Implemented filter-branch tasks for each target repository

splitting/build.gradle

@@ -7,8 +7,11 @@ def allHistoryFiles = file(outputFilesDir + "/all-files.txt")
 def allProjects = file(outputFilesDir + "/all-projects.txt")
 def unmappedPaths = file(outputFilesDir + "/unmapped-paths.txt")
 def splittingFile = file("splitting.txt")
+def repositories = ["core", "extras", "lib", "xtend", "eclipse", "idea", "web", "maven", "xtext-website", "xtend-website"]
 
 task listFiles(type: Exec) {
+	group 'Splitting Helper'
+	description 'Creates a list of all files that have ever been in the git history.'
 	outputs.file allHistoryFiles
 	workingDir '..'
 	commandLine 'git', 'log', '--pretty=format:', '--name-only', '--diff-filter=A'
@@ -19,6 +22,8 @@ task listFiles(type: Exec) {
 }
 
 task findProjects(type: JavaExec) {
+	group 'Splitting Helper'
+	description 'Creates a list of all projects that have ever been in the git history.'
 	dependsOn(sourceSets.main.runtimeClasspath, listFiles)
 	inputs.file allHistoryFiles
 	outputs.files allProjects, unmappedPaths
@@ -28,9 +33,34 @@ task findProjects(type: JavaExec) {
 }
 
 task validateSplitting(type: JavaExec) {
+	group 'Splitting Helper'
+	description 'Checks splitting.txt for validity.'
 	dependsOn(sourceSets.main.runtimeClasspath, listFiles)
 	inputs.files splittingFile, allHistoryFiles
 	classpath = sourceSets.main.runtimeClasspath.filter{it.exists()}
 	main = "org.eclipse.xtext.splitting.ValidateSplitting"
 	args splittingFile, outputFilesDir
 }
+
+task generateRemovals(type: JavaExec) {
+	group 'Splitting Helper'
+	description 'Generates a list of files to remove for each repository.'
+	dependsOn(sourceSets.main.runtimeClasspath, validateSplitting)
+	inputs.files splittingFile
+	outputs.files repositories.collect{ file("$outputFilesDir/removals-${it}.txt") }
+	classpath = sourceSets.main.runtimeClasspath.filter{it.exists()}
+	main = "org.eclipse.xtext.splitting.GenerateRemovals"
+	args splittingFile, outputFilesDir
+}
+
+repositories.each { targetRepo ->
+	def removalsFile = file("$outputFilesDir/removals-${targetRepo}.txt")
+	task "${targetRepo}FilterBranch"(type: Exec) {
+		group 'Git History Manipulation'
+		description "Filters the git history for the target repository ${targetRepo}."
+		dependsOn(generateRemovals)
+		inputs.file removalsFile
+		workingDir '..'
+		commandLine 'splitting/git-filter-branch.sh', removalsFile.path
+	}
+}

splitting/git-filter-branch.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+REMOVALS=`cat $1 | tr '\n' ' '`
+git filter-branch -f --prune-empty \
+    --index-filter "git rm -qrf --cached --ignore-unmatch $REMOVALS" \
+    --parent-filter splitting/parent-filter.sh \
+    HEAD

splitting/parent-filter.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+read INPUT
+if [ -n "$INPUT" ]
+then
+  SHOW_BRANCH=`git show-branch --independent ${INPUT//-p/}`
+  for PARENT in $SHOW_BRANCH
+  do
+    echo -n "-p $PARENT "
+  done
+fi

splitting/splitting.txt

@@ -247,6 +247,7 @@ plugins/org.eclipse.emf.index >> delete
 plugins/org.eclipse.emf.index.ui >> delete
 plugins/org.eclipse.xtext.doc.manual >> delete
 settings.gradle >> delete
+splitting >> delete
 test.txt >> delete
 tests/.settings >> delete
 tests/build.gradle >> delete

splitting/src/org/eclipse/xtext/splitting/FindProjects.java

@@ -26,12 +26,12 @@ public class FindProjects {
 
 	public static void main(String[] args) {
 		if (args.length != 1) {
-			fail("Expected path to working directory as argument.");
+			fail("Expected path to output files as argument.");
 		}
-		String workingDir = args[0];
+		String outputDir = args[0];
 		try {
 			final Directory root = new Directory(".", null);
-			try (BufferedReader reader = new BufferedReader(new FileReader(workingDir + "/" + ALL_FILES))) {
+			try (BufferedReader reader = new BufferedReader(new FileReader(outputDir + "/" + ALL_FILES))) {
 				// Gather all paths in a directory structure
 				String line;
 				while ((line = reader.readLine()) != null) {
@@ -64,7 +64,7 @@ public class FindProjects {
 			
