src/main/java/org/apache/maven/plugins/artifact/buildinfo/BuildinfoMojo.java - maven-artifact-plugin - Git at Google

 package org.apache.maven.plugins.artifact.buildinfo;

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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.
  */

 import org.apache.commons.codec.Charsets;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.artifact.factory.ArtifactFactory;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;

 import org.apache.maven.plugins.annotations.Component;
 import org.apache.maven.plugins.annotations.LifecyclePhase;
 import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.MavenProjectHelper;
 import org.apache.maven.shared.utils.logging.MessageUtils;
 import org.codehaus.plexus.util.StringUtils;
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.repository.RemoteRepository;

 import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;

 /**
  * Creates a buildinfo file recording build environment and output, as specified in
  * <a href="https://reproducible-builds.org/docs/jvm/">Reproducible Builds for the JVM</a>
  * for mono-module build, and extended for multi-module build.
  * Then if a remote repository is configured, check against reference content in it.
  */
 @Mojo( name = "buildinfo", defaultPhase = LifecyclePhase.VERIFY )
 public class BuildinfoMojo
     extends AbstractMojo
 {
     /**
      * The Maven project.
      */
     @Parameter( defaultValue = "${project}", readonly = true )
     protected MavenProject project;

     /**
      * The reactor projects.
      */
     @Parameter( defaultValue = "${reactorProjects}", required = true, readonly = true )
     protected List<MavenProject> reactorProjects;

     /**
      * Location of the generated buildinfo file.
      */
     @Parameter( defaultValue = "${project.build.directory}/${project.artifactId}-${project.version}.buildinfo",
                     required = true, readonly = true )
     private File buildinfoFile;

     /**
      * Specifies whether to attach the generated buildinfo file to the project.
      */
     @Parameter( property = "buildinfo.attach", defaultValue = "true" )
     private boolean attach;

     /**
      * Rebuild arguments.
      */
     //@Parameter( property = "buildinfo.rebuild-args", defaultValue = "-DskipTests verify" )
     //private String rebuildArgs;

     /**
      * Repository for reference build, containing either reference buildinfo file or reference artifacts.<br/>
      * Format: <code>id</code> or <code>url</code> or <code>id::url</code>
      * <dl>
      * <dt>id</dt>
      * <dd>The id can be used to pick up the correct credentials from the settings.xml</dd>
      * <dt>url</dt>
      * <dd>The location of the repository</dd>
      * </dl>
      */
     @Parameter( property = "reference.repo" )
     private String referenceRepo;

     /**
      * Specifies if reference comparison output file should be saved.
      * This is expected to be a temporary feature to ease
      * <a href="https://github.com/jvm-repo-rebuild/reproducible-central">Central Repository rebuild</a>
      * results display.
      */
     @Parameter( property = "reference.compare.save", defaultValue = "false" )
     private boolean referenceCompareSave;

     /**
      * Used for attaching the buildinfo file in the project.
      */
     @Component
     private MavenProjectHelper projectHelper;

     @Component
     private ArtifactFactory artifactFactory;

     /**
      * The entry point to Maven Artifact Resolver, i.e. the component doing all the work.
      */
     @Component
     private RepositorySystem repoSystem;

     /**
      * The current repository/network configuration of Maven.
      */
     @Parameter( defaultValue = "${repositorySystemSession}", readonly = true )
     private RepositorySystemSession repoSession;

     /**
      * The project's remote repositories to use for the resolution.
      */
     @Parameter( defaultValue = "${project.remoteProjectRepositories}", readonly = true )
     private List<RemoteRepository> remoteRepos;

     public void execute()
         throws MojoExecutionException
     {
         boolean mono = reactorProjects.size() == 1;

         if ( !mono )
         {
             // if module skips install and/or deploy
             if ( PluginUtil.isSkip( project ) )
             {
                 getLog().info( "Skipping buildinfo for module that skips install and/or deploy" );
                 return;
             }
             // if multi-module build, generate (aggregate) buildinfo only in last module
             MavenProject last = getLastProject();
             if  ( project != last )
             {
                 getLog().info( "Skipping intermediate buildinfo, aggregate will be " + last.getArtifactId() );
                 return;
             }
         }

