/*******************************************************************************
* Copyright (c) 2005, 2017 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
*******************************************************************************/
package org.eclipse.dltk.ui.text.completion;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IContributor;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.InvalidRegistryObjectException;
import org.eclipse.core.runtime.PerformanceStats;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.internal.corext.util.Messages;
import org.eclipse.dltk.ui.DLTKUIPlugin;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.osgi.framework.Bundle;
/**
* The description of an extension to the
* <code>org.eclipse.dltk.ui.javaCompletionProposalComputer</code> extension
* point. Instances are immutable. Instances can be obtained from a
* {@link CompletionProposalComputerRegistry}.
*
* @see CompletionProposalComputerRegistry
*
*/
final class CompletionProposalComputerDescriptor {
/** The default category id. */
private static final String DEFAULT_CATEGORY_ID = "org.eclipse.dltk.ui.defaultProposalCategory"; //$NON-NLS-1$
/** The extension schema name of the category id attribute. */
private static final String CATEGORY_ID = "categoryId"; //$NON-NLS-1$
/** The extension schema name of the partition type attribute. */
private static final String TYPE = "type"; //$NON-NLS-1$
/** The extension schema name of the class attribute. */
private static final String CLASS = "class"; //$NON-NLS-1$
/** The extension schema name of the activate attribute. */
private static final String ACTIVATE = "activate"; //$NON-NLS-1$
/** The extension schema name of the partition child elements. */
private static final String PARTITION = "partition"; //$NON-NLS-1$
public static final String TOOLKITID = "toolkitId"; //$NON-NLS-1$
/** Set of Script partition types. */
private static final Set<String> PARTITION_SET = new HashSet<>();
/** The name of the performance event used to trace extensions. */
private static final String PERFORMANCE_EVENT = DLTKUIPlugin.getPluginId()
+ "/perf/content_assist/extensions"; //$NON-NLS-1$
/**
* If <code>true</code>, execution time of extensions is measured and the
* data forwarded to core's {@link PerformanceStats} service.
*/
private static final boolean MEASURE_PERFORMANCE = PerformanceStats
.isEnabled(PERFORMANCE_EVENT);
/**
* Independently of the {@link PerformanceStats} service, any operation that
* takes longer than {@value} milliseconds will be flagged as an violation.
* This timeout does not apply to the first invocation, as it may take
* longer due to plug-in initialization etc. See also
* {@link #fIsReportingDelay}.
*/
private static final long MAX_DELAY = 25000;
/* log constants */
private static final String COMPUTE_COMPLETION_PROPOSALS = "computeCompletionProposals()"; //$NON-NLS-1$
private static final String COMPUTE_CONTEXT_INFORMATION = "computeContextInformation()"; //$NON-NLS-1$
private static final String SESSION_STARTED = "sessionStarted()"; //$NON-NLS-1$
private static final String SESSION_ENDED = "sessionEnded()"; //$NON-NLS-1$
static {
if (DLTKCore.DEBUG) {
System.err.println("TODO: Add langauge dependent code here..."); //$NON-NLS-1$
}
}
/** The identifier of the extension. */
private final String fId;
/** The name of the extension. */
private final String fName;
/**
* The class name of the provided
* <code>IScriptCompletionProposalComputer</code>.
*/
private final String fClass;
/** The activate attribute value. */
private final boolean fActivate;
/** The partition of the extension (element type: {@link String}). */
private final Set<String> fPartitions;
/** The configuration element of this extension. */
private final IConfigurationElement fElement;
/** The registry we are registered with. */
private final CompletionProposalComputerRegistry fRegistry;
/** The computer, if instantiated, <code>null</code> otherwise. */
private IScriptCompletionProposalComputer fComputer;
/** The ui category. */
private final CompletionProposalCategory fCategory;
/**
* The first error message in the most recent operation, or
* <code>null</code>.
*/
private String fLastError;
/**
* Tells whether to inform the user when <code>MAX_DELAY</code> has been
* exceeded. We start timing execution after the first session because the
* first may take longer due to plug-in activation and initialization.
*/
private boolean fIsReportingDelay = false;
/** The start of the last operation. */
private long fStart;
private String fToolkitID;
/**
* Creates a new descriptor.
