--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/SettingControl.java Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2016, 2018, 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.jfr;
+
+import java.security.AccessController;
+import java.util.Set;
+
+import jdk.jfr.internal.Control;
+
+/**
+ * Base class to extend to create setting controls.
+ * <p>
+ * The following example shows a naive implementation of a setting control for
+ * regular expressions:
+ *
+ * <pre>
+ * <code>
+ * final class RegExpControl extends SettingControl {
+ * private Pattern pattern = Pattern.compile(".*");
+ *
+ * {@literal @}Override
+ * public void setValue(String value) {
+ * this.pattern = Pattern.compile(value);
+ * }
+ *
+ * {@literal @}Override
+ * public String combine(Set{@literal <}String{@literal >} values) {
+ * return String.join("|", values);
+ * }
+ *
+ * {@literal @}Override
+ * public String getValue() {
+ * return pattern.toString();
+ * }
+ *
+ * public String matches(String s) {
+ * return pattern.matcher(s).find();
+ * }
+ * }
+ * </code>
+ * </pre>
+ *
+ * The {@code setValue(String)}, {@code getValue()} and
+ * {@code combine(Set<String>)} methods are invoked when a setting value
+ * changes, which typically happens when a recording is started or stopped. The
+ * {@code combine(Set<String>)} method is invoked to resolve what value to use
+ * when multiple recordings are running at the same time.
+ * <p>
+ * The setting control must have a default constructor that can be invoked when
+ * the event is registered.
+ * <p>
+ * To use a setting control with an event, add a method that returns a
+ * {@code boolean} value and takes the setting control as a parameter. Annotate
+ * the method with the {@code @SettingDefinition} annotation. By default, the
+ * method name is used as the setting name, but the name can be set explicitly
+ * by using the {@code @Name} annotation. If the method returns {@code true},
+ * the event will be committed.
+ * <p>
+ * It is recommended that the {@code setValue(String)} method updates an
+ * efficient data structure that can be quickly checked when the event is
+ * committed.
+ * <p>
+ * The following example shows how to create an event that uses the
+ * regular expression filter defined above.
+ *
+ * <pre>
+ * <code>
+ * abstract class HTTPRequest extends Event {
+ * {@literal @}Label("Request URI")
+ * protected String uri;
+ *
+ * {@literal @}Label("Servlet URI Filter")
+ * {@literal @}SettingDefinition
+ * protected boolean uriFilter(RegExpControl regExp) {
+ * return regExp.matches(uri);
+ * }
+ * }
+ *
+ * {@literal @}Label("HTTP Get Request")
+ * class HTTPGetRequest extends HTTPRequest {
+ * }
+ *
+ * {@literal @}Label("HTTP Post Request")
+ * class HTTPPostRequest extends HTTPRequest {
+ * }
+ *
+ * class ExampleServlet extends HTTPServlet {
+ * protected void doGet(HttpServletRequest req, HttpServletResponse resp) {
+ * HTTPGetRequest request = new HTTPGetRequest();
+ * request.begin();
+ * request.uri = req.getRequestURI();
+ * ...
+ * request.commit();
+ * }
+ *
+ * protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
+ * HTTPPostRequest request = new HTTPPostRequest();
+ * request.begin();
+ * request.uri = req.getRequestURI();
+ * ...
+ * request.commit();
+ * }
+ * }
+ * </code>
+ * </pre>
+ *
+ * The following example shows how an event can be filtered by assigning the
+ * {@code "uriFilter"} setting with the specified regular expressions.
+ *
+ * <pre>
+ * <code>
+ * Recording r = new Recording();
+ * r.enable("HTTPGetRequest").with("uriFilter", "https://www.example.com/list/.*");
+ * r.enable("HTTPPostRequest").with("uriFilter", "https://www.example.com/login/.*");
+ * r.start();
+ * </code>
+ * </pre>
+ *
+ *
+ *
+ * @see SettingDefinition
+ *
+ * @since 9
+ */
+@MetadataDefinition
+public abstract class SettingControl extends Control {
+
+ /**
+ * Constructor for invocation by subclass constructors.
+ */
+ protected SettingControl() {
+ super(AccessController.getContext());
+
+ }
+
+ /**
+ * Combines the setting values for all running recordings into one value when
+ * multiple recordings are running at the same time,
+ * <p>
+ * The semantics of how setting values are combined depends on the setting
+ * control that is implemented, but all recordings should get at least all the
+ * events they request.
+ * <p>
+ * This method should have no side effects, because the caller might cache values.
+ * This method should never return {@code null} or throw an exception. If a
+ * value is not valid for this setting control, the value should be ignored.
+ * <p>
+ * Examples:
+ * <p>
+ * if the setting control represents a threshold and three recordings are
+ * running at the same time with the setting values {@code "10 ms"},
+ * {@code "8 s"}, and {@code "1 ms"}, this method returns {@code "1 ms"}
+ * because it means that all recordings get at least all the requested data.
+ * <p>
+ * If the setting control represents a set of names and two recordings are
+ * running at the same time with the setting values {@code "Smith, Jones"} and {@code "Jones,
+ * Williams"} the returned value is {@code "Smith, Jones, Williams"} because all names would be accepted.
+ * <p>
+ * If the setting control represents a boolean condition and four recordings are
+ * running at the same time with the following values {@code "true"}, {@code "false"}, {@code "false"}, and
+ * {@code "incorrect"}, this method returns {@code "true"}, because all
+ * recordings get at least all the requested data.
+ *
+ * @param settingValues the set of values, not {@code null}
+ *
+ * @return the value to use, not {@code null}
+ */
+ @Override
+ public abstract String combine(Set<String> settingValues);
+
+ /**
+ * Sets the value for this setting.
+ * <p>
+ * If the setting value is not valid for this setting, this method
+ * does not throw an exception. Instead, the value is ignored.
+ *
+ * @param settingValue the string value, not {@code null}
+ */
+ @Override
+ public abstract void setValue(String settingValue);
+
+ /**
+ * Returns the currently used value for this setting, not {@code null}.
+ * <p>
+ * The value returned by this method is valid as an argument to both
+ * the {@code setValue(String)} method and {@code combine(Set)} method.
+ * <p>
+ * This method is invoked when an event is registered to obtain the
+ * default value. It is therefore important that a valid value can be
+ * returned immediately after an instance of this class is created. It is
+ * not valid to return {@code null}.
+ *
+ * @return the setting value, not {@code null}
+ */
+ @Override
+ public abstract String getValue();
+}