src/jdk.jshell/share/classes/jdk/jshell/execution/DirectExecutionControl.java
changeset 47216 71c04702a3d5
parent 45044 7c50549b7744
child 49515 083318155ad1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jshell/share/classes/jdk/jshell/execution/DirectExecutionControl.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,329 @@
+/*
+ * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.jshell.execution;
+
+import java.lang.reflect.Array;
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.stream.IntStream;
+import jdk.jshell.spi.ExecutionControl;
+import jdk.jshell.spi.SPIResolutionException;
+
+/**
+ * An {@link ExecutionControl} implementation that runs in the current process.
+ * May be used directly, or over a channel with
+ * {@link Util#forwardExecutionControl(ExecutionControl, java.io.ObjectInput, java.io.ObjectOutput) }.
+ *
+ * @author Robert Field
+ * @author Jan Lahoda
+ * @since 9
+ */
+public class DirectExecutionControl implements ExecutionControl {
+
+    private static final String[] charRep;
+
+    static {
+        charRep = new String[256];
+        for (int i = 0; i < charRep.length; ++i) {
+            charRep[i] = Character.isISOControl(i)
+                    ? String.format("\\%03o", i)
+                    : "" + (char) i;
+        }
+        charRep['\b'] = "\\b";
+        charRep['\t'] = "\\t";
+        charRep['\n'] = "\\n";
+        charRep['\f'] = "\\f";
+        charRep['\r'] = "\\r";
+        charRep['\\'] = "\\\\";
+    }
+
+    private final LoaderDelegate loaderDelegate;
+
+    /**
+     * Creates an instance, delegating loader operations to the specified
+     * delegate.
+     *
+     * @param loaderDelegate the delegate to handle loading classes
+     */
+    public DirectExecutionControl(LoaderDelegate loaderDelegate) {
+        this.loaderDelegate = loaderDelegate;
+    }
+
+    /**
+     * Create an instance using the default class loading.
+     */
+    public DirectExecutionControl() {
+        this(new DefaultLoaderDelegate());
+    }
+
+    @Override
+    public void load(ClassBytecodes[] cbcs)
+            throws ClassInstallException, NotImplementedException, EngineTerminationException {
+        loaderDelegate.load(cbcs);
+    }
+
+    @Override
+    public void redefine(ClassBytecodes[] cbcs)
+            throws ClassInstallException, NotImplementedException, EngineTerminationException {
+        throw new NotImplementedException("redefine not supported");
+    }
+
+    /**Notify that classes have been redefined.
+     *
+     * @param cbcs the class name and bytecodes to redefine
+     * @throws NotImplementedException if not implemented
+     * @throws EngineTerminationException the execution engine has terminated
+     */
+    protected void classesRedefined(ClassBytecodes[] cbcs)
+            throws NotImplementedException, EngineTerminationException {
+        loaderDelegate.classesRedefined(cbcs);
+    }
+
+    @Override
+    public String invoke(String className, String methodName)
+            throws RunException, InternalException, EngineTerminationException {
+        Method doitMethod;
+        try {
+            Class<?> klass = findClass(className);
+            doitMethod = klass.getDeclaredMethod(methodName, new Class<?>[0]);
+            doitMethod.setAccessible(true);
+        } catch (Throwable ex) {
+            throw new InternalException(ex.toString());
+        }
+
+        try {
+            clientCodeEnter();
+            String result = invoke(doitMethod);
+            System.out.flush();
+            return result;
+        } catch (RunException | InternalException | EngineTerminationException ex) {
+            throw ex;
+        } catch (SPIResolutionException ex) {
+            return throwConvertedInvocationException(ex);
+        } catch (InvocationTargetException ex) {
+            return throwConvertedInvocationException(ex.getCause());
+        } catch (Throwable ex) {
+            return throwConvertedOtherException(ex);
+        } finally {
+            clientCodeLeave();
+        }
+    }
+
+    @Override
+    public String varValue(String className, String varName)
+            throws RunException, EngineTerminationException, InternalException {
+        Object val;
+        try {
+            Class<?> klass = findClass(className);
+            Field var = klass.getDeclaredField(varName);
+            var.setAccessible(true);
+            val = var.get(null);
+        } catch (Throwable ex) {
+            throw new InternalException(ex.toString());
+        }
+
+        try {
+            clientCodeEnter();
+            return valueString(val);
+        } catch (Throwable ex) {
+            return throwConvertedInvocationException(ex);
+        } finally {
+            clientCodeLeave();
+        }
+    }
+
+    @Override
+    public void addToClasspath(String cp)
+            throws EngineTerminationException, InternalException {
+        loaderDelegate.addToClasspath(cp);
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p>
+     * Not supported.
+     */
+    @Override
+    public void stop()
+            throws EngineTerminationException, InternalException {
+        throw new NotImplementedException("stop: Not supported.");
+    }
+
+    @Override
+    public Object extensionCommand(String command, Object arg)
+            throws RunException, EngineTerminationException, InternalException {
+        throw new NotImplementedException("Unknown command: " + command);
+    }
+
+    @Override
+    public void close() {
+    }
+
+    /**
+     * Finds the class with the specified binary name.