         // generate buildinfo
         Map<Artifact, String> artifacts = generateBuildinfo( mono );
         getLog().info( "Saved " + ( mono ? "" : "aggregate " ) + "info on build to " + buildinfoFile );

         // eventually attach
         if ( attach )
         {
             projectHelper.attachArtifact( project, "buildinfo", buildinfoFile );
         }
         else
         {
             getLog().info( "NOT adding buildinfo to the list of attached artifacts." );
         }

         // eventually check against reference
         if ( referenceRepo != null )
         {
             getLog().info( "Checking against reference build from " + referenceRepo + "..." );
             checkAgainstReference( mono, artifacts );
         }
     }

     /**
      * Generate buildinfo file.
      *
      * @param mono is it a mono-module build?
      * @return a Map of artifacts added to the build info with their associated property key prefix
      *         (<code>outputs.[#module.].#artifact</code>)
      * @throws MojoExecutionException
      */
     private Map<Artifact, String> generateBuildinfo( boolean mono )
             throws MojoExecutionException
     {
         MavenProject root = mono ? project : getExecutionRoot();

         buildinfoFile.getParentFile().mkdirs();

         try ( PrintWriter p = new PrintWriter( new BufferedWriter(
                 new OutputStreamWriter( new FileOutputStream( buildinfoFile ), Charsets.ISO_8859_1 ) ) ) )
         {
             BuildInfoWriter bi = new BuildInfoWriter( getLog(), p, mono );

             bi.printHeader( root );

             // artifact(s) fingerprints
             if ( mono )
             {
                 bi.printArtifacts( project );
             }
             else
             {
                 for ( MavenProject project : reactorProjects )
                 {
                     if ( !PluginUtil.isSkip( project ) )
                     {
                         bi.printArtifacts( project );
                     }
                 }
             }

             return bi.getArtifacts();
         }
         catch ( IOException e )
         {
             throw new MojoExecutionException( "Error creating file " + buildinfoFile, e );
         }
     }

     /**
      * Check current build result with reference.
      *
      * @param mono is it a mono-module build?
      * @artifacts a Map of artifacts added to the build info with their associated property key prefix
      *            (<code>outputs.[#module.].#artifact</code>)
      * @throws MojoExecutionException
      */
     private void checkAgainstReference( boolean mono, Map<Artifact, String> artifacts )
         throws MojoExecutionException
     {
         MavenProject root = mono ? project : getExecutionRoot();
         File referenceDir = new File( root.getBuild().getDirectory(), "reference" );
         referenceDir.mkdirs();

         // download or create reference buildinfo
         File referenceBuildinfo = downloadOrCreateReferenceBuildinfo( mono, artifacts, referenceDir );

         // compare outputs from reference buildinfo vs actual
         compareWithReference( artifacts, referenceBuildinfo );
     }

     private File downloadOrCreateReferenceBuildinfo( boolean mono, Map<Artifact, String> artifacts, File referenceDir )
         throws MojoExecutionException
     {
         RemoteRepository repo = createReferenceRepo();

         ReferenceBuildinfoUtil rmb = new ReferenceBuildinfoUtil( getLog(), referenceDir, artifacts,
                                                                        artifactFactory, repoSystem, repoSession );

         return rmb.downloadOrCreateReferenceBuildinfo( repo, project, buildinfoFile, mono );
     }

     private void compareWithReference( Map<Artifact, String> artifacts, File referenceBuildinfo )
         throws MojoExecutionException
     {
         Properties actual = BuildInfoWriter.loadOutputProperties( buildinfoFile );
         Properties reference = BuildInfoWriter.loadOutputProperties( referenceBuildinfo );

