Implement bz2 support and test

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/repo/FSRepoStore.java

@@ -60,7 +60,7 @@ public class FSRepoStore implements RepoStore {
     @Override
     public InputStream bzip2Project(String projectName) throws IOException {
         Preconditions.checkArgument(Project.isValidProjectName(projectName));
-        return Tar.tar(getDotGitForProject(projectName));
+        return Tar.bz2.zip(getDotGitForProject(projectName));
     }
 
     @Override
@@ -76,7 +76,7 @@ public class FSRepoStore implements RepoStore {
     ) throws IOException {
         Preconditions.checkArgument(Project.isValidProjectName(projectName));
         Preconditions.checkState(getDirForProject(projectName).mkdirs());
-        Tar.untar(dataStream, getDirForProject(projectName));
+        Tar.bz2.unzip(dataStream, getDirForProject(projectName));
     }
 
     private File getDirForProject(String projectName) {

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/Tar.java

@@ -4,6 +4,8 @@ import com.google.api.client.repackaged.com.google.common.base.Preconditions;
 import org.apache.commons.compress.archivers.ArchiveEntry;
 import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
 import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
+import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
+import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream;
 import org.apache.commons.compress.utils.IOUtils;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.output.ByteArrayOutputStream;
@@ -17,18 +19,76 @@ import java.nio.file.Paths;
  */
 public class Tar {
 
+    public static class bz2 {
+
+        public static InputStream zip(
+                File fileOrDir
+        ) throws IOException {
+            ByteArrayOutputStream target = new ByteArrayOutputStream();
+            try (OutputStream bzip2 = new BZip2CompressorOutputStream(target)) {
+                tarTo(fileOrDir, bzip2);
+            }
+            return target.toInputStream();
+        }
+
+        public static void unzip(
+                InputStream tarbz2,
+                File parentDir
+        ) throws IOException {
+            try (InputStream tar = new BZip2CompressorInputStream(tarbz2)) {
+                untar(tar, parentDir);
+            }
+        }
+
+    }
+
     private Tar() {}
 
     public static InputStream tar(File fileOrDir) throws IOException {
-        ByteArrayOutputStream bout = new ByteArrayOutputStream();
-        TarArchiveOutputStream tout = new TarArchiveOutputStream(bout);
-        addTarEntry(
-                tout,
-                Paths.get(fileOrDir.getParentFile().getAbsolutePath()),
-                fileOrDir
-        );
-        tout.close();
-        return new ByteArrayInputStream(bout.toByteArray());
+        ByteArrayOutputStream target = new ByteArrayOutputStream();
+        tarTo(fileOrDir, target);
+        return target.toInputStream();
+    }
+
+    public static void tarTo(
+            File fileOrDir,
+            OutputStream target
+    ) throws IOException {
+        try (TarArchiveOutputStream tout = new TarArchiveOutputStream(target)) {
+            addTarEntry(
+                    tout,
+                    Paths.get(fileOrDir.getParentFile().getAbsolutePath()),
+                    fileOrDir
+            );
+            tout.close();
+        }
+    }
+
+    public static void untar(
+            InputStream tar,
+            File parentDir
+    ) throws IOException {
+        TarArchiveInputStream tin = new TarArchiveInputStream(tar);
+        ArchiveEntry e;
+        while ((e = tin.getNextEntry()) != null) {
+            File f = new File(parentDir, e.getName());
+            f.setLastModified(e.getLastModifiedDate().getTime());
+            f.getParentFile().mkdirs();
+            if (e.isDirectory()) {
+                f.mkdir();
+                continue;
+            }
+            long size = e.getSize();
+            Preconditions.checkArgument(
+                    size > 0 && size < Integer.MAX_VALUE,
+                    "file too big: tarTo should have thrown an IOException"
+            );
+            try (OutputStream out = new FileOutputStream(f)) {
+                /* TarInputStream pretends each
+                   entry's EOF is the stream's EOF */
+                IOUtils.copy(tin, out);
+            }
+        }
     }
 
     private static void addTarEntry(
@@ -79,28 +139,4 @@ public class Tar {
         tout.closeArchiveEntry();
     }
 
-    public static void untar(InputStream tar, File parentDir) throws IOException {
-        TarArchiveInputStream tin = new TarArchiveInputStream(tar);
-        ArchiveEntry e;
-        while ((e = tin.getNextEntry()) != null) {
-            File f = new File(parentDir, e.getName());
-            f.setLastModified(e.getLastModifiedDate().getTime());
-            f.getParentFile().mkdirs();
-            if (e.isDirectory()) {
-                f.mkdir();
-                continue;
-            }
-            long size = e.getSize();
-            Preconditions.checkArgument(
-                    size > 0 && size < Integer.MAX_VALUE,
-                    "file too big: tar should have thrown an IOException"
-            );
-            try (OutputStream out = new FileOutputStream(f)) {
-                /* TarInputStream pretends each
-                   entry's EOF is the stream's EOF */
-                IOUtils.copy(tin, out);
-            }
-        }
-    }
-
 }

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/util/TarTest.java

@@ -19,6 +19,7 @@ import static org.junit.Assert.assertTrue;
 public class TarTest {
 
     private File testDir;
+    private File tmpDir;
 
     @Before
     public void setup() throws IOException {
@@ -29,17 +30,23 @@ public class TarTest {
                 "src/test/resources/uk/ac/ic/wlgitbridge/util/TarTest/testdir"
         );
         FileUtils.copyDirectory(resdir.toFile(), testDir);
+        tmpDir = tmpFolder.newFolder();
     }
 
     @Test
     public void tarAndUntarProducesTheSameResult() throws IOException {
         InputStream tar = Tar.tar(testDir);
-        TemporaryFolder tmpF = new TemporaryFolder();
-        tmpF.create();
-        File parentDir = tmpF.newFolder();
-        Tar.untar(tar, parentDir);
-        File untarred = new File(parentDir, "testdir");
+        Tar.untar(tar, tmpDir);
+        File untarred = new File(tmpDir, "testdir");
         assertTrue(Files.contentsAreEqual(testDir, untarred));
     }
 
+    @Test
+    public void tarbz2AndUntarbz2ProducesTheSameResult() throws IOException {
+        InputStream tarbz2 = Tar.bz2.zip(testDir);
+        Tar.bz2.unzip(tarbz2, tmpDir);
+        File unzipped = new File(tmpDir, "testdir");
+        assertTrue(Files.contentsAreEqual(testDir, unzipped));
+    }
+
 }