 * <p>
 * Given a user-defined function defined by
 *
 * <pre>
 *     class MyClass {
 *       {@literal @}Context
 *        public Log log;
 *
 *       {@literal @}UserFunction
 *        public double addPi(long value) {
 *            return value + Math.PI;
 *        }
 *     }
 * </pre>
 * <p>
 * we will generate something like
 *
 * <pre>
 *     class GeneratedAddPi implements CallableUserFunction {
 *         public static UserFunctionSignature SIGNATURE;
 *         public static FieldSetter SETTER_0;
 *
 *         public AnyValue apply(Context ctx, AnyValue[] input) {
 *              try {
 *                  MyClass userClass = new MyClass();
 *                  userClass.log = (Log) SETTER_0.get(ctx);
 *                  return Values.doubleValue(userClass.addPi( ((NumberValue) input[0]).longValue() );
 *              } catch (Throwable T) {
 *                  throw new ProcedureException([appropriate error msg], T);
 *              }
 *         }
 *
 *         public UserFunctionSignature signature() {return SIGNATURE;}
 *     }
 * </pre>
 * <p>
 * where the static fields are set once during loading via reflection.
 *
 * @param signature the signature of the user-defined function
 * @param fieldSetters the fields to set before each call.
 * @param methodToCall the method to call
 * @return a CallableUserFunction delegating to the underlying user-defined function.
 * @throws ProcedureException if something went wrong when compiling the user-defined function.
 */
static CallableUserFunction compileFunction(UserFunctionSignature signature, List<FieldSetter> fieldSetters, Method methodToCall) throws ProcedureException {
    ClassHandle handle;
    try {
        CodeGenerator codeGenerator = codeGenerator();
        try (ClassGenerator generator = codeGenerator.generateClass(PACKAGE, className(signature), CallableUserFunction.class)) {
            // static fields
            FieldReference signatureField = generator.publicStaticField(typeReference(UserFunctionSignature.class), SIGNATURE_NAME);
            List<FieldReference> fieldsToSet = createContextSetters(fieldSetters, generator);
            // CallableUserFunction::apply
            try (CodeBlock method = generator.generate(USER_FUNCTION)) {
                method.tryCatch(body -> functionBody(body, fieldSetters, fieldsToSet, methodToCall), onError -> onError(onError, format("function `%s`", signature.name())), param(Throwable.class, "T"));
            }
            // CallableUserFunction::signature
            try (CodeBlock method = generator.generateMethod(UserFunctionSignature.class, "signature")) {
                method.returns(getStatic(signatureField));
            }
            handle = generator.handle();
        }
        Class<?> clazz = handle.loadClass();
        // set all static fields
        setAllStaticFields(signature, fieldSetters, methodToCall, clazz);
        return (CallableUserFunction) clazz.getConstructor().newInstance();
    } catch (Throwable e) {
        throw new ProcedureException(Status.Procedure.ProcedureRegistrationFailed, e, "Failed to compile function defined in `%s`: %s", methodToCall.getDeclaringClass().getSimpleName(), e.getMessage());
    }
}

Example 2 with CodeGenerator

use of org.neo4j.codegen.CodeGenerator in project neo4j by neo4j.

the class ProcedureCompilation method compileProcedure.

