/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.core.ext.linker.impl;
import com.google.gwt.core.ext.LinkerContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.TreeLogger.Type;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.linker.AbstractLinker;
import com.google.gwt.core.ext.linker.Artifact;
import com.google.gwt.core.ext.linker.ArtifactSet;
import com.google.gwt.core.ext.linker.CompilationResult;
import com.google.gwt.core.ext.linker.ConfigurationProperty;
import com.google.gwt.core.ext.linker.EmittedArtifact;
import com.google.gwt.core.ext.linker.SelectionProperty;
import com.google.gwt.core.ext.linker.SoftPermutation;
import com.google.gwt.core.ext.linker.StatementRanges;
import com.google.gwt.core.linker.SymbolMapsLinker;
import com.google.gwt.dev.util.Util;
import com.google.gwt.util.tools.Utility;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
/**
* A base class for Linkers that use an external script to boostrap the GWT module. This
* implementation injects JavaScript Snippets into a JS program defined in an external file.<br />
*
* Created nocache.js files must provide an implementation of both __gwt_isKnownPropertyValue() and
* __gwt_getMetaProperty() to support the permutation selection process. These functions must be
* available within the nocache.js scope and must be made available to the permutation js scope.
*/
public abstract class SelectionScriptLinker extends AbstractLinker {
public static final String USE_SOURCE_MAPS_PROPERTY = "compiler.useSourceMaps";
/**
* File name for computeScriptBase.js.
*/
protected static final String COMPUTE_SCRIPT_BASE_JS = "com/google/gwt/core/ext/linker/impl/computeScriptBaseOld.js";
/**
* The extension added to demand-loaded fragment files.
*/
protected static final String FRAGMENT_EXTENSION = ".cache.js";
/**
* A subdirectory to hold all the generated fragments.
*/
protected static final String FRAGMENT_SUBDIR = "deferredjs";
/**
* Utility class to handle insertion of permutations code.
*/
protected static PermutationsUtil permutationsUtil = new PermutationsUtil();
/**
* File name for processMetas.js.
*/
protected static final String PROCESS_METAS_JS = "com/google/gwt/core/ext/linker/impl/processMetasOld.js";
/**
* TODO(bobv): Move this class into c.g.g.core.linker when HostedModeLinker
* goes away?
*/
/**
* A configuration property indicating how large each script tag should be.
*/
private static final String CHUNK_SIZE_PROPERTY = "iframe.linker.script.chunk.size";
/**
* A configuration property that can be used to have the linker load from somewhere other than
* {@link #FRAGMENT_SUBDIR}.
*/
private static final String PROP_FRAGMENT_SUBDIR_OVERRIDE = "iframe.linker.deferredjs.subdir";
/**
* Split a JavaScript string into multiple chunks, at statement boundaries. This method is made
* default access for testing.
*
* @param ranges Describes where the statements are located within the JavaScript
* code. If <code>null</code>, then return <code>js</code> unchanged.
* @param js The JavaScript code to be split up.
* @param charsPerChunk The number of characters to be put in each script tag.
* @param scriptChunkSeparator The string to insert between chunks.
* @param context
*/
public static String splitPrimaryJavaScript(StatementRanges ranges, String js,
int charsPerChunk, String scriptChunkSeparator, LinkerContext context) {
boolean useSourceMaps = false;
for (SelectionProperty prop : context.getProperties()) {
if (USE_SOURCE_MAPS_PROPERTY.equals(prop.getName())) {
String str = prop.tryGetValue();
useSourceMaps = str == null ? false : Boolean.parseBoolean(str);
break;
}
}
// TODO(cromwellian) enable chunking with sourcemaps
if (charsPerChunk < 0 || ranges == null || useSourceMaps) {
return js;
}
StringBuilder sb = new StringBuilder((int) (js.length() * 1.05));
int bytesInCurrentChunk = 0;
for (int i = 0; i < ranges.numStatements(); i++) {
int start = ranges.start(i);
int end = ranges.end(i);
int length = end - start;
if (bytesInCurrentChunk > 0 && bytesInCurrentChunk + length > charsPerChunk) {
if (lastChar(sb) != '\n') {
sb.append('\n');
}
sb.append(scriptChunkSeparator);
bytesInCurrentChunk = 0;
}
if (bytesInCurrentChunk > 0) {
char lastChar = lastChar(sb);
if (lastChar != '\n' && lastChar != ';' && lastChar != '}') {
/*
* Make sure this statement has a separator from the last one.
