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#include "StatusFile.h"
#include <sys/file.h>
#include <fcntl.h>
#include <cerrno>
#include <Common/logger_useful.h>
#include <Common/ClickHouseRevision.h>
#include <Common/LocalDateTime.h>
#include <base/errnoToString.h>
#include <base/defines.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/LimitReadBuffer.h>
#include <IO/WriteBufferFromFileDescriptor.h>
#include <IO/Operators.h>
#include <filesystem>
namespace fs = std::filesystem;
namespace DB
{
namespace ErrorCodes
{
extern const int CANNOT_OPEN_FILE;
extern const int CANNOT_TRUNCATE_FILE;
extern const int CANNOT_SEEK_THROUGH_FILE;
}
StatusFile::FillFunction StatusFile::write_pid = [](WriteBuffer & out)
{
out << getpid();
};
StatusFile::FillFunction StatusFile::write_full_info = [](WriteBuffer & out)
{
out << "PID: " << getpid() << "\n"
<< "Started at: " << LocalDateTime(time(nullptr)) << "\n"
<< "Revision: " << ClickHouseRevision::getVersionRevision() << "\n";
};
StatusFile::StatusFile(std::string path_, FillFunction fill_)
: path(std::move(path_)), fill(std::move(fill_))
{
/// If file already exists. NOTE Minor race condition.
if (fs::exists(path))
{
std::string contents;
{
ReadBufferFromFile in(path, 1024);
LimitReadBuffer limit_in(in, 1024, /* trow_exception */ false, /* exact_limit */ {});
readStringUntilEOF(contents, limit_in);
}
if (!contents.empty())
LOG_INFO(&Poco::Logger::get("StatusFile"), "Status file {} already exists - unclean restart. Contents:\n{}", path, contents);
else
LOG_INFO(&Poco::Logger::get("StatusFile"), "Status file {} already exists and is empty - probably unclean hardware restart.", path);
}
fd = ::open(path.c_str(), O_WRONLY | O_CREAT | O_CLOEXEC, 0666);
if (-1 == fd)
throwFromErrnoWithPath("Cannot open file " + path, path, ErrorCodes::CANNOT_OPEN_FILE);
try
{
int flock_ret = flock(fd, LOCK_EX | LOCK_NB);
if (-1 == flock_ret)
{
if (errno == EWOULDBLOCK)
throw Exception(ErrorCodes::CANNOT_OPEN_FILE, "Cannot lock file {}. Another server instance in same directory is already running.", path);
else
throwFromErrnoWithPath("Cannot lock file " + path, path, ErrorCodes::CANNOT_OPEN_FILE);
}
if (0 != ftruncate(fd, 0))
throwFromErrnoWithPath("Cannot ftruncate " + path, path, ErrorCodes::CANNOT_TRUNCATE_FILE);
if (0 != lseek(fd, 0, SEEK_SET))
throwFromErrnoWithPath("Cannot lseek " + path, path, ErrorCodes::CANNOT_SEEK_THROUGH_FILE);
/// Write information about current server instance to the file.
WriteBufferFromFileDescriptor out(fd, 1024);
fill(out);
}
catch (...)
{
int err = close(fd);
chassert(!err || errno == EINTR);
throw;
}
}
StatusFile::~StatusFile()
{
if (0 != close(fd))
LOG_ERROR(&Poco::Logger::get("StatusFile"), "Cannot close file {}, {}", path, errnoToString());
if (0 != unlink(path.c_str()))
LOG_ERROR(&Poco::Logger::get("StatusFile"), "Cannot unlink file {}, {}", path, errnoToString());
}
}
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