static void renameFile()

in src/main/java/com/spotify/sparkey/Util.java [270:307]
33 lines of code
9 McCabe index (conditional complexity)

  static void renameFile(File srcFile, File destFile) throws IOException {
    if (!srcFile.exists()) {
      throw new FileNotFoundException(srcFile.getPath());
    }
    if (srcFile.equals(destFile)) {
      return;
    }
    if (!destFile.exists()) {
      rename(srcFile, destFile);
      return;
    }

    File backupFile = new File(destFile.getParent(), destFile.getName() + "-backup" + UUID.randomUUID().toString());
    if (backupFile.exists()) {
      // Edge case, but let's be safe.
      throw new IOException("Expected duplicate temporary backup file: " + backupFile.getPath());
    }
    rename(destFile, backupFile);
    if (destFile.exists()) {
      // This is strange, it should be renamed by now. But let's be safe.
      throw new IOException("Unexpected file still existing: " + destFile.getPath() + ", should have been renamed to: " + backupFile.getPath());
    }

    try {
      rename(srcFile, destFile);
      if (!backupFile.delete()) {
        log.warn("Could not delete backup file: " + backupFile.getPath());
      }
    } catch (IOException e) {
      // roll back failed rename
      try {
        rename(backupFile, destFile);
      } catch (IOException e2) {
        log.warn("Failed to roll back failed rename - file still exists: {}", backupFile);
      }
      throw new IOException("Could not rename " + srcFile.getPath() + " to " + destFile.getPath(), e);
    }
  }