 			// Write the collected projects into a file
 			Collections.sort(projects);
-			try (FileWriter writer = new FileWriter(workingDir + "/" + ALL_PROJECTS)) {
+			try (FileWriter writer = new FileWriter(outputDir + "/" + ALL_PROJECTS)) {
 				for (Directory project : projects) {
 					writer.write(project.toString());
 					writer.write('\n');
@@ -73,7 +73,7 @@ public class FindProjects {
 			
 			// Write the unmapped paths into another file
 			Collections.sort(otherPaths);
-			try (FileWriter writer = new FileWriter(workingDir + "/" + UNMAPPED_PATHS)) {
+			try (FileWriter writer = new FileWriter(outputDir + "/" + UNMAPPED_PATHS)) {
 				for (DirectoryEntry path : otherPaths) {
 					writer.write(path.toString());
 					writer.write('\n');

splitting/src/org/eclipse/xtext/splitting/GenerateRemovals.java

@@ -0,0 +1,77 @@
+/*******************************************************************************
+ * Copyright (c) 2016 TypeFox GmbH (http://www.typefox.io) 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.xtext.splitting;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class GenerateRemovals {
+
+	public static void main(String[] args) {
+		if (args.length != 2) {
+			fail("Expected paths to splitting.txt and output files as arguments.");
+		}
+		String outputDir = args[1];
+		try {
+			final Map<String, List<String>> removalPaths = new HashMap<>();
+			for (String targetRepo : ValidateSplitting.REPOSITORIES) {
+				removalPaths.put(targetRepo, new ArrayList<>());
+			}
+			
+			// Gather paths to be removed from the history for each target repository
+			try (BufferedReader reader = new BufferedReader(new FileReader(args[0]))) {
+				String line;
+				while ((line = reader.readLine()) != null) {
+					if (!line.isEmpty()) {
+						String[] parts = line.split(">>");
+						String[] repos = parts[1].split(",");
+						for (String targetRepo :  ValidateSplitting.REPOSITORIES) {
+							boolean isInTargetRepo = false;
+							for (String repo : repos) {
+								if (targetRepo.equals(repo.trim())) {
+									isInTargetRepo = true;
+									break;
+								}
+							}
+							if (!isInTargetRepo) {
+								String path = parts[0].trim();
+								removalPaths.get(targetRepo).add(path);
+							}
+						}
+					}
+				}
+			}
+			
+			// Write a removal list for each target repository
+			for (String targetRepo : ValidateSplitting.REPOSITORIES) {
+				try (FileWriter writer = new FileWriter(outputDir + "/removals-" + targetRepo + ".txt")) {
+					for (String path : removalPaths.get(targetRepo)) {
+						writer.write(path);
+						writer.write('\n');
+					}
+				}
+			}
+			
+		} catch (Exception e) {
+			e.printStackTrace();
+			System.exit(1);
+		}
+	}
+	
+	private static void fail(String message) {
+		System.err.print("ERROR: ");
+		System.err.println(message);
+		System.exit(1);
+	}
+
+}

splitting/src/org/eclipse/xtext/splitting/ValidateSplitting.java

@@ -12,23 +12,24 @@ import java.io.FileReader;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 public class ValidateSplitting {
 	
-	public static final Set<String> REPOSITORIES = Collections.unmodifiableSet(new HashSet<>(Arrays.asList(
-		"core", "extras", "lib", "xtend", "eclipse", "idea", "web", "maven", "xtext-website", "xtend-website" 
+	public static final Set<String> REPOSITORIES = Collections.unmodifiableSet(new LinkedHashSet<>(Arrays.asList(
+		"core", "extras", "lib", "xtend", "eclipse", "idea", "web", "maven", "xtext-website", "xtend-website"
 	)));
 	
 	public static final String DELETE = "delete";
 	
 	public static void main(String[] args) {
 		if (args.length != 2) {
-			fail("Expected paths to splitting.txt and working directory as arguments.");
+			fail("Expected paths to splitting.txt and output files as arguments.");
 		}
-		String workingDir = args[1];
+		String outputDir = args[1];
 		try {
 			
 			// Validate repositories and gather all paths from the splitting file
@@ -59,7 +60,7 @@ public class ValidateSplitting {
 			
 			// Check whether each file has a specified path as prefix
 			final Pattern segmentPattern = Pattern.compile("/");
-			try (BufferedReader reader = new BufferedReader(new FileReader(workingDir + "/" + FindProjects.ALL_FILES))) {
+			try (BufferedReader reader = new BufferedReader(new FileReader(outputDir + "/" + FindProjects.ALL_FILES))) {
 				String line;
 				while ((line = reader.readLine()) != null) {
 					if (!line.isEmpty()) {