380872 sourceref provider for jgitrefs/changes/54/8154/1

Implement SourceReferenceProvider
for SCM type "git".
Use jgit to find the git repo root
and calculate path of project basedir
relative to the repo root.
Add it as ";path=..." header attribute.
Resolve HEAD commit and add it
as ";commitId=<SHA1>" attribute
If HEAD is also a tag, add it as
";tag=..." attribute.

To enable Eclipse-SourceReferences generation
for projects using git, you have to:

1. declare ${tycho.scmUrl} in your (parent)
   pom using maven SCM format [1]

2. Configure tycho-packaging-plugin to
   generate source reference headers and
   add a dependency to tycho-sourceref-jgit:

<plugin>
 <groupId>org.eclipse.tycho</groupId>
 <artifactId>tycho-packaging-plugin</artifactId>
 <version>${tycho-version}</version>
 <configuration>
  <sourceReferences>
   <generate>true</generate>
  </sourceReferences>
 </configuration>
 <dependencies>
  <dependency>
   <groupId>org.eclipse.tycho.extras</groupId>
   <artifactId>tycho-sourceref-jgit</artifactId>
   <version>${tycho-extras-version}</version>
  </dependency>
 </dependencies>
</plugin>

[1] http://maven.apache.org/scm/scm-url-format.html

Change-Id: I447d7dc244e6d73c797bf43877b13f9e49fd0ded

5 files changed, 302 insertions, 5 deletions

diff --git a/pom.xml b/pom.xml
index 103ab89..fff38d7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -73,6 +73,7 @@
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<maven-version>3.0</maven-version>
+		<jgit-version>2.0.0.201206130900-r</jgit-version>
 		<tycho-version>0.16.0-SNAPSHOT</tycho-version>
 	</properties>
 
@@ -84,6 +85,7 @@
         <module>tycho-source-feature-plugin</module>
         <module>pack200</module>
         <module>tycho-buildtimestamp-jgit</module>
+        <module>tycho-sourceref-jgit</module>
 		<module>target-platform-validation-plugin</module>
 	</modules>
 
@@ -140,6 +142,17 @@
 				<artifactId>tycho-testing-harness</artifactId>
 				<version>${tycho-version}</version>
 			</dependency>
+			<dependency>
+				<groupId>org.eclipse.jgit</groupId>
+				<artifactId>org.eclipse.jgit</artifactId>
+				<version>${jgit-version}</version>
+			</dependency>
+			<dependency>
+				<groupId>junit</groupId>
+				<artifactId>junit</artifactId>
+				<version>4.10</version>
+				<scope>test</scope>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>
 
diff --git a/tycho-buildtimestamp-jgit/pom.xml b/tycho-buildtimestamp-jgit/pom.xml
index 8503ff2..ba079dc 100644
--- a/tycho-buildtimestamp-jgit/pom.xml
+++ b/tycho-buildtimestamp-jgit/pom.xml
@@ -19,10 +19,6 @@
   </parent>
   <artifactId>tycho-buildtimestamp-jgit</artifactId>
 
-  <properties>
-    <jgit-version>2.0.0.201206130900-r</jgit-version>
-  </properties>
-
   <dependencies>
     <dependency>
       <groupId>org.eclipse.tycho</groupId>
@@ -32,7 +28,6 @@
     <dependency>
       <groupId>org.eclipse.jgit</groupId>
       <artifactId>org.eclipse.jgit</artifactId>
-      <version>${jgit-version}</version>
     </dependency>
   </dependencies>
 
