private boolean compressOldFiles() {
        long now = System.currentTimeMillis();
        int count = 0;
        for (LogFile lf : knownFiles) {
            // avoid compressing entire archive at once
            if (lf.canCompress(now) && (count++ < 5)) {
                compress(lf.path);
            }
        }
        return count > 0;
    }
Creates an instance of FilesArchive managing the given directory
logserver/src/main/java/com/yahoo/logserver/handlers/archive/FilesArchived.java