/*
*
* Copyright 2002-2004 The Ant-Contrib project
*
* 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 net.sf.antcontrib.cpptasks;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import net.sf.antcontrib.cpptasks.compiler.CompilerConfiguration;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
/**
* @author Curt Arnold
*/
public final class DependencyTable {
/**
* This class handles populates the TargetHistory hashtable in response to
* SAX parse events
*/
private class DependencyTableHandler extends DefaultHandler {
private File baseDir;
private final DependencyTable dependencyTable;
private String includePath;
private Vector includes;
private String source;
private long sourceLastModified;
private Vector sysIncludes;
/**
* Constructor
*
* @param history
* hashtable of TargetHistory keyed by output name
* @param outputFiles
* existing files in output directory
*/
private DependencyTableHandler(DependencyTable dependencyTable,
File baseDir) {
this.dependencyTable = dependencyTable;
this.baseDir = baseDir;
includes = new Vector();
sysIncludes = new Vector();
source = null;
}
public void endElement(String namespaceURI, String localName,
String qName) throws SAXException {
//
// if </source> then
// create Dependency object and add to hashtable
// if corresponding source file exists and
// has the same timestamp
//
if (qName.equals("source")) {
if (source != null && includePath != null) {
File existingFile = new File(baseDir, source);
//
// if the file exists and the time stamp is right
// preserve the dependency info
if (existingFile.exists()) {
//
// would have expected exact matches
// but was seeing some unexpected difference by
// a few tens of milliseconds, as long
// as the times are within a second
long existingLastModified = existingFile.lastModified();
long diff = existingLastModified - sourceLastModified;
if (diff >= -500 && diff <= 500) {
DependencyInfo dependInfo = new DependencyInfo(
includePath, source, sourceLastModified,
includes, sysIncludes);
dependencyTable.putDependencyInfo(source,
dependInfo);
}
}
source = null;
includes.setSize(0);
}
} else {
//
// this causes any <source> elements outside the
// scope of an <includePath> to be discarded
//
if (qName.equals("includePath")) {
includePath = null;
}
}
}
/**
* startElement handler
*/
public void startElement(String namespaceURI, String localName,
String qName, Attributes atts) throws SAXException {
//
// if includes, then add relative file name to vector
//
if (qName.equals("include")) {
includes.addElement(atts.getValue("file"));
} else {
if (qName.equals("sysinclude")) {
sysIncludes.addElement(atts.getValue("file"));
} else {
//
// if source then
// capture source file name,
// modification time and reset includes vector
//
if (qName.equals("source")) {
source = atts.getValue("file");
sourceLastModified = Long.parseLong(atts
.getValue("lastModified"), 16);
includes.setSize(0);
sysIncludes.setSize(0);
} else {
if (qName.equals("includePath")) {
includePath = atts.getValue("signature");
}
}
}
}
}
}
public abstract class DependencyVisitor {
/**
* Previews all the children of this source file.
*
* May be called multiple times as DependencyInfo's for children are
* filled in.
*
* @return true to continue towards recursion into included files
*/
public abstract boolean preview(DependencyInfo parent,
DependencyInfo[] children);
/**
* Called if the dependency depth exhausted the stack.
*/
public abstract void stackExhausted();
/**
* Visits the dependency info.
