```
ubuntu@ip-172-31-79-147:/opt/downloads$ clickhouse-local --max_threads 8 --query "WITH parseDateTimeBestEffort(extract(_path, 'pageviews-([\\d\\-]+)\\.gz$')) AS time, splitByChar(' ', line) AS values, splitByChar('.', values[1]) AS projects SELECT time, projects[1] AS project, projects[2] AS subproject, values[2] AS path, (values[3])::UInt64 AS hits FROM file('pageviews*.gz', LineAsString) WHERE length(values) >= 3" | pv > /dev/null
^C01GiB 0:01:08 [ 129MiB/s] [                                                                                                                                                                   <=>                                                                                    ]

ubuntu@ip-172-31-79-147:/opt/downloads$ clickhouse-local --max_threads 8 --query "WITH parseDateTimeBestEffort(extract(toLowCardinality(_path), 'pageviews-([\\d\\-]+)\\.gz$')) AS time, splitByChar(' ', line) AS values, splitByChar('.', values[1]) AS projects SELECT time, projects[1] AS project, projects[2] AS subproject, values[2] AS path, (values[3])::UInt64 AS hits FROM file('pageviews*.gz', LineAsString) WHERE length(values) >= 3" | pv > /dev/null
^C46GiB 0:00:48 [ 175MiB/s] [                                                                                                                                                                                                                                        <=>               ]
```

using OutputFormatPtr = std::shared_ptr<IOutputFormat>;
class StorageS3Source::DisclosedGlobIterator::Impl
{
public:
    Impl(Aws::S3::S3Client & client_, const S3::URI & globbed_uri_)
        : client(client_), globbed_uri(globbed_uri_)
    {
        if (globbed_uri.bucket.find_first_of("*?{") != globbed_uri.bucket.npos)
            throw Exception("Expression can not have wildcards inside bucket name", ErrorCodes::UNEXPECTED_EXPRESSION);
        const String key_prefix = globbed_uri.key.substr(0, globbed_uri.key.find_first_of("*?{"));
        
        if (key_prefix.size() == globbed_uri.key.size())
        {
            buffer.emplace_back(globbed_uri.key);
            buffer_iter = buffer.begin();
            is_finished = true;
            return;
        }
        request.SetBucket(globbed_uri.bucket);
        request.SetPrefix(key_prefix);
        matcher = std::make_unique<re2::RE2>(makeRegexpPatternFromGlobs(globbed_uri.key));
        fillInternalBufferAssumeLocked();
    }
    String next()