dbms: Compression: fixed.

This commit is contained in:
Alexey Milovidov 2009-08-07 14:14:06 +00:00
parent a7cf7ab36f
commit e4f8762e20
3 changed files with 82 additions and 5 deletions

View File

@ -59,11 +59,17 @@ int DecompressingStreamBuf::readFromDevice(char * buffer, std::streamsize length
pos_in_buffer = 0;
if (!p_istr->good())
{
p_istr = 0;
return bytes_processed;
}
}
size_t bytes_to_copy = std::min(uncompressed_buffer.size() - pos_in_buffer, static_cast<size_t>(length));
memcpy(buffer, &uncompressed_buffer[0], bytes_to_copy);
size_t bytes_to_copy = std::min(
uncompressed_buffer.size() - pos_in_buffer,
static_cast<size_t>(length) - bytes_processed);
memcpy(buffer + bytes_processed, &uncompressed_buffer[pos_in_buffer], bytes_to_copy);
pos_in_buffer += bytes_to_copy;
bytes_processed += bytes_to_copy;
}

View File

@ -57,16 +57,21 @@ int CompressingStreamBuf::writeToDevice(const char * buffer, std::streamsize len
while (bytes_processed < static_cast<size_t>(length))
{
size_t bytes_to_copy = std::min(uncompressed_buffer.size() - pos_in_buffer, static_cast<size_t>(length));
memcpy(&uncompressed_buffer[0], buffer, bytes_to_copy);
size_t bytes_to_copy = std::min(
uncompressed_buffer.size() - pos_in_buffer,
static_cast<size_t>(length) - bytes_processed);
memcpy(&uncompressed_buffer[pos_in_buffer], buffer + bytes_processed, bytes_to_copy);
pos_in_buffer += bytes_to_copy;
bytes_processed += bytes_to_copy;
if (pos_in_buffer == uncompressed_buffer.size())
writeCompressedChunk();
if (!p_ostr->good())
{
p_ostr = 0;
return bytes_processed;
}
}
return static_cast<int>(length);

View File

@ -0,0 +1,66 @@
#include <iostream>
#include <fstream>
#include <Poco/Stopwatch.h>
#include <Poco/Exception.h>
#include <Poco/NumberFormatter.h>
#include <DB/CompressedOutputStream.h>
#include <DB/CompressedInputStream.h>
int main(int argc, char ** argv)
{
try
{
int n = 1024 * 1024 * 10;
std::string str = "123456789";
Poco::Stopwatch stopwatch;
std::ofstream out_f("test");
DB::CompressedOutputStream compressor(out_f);
{
stopwatch.restart();
for (int i = 0; i < n; ++i)
compressor << str << std::endl;
compressor.close();
out_f.close();
stopwatch.stop();
std::cout << "Compressing: " << static_cast<double>(stopwatch.elapsed()) / 1000000 << std::endl;
}
std::ifstream in_f("test");
DB::CompressedInputStream decompressor(in_f);
int i = 0;
std::string read_str;
{
stopwatch.restart();
while (std::getline(decompressor, read_str))
{
++i;
/*if (read_str != str)
throw Poco::Exception(read_str);*/
}
stopwatch.stop();
std::cout << "Decompressing: " << static_cast<double>(stopwatch.elapsed()) / 1000000 << std::endl;
}
if (i != n)
throw Poco::Exception(Poco::NumberFormatter::format(i));
}
catch (Poco::Exception & e)
{
std::cerr << e.message() << std::endl;
return 1;
}
return 0;
}