```
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] [                                                                                                                                                                                                                                        <=>               ]
```

{
    std::lock_guard lock(mutex);
    buffers.push_back(buffer);
    semaphore.set();
}
ConsumerBufferPtr StorageKafka::popReadBuffer()
{
    return popReadBuffer(std::chrono::milliseconds::zero());
}
ConsumerBufferPtr StorageKafka::popReadBuffer(std::chrono::milliseconds timeout)
{
    
    if (timeout == std::chrono::milliseconds::zero())
        semaphore.wait();
    else
    {
        if (!semaphore.tryWait(timeout.count()))
            return nullptr;
    }
    
    std::lock_guard lock(mutex);
    auto buffer = buffers.back();
    buffers.pop_back();
    return buffer;
}
ProducerBufferPtr StorageKafka::createWriteBuffer(const Block & header)