*
* @returns true to continue towards recursion into included files
*/
public abstract boolean visit(DependencyInfo dependInfo);
}
public class TimestampChecker extends DependencyVisitor {
private boolean noNeedToRebuild;
private long outputLastModified;
private boolean rebuildOnStackExhaustion;
public TimestampChecker(final long outputLastModified,
boolean rebuildOnStackExhaustion) {
this.outputLastModified = outputLastModified;
noNeedToRebuild = true;
this.rebuildOnStackExhaustion = rebuildOnStackExhaustion;
}
public boolean getMustRebuild() {
return !noNeedToRebuild;
}
public boolean preview(DependencyInfo parent, DependencyInfo[] children) {
int withCompositeTimes = 0;
long parentCompositeLastModified = parent.getSourceLastModified();
for (int i = 0; i < children.length; i++) {
if (children[i] != null) {
//
// expedient way to determine if a child forces us to
// rebuild
//
visit(children[i]);
long childCompositeLastModified = children[i]
.getCompositeLastModified();
if (childCompositeLastModified != Long.MIN_VALUE) {
withCompositeTimes++;
if (childCompositeLastModified > parentCompositeLastModified) {
parentCompositeLastModified = childCompositeLastModified;
}
}
}
}
if (withCompositeTimes == children.length) {
parent.setCompositeLastModified(parentCompositeLastModified);
}
//
// may have been changed by an earlier call to visit()
//
return noNeedToRebuild;
}
public void stackExhausted() {
if (rebuildOnStackExhaustion) {
noNeedToRebuild = false;
}
}
public boolean visit(DependencyInfo dependInfo) {
if (noNeedToRebuild) {
if (dependInfo.getSourceLastModified() > outputLastModified
|| dependInfo.getCompositeLastModified() > outputLastModified) {
noNeedToRebuild = false;
}
}
//
// only need to process the children if
// it has not yet been determined whether
// we need to rebuild and the composite modified time
// has not been determined for this file
return noNeedToRebuild
&& dependInfo.getCompositeLastModified() == Long.MIN_VALUE;
}
}
private/* final */File baseDir;
private String baseDirPath;
/**
* a hashtable of DependencyInfo[] keyed by output file name
*/
private final Hashtable dependencies = new Hashtable();
/** The file the cache was loaded from. */
private/* final */File dependenciesFile;
/** Flag indicating whether the cache should be written back to file. */
private boolean dirty;
/**
* Creates a target history table from dependencies.xml in the prject
* directory, if it exists. Otherwise, initializes the dependencies empty.
*
* @param task
* task used for logging history load errors
* @param baseDir
* output directory for task
*/
public DependencyTable(File baseDir) {
if (baseDir == null) {
throw new NullPointerException("baseDir");
}
this.baseDir = baseDir;
try {
baseDirPath = baseDir.getCanonicalPath();
} catch (IOException ex) {
baseDirPath = baseDir.toString();
}
dirty = false;
//
// load any existing dependencies from file
dependenciesFile = new File(baseDir, "dependencies.xml");
}
public void commit(CCTask task) {
//
// if not dirty, no need to update file
//
if (dirty) {
//
// walk through dependencies to get vector of include paths
// identifiers
//
Vector includePaths = getIncludePaths();
//
//
// write dependency file
//
try {
FileOutputStream outStream = new FileOutputStream(
dependenciesFile);
OutputStreamWriter streamWriter;
//
// Early VM's may not have UTF-8 support
// fallback to default code page which
// "should" be okay unless there are
// non ASCII file names
String encodingName = "UTF-8";
try {
streamWriter = new OutputStreamWriter(outStream, "UTF-8");
} catch (UnsupportedEncodingException ex) {
streamWriter = new OutputStreamWriter(outStream);
encodingName = streamWriter.getEncoding();
}
BufferedWriter writer = new BufferedWriter(streamWriter);
writer.write("<?xml version='1.0' encoding='");
writer.write(encodingName);
writer.write("'?>\n");
writer.write("<dependencies>\n");
StringBuffer buf = new StringBuffer();
Enumeration includePathEnum = includePaths.elements();
while (includePathEnum.hasMoreElements()) {
writeIncludePathDependencies((String) includePathEnum
.nextElement(), writer, buf);
}
writer.write("</dependencies>\n");
writer.close();
dirty = false;
} catch (IOException ex) {
task.log("Error writing " + dependenciesFile.toString() + ":"
+ ex.toString());
}
}
}
/**
* Returns an enumerator of DependencyInfo's
*/
public Enumeration elements() {
return dependencies.elements();
}
/**
* This method returns a DependencyInfo for the specific source file and
* include path identifier
*
*/
public DependencyInfo getDependencyInfo(String sourceRelativeName,
String includePathIdentifier) {
DependencyInfo dependInfo = null;
DependencyInfo[] dependInfos = (DependencyInfo[]) dependencies
.get(sourceRelativeName);
if (dependInfos != null) {
for (int i = 0; i < dependInfos.length; i++) {
dependInfo = dependInfos[i];
if (dependInfo.getIncludePathIdentifier().equals(
includePathIdentifier)) {
return dependInfo;
}
}
}
return null;
}
private Vector getIncludePaths() {
Vector includePaths = new Vector();
DependencyInfo[] dependInfos;
Enumeration dependenciesEnum = dependencies.elements();
while (dependenciesEnum.hasMoreElements()) {
dependInfos = (DependencyInfo[]) dependenciesEnum.nextElement();
for (int i = 0; i < dependInfos.length; i++) {
DependencyInfo dependInfo = dependInfos[i];
boolean matchesExisting = false;
final String dependIncludePath = dependInfo
.getIncludePathIdentifier();
Enumeration includePathEnum = includePaths.elements();
while (includePathEnum.hasMoreElements()) {
if (dependIncludePath.equals(includePathEnum.nextElement())) {
matchesExisting = true;
break;
}
}
if (!matchesExisting) {
includePaths.addElement(dependIncludePath);
}
}
}
return includePaths;
}
public void load() throws IOException, ParserConfigurationException,
SAXException {
dependencies.clear();
if (dependenciesFile.exists()) {
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setValidating(false);
SAXParser parser = factory.newSAXParser();
parser.parse(dependenciesFile, new DependencyTableHandler(this,
baseDir));
dirty = false;
}
}
/**
* Determines if the specified target needs to be rebuilt.