*
* @param element
* the configuration element to read
* @param registry
* the computer registry creating this descriptor
*/
CompletionProposalComputerDescriptor(IConfigurationElement element,
CompletionProposalComputerRegistry registry,
List<CompletionProposalCategory> categories)
throws InvalidRegistryObjectException {
Assert.isLegal(registry != null);
Assert.isLegal(element != null);
fRegistry = registry;
fElement = element;
IExtension extension = element.getDeclaringExtension();
fId = extension.getUniqueIdentifier();
checkNotNull(fId, "id"); //$NON-NLS-1$
String name = extension.getLabel();
if (name.length() == 0)
fName = fId;
else
fName = name;
Set<String> partitions = new HashSet<>();
IConfigurationElement[] children = element.getChildren(PARTITION);
if (children.length == 0) {
fPartitions = PARTITION_SET; // add to all partition types if no
// partition is configured
} else {
for (int i = 0; i < children.length; i++) {
String type = children[i].getAttribute(TYPE);
checkNotNull(type, TYPE);
partitions.add(type);
}
fPartitions = Collections.unmodifiableSet(partitions);
}
String activateAttribute = element.getAttribute(ACTIVATE);
fActivate = Boolean.valueOf(activateAttribute).booleanValue();
fClass = element.getAttribute(CLASS);
checkNotNull(fClass, CLASS);
String categoryId = element.getAttribute(CATEGORY_ID);
if (categoryId == null)
categoryId = DEFAULT_CATEGORY_ID;
CompletionProposalCategory category = null;
for (CompletionProposalCategory cat : categories) {
if (cat.getId().equals(categoryId)) {
category = cat;
break;
}
}
String toolkitId = element.getAttribute(TOOLKITID);
this.fToolkitID = toolkitId;
if (category == null) {
// create a category if it does not exist
fCategory = new CompletionProposalCategory(categoryId, fName,
registry, toolkitId);
categories.add(fCategory);
} else {
fCategory = category;
}
}
public String getLanguageToolkitID() {
return this.fToolkitID;
}
/**
* Checks an element that must be defined according to the extension point
* schema. Throws an <code>InvalidRegistryObjectException</code> if
* <code>obj</code> is <code>null</code>.
*/
private void checkNotNull(Object obj, String attribute)
throws InvalidRegistryObjectException {
if (obj == null) {
Object[] args = { getId(), fElement.getContributor().getName(),
attribute };
String message = Messages.format(
ScriptTextMessages.CompletionProposalComputerDescriptor_illegal_attribute_message,
args);
IStatus status = new Status(IStatus.WARNING,
DLTKUIPlugin.getPluginId(), IStatus.OK, message, null);
DLTKUIPlugin.log(status);
throw new InvalidRegistryObjectException();
}
}
/**
* Returns the identifier of the described extension.
*
* @return Returns the id
*/
public String getId() {
return fId;
}
/**
* Returns the name of the described extension.
*
* @return Returns the name
*/
public String getName() {
return fName;
}
/**
* Returns the partition types of the described extension.
*
* @return the set of partition types (element type: {@link String})
*/
public Set<String> getPartitions() {
return fPartitions;
}
/**
* Tells whether we tried to load the computer.
*
* @since 3.0
*/
private boolean fTriedLoadingComputer = false;
/**
* Returns a cached instance of the computer as described in the extension's
* xml. The computer is {@link #createComputer() created} the first time
* that this method is called and then cached.
*
* @return a new instance of the completion proposal computer as described
* by this descriptor
* @throws CoreException
* if the creation fails
* @throws InvalidRegistryObjectException
* if the extension is not valid any longer (e.g. due to plug-in
* unloading)
*/
private synchronized IScriptCompletionProposalComputer getComputer(
boolean canCreate)
throws CoreException, InvalidRegistryObjectException {
if (fComputer == null && canCreate && !fTriedLoadingComputer
&& (fActivate || isPluginLoaded())) {
fTriedLoadingComputer = true;
fComputer = createComputer();
}
return fComputer;
}
private boolean isPluginLoaded() {
Bundle bundle = getBundle();
return bundle != null && bundle.getState() == Bundle.ACTIVE;
}
private Bundle getBundle() {
String namespace = fElement.getDeclaringExtension().getContributor()
.getName();
Bundle bundle = Platform.getBundle(namespace);
return bundle;
}
/**
* Returns a new instance of the computer as described in the extension's
* xml. Note that the safest way to access the computer is by using the
* {@linkplain #computeCompletionProposals(ContentAssistInvocationContext, IProgressMonitor)
* computeCompletionProposals} and
* {@linkplain #computeContextInformation(ContentAssistInvocationContext, IProgressMonitor)
* computeContextInformation} methods. These delegate the functionality to
* the contributed computer, but handle instance creation and any exceptions
* thrown.