*/
sb.append(";");
}
}
sb.append(js, start, end);
bytesInCurrentChunk += length;
}
return sb.toString();
}
protected static void replaceAll(StringBuffer buf, String search,
String replace) {
int len = search.length();
for (int pos = buf.indexOf(search); pos >= 0; pos = buf.indexOf(search,
pos + 1)) {
buf.replace(pos, pos + len, replace);
}
}
private static char lastChar(StringBuilder sb) {
return sb.charAt(sb.length() - 1);
}
/**
* This method is left in place for existing subclasses of SelectionScriptLinker that have not
* been upgraded for the sharding API.
*/
@Override
public ArtifactSet link(TreeLogger logger, LinkerContext context,
ArtifactSet artifacts) throws UnableToCompleteException {
ArtifactSet toReturn = link(logger, context, artifacts, true);
toReturn = link(logger, context, toReturn, false);
return toReturn;
}
@Override
public ArtifactSet link(TreeLogger logger, LinkerContext context,
ArtifactSet artifacts, boolean onePermutation)
throws UnableToCompleteException {
if (onePermutation) {
ArtifactSet toReturn = new ArtifactSet(artifacts);
ArtifactSet writableArtifacts = new ArtifactSet(artifacts);
/*
* Support having multiple compilation results because this method is also
* called from the legacy link method.
*/
for (CompilationResult compilation : toReturn.find(CompilationResult.class)) {
// pass a writable set so that other stages can use this set for temporary storage
toReturn.addAll(doEmitCompilation(logger, context, compilation, writableArtifacts));
maybeAddHostedModeFile(logger, context, toReturn, compilation);
}
/*
* Find edit artifacts added during linking and add them. This is done as a way of returning
* arbitrary extra outputs from within the linker methods without having to modify
* their return signatures to pass extra return data around.
*/
for (SymbolMapsLinker.ScriptFragmentEditsArtifact ea : writableArtifacts.find(
SymbolMapsLinker.ScriptFragmentEditsArtifact.class)) {
toReturn.add(ea);
}
return toReturn;
} else {
permutationsUtil.setupPermutationsMap(artifacts);
ArtifactSet toReturn = new ArtifactSet(artifacts);
EmittedArtifact art = emitSelectionScript(logger, context, artifacts);
if (art != null) {
toReturn.add(art);
}
maybeOutputPropertyMap(logger, context, toReturn);
maybeAddHostedModeFile(logger, context, toReturn, null);
return toReturn;
}
}
@Override
public boolean supportsDevModeInJunit(LinkerContext context) {
return (getHostedFilename() != "");
}
/**
* Extract via {@link #CHUNK_SIZE_PROPERTY} the number of characters to be included in each
* chunk.
*/
protected int charsPerChunk(LinkerContext context, TreeLogger logger) {
SortedSet<ConfigurationProperty> configProps = context.getConfigurationProperties();
for (ConfigurationProperty prop : configProps) {
if (prop.getName().equals(CHUNK_SIZE_PROPERTY)) {
return Integer.parseInt(prop.getValues().get(0));
}
}
// CompilerParameters.gwt.xml indicates that if this property is -1, then
// no chunking is performed, so we return that as the default. Since
// Core.gwt.xml contains a definition for this property, this should never
// happen in production, but some tests mock out the ConfigurationProperties
// so we want to have a reasonable default rather than making them all add
// a value for this property.