         int ok = 0;
         List<String> okFilenames = new ArrayList<>();
         List<String> koFilenames = new ArrayList<>();
         File referenceDir = referenceBuildinfo.getParentFile();
         for ( Map.Entry<Artifact, String> entry : artifacts.entrySet() )
         {
             Artifact artifact = entry.getKey();
             String prefix = entry.getValue();

             if ( checkArtifact( artifact, prefix, reference, actual, referenceDir ) )
             {
                 ok++;
                 okFilenames.add( artifact.getFile().getName() );
             }
             else
             {
                 koFilenames.add( artifact.getFile().getName() );
             }
         }

         int ko = artifacts.size() - ok;
         int missing = reference.size() / 3 /* 3 property keys par file: filename, length and checksums.sha512 */;

         if ( ko + missing > 0 )
         {
             getLog().warn( "Reproducible Build output summary: " + MessageUtils.buffer().success( ok + " files ok" )
                 + ", " + MessageUtils.buffer().failure( ko + " different" )
                 + ( ( missing == 0 ) ? "" : ( ", " + MessageUtils.buffer().warning( missing + " missing" ) ) ) );
             getLog().warn( "see " + MessageUtils.buffer().project( "diff " + relative( referenceBuildinfo ) + " "
                 + relative( buildinfoFile ) ).toString() );
           }
         else
         {
             getLog().info( "Reproducible Build output summary: " + MessageUtils.buffer().strong( ok + " files ok" ) );
         }

         if ( referenceCompareSave )
         {
             File compare = new File( buildinfoFile.getParentFile(), buildinfoFile.getName() + ".compare" );
             try ( PrintWriter p =
                 new PrintWriter( new BufferedWriter( new OutputStreamWriter( new FileOutputStream( compare ),
                                                                              Charsets.ISO_8859_1 ) ) ) )
             {
                 p.println( "version=" + project.getVersion() );
                 p.println( "ok=" + ok );
                 p.println( "ko=" + ko );
                 p.println( "okFiles=\"" + StringUtils.join( okFilenames.iterator(), " " ) + '"' );
                 p.println( "koFiles=\"" + StringUtils.join( koFilenames.iterator(), " " ) + '"' );
                 getLog().info( "Reproducible Build comparison saved to " + compare );
             }
             catch ( IOException e )
             {
                 throw new MojoExecutionException( "Error creating file " + compare, e );
             }
         }
     }

     private boolean checkArtifact( Artifact artifact, String prefix, Properties reference, Properties actual,
                                    File referenceDir )
     {
         String actualFilename = (String) actual.remove( prefix + ".filename" );
         String actualLength = (String) actual.remove( prefix + ".length" );
         String actualSha512 = (String) actual.remove( prefix + ".checksums.sha512" );

         String referencePrefix = findPrefix( reference, actualFilename );
         String referenceLength = (String) reference.remove( referencePrefix + ".length" );
         String referenceSha512 = (String) reference.remove( referencePrefix + ".checksums.sha512" );

         if ( !actualLength.equals( referenceLength ) )
         {
             getLog().warn( "size mismatch " + MessageUtils.buffer().strong( actualFilename )
                 + diffoscope( artifact, referenceDir ) );
             return false;
         }
         else if ( !actualSha512.equals( referenceSha512 ) )
         {
             getLog().warn( "sha512 mismatch " + MessageUtils.buffer().strong( actualFilename )
                 + diffoscope( artifact, referenceDir ) );
             return false;
         }
         return true;
     }

     private String diffoscope( Artifact a, File referenceDir )
     {
         File actual = a.getFile();
         File reference = new File( referenceDir, actual.getName() );
         return ": investigate with "
             + MessageUtils.buffer().project( "diffoscope " + relative( reference ) + " " + relative( actual ) );
     }

     private String relative( File file )
     {
         return file.getPath().substring( getExecutionRoot().getBasedir().getPath().length() + 1 );
     }