diff --git a/tycho-sourceref-jgit/pom.xml b/tycho-sourceref-jgit/pom.xml
new file mode 100644
index 0000000..b42fed9
--- a/dev/null
+++ b/tycho-sourceref-jgit/pom.xml
@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+- Copyright (c) 2012 SAP AG 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
+-
+- Contributors:
+-    SAP AG - initial API and implementation
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		<modelVersion>4.0.0</modelVersion>
+		<parent>
+				<groupId>org.eclipse.tycho.extras</groupId>
+				<artifactId>tycho-extras</artifactId>
+				<version>0.16.0-SNAPSHOT</version>
+		</parent>
+		<artifactId>tycho-sourceref-jgit</artifactId>
+
+		<dependencies>
+				<dependency>
+						<groupId>org.eclipse.tycho</groupId>
+						<artifactId>tycho-packaging-plugin</artifactId>
+						<version>${tycho-version}</version>
+				</dependency>
+				<dependency>
+						<groupId>org.eclipse.jgit</groupId>
+						<artifactId>org.eclipse.jgit</artifactId>
+				</dependency>
+				<dependency>
+						<groupId>junit</groupId>
+						<artifactId>junit</artifactId>
+						<scope>test</scope>
+				</dependency>
+		</dependencies>
+
+		<build>
+				<plugins>
+						<plugin>
+								<groupId>org.apache.maven.plugins</groupId>
+								<artifactId>maven-compiler-plugin</artifactId>
+								<configuration>
+										<source>1.5</source>
+										<target>1.5</target>
+								</configuration>
+						</plugin>
+
+						<plugin>
+								<groupId>org.codehaus.plexus</groupId>
+								<artifactId>plexus-component-metadata</artifactId>
+								<version>1.5.5</version>
+								<executions>
+										<execution>
+												<goals>
+														<goal>generate-metadata</goal>
+														<goal>generate-test-metadata</goal>
+												</goals>
+										</execution>
+								</executions>
+						</plugin>
+				</plugins>
+		</build>
+
+</project>
\ No newline at end of file
diff --git a/tycho-sourceref-jgit/src/main/java/org/eclipse/tycho/extras/sourceref/jgit/JGitSourceReferencesProvider.java b/tycho-sourceref-jgit/src/main/java/org/eclipse/tycho/extras/sourceref/jgit/JGitSourceReferencesProvider.java
new file mode 100644
index 0000000..182a729
--- a/dev/null
+++ b/tycho-sourceref-jgit/src/main/java/org/eclipse/tycho/extras/sourceref/jgit/JGitSourceReferencesProvider.java
@@ -0,0 +1,146 @@
+/*******************************************************************************
+ * Copyright (c) 2012 SAP AG 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
+ *
+ * Contributors:
+ *    SAP AG - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.tycho.extras.sourceref.jgit;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URI;
+
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.project.MavenProject;
+import org.codehaus.plexus.component.annotations.Component;
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.errors.AmbiguousObjectException;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.RepositoryBuilder;
+import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
+import org.eclipse.tycho.packaging.sourceref.ScmUrl;
+import org.eclipse.tycho.packaging.sourceref.SourceReferencesProvider;
+
+@Component( role = SourceReferencesProvider.class, hint = "git" )
+public class JGitSourceReferencesProvider
+    implements SourceReferencesProvider
+{
+
+    public String getSourceReferencesHeader( MavenProject project, ScmUrl scmUrl )
+        throws MojoExecutionException
+    {
+        File basedir = project.getBasedir().getAbsoluteFile();
+        FileRepositoryBuilder builder =
+            new FileRepositoryBuilder().readEnvironment().findGitDir( basedir ).setMustExist( true );
+        Repository repo;
+        Git git;
+        try
+        {
+            repo = builder.build();
+            git = Git.wrap( repo );
+        }
+        catch ( IOException e )
+        {
+            throw new MojoExecutionException( "IO exception trying to create git repo ", e );
+        }
+        ObjectId head = resolveHead( repo );
+
+        StringBuilder result = new StringBuilder( scmUrl.getUrl() );
+        result.append( ";path=\"" );
+        result.append( getRelativePath( basedir, repo.getDirectory().getParentFile() ) );
+        result.append( "\"" );
+
+        String tag = findTagForHead( git, head );
+        if ( tag != null )
+        {
+            // may contain e.g. spaces, so we quote it
+            result.append( ";tag=\"" );
+            result.append( tag );
+            result.append( "\"" );
+        }
+        result.append( ";commitId=" );
+        result.append( head.getName() );
+        return result.toString();
+    }
+
+    private ObjectId resolveHead( Repository repo )
+        throws MojoExecutionException
+    {
+        ObjectId head;
+        try
+        {
+            head = repo.resolve( Constants.HEAD );
+        }
+        catch ( AmbiguousObjectException e )
+        {
+            throw new MojoExecutionException( "exception trying resolve HEAD", e );
+        }