/**
 * Generates code for a user-defined procedure.
 * <p>
 * Given a user-defined function defined by
 *
 * <pre>
 *     class MyClass {
 *       {@literal @}Context
 *        public Log log;
 *
 *       {@literal @}Procedure
 *        public Stream<MyOut> myStream(long value) {
 *            ...
 *        }
 *     }
 * </pre>
 * <p>
 * we will generate something like
 *
 * <pre>
 *     class GeneratedMyStream implements CallableProcedure {
 *         public static ProcedureSignature SIGNATURE;
 *         public static FieldSetter SETTER_0;
 *
 *          RawIterator<AnyValue[], ProcedureException> apply( Context ctx, AnyValue[] in, ResourceTracker tracker ) throws ProcedureException {
 *              try {
 *                  MyClass userClass = new MyClass();
 *                  userClass.log = (Log) SETTER_0.get(ctx);
 *                  Stream<MyOut> fromUser = userClass.myStream(((NumberValue) input[0]).longValue() );
 *                  return new GeneratedIterator(fromUser, tracker, SIGNATURE);
 *              } catch (Throwable T) {
 *                  throw new ProcedureException([appropriate error msg], T);
 *              }
 *         }
 *
 *         public ProcedureSignature signature() {return SIGNATURE;}
 *     }
 * </pre>
 * <p>
 * where the static fields are set once during loading via reflection and where the <tt>GeneratedIterator</tt>
 * implements the appropriate mapping from user-types Object[] to AnyValue[].
 *
 * @param signature the signature of the procedure
 * @param fieldSetters the fields to set before each call.
 * @param methodToCall the method to call
 * @return a CallableProcedure delegating to the underlying procedure method.
 * @throws ProcedureException if something went wrong when compiling the user-defined function.
 */
static CallableProcedure compileProcedure(ProcedureSignature signature, List<FieldSetter> fieldSetters, Method methodToCall) throws ProcedureException {
    ClassHandle handle;
    try {
        CodeGenerator codeGenerator = codeGenerator();
        Class<?> iterator = generateIterator(codeGenerator, procedureType(methodToCall));
        try (ClassGenerator generator = codeGenerator.generateClass(PACKAGE, className(signature), CallableProcedure.class)) {
            // static fields
            FieldReference signatureField = generator.publicStaticField(typeReference(ProcedureSignature.class), SIGNATURE_NAME);
            List<FieldReference> fieldsToSet = createContextSetters(fieldSetters, generator);
            // CallableProcedure::apply
            try (CodeBlock method = generator.generate(USER_PROCEDURE)) {
                method.tryCatch(body -> procedureBody(body, fieldSetters, fieldsToSet, signatureField, methodToCall, iterator), onError -> onError(onError, format("procedure `%s`", signature.name())), param(Throwable.class, "T"));
            }
            // CallableUserFunction::signature
            try (CodeBlock method = generator.generateMethod(ProcedureSignature.class, "signature")) {
                method.returns(getStatic(signatureField));
            }
            handle = generator.handle();
        }
        Class<?> clazz = handle.loadClass();
        // set all static fields
        setAllStaticFields(signature, fieldSetters, methodToCall, clazz);
        return (CallableProcedure) clazz.getConstructor().newInstance();
    } catch (Throwable e) {
        throw new ProcedureException(Status.Procedure.ProcedureRegistrationFailed, e, "Failed to compile procedure defined in `%s`: %s", methodToCall.getDeclaringClass().getSimpleName(), e.getMessage());
    }
}

Example 3 with CodeGenerator

use of org.neo4j.codegen.CodeGenerator in project neo4j by neo4j.

the class ByteCodeVerifierTest method shouldVerifyBytecode.

@Test
void shouldVerifyBytecode() throws Throwable {
    // given
    CodeGenerator generator = generateCode(BYTECODE, VERIFY_GENERATED_BYTECODE);
    ClassHandle handle;
    try (ClassGenerator clazz = generator.generateClass(PACKAGE, "SimpleClass");
        CodeBlock code = clazz.generateMethod(Integer.class, "box", param(int.class, "value"))) {
        handle = clazz.handle();
        code.returns(code.load("value"));
    }
    CompilationFailureException exception = assertThrows(CompilationFailureException.class, handle::loadClass);
    assertThat(exception.toString()).contains("box(I)");
}

Example 4 with CodeGenerator

use of org.neo4j.codegen.CodeGenerator in project neo4j by neo4j.

the class ProcedureCompilation method compileAggregation.