+     *
+     * @param name the binary name of the class
+     * @return the Class Object
+     * @throws ClassNotFoundException if the class could not be found
+     */
+    protected Class<?> findClass(String name) throws ClassNotFoundException {
+        return loaderDelegate.findClass(name);
+    }
+
+    /**
+     * Invoke the specified "doit-method", a static method with no parameters.
+     * The {@link DirectExecutionControl#invoke(java.lang.String, java.lang.String) }
+     * in this class will call this to invoke.
+     *
+     * @param doitMethod the Method to invoke
+     * @return the value or null
+     * @throws Exception any exceptions thrown by
+     * {@link java.lang.reflect.Method#invoke(Object, Object...) }
+     * or any {@link ExecutionControl.ExecutionControlException}
+     * to pass-through.
+     */
+    protected String invoke(Method doitMethod) throws Exception {
+        Object res = doitMethod.invoke(null, new Object[0]);
+        return valueString(res);
+    }
+
+    /**
+     * Converts the {@code Object} value from
+     * {@link ExecutionControl#invoke(String, String)  } or
+     * {@link ExecutionControl#varValue(String, String)   } to {@code String}.
+     *
+     * @param value the value to convert
+     * @return the {@code String} representation
+     */
+    protected static String valueString(Object value) {
+        if (value == null) {
+            return "null";
+        } else if (value instanceof String) {
+            return "\"" + ((String) value).codePoints()
+                    .flatMap(cp ->
+                        (cp == '"')
+                            ? "\\\"".codePoints()
+                            : (cp < 256)
+                                ? charRep[cp].codePoints()
+                                : IntStream.of(cp))
+                    .collect(
+                            StringBuilder::new,
+                            StringBuilder::appendCodePoint,
+                            StringBuilder::append)
+                    .toString() + "\"";
+        } else if (value instanceof Character) {
+            char cp = (char) (Character) value;
+            return "'" + (
+                (cp == '\'')
+                    ? "\\\'"
+                    : (cp < 256)
+                            ? charRep[cp]
+                            : String.valueOf(cp)) + "'";
+        } else if (value.getClass().isArray()) {
+            int dims = 0;
+            Class<?> t = value.getClass();
+            while (true) {
+                Class<?> ct = t.getComponentType();
+                if (ct == null) {
+                    break;
+                }
+                ++dims;
+                t = ct;
+            }
+            String tn = t.getTypeName();
+            int len = Array.getLength(value);
+            StringBuilder sb = new StringBuilder();
+            sb.append(tn.substring(tn.lastIndexOf('.') + 1, tn.length()));
+            sb.append("[");
+            sb.append(len);
+            sb.append("]");
+            for (int i = 1; i < dims; ++i) {
+                sb.append("[]");
+            }
+            sb.append(" { ");
+            for (int i = 0; i < len; ++i) {
+                sb.append(valueString(Array.get(value, i)));
+                if (i < len - 1) {
+                    sb.append(", ");
+                }
+            }
+            sb.append(" }");
+            return sb.toString();
+        } else {
+            return value.toString();
+        }
+    }
+
+    /**
+     * Converts incoming exceptions in user code into instances of subtypes of
+     * {@link ExecutionControl.ExecutionControlException} and throws the
+     * converted exception.
+     *
+     * @param cause the exception to convert
+     * @return never returns as it always throws
+     * @throws ExecutionControl.RunException for normal exception occurrences
+     * @throws ExecutionControl.InternalException for internal problems
+     */
+    protected String throwConvertedInvocationException(Throwable cause) throws RunException, InternalException {
+        if (cause instanceof SPIResolutionException) {
+            SPIResolutionException spire = (SPIResolutionException) cause;
+            throw new ResolutionException(spire.id(), spire.getStackTrace());
+        } else {
+            throw new UserException(cause.getMessage(), cause.getClass().getName(), cause.getStackTrace());
+        }
+    }
+
+    /**
+     * Converts incoming exceptions in agent code into instances of subtypes of
+     * {@link ExecutionControl.ExecutionControlException} and throws the
+     * converted exception.
+     *
+     * @param ex the exception to convert
+     * @return never returns as it always throws
+     * @throws ExecutionControl.RunException for normal exception occurrences
+     * @throws ExecutionControl.InternalException for internal problems
+     */
+    protected String throwConvertedOtherException(Throwable ex) throws RunException, InternalException {
+        throw new InternalException(ex.toString());
+    }
+
+    /**
+     * Marks entry into user code.
+     *
+     * @throws ExecutionControl.InternalException in unexpected failure cases
+     */
+    protected void clientCodeEnter() throws InternalException {
+    }
+
+    /**
+     * Marks departure from user code.
+     *
+     * @throws ExecutionControl.InternalException in unexpected failure cases
+     */
+    protected void clientCodeLeave() throws InternalException {
+    }
+
+}