     private static String findPrefix( Properties reference, String actualFilename )
     {
         for ( String name : reference.stringPropertyNames() )
         {
             if ( name.endsWith( ".filename" ) && actualFilename.equals( reference.getProperty( name ) ) )
             {
                 reference.remove( name );
                 return name.substring( 0, name.length() - ".filename".length() );
             }
         }
         return null;
     }

     private RemoteRepository createReferenceRepo()
         throws MojoExecutionException
     {
         if ( referenceRepo.contains( "::" ) )
         {
             // id::url
             int index = referenceRepo.indexOf( "::" );
             String id = referenceRepo.substring( 0, index );
             String url = referenceRepo.substring( index + 2 );
             return createDeploymentArtifactRepository( id, url );
         }
         else if ( referenceRepo.contains( ":" ) )
         {
             // url, will use default "reference" id
             return createDeploymentArtifactRepository( "reference", referenceRepo );
         }

         // id
         for ( RemoteRepository repo : remoteRepos )
         {
             if ( referenceRepo.equals( repo.getId() ) )
             {
                 return repo;
             }
         }
         throw new MojoExecutionException( "Could not find repository with id = " + referenceRepo );
     }

     private static RemoteRepository createDeploymentArtifactRepository( String id, String url )
     {
         return new RemoteRepository.Builder( id, "default", url ).build();
     }

     private MavenProject getExecutionRoot()
     {
         for ( MavenProject p : reactorProjects )
         {
             if ( p.isExecutionRoot() )
             {
                 return p;
             }
         }
         return null;
     }

     private MavenProject getLastProject()
     {
         int i = reactorProjects.size();
         while ( i > 0 )
         {
             MavenProject project = reactorProjects.get( --i );
             if ( !PluginUtil.isSkip( project ) )
             {
                 return project;
             }
         }
         return null;
     }
 }
	package org.apache.maven.plugins.artifact.buildinfo;

	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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.
	*/

	import org.apache.commons.codec.Charsets;
	import org.apache.maven.artifact.Artifact;
	import org.apache.maven.artifact.factory.ArtifactFactory;
	import org.apache.maven.plugin.AbstractMojo;
	import org.apache.maven.plugin.MojoExecutionException;

	import org.apache.maven.plugins.annotations.Component;
	import org.apache.maven.plugins.annotations.LifecyclePhase;
	import org.apache.maven.plugins.annotations.Mojo;
	import org.apache.maven.plugins.annotations.Parameter;
	import org.apache.maven.project.MavenProject;
	import org.apache.maven.project.MavenProjectHelper;
	import org.apache.maven.shared.utils.logging.MessageUtils;
	import org.codehaus.plexus.util.StringUtils;
	import org.eclipse.aether.RepositorySystem;
	import org.eclipse.aether.RepositorySystemSession;
	import org.eclipse.aether.repository.RemoteRepository;

	import java.io.BufferedWriter;
	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.OutputStreamWriter;
	import java.io.PrintWriter;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Map;
	import java.util.Properties;

	/**
	* Creates a buildinfo file recording build environment and output, as specified in
	* <a href="https://reproducible-builds.org/docs/jvm/">Reproducible Builds for the JVM</a>
	* for mono-module build, and extended for multi-module build.
	* Then if a remote repository is configured, check against reference content in it.
	*/
	@Mojo( name = "buildinfo", defaultPhase = LifecyclePhase.VERIFY )
	public class BuildinfoMojo
	extends AbstractMojo
	{
	/**
	* The Maven project.
	*/
	@Parameter( defaultValue = "${project}", readonly = true )
	protected MavenProject project;

	/**
	* The reactor projects.
	*/
	@Parameter( defaultValue = "${reactorProjects}", required = true, readonly = true )
	protected List<MavenProject> reactorProjects;

	/**
	* Location of the generated buildinfo file.
	*/
	@Parameter( defaultValue = "${project.build.directory}/${project.artifactId}-${project.version}.buildinfo",
	required = true, readonly = true )
	private File buildinfoFile;

