0,0 → 1,352 |
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.VERSION; |
// 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(); |
|
// plugin is guaranteed to be a SandboxAccessor, regardless of which |
// exact object it ends up mapping to, see enableSandboxAccess() |
boilerPlate.append("plugin.sandboxGetter = new java.util.concurrent.Callable(function() {") |
.append(" return $net.outlyer.runtime.sandbox; });\n"); |
} |
|
//////////////////////////////////////////////////////// |
// 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"); |
|
PluginProperties pp; |
|
if (null != forUri) { |
pp = checkForSupport(forUri); |
} |
else { |
pp = new PluginProperties(); |
pp.apiVersion = API.VERSION; |
pp.name = "none"; |
pp.type = ""; |
} |
|
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(this, 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 |
* @throws IllegalArgumentException If name is <code>null</code> |
* @throws IllegalArgumentException If name is "<code>plugin</code>" (use |
* {@link #setPluginObject()} instead). |
*/ |
public void exportObject(final String name, final Object object) { |
if (null == name) { |
throw new IllegalArgumentException("Can't export an object with" + |
"a null name"); |
} |
// Since the plugin object rules' are special (it will be cloned) |
// being nice could (?) lead to confusion |
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); |
} |
} |
|
/** |
* Makes a package's contents available in the global namespace. |
* (<em>Imports</em> it into JavaScript). |
* @param pkg Package to export |
* @see #exportPackage(String) |
*/ |
public void exportPackage(final Package pkg) { |
if (null == pkg) { |
throw new IllegalArgumentException("Can't export a null package"); |
} |
|
boilerPlate.append("importPackage("+pkg.getName()+")"); |
} |
|
/** |
* Makes a package's contents available in the global namespace. |
* Like {@see #exportPackage(Package)} but exporting by name. |
* @param packageName |
* @see #exportPackage(Package) |
*/ |
public void exportPackage(final String packageName) { |
if (null == packageName) { |
throw new IllegalArgumentException("Can't export a null-named package"); |
} |
final Package pkg = Package.getPackage(packageName); |
if (null == pkg) { |
throw new IllegalArgumentException("Failed to find package "+packageName); |
} |
exportPackage(pkg); |
} |
|
/** |
* 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 |
//////////////////////////////////////////////////////// |
|
/** |
* Makes a {@link SanboxAccessor}'s field <code>getSandbox</code> |
* be evaluable as a <code>Callable<Sandbox></code>, i.e., |
* from Java it will be possible to use:<br /> |
* <pre> |
* Sandbox sb = ( (Callable<Sandbox>) object.getSandbox ).call() |
* </pre> |
* to retrieve the sandbox, while from JavaScript it will be enough |
* with: |
* <pre> |
* var sb = object.getSandbox() |
* </pre> |
* @param name Exported object's name |
* @param sa Exported object |
*/ |
private void enableSandboxAccess(final String name, final SandboxAccessor sa) { |
try { |
Field f = sa.getClass().getField("sandboxGetter"); |
} |
catch (final NoSuchFieldException e) { |
throw new IllegalArgumentException("object " + name + " must comply " + |
"with the contract of SandboxAccessor"); |
} |
|
boilerPlate.append(name).append(".sandboxGetter=new java.util.concurrent.Callable(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 |