File validateFilesAction()

in server/src/main/java/org/apache/cassandra/sidecar/restore/RestoreRangeTask.java [420:462]
32 lines of code
8 McCabe index (conditional complexity)

    File validateFilesAction(File directory) throws RestoreJobException, IOException
    {
        File manifestFile = new File(directory, RestoreSliceManifest.MANIFEST_FILE_NAME);
        RestoreSliceManifest manifest = RestoreSliceManifest.read(manifestFile);

        if (manifest.isEmpty())
        {
            throw new RestoreJobFatalException("The downloaded slice has no data. " +
                                               "Directory: " + directory);
        }

        // validate the SSTable ranges with the owning range of the node and remove the out-of-range sstables
        if (range.job().isManagedBySidecar())
        {
            removeOutOfRangeSSTables(directory, manifest);
        }

        Map<String, String> checksums = manifest.mergeAllChecksums();

        // exclude the manifest file
        File[] files = directory.listFiles((dir, name) -> !name.equals(RestoreSliceManifest.MANIFEST_FILE_NAME));
        if (files == null || files.length != checksums.size())
        {
            String msg = "Number of files does not match. Expected: " + checksums.size() +
                         "; Actual: " + (files == null ? 0 : files.length) +
                         "; Directory: " + directory;
            throw new RestoreJobFatalException(msg);
        }

        compareChecksums(checksums, files);

        // capture the data component size of sstables
        for (File file : files)
        {
            if (file.getName().endsWith("-Data.db"))
            {
                instanceMetrics.restore().dataSSTableComponentSize.metric.update(file.length());
            }
        }

        // all files match with the provided checksums
        return directory;
    }