ClickHouse/dbms/src/IO/tests/cached_compressed_read_buffer.cpp

#include <iostream>
#include <iomanip>

#include <DB/IO/CachedCompressedReadBuffer.h>
#include <DB/IO/WriteBufferFromFile.h>
#include <DB/IO/copyData.h>

#include <statdaemons/Stopwatch.h>


int main(int argc, char ** argv)
{
	using namespace DB;
	
	try
	{
		UncompressedCache cache(1024);
		std::string path = argv[1];

		std::cerr << std::fixed << std::setprecision(3);

		size_t hits = 0;
		size_t misses = 0;

		{
			Stopwatch watch;
			CachedCompressedReadBuffer in(path, &cache);
			WriteBufferFromFile out("/dev/null");
			copyData(in, out);

			std::cerr << "Elapsed: " << watch.elapsedSeconds() << std::endl;
		}

		cache.getStats(hits, misses);
		std::cerr << "Hits: " << hits << ", misses: " << misses << std::endl;

		{
			Stopwatch watch;
			CachedCompressedReadBuffer in(path, &cache);
			WriteBufferFromFile out("/dev/null");
			copyData(in, out);

			std::cerr << "Elapsed: " << watch.elapsedSeconds() << std::endl;
		}

		cache.getStats(hits, misses);
		std::cerr << "Hits: " << hits << ", misses: " << misses << std::endl;
	}
	catch (const Exception & e)
	{
		std::cerr << e.what() << ", " << e.displayText() << std::endl;
		return 1;
	}

	return 0;
}