return -1;
}
protected Collection<Artifact<?>> doEmitCompilation(TreeLogger logger,
LinkerContext context, CompilationResult result, ArtifactSet artifacts)
throws UnableToCompleteException {
String[] js = result.getJavaScript();
Collection<Artifact<?>> toReturn = new ArrayList<Artifact<?>>();
byte[] primary = generatePrimaryFragment(logger, context, result, js, artifacts);
toReturn.add(emitBytes(logger, primary, result.getStrongName()
+ getCompilationExtension(logger, context)));
primary = null;
for (int i = 1; i < js.length; i++) {
byte[] bytes = Util.getBytes(generateDeferredFragment(logger, context, i, js[i], artifacts,
result));
toReturn.add(emitBytes(logger, bytes, FRAGMENT_SUBDIR + File.separator
+ result.getStrongName() + File.separator + i + FRAGMENT_EXTENSION));
}
toReturn.addAll(emitSelectionInformation(result.getStrongName(), result));
return toReturn;
}
protected List<Artifact<?>> emitSelectionInformation(String strongName,
CompilationResult result) {
List<Artifact<?>> emitted = new ArrayList<Artifact<?>>();
for (SortedMap<SelectionProperty, String> propertyMap : result.getPropertyMap()) {
TreeMap<String, String> propMap = new TreeMap<String, String>();
for (Map.Entry<SelectionProperty, String> entry : propertyMap.entrySet()) {
propMap.put(entry.getKey().getName(), entry.getValue());
}
// The soft properties may not be a subset of the existing set
for (SoftPermutation soft : result.getSoftPermutations()) {
// Make a copy we can add add more properties to
TreeMap<String, String> softMap = new TreeMap<String, String>(propMap);
// Make sure this SelectionInformation contains the soft properties
for (Map.Entry<SelectionProperty, String> entry : soft.getPropertyMap().entrySet()) {
softMap.put(entry.getKey().getName(), entry.getValue());
}
emitted.add(new SelectionInformation(strongName, soft.getId(), softMap));
}
}
return emitted;
}
protected EmittedArtifact emitSelectionScript(TreeLogger logger,
LinkerContext context, ArtifactSet artifacts)
throws UnableToCompleteException {
/*
* Last modified is important to keep Development Mode refreses from
* clobbering Production Mode compiles. We set the timestamp on the
* Development Mode selection script to the same mod time as the module (to
* allow updates). For Production Mode, we just set it to now.
*/
long lastModified;
if (permutationsUtil.getPermutationsMap().isEmpty()) {
lastModified = context.getModuleLastModified();
} else {
lastModified = System.currentTimeMillis();
}
String ss = generateSelectionScript(logger, context, artifacts);
return emitString(logger, ss, context.getModuleName()
+ ".nocache.js", lastModified);
}
/**
* Generate a selection script. The selection information should previously have been scanned
* using {@link PermutationsUtil#setupPermutationsMap(ArtifactSet)}.
*/
protected String fillSelectionScriptTemplate(StringBuffer selectionScript,
TreeLogger logger, LinkerContext context, ArtifactSet artifacts,
CompilationResult result) throws
UnableToCompleteException {
String computeScriptBase;
String processMetas;
try {
computeScriptBase = Utility.getFileFromClassPath(COMPUTE_SCRIPT_BASE_JS);
processMetas = Utility.getFileFromClassPath(PROCESS_METAS_JS);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to read selection script template",
e);
throw new UnableToCompleteException();
}
replaceAll(selectionScript, "__COMPUTE_SCRIPT_BASE__", computeScriptBase);
replaceAll(selectionScript, "__PROCESS_METAS__", processMetas);
selectionScript = ResourceInjectionUtil.injectResources(selectionScript, artifacts);
permutationsUtil.addPermutationsJs(selectionScript, logger, context);
replaceAll(selectionScript, "__MODULE_FUNC__",
context.getModuleFunctionName());
replaceAll(selectionScript, "__MODULE_NAME__", context.getModuleName());
replaceAll(selectionScript, "__HOSTED_FILENAME__", getHostedFilename());
return selectionScript.toString();
}
/**
* @param logger a TreeLogger
* @param context a LinkerContext
* @param fragment the fragment number
*/
protected String generateDeferredFragment(TreeLogger logger,
LinkerContext context, int fragment, String js, ArtifactSet artifacts,
CompilationResult result)
throws UnableToCompleteException {
StringBuilder b = new StringBuilder();
String strongName = result == null ? "" : result.getStrongName();
String prefix = getDeferredFragmentPrefix(logger, context, fragment);
b.append(prefix);
b.append(js);
String suffix = getDeferredFragmentSuffix(logger, context, fragment);
if (suffix == null) {
suffix = getDeferredFragmentSuffix2(logger, context, fragment, strongName);
if (suffix == null) {
logger.log(Type.ERROR, "Neither getDeferredFragmentSuffix nor getDeferredFragmentSuffix2 "
+ "were overridden in linker: " + getClass().getName());
throw new UnableToCompleteException();
}
}
b.append(suffix);
SymbolMapsLinker.ScriptFragmentEditsArtifact editsArtifact
= new SymbolMapsLinker.ScriptFragmentEditsArtifact(strongName, fragment);
editsArtifact.prefixLines(prefix);
artifacts.add(editsArtifact);
return wrapDeferredFragment(logger, context, fragment, b.toString(), artifacts);
}
/**
* Generate the primary fragment. The default implementation is based on {@link
* #getModulePrefix(TreeLogger, LinkerContext, String, int)} and {@link
* #getModuleSuffix(TreeLogger, LinkerContext)}.