*
* @return a new instance of the completion proposal computer as described
* by this descriptor
* @throws CoreException
* if the creation fails
* @throws InvalidRegistryObjectException
* if the extension is not valid any longer (e.g. due to plug-in
* unloading)
*/
public IScriptCompletionProposalComputer createComputer()
throws CoreException, InvalidRegistryObjectException {
return (IScriptCompletionProposalComputer) fElement
.createExecutableExtension(CLASS);
}
/**
* Safely computes completion proposals through the described extension. If
* the extension is disabled, throws an exception or otherwise does not
* adhere to the contract described in
* {@link IScriptCompletionProposalComputer}, an empty list is returned.
*
* @param context
* the invocation context passed on to the extension
* @param monitor
* the progress monitor passed on to the extension
* @return the list of computed completion proposals (element type:
* {@link org.eclipse.jface.text.contentassist.ICompletionProposal})
*/
public List<ICompletionProposal> computeCompletionProposals(
ContentAssistInvocationContext context, IProgressMonitor monitor) {
if (!isEnabled())
return Collections.emptyList();
IStatus status;
try {
IScriptCompletionProposalComputer computer = getComputer(true);
if (computer == null) // not active yet
return Collections.emptyList();
try {
PerformanceStats stats = startMeter(context, computer);
List<ICompletionProposal> proposals = computer
.computeCompletionProposals(context, monitor);
stopMeter(stats, COMPUTE_COMPLETION_PROPOSALS);
if (proposals != null) {
fLastError = computer.getErrorMessage();
return proposals;
}
} finally {
fIsReportingDelay = true;
}
status = createAPIViolationStatus(COMPUTE_COMPLETION_PROPOSALS);
} catch (InvalidRegistryObjectException x) {
status = createExceptionStatus(x);
} catch (CoreException x) {
status = createExceptionStatus(x);
} catch (RuntimeException x) {
status = createExceptionStatus(x);
} finally {
monitor.done();
}
fRegistry.informUser(this, status);
return Collections.emptyList();
}
/**
* Safely computes context information objects through the described
* extension. If the extension is disabled, throws an exception or otherwise
* does not adhere to the contract described in
* {@link IScriptCompletionProposalComputer}, an empty list is returned.
*
* @param context
* the invocation context passed on to the extension
* @param monitor
* the progress monitor passed on to the extension
* @return the list of computed context information objects (element type:
* {@link org.eclipse.jface.text.contentassist.IContextInformation})
*/
public List<IContextInformation> computeContextInformation(
ContentAssistInvocationContext context, IProgressMonitor monitor) {
if (!isEnabled())
return Collections.emptyList();
IStatus status;
try {
IScriptCompletionProposalComputer computer = getComputer(true);
if (computer == null) // not active yet
return Collections.emptyList();
PerformanceStats stats = startMeter(context, computer);
List<IContextInformation> proposals = computer
.computeContextInformation(context, monitor);
stopMeter(stats, COMPUTE_CONTEXT_INFORMATION);
if (proposals != null) {
fLastError = computer.getErrorMessage();
return proposals;
}
status = createAPIViolationStatus(COMPUTE_CONTEXT_INFORMATION);
} catch (InvalidRegistryObjectException x) {
status = createExceptionStatus(x);
} catch (CoreException x) {
status = createExceptionStatus(x);
} catch (RuntimeException x) {
status = createExceptionStatus(x);
} finally {
monitor.done();
}
fRegistry.informUser(this, status);
return Collections.emptyList();
}
/**
* Notifies the described extension of a proposal computation session start.
* <p>
* <em> Note: This method is called every time code assist is invoked and is
* <strong>not</strong> filtered by partition type. </em>
* </p>
*/
public void sessionStarted() {
if (!isEnabled())
return;
IStatus status;
try {
IScriptCompletionProposalComputer computer = getComputer(true);
if (computer == null) // not active yet
return;
PerformanceStats stats = startMeter(SESSION_STARTED, computer);
computer.sessionStarted();
stopMeter(stats, SESSION_ENDED);
return;
} catch (InvalidRegistryObjectException x) {
status = createExceptionStatus(x);
} catch (CoreException x) {
status = createExceptionStatus(x);
} catch (RuntimeException x) {
status = createExceptionStatus(x);
}
fRegistry.informUser(this, status);
}
/**
* Notifies the described extension of a proposal computation session end.
