/*
 * ================================
 * eli960@qq.com
 * http://linuxmail.cn/
 * 2025年06月09日
 * ================================
 */

#include "zcc/zcc_win64.h"
#include "zcc/zcc_errno.h"
#include <stdio.h>
#ifdef _WIN64
#include <winbase.h>
#include <fileapi.h>
#include <shellapi.h>
#include <shlobj.h>
#include <wchar.h>
#include <sys/utime.h>
#include <direct.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <io.h>
#else // _WIN64
#include <unistd.h>
#include <fcntl.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <utime.h>
#include <stdarg.h>
#include <dirent.h>
#endif // _WIN64

zcc_namespace_begin;

// 下面是夸平台的flock实现方案

#ifdef _WIN64

static inline int __flock(int fd, bool exclusive, DWORD action)
{
 HANDLE hd = (HANDLE)_get_osfhandle(fd);
 if (hd == INVALID_HANDLE_VALUE)
 {
 return -1;
 }
 if (LockFileEx(hd, action, 0, 1, 0, NULL))
 {
 return 1;
 }
 auto err = GetLastError();
 if (ERROR_LOCK_VIOLATION == err || ERROR_SHARING_VIOLATION == err)
 {
 return 0;
 }
 return -1;
}
int flock(int fd, bool exclusive)
{
 DWORD action = exclusive ? LOCKFILE_EXCLUSIVE_LOCK : 0;
 return __flock(fd, exclusive, action);
}

int try_flock(int fd, bool exclusive)
{
 DWORD action = exclusive ? LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY : LOCKFILE_FAIL_IMMEDIATELY;
 return __flock(fd, exclusive, action);
}

bool funlock(int fd)
{
 HANDLE hd = (HANDLE)_get_osfhandle(fd);
 if (hd == INVALID_HANDLE_VALUE)
 {
 return false;
 }
 if (UnlockFileEx(hd, 0, 1, 0, NULL))
 {
 return true;
 }
 return false;
}
#else // _WIN64
int flock(int fd, bool exclusive)
{
 while (1)
 {
 if (::flock(fd, exclusive ? LOCK_EX : LOCK_SH) == 0)
 {
 return 1;
 }
 if (errno == EINTR)
 {
 continue;
 }
 return -1;
 }
 return 0;
}

int try_flock(int fd, bool exclusive)
{
 while (1)
 {
 if (::flock(fd, exclusive ? LOCK_EX | LOCK_NB : LOCK_SH | LOCK_NB) == 0)
 {
 return 1;
 }
 if (errno == EINTR)
 {
 continue;
 }
 if (errno == EWOULDBLOCK)
 {
 return 0;
 }
 return -1;
 }
 return 0;
}

bool funlock(int fd)
{
 return ::flock(fd, LOCK_UN) == 0;
}
#endif // _WIN64

flocker::flocker()
{
}

flocker::~flocker()
{
 unlock();
}

int flocker::__lock(const std::string &pathname, bool exclusive, bool try_mode)
{
 if (pathname != pathname_)
 {
 unlock();
 }
 if (fd_ == -1)
 {
 fd_ = open(pathname.c_str(), O_RDONLY | O_CREAT, 0666);
 if (fd_ == -1)
 {
 return -1;
 }
 }
 int r;
 if (try_mode)
 {
 r = try_flock(fd_, exclusive);
 }
 else
 {
 r = flock(fd_, exclusive);
 }
 if (r == 1)
 {
 pathname_ = pathname;
 return 1;
 }
 return r;
}

int flocker::unlock()
{
 pathname_.clear();
 if (fd_ != -1)
 {
#ifdef _WIN64
 ::_close(fd_);
#else // _WIN64
 ::close(fd_);
#endif // _WIN64
 }
 fd_ = -1;
 return 1;
}
zcc_namespace_end;