| 0,0 → 1,289 |
|---|
| package net.outlyer.plugins; |
| |
| /* |
| * Copyright (c) 2008, Toni Corvera. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, |
| * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, |
| * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| // $Id$ |
| |
| import java.io.IOException; |
| import java.io.LineNumberReader; |
| import java.lang.reflect.Field; |
| import java.net.URI; |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import javax.script.Bindings; |
| import javax.script.ScriptEngine; |
| import javax.script.ScriptEngineManager; |
| import javax.script.ScriptException; |
| |
| /** |
| * Provides the environment for {@link net.outlyer.plugins.Sandbox}es. |
| */ |
| public class PluginEnvironment { |
| |
| static class UnsupportedAPIException extends PluginException { |
| public UnsupportedAPIException(int providedApi) { |
| super("Plugin has unsupported API ("+providedApi+")"); |
| } |
| } |
| |
| static class UnsupportedTypeException extends PluginException { |
| public UnsupportedTypeException(String pluginType) { |
| super("Plugin has unsupported type ("+pluginType+")"); |
| } |
| } |
| |
| private final Map<String, Object> exportedObjects; |
| private BasePluginObject pluginObject; |
| private StringBuilder boilerPlate; |
| private List<String> acceptedTypes = null; |
| private int maxApi=API.REVISION; |
| // Since these lines are evaluated they'll be executed twice |
| // so the lower the number the better to reduce unexpected side effects |
| private static int linesToCheckForSupport = 1; |
| |
| static final String EXPORTED_SANDBOX_VARIABLE = "$net.outlyer.runtime.sandbox"; |
| |
| { |
| exportedObjects = new HashMap(); |
| pluginObject = null; |
| boilerPlate = new StringBuilder(); |
| } |
| |
| //////////////////////////////////////////////////////// |
| // Public interface |
| //////////////////////////////////////////////////////// |
| |
| /** |
| * Creates a sandbox associated to the script found in uri |
| * @param uri Plugin uri |
| * @return Sandbox associated to uri |
| * @throws net.outlyer.plugins.PluginException |
| */ |
| public Sandbox createSandbox(final URI forUri) throws PluginException { |
| final ScriptEngine rhino = new ScriptEngineManager().getEngineByName("rhino"); |
| |
| final PluginProperties pp = checkForSupport(forUri); |
| |
| if (null == pluginObject) { |
| pluginObject = new PluginObject(); |
| } |
| |
| try { |
| final PluginObject po = (PluginObject) pluginObject.clone(); |
| |
| final Bindings bindings = rhino.createBindings(); |
| |
| for (final String objectName : exportedObjects.keySet()) { |
| bindings.put(objectName, exportedObjects.get(objectName)); |
| } |
| bindings.put("plugin", po); |
| enableSandboxAccess("plugin", po); |
| |
| return new SandboxImpl(forUri, bindings, pp, boilerPlate.toString()); |
| } |
| catch (final CloneNotSupportedException e) { |
| assert false; |
| throw new IllegalStateException("Incorrect implementation"); |
| } |
| } |
| |
| /** |
| * Makes an object accessible from the plugin. |
| * Note the object will be shared amongst any sandboxes created after |
| * the exporting it. |
| * @param name Name with which to access the object |
| * @param object Object to export |
| */ |
| public void exportGlobalObject(final String name, final Object object) { |
| if (null == name) { |
| throw new IllegalArgumentException("Can't export an object with" + |
| "a null name"); |
| } |
| if (name.equals("plugin")) { |
| throw new IllegalArgumentException("Can't export an object named " + |
| "plugin, use setPluginObject() instead"); |
| } |
| exportedObjects.put(name, object); |
| |
| if (object instanceof SandboxAccessor) { |
| enableSandboxAccess(name, (SandboxAccessor)object); |
| } |
| } |
| |
| /** |
| * Defines the object to be exported as <code>plugin</code>. |
| * The <code>plugin</code> object is the only one exported by default. |
| * If none is set, a default one will be provided. |
| * <br /> |
| * <b>Note</b> that, unlike for other objects, plugin objects aren't |
| * shared amongst sandboxes, a clone of the one provided will be used. |
| * @param pluginObject Object to export, set to null to use a default one. |
| */ |
| public void setPluginObject(BasePluginObject pObject) { |
| pluginObject = pObject; |
| } |
| |
| /** |