	/**
	* Specifies whether to attach the generated buildinfo file to the project.
	*/
	@Parameter( property = "buildinfo.attach", defaultValue = "true" )
	private boolean attach;

	/**
	* Rebuild arguments.
	*/
	//@Parameter( property = "buildinfo.rebuild-args", defaultValue = "-DskipTests verify" )
	//private String rebuildArgs;

	/**
	* Repository for reference build, containing either reference buildinfo file or reference artifacts.<br/>
	* Format: <code>id</code> or <code>url</code> or <code>id::url</code>
	* <dl>
	* <dt>id</dt>
	* <dd>The id can be used to pick up the correct credentials from the settings.xml</dd>
	* <dt>url</dt>
	* <dd>The location of the repository</dd>
	* </dl>
	*/
	@Parameter( property = "reference.repo" )
	private String referenceRepo;

	/**
	* Specifies if reference comparison output file should be saved.
	* This is expected to be a temporary feature to ease
	* <a href="https://github.com/jvm-repo-rebuild/reproducible-central">Central Repository rebuild</a>
	* results display.
	*/
	@Parameter( property = "reference.compare.save", defaultValue = "false" )
	private boolean referenceCompareSave;

	/**
	* Used for attaching the buildinfo file in the project.
	*/
	@Component
	private MavenProjectHelper projectHelper;

	@Component
	private ArtifactFactory artifactFactory;

	/**
	* The entry point to Maven Artifact Resolver, i.e. the component doing all the work.
	*/
	@Component
	private RepositorySystem repoSystem;

	/**
	* The current repository/network configuration of Maven.
	*/
	@Parameter( defaultValue = "${repositorySystemSession}", readonly = true )
	private RepositorySystemSession repoSession;

	/**
	* The project's remote repositories to use for the resolution.
	*/
	@Parameter( defaultValue = "${project.remoteProjectRepositories}", readonly = true )
	private List<RemoteRepository> remoteRepos;

	public void execute()
	throws MojoExecutionException
	{
	boolean mono = reactorProjects.size() == 1;

	if ( !mono )
	{
	// if module skips install and/or deploy
	if ( PluginUtil.isSkip( project ) )
	{
	getLog().info( "Skipping buildinfo for module that skips install and/or deploy" );
	return;
	}
	// if multi-module build, generate (aggregate) buildinfo only in last module
	MavenProject last = getLastProject();
	if ( project != last )
	{
	getLog().info( "Skipping intermediate buildinfo, aggregate will be " + last.getArtifactId() );
	return;
	}
	}

	// generate buildinfo
	Map<Artifact, String> artifacts = generateBuildinfo( mono );
	getLog().info( "Saved " + ( mono ? "" : "aggregate " ) + "info on build to " + buildinfoFile );

	// eventually attach
	if ( attach )
	{
	projectHelper.attachArtifact( project, "buildinfo", buildinfoFile );
	}
	else
	{
	getLog().info( "NOT adding buildinfo to the list of attached artifacts." );
	}

	// eventually check against reference
	if ( referenceRepo != null )
	{
	getLog().info( "Checking against reference build from " + referenceRepo + "..." );
	checkAgainstReference( mono, artifacts );
	}
	}

	/**
	* Generate buildinfo file.
	*
	* @param mono is it a mono-module build?
	* @return a Map of artifacts added to the build info with their associated property key prefix
	* (<code>outputs.[#module.].#artifact</code>)
	* @throws MojoExecutionException
	*/
	private Map<Artifact, String> generateBuildinfo( boolean mono )
	throws MojoExecutionException
	{
	MavenProject root = mono ? project : getExecutionRoot();

	buildinfoFile.getParentFile().mkdirs();

	try ( PrintWriter p = new PrintWriter( new BufferedWriter(
	new OutputStreamWriter( new FileOutputStream( buildinfoFile ), Charsets.ISO_8859_1 ) ) ) )
	{
	BuildInfoWriter bi = new BuildInfoWriter( getLog(), p, mono );

	bi.printHeader( root );

