ClickHouse/dbms/src/IO/WriteBufferAIO.cpp
2015-03-05 17:21:55 +03:00

139 lines
3.1 KiB
C++

#include <DB/IO/WriteBufferAIO.h>
#include <DB/Common/ProfileEvents.h>
#include <DB/Core/ErrorCodes.h>
#include <sys/types.h>
#include <sys/stat.h>
namespace DB
{
WriteBufferAIO::WriteBufferAIO(const std::string & filename_, size_t buffer_size_, int flags_, mode_t mode_,
char * existing_memory_)
: BufferWithOwnMemory(buffer_size_, existing_memory_, BLOCK_SIZE),
flush_buffer(BufferWithOwnMemory(buffer_size_, nullptr, BLOCK_SIZE)),
filename(filename_), request_ptrs{ &cb }, events(1)
{
ProfileEvents::increment(ProfileEvents::FileOpen);
int open_flags = ((flags_ == -1) ? O_WRONLY | O_TRUNC | O_CREAT : flags_);
open_flags |= O_DIRECT;
fd = ::open(filename_.c_str(), open_flags, mode_);
if (fd == -1)
{
got_exception = true;
throwFromErrno("Cannot open file " + filename_, errno == ENOENT ? ErrorCodes::FILE_DOESNT_EXIST : ErrorCodes::CANNOT_OPEN_FILE);
}
}
WriteBufferAIO::~WriteBufferAIO()
{
if (!got_exception)
{
try
{
next();
waitForCompletion();
}
catch (...)
{
tryLogCurrentException(__PRETTY_FUNCTION__);
}
}
if (fd != -1)
::close(fd);
}
off_t WriteBufferAIO::seek(off_t offset, int whence)
{
waitForCompletion();
off_t res = ::lseek(fd, offset, whence);
if (res == -1)
{
got_exception = true;
throwFromErrno("Cannot seek through file " + getFileName(), ErrorCodes::CANNOT_SEEK_THROUGH_FILE);
}
return res;
}
void WriteBufferAIO::truncate(off_t length)
{
waitForCompletion();
int res = ::ftruncate(fd, length);
if (res == -1)
{
got_exception = true;
throwFromErrno("Cannot truncate file " + getFileName(), ErrorCodes::CANNOT_TRUNCATE_FILE);
}
}
void WriteBufferAIO::sync() noexcept
{
::fsync(fd);
}
void WriteBufferAIO::nextImpl()
{
if (!offset())
return;
waitForCompletion();
swapBuffers();
// Create request.
::memset(&cb, 0, sizeof(cb));
cb.aio_lio_opcode = IOCB_CMD_PWRITE;
cb.aio_fildes = fd;
cb.aio_buf = reinterpret_cast<UInt64>(flush_buffer.buffer().begin());
cb.aio_nbytes = flush_buffer.offset();
cb.aio_offset = 0;
cb.aio_reqprio = 0;
// Submit request.
while (io_submit(aio_context.ctx, request_ptrs.size(), &request_ptrs[0]) < 0)
if (errno != EINTR)
{
got_exception = true;
throw Exception("Cannot submit request for asynchronous IO", ErrorCodes::AIO_SUBMIT_ERROR);
}
is_pending_write = true;
}
void WriteBufferAIO::waitForCompletion()
{
if (is_pending_write)
{
::memset(&events[0], 0, sizeof(events[0]) * events.size());
while (io_getevents(aio_context.ctx, events.size(), events.size(), &events[0], nullptr) < 0)
if (errno != EINTR)
{
got_exception = true;
throw Exception("Failed to wait for asynchronous IO completion", ErrorCodes::AIO_COMPLETION_ERROR);
}
size_t bytes_written = (events[0].res > 0) ? static_cast<size_t>(events[0].res) : 0;
if (bytes_written < flush_buffer.offset())
{
got_exception = true;
throw Exception("Asynchronous write error", ErrorCodes::AIO_WRITE_ERROR);
}
is_pending_write = false;
}
}
void WriteBufferAIO::swapBuffers() noexcept
{
buffer().swap(flush_buffer.buffer());
std::swap(position(), flush_buffer.position());
}
}