void put(final URI uri, ArtifactData data) throws Exception {
   reporter.trace("put %s %s", uri, data);
   File tmp = createTempFile(repoDir, "mtp", ".whatever");
   tmp.deleteOnExit();
   try {
     copy(uri.toURL(), tmp);
     byte[] sha = SHA1.digest(tmp).digest();
     reporter.trace("SHA %s %s", uri, Hex.toHexString(sha));
     ArtifactData existing = get(sha);
     if (existing != null) {
       reporter.trace("existing");
       xcopy(existing, data);
       return;
     }
     File meta = new File(repoDir, Hex.toHexString(sha) + ".json");
     File file = new File(repoDir, Hex.toHexString(sha));
     rename(tmp, file);
     reporter.trace("file %s", file);
     data.file = file.getAbsolutePath();
     data.sha = sha;
     data.busy = false;
     CommandData cmddata = parseCommandData(data);
     if (cmddata.bsn != null) {
       data.name = cmddata.bsn + "-" + cmddata.version;
     } else data.name = Strings.display(cmddata.title, cmddata.bsn, cmddata.name, uri);
     codec.enc().to(meta).put(data);
     reporter.trace("TD = " + data);
   } finally {
     tmp.delete();
     reporter.trace("puted %s %s", uri, data);
   }
 }
  /**
   * Garbage collect repository
   *
   * @throws Exception
   */
  public void gc() throws Exception {
    HashSet<byte[]> deps = new HashSet<byte[]>();

    // deps.add(SERVICE_JAR_FILE);

    for (File cmd : commandDir.listFiles()) {
      CommandData data = getData(CommandData.class, cmd);
      addDependencies(deps, data);
    }

    for (File service : serviceDir.listFiles()) {
      File dataFile = new File(service, "data");
      ServiceData data = getData(ServiceData.class, dataFile);
      addDependencies(deps, data);
    }

    int count = 0;
    for (File f : repoDir.listFiles()) {
      String name = f.getName();
      if (!deps.contains(name)) {
        if (!name.endsWith(".json")
            || !deps.contains(name.substring(0, name.length() - ".json".length()))) { // Remove
          // json
          // files
          // only
          // if
          // the
          // bin
          // is
          // going
          // as
          // well
          f.delete();
          count++;
        } else {

        }
      }
    }
    System.out.format("Garbage collection done (%d file(s) removed)%n", count);
  }