*/
protected byte[] generatePrimaryFragment(TreeLogger logger,
LinkerContext context, CompilationResult result, String[] js,
ArtifactSet artifacts) throws UnableToCompleteException {
String temp = splitPrimaryJavaScript(result.getStatementRanges()[0], js[0],
charsPerChunk(context, logger), getScriptChunkSeparator(logger, context), context);
String primaryFragmentString =
generatePrimaryFragmentString(logger, context, result, temp, js.length, artifacts);
return Util.getBytes(primaryFragmentString);
}
protected String generatePrimaryFragmentString(TreeLogger logger,
LinkerContext context, CompilationResult result, String js, int length,
ArtifactSet artifacts)
throws UnableToCompleteException {
StringBuilder b = new StringBuilder();
String strongName = result == null ? "" : result.getStrongName();
String modulePrefix = getModulePrefix(logger, context, strongName, length);
SymbolMapsLinker.ScriptFragmentEditsArtifact editsArtifact
= new SymbolMapsLinker.ScriptFragmentEditsArtifact(strongName, 0);
editsArtifact.prefixLines(modulePrefix);
artifacts.add(editsArtifact);
b.append(modulePrefix);
b.append(js);
String suffix = getModuleSuffix(logger, context);
if (suffix == null) {
suffix = getModuleSuffix2(logger, context, strongName);
if (suffix == null) {
logger.log(Type.ERROR, "Neither getModuleSuffix nor getModuleSuffix2 were overridden in "
+ "linker: " + getClass().getName());
throw new UnableToCompleteException();
}
}
b.append(suffix);
return wrapPrimaryFragment(logger, context, b.toString(), artifacts, result);
}
protected String generateSelectionScript(TreeLogger logger,
LinkerContext context, ArtifactSet artifacts) throws UnableToCompleteException {
return generateSelectionScript(logger, context, artifacts, null);
}
protected String generateSelectionScript(TreeLogger logger,
LinkerContext context, ArtifactSet artifacts, CompilationResult result)
throws UnableToCompleteException {
String selectionScriptText;
StringBuffer buffer = readFileToStringBuffer(
getSelectionScriptTemplate(logger, context), logger);
selectionScriptText = fillSelectionScriptTemplate(
buffer, logger, context, artifacts, result);
selectionScriptText =
context.optimizeJavaScript(logger, selectionScriptText);
return selectionScriptText;
}
protected abstract String getCompilationExtension(TreeLogger logger,
LinkerContext context) throws UnableToCompleteException;
protected String getDeferredFragmentPrefix(TreeLogger logger, LinkerContext context,
int fragment) {
return "";
}
/**
* Returns the suffix at the end of a JavaScript fragment other than the initial fragment
* (deprecated version). The default version returns null, which will cause
* {@link #getDeferredFragmentSuffix2} to be called instead. Subclasses should switch to
* extending getDeferredFragmentSuffix2.
*/
@Deprecated
protected String getDeferredFragmentSuffix(TreeLogger logger, LinkerContext context,
int fragment) {
return null;
}
/**
* Returns the suffix at the end of a JavaScript fragment other than the initial fragment
* (new version). This method won't be called if {@link #getDeferredFragmentSuffix} is overridden
* to return non-null. Subclasses should stop implementing getDeferredFramgnentSuffix and
* implement getDeferredFragmentSuffix2 instead.
*/
protected String getDeferredFragmentSuffix2(TreeLogger logger, LinkerContext context,
int fragment, String strongName) {
return "";
}
/**
* Returns the subdirectory name to be used by getModulPrefix when requesting a runAsync module.
* It is specified by {@link #PROP_FRAGMENT_SUBDIR_OVERRIDE} and, aside from test cases, is always
* {@link #FRAGMENT_SUBDIR}.
