int direct_io_fsync(int fd)
{
if(DIRECT_IO_READ_FILED == fd){
return sync_from_file();
}else if(DIRECT_IO_WRITE_FILED == fd){
return sync_to_file();
}
return -1;
}
/* sync everything to disk */
void sync_all()
{
char c, *oldstack;
oldstack = stack;
/* sync the cache first */
sync_whole_cache();
for(c='a'; c<='z'; c++)
sync_to_file(c, 0);
log("sync", "Full Sync Completed.");
}
void direct_io_close(int fd)
{
if(DIRECT_IO_READ_FILED == fd && read_fd){
close(read_fd);
read_fd = -1;
strcpy(read_file, "null");
}else if(DIRECT_IO_WRITE_FILED == fd){
sync_to_file(); // sync buffer to file
close(write_fd);
write_fd = -1;
strcpy(write_file, "null");
}
}
void do_sync()
{
int origin;
action="doing sync";
sync_counter=SYNC_TIME;
origin=synct;
while(!update[synct]) {
synct=(synct+1)%26;
if (synct==origin) break;
}
if (update[synct]) {
sync_to_file(synct+'a',0);
synct=(synct+1)%26;
}
}
int direct_io_seek(int fd, off_t offset, int whence)
{
if(SEEK_SET == whence){
// only supported
// int file_locate = 0;
// int file_size = 0;
if(DIRECT_IO_WRITE_FILED == fd){
//同步缓冲
sync_to_file();
//移动指针
//--计算文件总大小
// int file_size = lseek(write_fd, 0, SEEK_END);
// assert(offset <= file_size);
//--计算块索引
int file_block_index = offset / DIRECT_IO_BUFFER_SZ;
//--计算缓冲中的索引
write_pos = offset % DIRECT_IO_BUFFER_SZ;
//--读入缓冲
lseek(write_fd, file_block_index * DIRECT_IO_BUFFER_SZ, SEEK_SET);
int read_ret = read(write_fd, s_rw_buf.write_buf, DIRECT_IO_BUFFER_SZ);
assert(read_ret != -1);
lseek(write_fd, -1 * read_ret, SEEK_CUR);
// int sync_size = 0;
// // backup current location
// file_locate = lseek(write_fd, 0, SEEK_CUR);
// // get the max file size
// file_size = lseek(write_fd, 0, SEEK_END);
// //DIO_TRACE("size = %d", file_size);
// if(!(offset < file_size)){
// // reset pointer
// lseek(write_fd, file_locate, SEEK_SET);
// errno = ESPIPE;
// return -ESPIPE;
// }
// //update_to_file();
// sync_to_file();
// lseek(write_fd, offset, SEEK_SET);
// // very important
// sync_size = read_from_file(fd, s_rw_buf.write_buf, DIRECT_IO_BUFFER_SZ);
// lseek(write_fd, -1 * sync_size - 1, SEEK_CUR);
// write_pos = 0;
}else if(DIRECT_IO_READ_FILED == fd){
//移动指针
//--计算文件总大小
int file_block_index_cur = lseek(read_fd, 0, SEEK_CUR) / DIRECT_IO_BUFFER_SZ - 1;
// int file_size = lseek(read_fd, 0, SEEK_END);
// assert(offset <= file_size);
//--计算块索引
int file_block_index = offset / DIRECT_IO_BUFFER_SZ;
//--计算缓冲中的索引
read_pos = offset % DIRECT_IO_BUFFER_SZ;
if(file_block_index != file_block_index_cur)
{
//--读入缓冲
lseek(read_fd, file_block_index * DIRECT_IO_BUFFER_SZ, SEEK_SET);
int read_ret = read(read_fd, s_rw_buf.read_buf, DIRECT_IO_BUFFER_SZ);
assert(read_ret != -1);
// DIO_TRACE("read from file,pid=%d,file_block_index=%d,file_block_index_cur=%d"
// , getpid(), file_block_index, file_block_index_cur);
}
// // backup current location
// file_locate = lseek(read_fd, 0, SEEK_CUR);
// // get the max file size
// file_size = lseek(read_fd, 0, SEEK_END);
// //DIO_TRACE("size = %d", file_size);
// if(!(offset < file_size)){
// // reset pointer
// lseek(read_fd, file_locate, SEEK_SET);
// errno = ESPIPE;
// return -ESPIPE;
// }
// // seek to object position and update buffer
// lseek(read_fd, offset, SEEK_SET);
// update_from_file();
}else{
errno = EPERM;
return -EPERM;
}
return 0;
}
errno = EPERM;
return -EPERM;
}