| * Restricts the set of supported plugins to the ones with the given plugin |
| * type (by default no restriction is applied). |
| * @see PluginProperties#type |
| * @param pluginTypes Set of types to allow; use null to allow all types |
| */ |
| public void setAcceptedTypes(final String ... pluginTypes) { |
| if (null != pluginTypes) { |
| for (final String type : pluginTypes) { |
| if (null == type) { |
| throw new IllegalArgumentException("The set of plugin types" + |
| " must be either null, or a set of non-null values"); |
| } |
| } |
| } |
| acceptedTypes = Arrays.asList(pluginTypes); |
| } |
| |
| //////////////////////////////////////////////////////// |
| // Non-public interface |
| //////////////////////////////////////////////////////// |
| |
| private void enableSandboxAccess(final String name, final SandboxAccessor sa) { |
| try { |
| Field f = sa.getClass().getField("_getSandbox"); |
| } |
| catch (final NoSuchFieldException e) { |
| throw new IllegalArgumentException("object " + name + " must comply " + |
| "with the contract of SandboxAccessor"); |
| } |
| |
| final String callback = name + "._getSandbox"; |
| |
| boilerPlate.append(callback).append("=function() {") |
| .append(" return ") |
| .append(EXPORTED_SANDBOX_VARIABLE).append(";\n};"); |
| |
| } |
| |
| PluginProperties checkForSupport(final URI uri) throws PluginException { |
| assert null != uri; |
| |
| final PluginProperties pp = fetchPluginProperties(uri); |
| if (null == pp) { |
| throw new PluginExecutionException("Failed while inspecting plugin "+uri); |
| } |
| |
| if (null != acceptedTypes) { |
| if (!acceptedTypes.contains(pp.type)) { |
| throw new UnsupportedTypeException(pp.type); |
| } |
| } |
| if (pp.apiVersion > maxApi) { |
| throw new UnsupportedAPIException(pp.apiVersion); |
| } |
| |
| return pp; |
| } |
| |
| // TODO: ? Possibly cache this, so that the first line is only eval'ed |
| // once more than the # of executions |
| static PluginProperties fetchPluginProperties(final URI uri) { |
| assert null != uri; |
| |
| final ScriptEngine rhino = new ScriptEngineManager().getEngineByName("rhino"); |
| |
| try { |
| // Define a Plugin object with a field named type |
| rhino.eval("var plugin={ type: null, apiVersion: null };"); |
| } |
| catch (ScriptException e) { |
| assert false; |
| throw new IllegalStateException("Unknown error encountered"); |
| } |
| |
| // First of all check the script for support |
| Object type = null, name = null; |
| Object apiVersion = null; |
| // Try to eval each line, since it executes in a sandbox this is |
| // *relatively* safe |
| String line; |
| try { |
| final LineNumberReader script = new LineNumberReader(new PluginReader(uri)); |
| try { |
| while ((null == type || null == apiVersion || null == name) && |
| (null != (line = script.readLine())) && |
| script.getLineNumber() <= linesToCheckForSupport) { |
| try { |
| rhino.eval(line); |
| // Note that undefined doesn't convert to null! |
| if (null == type) { |
| rhino.eval("$_1_$ = (undefined===plugin.type)?null:plugin.type;"); |
| type = rhino.get("$_1_$"); |
| } |
| if (null == apiVersion) { |
| rhino.eval("$_1_$ = (undefined===plugin.apiVersion)?null:plugin.apiVersion;"); |
| apiVersion = rhino.get("$_1_$"); |
| } |
| if (null == name) { |
| rhino.eval("$_1_$ = (undefined===plugin.name)?null:plugin.name;"); |
| name = rhino.get("$_1_$"); |
| } |
| } |
| catch (final ScriptException e) { |
| // Exceptions are to be expected since none of the guaranteed |
| // plugin tools are provided in this context they'll try to |
| // access unexisting objects |
| } |
| } |
| } |
| finally { |
| script.close(); |
| } |
| } |
| catch (final IOException e) { |
| // XXX: Evil silent failure |
| return null; |
| } |
| |
| if (null == type) { |
| type = ""; |
| } |
| if (null == apiVersion) { |
| apiVersion = 0; |
| } |
| // name can be null |
| |
| final PluginProperties pp = new PluginProperties(); |
| try { |
| pp.apiVersion = Double.valueOf(apiVersion.toString()).intValue(); |
| pp.type = type.toString(); |
| pp.name = (null != name) ? name.toString(): null; |
| } |
| catch (final NumberFormatException e) { |
| // XXX: Evil silent failure |
| return null; |
| } |
| return pp; |
| } |
| } |
| Property changes: |
|---|
| Added: svn:keywords |
|---|
| +Rev Id Date |
|---|
| \ No newline at end of property |
|---|