*
* This task may result in substantial IO as files are parsed to determine
* their dependencies
*/
public boolean needsRebuild(CCTask task, TargetInfo target,
int dependencyDepth) {
// look at any files where the compositeLastModified
// is not known, but the includes are known
//
boolean mustRebuild = false;
CompilerConfiguration compiler = (CompilerConfiguration) target
.getConfiguration();
String includePathIdentifier = compiler.getIncludePathIdentifier();
File[] sources = target.getSources();
DependencyInfo[] dependInfos = new DependencyInfo[sources.length];
long outputLastModified = target.getOutput().lastModified();
//
// try to solve problem using existing dependency info
// (not parsing any new files)
//
DependencyInfo[] stack = new DependencyInfo[50];
boolean rebuildOnStackExhaustion = true;
if (dependencyDepth >= 0) {
if (dependencyDepth < 50) {
stack = new DependencyInfo[dependencyDepth];
}
rebuildOnStackExhaustion = false;
}
TimestampChecker checker = new TimestampChecker(outputLastModified,
rebuildOnStackExhaustion);
for (int i = 0; i < sources.length && !mustRebuild; i++) {
File source = sources[i];
String relative = CUtil.getRelativePath(baseDirPath, source);
DependencyInfo dependInfo = getDependencyInfo(relative,
includePathIdentifier);
if (dependInfo == null) {
task.log("Parsing " + relative, Project.MSG_VERBOSE);
dependInfo = parseIncludes(task, compiler, source);
}
walkDependencies(task, dependInfo, compiler, stack, checker);
mustRebuild = checker.getMustRebuild();
}
return mustRebuild;
}
public DependencyInfo parseIncludes(CCTask task,
CompilerConfiguration compiler, File source) {
DependencyInfo dependInfo = compiler.parseIncludes(task, baseDir,
source);
String relativeSource = CUtil.getRelativePath(baseDirPath, source);
putDependencyInfo(relativeSource, dependInfo);
return dependInfo;
}
private void putDependencyInfo(String key, DependencyInfo dependInfo) {
//
// optimistic, add new value
//
DependencyInfo[] old = (DependencyInfo[]) dependencies.put(key,
new DependencyInfo[]{dependInfo});
dirty = true;
//
// something was already there
//
if (old != null) {
//
// see if the include path matches a previous entry
// if so replace it
String includePathIdentifier = dependInfo
.getIncludePathIdentifier();
for (int i = 0; i < old.length; i++) {
DependencyInfo oldDepend = old[i];
if (oldDepend.getIncludePathIdentifier().equals(
includePathIdentifier)) {
old[i] = dependInfo;
dependencies.put(key, old);
return;
}
}
//
// no match prepend the new entry to the array
// of dependencies for the file
DependencyInfo[] combined = new DependencyInfo[old.length + 1];
combined[0] = dependInfo;
for (int i = 0; i < old.length; i++) {
combined[i + 1] = old[i];
}
dependencies.put(key, combined);
}
return;
}
public void walkDependencies(CCTask task, DependencyInfo dependInfo,
CompilerConfiguration compiler, DependencyInfo[] stack,
DependencyVisitor visitor) throws BuildException {
//
// visit this node
// if visit returns true then
// visit the referenced include and sysInclude dependencies
//
if (visitor.visit(dependInfo)) {
//
// find first null entry on stack
//
int stackPosition = -1;
for (int i = 0; i < stack.length; i++) {
if (stack[i] == null) {
stackPosition = i;
stack[i] = dependInfo;
break;
} else {
//
// if we have appeared early in the calling history
// then we didn't exceed the criteria
if (stack[i] == dependInfo) {
return;