/**
 * Generates code for a user-defined aggregation function.
 * <p>
 * Given a user-defined aggregation function defined by
 *
 * <pre>
 *     class MyClass {
 *       {@literal @}Context
 *        public Log log;
 *
 *       {@literal @}UserAggregationFunction
 *        public Adder create() {
 *            return new Adder;
 *        }
 *     }
 *
 *     class Adder {
 *       private long sum;
 *       {@literal @}UserAggregationUpdate
 *       public void update(long in) {
 *           sum += in;
 *       }
 *       {@literal @}UserAggregationResult
 *       public long result() {
 *         return sum;
 *       }
 *    }
 *     }
 * </pre>
 * <p>
 * we will generate two classe looking something like
 *
 * <pre>
 *     class Generated implements CallableUserAggregationFunction {
 *         public static UserFunctionSignature SIGNATURE;
 *         public static FieldSetter SETTER_0;
 *
 *         public UserAggregator create(Context ctx) {
 *              try {
 *                  MyClass userClass = new MyClass();
 *                  userClass.log = (Log) SETTER_0.get(ctx);
 *                  return new GeneratedAdder(userClass.create());
 *              } catch (Throwable T) {
 *                  throw new ProcedureException([appropriate error msg], T);
 *              }
 *         }
 *
 *         public UserFunctionSignature signature() {return SIGNATURE;}
 *     }
 *     class GeneratedAdder implements UserAggregator {
 *       private Adder adder;
 *
 *       GeneratedAdder(Adder adder) {
 *         this.adder = adder;
 *       }
 *
 *       void update(AnyValue[] in) {
 *          adder.update(((NumberValue) in).longValue());
 *       }
 *
 *       AnyValue result() {
 *          return adder.result(Values.longValue(adder.result());
 *       }
 *     }
 * </pre>
 * <p>
 * where the static fields are set once during loading via reflection.
 *
 * @param signature the signature of the user-defined function
 * @param fieldSetters the fields to set before each call.
 * @param create the method that creates the aggregator
 * @param update the update method of the aggregator
 * @param result the result method of the aggregator
 * @return a CallableUserFunction delegating to the underlying user-defined function.
 * @throws ProcedureException if something went wrong when compiling the user-defined function.
 */
static CallableUserAggregationFunction compileAggregation(UserFunctionSignature signature, List<FieldSetter> fieldSetters, Method create, Method update, Method result) throws ProcedureException {
    ClassHandle handle;
    try {
        CodeGenerator codeGenerator = codeGenerator();
        Class<?> aggregator = generateAggregator(codeGenerator, update, result, signature);
        try (ClassGenerator generator = codeGenerator.generateClass(PACKAGE, className(signature), CallableUserAggregationFunction.class)) {
            // static fields
            FieldReference signatureField = generator.publicStaticField(typeReference(UserFunctionSignature.class), SIGNATURE_NAME);
            List<FieldReference> fieldsToSet = createContextSetters(fieldSetters, generator);
            // CallableUserAggregationFunction::create
            try (CodeBlock method = generator.generate(AGGREGATION_CREATE)) {
                method.tryCatch(body -> createAggregationBody(body, fieldSetters, fieldsToSet, create, aggregator), onError -> onError(onError, format("function `%s`", signature.name())), param(Throwable.class, "T"));
            }
            // CallableUserFunction::signature
            try (CodeBlock method = generator.generateMethod(UserFunctionSignature.class, "signature")) {
                method.returns(getStatic(signatureField));
            }
            handle = generator.handle();
        }
        Class<?> clazz = handle.loadClass();
        // set all static fields
        setAllStaticFields(signature, fieldSetters, create, clazz);
        return (CallableUserAggregationFunction) clazz.getConstructor().newInstance();
    } catch (Throwable e) {
        throw new ProcedureException(Status.Procedure.ProcedureRegistrationFailed, e, "Failed to compile function defined in `%s`: %s", create.getDeclaringClass().getSimpleName(), e.getMessage());
    }
}