	// artifact(s) fingerprints
	if ( mono )
	{
	bi.printArtifacts( project );
	}
	else
	{
	for ( MavenProject project : reactorProjects )
	{
	if ( !PluginUtil.isSkip( project ) )
	{
	bi.printArtifacts( project );
	}
	}
	}

	return bi.getArtifacts();
	}
	catch ( IOException e )
	{
	throw new MojoExecutionException( "Error creating file " + buildinfoFile, e );
	}
	}

	/**
	* Check current build result with reference.
	*
	* @param mono is it a mono-module build?
	* @artifacts a Map of artifacts added to the build info with their associated property key prefix
	* (<code>outputs.[#module.].#artifact</code>)
	* @throws MojoExecutionException
	*/
	private void checkAgainstReference( boolean mono, Map<Artifact, String> artifacts )
	throws MojoExecutionException
	{
	MavenProject root = mono ? project : getExecutionRoot();
	File referenceDir = new File( root.getBuild().getDirectory(), "reference" );
	referenceDir.mkdirs();

	// download or create reference buildinfo
	File referenceBuildinfo = downloadOrCreateReferenceBuildinfo( mono, artifacts, referenceDir );

	// compare outputs from reference buildinfo vs actual
	compareWithReference( artifacts, referenceBuildinfo );
	}

	private File downloadOrCreateReferenceBuildinfo( boolean mono, Map<Artifact, String> artifacts, File referenceDir )
	throws MojoExecutionException
	{
	RemoteRepository repo = createReferenceRepo();

	ReferenceBuildinfoUtil rmb = new ReferenceBuildinfoUtil( getLog(), referenceDir, artifacts,
	artifactFactory, repoSystem, repoSession );

	return rmb.downloadOrCreateReferenceBuildinfo( repo, project, buildinfoFile, mono );
	}

	private void compareWithReference( Map<Artifact, String> artifacts, File referenceBuildinfo )
	throws MojoExecutionException
	{
	Properties actual = BuildInfoWriter.loadOutputProperties( buildinfoFile );
	Properties reference = BuildInfoWriter.loadOutputProperties( referenceBuildinfo );

	int ok = 0;
	List<String> okFilenames = new ArrayList<>();
	List<String> koFilenames = new ArrayList<>();
	File referenceDir = referenceBuildinfo.getParentFile();
	for ( Map.Entry<Artifact, String> entry : artifacts.entrySet() )
	{
	Artifact artifact = entry.getKey();
	String prefix = entry.getValue();

	if ( checkArtifact( artifact, prefix, reference, actual, referenceDir ) )
	{
	ok++;
	okFilenames.add( artifact.getFile().getName() );
	}
	else
	{
	koFilenames.add( artifact.getFile().getName() );
	}
	}

	int ko = artifacts.size() - ok;
	int missing = reference.size() / 3 /* 3 property keys par file: filename, length and checksums.sha512 */;

	if ( ko + missing > 0 )
	{
	getLog().warn( "Reproducible Build output summary: " + MessageUtils.buffer().success( ok + " files ok" )
	+ ", " + MessageUtils.buffer().failure( ko + " different" )
	+ ( ( missing == 0 ) ? "" : ( ", " + MessageUtils.buffer().warning( missing + " missing" ) ) ) );
	getLog().warn( "see " + MessageUtils.buffer().project( "diff " + relative( referenceBuildinfo ) + " "
	+ relative( buildinfoFile ) ).toString() );
	}
	else
	{
	getLog().info( "Reproducible Build output summary: " + MessageUtils.buffer().strong( ok + " files ok" ) );
	}