+        catch ( IOException e )
+        {
+            throw new MojoExecutionException( "exception trying resolve HEAD", e );
+        }
+        return head;
+    }
+
+    private String findTagForHead( Git git, ObjectId head )
+        throws MojoExecutionException
+    {
+        String tag = null;
+        try
+        {
+            for ( Ref ref : git.tagList().call() )
+            {
+                ObjectId objectId = ref.getPeeledObjectId();
+                if ( objectId == null )
+                {
+                    objectId = ref.getObjectId();
+                }
+                if ( head.equals( objectId ) )
+                {
+                    tag = ref.getName();
+                    if ( tag.startsWith( Constants.R_TAGS ) )
+                    {
+                        tag = tag.substring( Constants.R_TAGS.length() );
+                    }
+                    break;
+                }
+            }
+        }
+        catch ( GitAPIException e )
+        {
+            throw new MojoExecutionException( "exception trying to get tag list", e );
+        }
+        return tag;
+    }
+
+    String getRelativePath( File subDir, File parentDir )
+        throws MojoExecutionException
+    {
+        URI subDirUri = subDir.toURI();
+        URI relativeUri = parentDir.toURI().relativize( subDirUri );
+        if ( relativeUri.equals( subDirUri ) )
+        {
+            throw new MojoExecutionException( "Could not find a common basedir of " + subDir + " and " + parentDir );
+        }
+        String relative = relativeUri.getPath();
+        // remove surrounding slashes
+        if ( relative.startsWith( "/" ) )
+        {
+            relative = relative.substring( 1 );
+        }
+        if ( relative.endsWith( "/" ) )
+        {
+            relative = relative.substring( 0, relative.length() - 1 );
+        }
+        return relative;
+    }
+
+}
diff --git a/tycho-sourceref-jgit/src/test/java/org/eclipse/tycho/extras/sourceref/jgit/JGitSourceReferencesProviderTest.java b/tycho-sourceref-jgit/src/test/java/org/eclipse/tycho/extras/sourceref/jgit/JGitSourceReferencesProviderTest.java
new file mode 100644
index 0000000..be05656
--- a/dev/null
+++ b/tycho-sourceref-jgit/src/test/java/org/eclipse/tycho/extras/sourceref/jgit/JGitSourceReferencesProviderTest.java
@@ -0,0 +1,77 @@
+/*******************************************************************************
+ * Copyright (c) 2012 SAP AG 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
+ *
+ * Contributors:
+ *     SAP AG - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.tycho.extras.sourceref.jgit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.util.Properties;
+
+import org.apache.maven.model.Scm;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.project.MavenProject;
+import org.eclipse.tycho.packaging.sourceref.ScmUrl;
+import org.hamcrest.CoreMatchers;
+import org.junit.Test;
+import org.junit.matchers.JUnitMatchers;
+
+public class JGitSourceReferencesProviderTest
+{
+
+    @Test
+    public void testGetRelativePathWithDots() throws MojoExecutionException
+    {
+        JGitSourceReferencesProvider provider = new JGitSourceReferencesProvider();
+        File projectBasedir = new File("/foo/../test/bar/baz" );
+        File repoRoot = new File("/test/foo/../bar");
+        assertEquals( "baz", provider.getRelativePath( projectBasedir, repoRoot));
+    }
+
+    @Test
+    public void testGetRelativePathWithSpaces() throws MojoExecutionException
+    {
+        JGitSourceReferencesProvider provider = new JGitSourceReferencesProvider();
+        File projectBasedir = new File("/foo/test me/bar/baz" );
+        File repoRoot = new File("/foo/test me/");
+        assertEquals( "bar/baz", provider.getRelativePath( projectBasedir, repoRoot));
+    }
+
+    @Test(expected = MojoExecutionException.class)
+    public void testGetRelativePathNoCommonBasedir() throws MojoExecutionException
+    {
+        JGitSourceReferencesProvider provider = new JGitSourceReferencesProvider();
+        File projectBasedir = new File("/foo/test/bar" );
+        File repoRoot = new File("/baz");
+        provider.getRelativePath( projectBasedir, repoRoot);
+    }
+
+    @Test
+    public void testGetSourceReferencesHeader() throws MojoExecutionException
+    {
+        JGitSourceReferencesProvider provider = new JGitSourceReferencesProvider();
+        MavenProject mockProject = new MavenProject();
+        ScmUrl scmUrl = new ScmUrl( properties("scm:git:foo") );
+        mockProject.setFile( new File("src/test/resources/pom.xml").getAbsoluteFile() );
+        String sourceRef = provider.getSourceReferencesHeader( mockProject , scmUrl);
+        assertTrue(  sourceRef.startsWith( "scm:git:foo;path=\"tycho-sourceref-jgit/src/test/resources\""));
+    }
+
+    private Properties properties( String scmUrl )
+    {
+        Properties p = new Properties();
+        p.setProperty( "tycho.scmUrl", scmUrl );
+        return p;
+    }
+
+}