* <p>
* <em> Note: This method is called every time code assist is invoked and is
* <strong>not</strong> filtered by partition type. </em>
* </p>
*/
public void sessionEnded() {
if (!isEnabled())
return;
IStatus status;
try {
IScriptCompletionProposalComputer computer = getComputer(false);
if (computer == null) // not active yet
return;
PerformanceStats stats = startMeter(SESSION_ENDED, computer);
computer.sessionEnded();
stopMeter(stats, SESSION_ENDED);
return;
} catch (InvalidRegistryObjectException x) {
status = createExceptionStatus(x);
} catch (CoreException x) {
status = createExceptionStatus(x);
} catch (RuntimeException x) {
status = createExceptionStatus(x);
}
fRegistry.informUser(this, status);
}
private PerformanceStats startMeter(Object context,
IScriptCompletionProposalComputer computer) {
final PerformanceStats stats;
if (MEASURE_PERFORMANCE) {
stats = PerformanceStats.getStats(PERFORMANCE_EVENT, computer);
stats.startRun(context.toString());
} else {
stats = null;
}
if (fIsReportingDelay) {
fStart = System.currentTimeMillis();
}
return stats;
}
private void stopMeter(final PerformanceStats stats, String operation) {
if (MEASURE_PERFORMANCE) {
stats.endRun();
if (stats.isFailure()) {
IStatus status = createPerformanceStatus(operation);
fRegistry.informUser(this, status);
return;
}
}
if (fIsReportingDelay) {
long current = System.currentTimeMillis();
if (current - fStart > MAX_DELAY) {
IStatus status = createPerformanceStatus(operation);
fRegistry.informUser(this, status);
}
}
}
private IStatus createExceptionStatus(InvalidRegistryObjectException x) {
// extension has become invalid - log & disable
String blame = createBlameMessage();
String reason = ScriptTextMessages.CompletionProposalComputerDescriptor_reason_invalid;
return new Status(IStatus.INFO, DLTKUIPlugin.getPluginId(), IStatus.OK,
blame + " " + reason, x); //$NON-NLS-1$
}
private IStatus createExceptionStatus(CoreException x) {
// unable to instantiate the extension - log & disable
String blame = createBlameMessage();
String reason = ScriptTextMessages.CompletionProposalComputerDescriptor_reason_instantiation;
return new Status(IStatus.ERROR, DLTKUIPlugin.getPluginId(), IStatus.OK,
blame + " " + reason, x); //$NON-NLS-1$
}
private IStatus createExceptionStatus(RuntimeException x) {
// misbehaving extension - log & disable
String blame = createBlameMessage();
String reason = ScriptTextMessages.CompletionProposalComputerDescriptor_reason_runtime_ex;
return new Status(IStatus.WARNING, DLTKUIPlugin.getPluginId(),
IStatus.OK, blame + " " + reason, x); //$NON-NLS-1$
}
private IStatus createAPIViolationStatus(String operation) {
String blame = createBlameMessage();
Object[] args = { operation };
String reason = Messages.format(
ScriptTextMessages.CompletionProposalComputerDescriptor_reason_API,
args);
return new Status(IStatus.WARNING, DLTKUIPlugin.getPluginId(),
IStatus.OK, blame + " " + reason, null); //$NON-NLS-1$
}
private IStatus createPerformanceStatus(String operation) {
String blame = createBlameMessage();
Object[] args = { operation };
String reason = Messages.format(
ScriptTextMessages.CompletionProposalComputerDescriptor_reason_performance,
args);
return new Status(IStatus.WARNING, DLTKUIPlugin.getPluginId(),
IStatus.OK, blame + " " + reason, null); //$NON-NLS-1$
}
private String createBlameMessage() {
Object[] args = { getName(),
fElement.getDeclaringExtension().getContributor().getName() };
String disable = Messages.format(
ScriptTextMessages.CompletionProposalComputerDescriptor_blame_message,
args);
return disable;
}
/**
* Returns the enablement state of the described extension.
*
* @return the enablement state of the described extension
*/
private boolean isEnabled() {
return fCategory.isEnabled();
}
CompletionProposalCategory getCategory() {
return fCategory;
}
/**
* Returns the error message from the described extension.
*
* @return the error message from the described extension
*/
public String getErrorMessage() {
return fLastError;
}
/**
* Returns the contributor of the described extension.
*
* @return the contributor of the described extension
*/
IContributor getContributor() {
try {
return fElement.getContributor();
} catch (InvalidRegistryObjectException e) {
return null;
}
}
}