}
}
}
if (stackPosition == -1) {
visitor.stackExhausted();
return;
}
//
// locate dependency infos
//
String[] includes = dependInfo.getIncludes();
String includePathIdentifier = compiler.getIncludePathIdentifier();
DependencyInfo[] includeInfos = new DependencyInfo[includes.length];
for (int i = 0; i < includes.length; i++) {
DependencyInfo includeInfo = getDependencyInfo(includes[i],
includePathIdentifier);
includeInfos[i] = includeInfo;
}
//
// preview with only the already available dependency infos
//
if (visitor.preview(dependInfo, includeInfos)) {
//
// now need to fill in the missing DependencyInfos
//
int missingCount = 0;
for (int i = 0; i < includes.length; i++) {
if (includeInfos[i] == null) {
missingCount++;
task.log("Parsing " + includes[i], Project.MSG_VERBOSE);
// If the include is part of a UNC don't go building a
// relative file name.
File src = includes[i].startsWith("\\\\") ? new File(
includes[i]) : new File(baseDir, includes[i]);
DependencyInfo includeInfo = parseIncludes(task,
compiler, src);
includeInfos[i] = includeInfo;
}
}
//
// if it passes a review the second time
// then recurse into all the children
if (missingCount == 0
|| visitor.preview(dependInfo, includeInfos)) {
//
// recurse into
//
for (int i = 0; i < includeInfos.length; i++) {
DependencyInfo includeInfo = includeInfos[i];
walkDependencies(task, includeInfo, compiler, stack,
visitor);
}
}
}
stack[stackPosition] = null;
}
}
private void writeDependencyInfo(BufferedWriter writer, StringBuffer buf,
DependencyInfo dependInfo) throws IOException {
String[] includes = dependInfo.getIncludes();
String[] sysIncludes = dependInfo.getSysIncludes();
//
// if the includes have not been evaluted then
// it is not worth our time saving it
// and trying to distiguish between files with
// no dependencies and those with undetermined dependencies
buf.setLength(0);
buf.append(" <source file=\"");
buf.append(CUtil.xmlAttribEncode(dependInfo.getSource()));
buf.append("\" lastModified=\"");
buf.append(Long.toHexString(dependInfo.getSourceLastModified()));
buf.append("\">\n");
writer.write(buf.toString());
for (int i = 0; i < includes.length; i++) {
buf.setLength(0);
buf.append(" <include file=\"");
buf.append(CUtil.xmlAttribEncode(includes[i]));
buf.append("\"/>\n");
writer.write(buf.toString());
}
for (int i = 0; i < sysIncludes.length; i++) {
buf.setLength(0);
buf.append(" <sysinclude file=\"");
buf.append(CUtil.xmlAttribEncode(sysIncludes[i]));
buf.append("\"/>\n");
writer.write(buf.toString());
}
writer.write(" </source>\n");
return;
}
private void writeIncludePathDependencies(String includePathIdentifier,
BufferedWriter writer, StringBuffer buf) throws IOException {
//
// include path element
//
buf.setLength(0);
buf.append(" <includePath signature=\"");
buf.append(CUtil.xmlAttribEncode(includePathIdentifier));
buf.append("\">\n");
writer.write(buf.toString());
Enumeration dependenciesEnum = dependencies.elements();
while (dependenciesEnum.hasMoreElements()) {
DependencyInfo[] dependInfos = (DependencyInfo[]) dependenciesEnum
.nextElement();
for (int i = 0; i < dependInfos.length; i++) {
DependencyInfo dependInfo = dependInfos[i];
//
// if this is for the same include path
// then output the info
if (dependInfo.getIncludePathIdentifier().equals(
includePathIdentifier)) {
writeDependencyInfo(writer, buf, dependInfo);
}
}
}
writer.write(" </includePath>\n");
}
}