ClickHouse/dbms/src/IO/ReadBufferFromFile.cpp
2018-05-09 07:22:30 +03:00

94 lines
2.0 KiB
C++

#include <fcntl.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/WriteHelpers.h>
#include <Common/ProfileEvents.h>
#include <errno.h>
namespace ProfileEvents
{
extern const Event FileOpen;
extern const Event FileOpenFailed;
}
namespace DB
{
namespace ErrorCodes
{
extern const int FILE_DOESNT_EXIST;
extern const int CANNOT_OPEN_FILE;
extern const int CANNOT_CLOSE_FILE;
}
ReadBufferFromFile::ReadBufferFromFile(
const std::string & file_name_,
size_t buf_size,
int flags,
char * existing_memory,
size_t alignment)
: ReadBufferFromFileDescriptor(-1, buf_size, existing_memory, alignment), file_name(file_name_)
{
ProfileEvents::increment(ProfileEvents::FileOpen);
#ifdef __APPLE__
bool o_direct = (flags != -1) && (flags & O_DIRECT);
if (o_direct)
flags = flags & ~O_DIRECT;
#endif
fd = open(file_name.c_str(), flags == -1 ? O_RDONLY : flags);
if (-1 == fd)
{
ProfileEvents::increment(ProfileEvents::FileOpenFailed);
throwFromErrno("Cannot open file " + file_name, errno == ENOENT ? ErrorCodes::FILE_DOESNT_EXIST : ErrorCodes::CANNOT_OPEN_FILE);
}
#ifdef __APPLE__
if (o_direct)
{
if (fcntl(fd, F_NOCACHE, 1) == -1)
{
ProfileEvents::increment(ProfileEvents::FileOpenFailed);
throwFromErrno("Cannot set F_NOCACHE on file " + file_name, ErrorCodes::CANNOT_OPEN_FILE);
}
}
#endif
}
ReadBufferFromFile::ReadBufferFromFile(
int fd,
const std::string & original_file_name,
size_t buf_size,
char * existing_memory,
size_t alignment)
:
ReadBufferFromFileDescriptor(fd, buf_size, existing_memory, alignment),
file_name(original_file_name.empty() ? "(fd = " + toString(fd) + ")" : original_file_name)
{
}
ReadBufferFromFile::~ReadBufferFromFile()
{
if (fd < 0)
return;
::close(fd);
}
void ReadBufferFromFile::close()
{
if (0 != ::close(fd))
throw Exception("Cannot close file", ErrorCodes::CANNOT_CLOSE_FILE);
fd = -1;
metric_increment.destroy();
}
}