	if ( referenceCompareSave )
	{
	File compare = new File( buildinfoFile.getParentFile(), buildinfoFile.getName() + ".compare" );
	try ( PrintWriter p =
	new PrintWriter( new BufferedWriter( new OutputStreamWriter( new FileOutputStream( compare ),
	Charsets.ISO_8859_1 ) ) ) )
	{
	p.println( "version=" + project.getVersion() );
	p.println( "ok=" + ok );
	p.println( "ko=" + ko );
	p.println( "okFiles=\"" + StringUtils.join( okFilenames.iterator(), " " ) + '"' );
	p.println( "koFiles=\"" + StringUtils.join( koFilenames.iterator(), " " ) + '"' );
	getLog().info( "Reproducible Build comparison saved to " + compare );
	}
	catch ( IOException e )
	{
	throw new MojoExecutionException( "Error creating file " + compare, e );
	}
	}
	}

	private boolean checkArtifact( Artifact artifact, String prefix, Properties reference, Properties actual,
	File referenceDir )
	{
	String actualFilename = (String) actual.remove( prefix + ".filename" );
	String actualLength = (String) actual.remove( prefix + ".length" );
	String actualSha512 = (String) actual.remove( prefix + ".checksums.sha512" );

	String referencePrefix = findPrefix( reference, actualFilename );
	String referenceLength = (String) reference.remove( referencePrefix + ".length" );
	String referenceSha512 = (String) reference.remove( referencePrefix + ".checksums.sha512" );

	if ( !actualLength.equals( referenceLength ) )
	{
	getLog().warn( "size mismatch " + MessageUtils.buffer().strong( actualFilename )
	+ diffoscope( artifact, referenceDir ) );
	return false;
	}
	else if ( !actualSha512.equals( referenceSha512 ) )
	{
	getLog().warn( "sha512 mismatch " + MessageUtils.buffer().strong( actualFilename )
	+ diffoscope( artifact, referenceDir ) );
	return false;
	}
	return true;
	}

	private String diffoscope( Artifact a, File referenceDir )
	{
	File actual = a.getFile();
	File reference = new File( referenceDir, actual.getName() );
	return ": investigate with "
	+ MessageUtils.buffer().project( "diffoscope " + relative( reference ) + " " + relative( actual ) );
	}

	private String relative( File file )
	{
	return file.getPath().substring( getExecutionRoot().getBasedir().getPath().length() + 1 );
	}

	private static String findPrefix( Properties reference, String actualFilename )
	{
	for ( String name : reference.stringPropertyNames() )
	{
	if ( name.endsWith( ".filename" ) && actualFilename.equals( reference.getProperty( name ) ) )
	{
	reference.remove( name );
	return name.substring( 0, name.length() - ".filename".length() );
	}
	}
	return null;
	}

	private RemoteRepository createReferenceRepo()
	throws MojoExecutionException
	{
	if ( referenceRepo.contains( "::" ) )
	{
	// id::url
	int index = referenceRepo.indexOf( "::" );
	String id = referenceRepo.substring( 0, index );
	String url = referenceRepo.substring( index + 2 );
	return createDeploymentArtifactRepository( id, url );
	}
	else if ( referenceRepo.contains( ":" ) )
	{
	// url, will use default "reference" id
	return createDeploymentArtifactRepository( "reference", referenceRepo );
	}

	// id
	for ( RemoteRepository repo : remoteRepos )
	{
	if ( referenceRepo.equals( repo.getId() ) )
	{
	return repo;
	}
	}
	throw new MojoExecutionException( "Could not find repository with id = " + referenceRepo );
	}

	private static RemoteRepository createDeploymentArtifactRepository( String id, String url )
	{
	return new RemoteRepository.Builder( id, "default", url ).build();
	}

	private MavenProject getExecutionRoot()
	{
	for ( MavenProject p : reactorProjects )
	{
	if ( p.isExecutionRoot() )
	{
	return p;
	}
	}
	return null;
	}

	private MavenProject getLastProject()
	{
	int i = reactorProjects.size();
	while ( i > 0 )
	{
	MavenProject project = reactorProjects.get( --i );
	if ( !PluginUtil.isSkip( project ) )
	{
	return project;
	}
	}
	return null;
	}
	}