*/
protected final String getFragmentSubdir(TreeLogger logger,
LinkerContext context) throws UnableToCompleteException {
String subdir = null;
for (ConfigurationProperty prop : context.getConfigurationProperties()) {
if (prop.getName().equals(PROP_FRAGMENT_SUBDIR_OVERRIDE)) {
subdir = prop.getValues().get(0);
}
}
if (subdir == null) {
logger.log(TreeLogger.ERROR, "Could not find property "
+ PROP_FRAGMENT_SUBDIR_OVERRIDE);
throw new UnableToCompleteException();
}
return subdir;
}
protected String getHostedFilename() {
return "";
}
/**
* Compute the beginning of a JavaScript file that will hold the main module implementation.
*/
protected abstract String getModulePrefix(TreeLogger logger,
LinkerContext context, String strongName)
throws UnableToCompleteException;
/**
* Compute the beginning of a JavaScript file that will hold the main module implementation. By
* default, calls {@link #getModulePrefix(TreeLogger, LinkerContext, String)}.
*
* @param strongName strong name of the module being emitted
* @param numFragments the number of fragments for this module, including the main fragment
* (fragment 0)
*/
protected String getModulePrefix(TreeLogger logger, LinkerContext context,
String strongName, int numFragments) throws UnableToCompleteException {
return getModulePrefix(logger, context, strongName);
}
/**
* Returns the suffix for the initial JavaScript fragment (deprecated version).
* The default returns null, which will cause {@link #getModuleSuffix2} to be called instead.
* Subclasses should switch to extending getModuleSuffix2.
*/
@Deprecated
protected String getModuleSuffix(TreeLogger logger,
LinkerContext context) throws UnableToCompleteException {
return null;
}
/**
* Returns the suffix for the initial JavaScript fragment (new version). This version
* will not be called if {@link #getModuleSuffix} is overridden so that it doesn't return null.
* Subclasses should stop implementing getModuleSuffix and implmenet getModuleSuffix2 instead.
*/
protected String getModuleSuffix2(TreeLogger logger,
LinkerContext context, String strongName) throws UnableToCompleteException {
return null;
}
/**
* Some subclasses support "chunking" of the primary fragment. If chunking will be supported, this
* function should be overridden to return the string which should be inserted between each
* chunk.
*/
protected String getScriptChunkSeparator(TreeLogger logger, LinkerContext context) {
return "";
}
protected abstract String getSelectionScriptTemplate(TreeLogger logger,
LinkerContext context) throws UnableToCompleteException;
/**
* Add the Development Mode file to the artifact set.
*/
protected void maybeAddHostedModeFile(TreeLogger logger,
LinkerContext context, ArtifactSet artifacts, CompilationResult result)
throws UnableToCompleteException {
String hostedFilename = getHostedFilename();
if ("".equals(hostedFilename) || result != null) {
return;
}
try {
URL resource = SelectionScriptLinker.class.getResource(hostedFilename);
if (resource == null) {
logger.log(TreeLogger.ERROR,
"Unable to find support resource: " + hostedFilename);
throw new UnableToCompleteException();
}
final URLConnection connection = resource.openConnection();
// TODO: extract URLArtifact class?
EmittedArtifact hostedFile = new EmittedArtifact(
SelectionScriptLinker.class, hostedFilename) {
@Override
public InputStream getContents(TreeLogger logger)
throws UnableToCompleteException {
try {
return connection.getInputStream();
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to copy support resource", e);
throw new UnableToCompleteException();
}
}
@Override
public long getLastModified() {
return connection.getLastModified();
}
};
artifacts.add(hostedFile);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to copy support resource", e);
throw new UnableToCompleteException();
}
}
protected void maybeOutputPropertyMap(TreeLogger logger,
LinkerContext context, ArtifactSet toReturn) {
return;
}
protected StringBuffer readFileToStringBuffer(String filename,
TreeLogger logger) throws UnableToCompleteException {
StringBuffer buffer;
try {
buffer = new StringBuffer(Utility.getFileFromClassPath(filename));
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to read file: " + filename, e);
throw new UnableToCompleteException();
}
return buffer;
}
protected String wrapDeferredFragment(TreeLogger logger,
LinkerContext context, int fragment, String script, ArtifactSet artifacts)
throws UnableToCompleteException {
return script;
}
protected String wrapPrimaryFragment(TreeLogger logger,
LinkerContext context, String script, ArtifactSet artifacts,
CompilationResult result) throws UnableToCompleteException {
return script;
}
}