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use crate::disk::block::{DirectoryBlock, DirectoryEntry};
use crate::disk::inode::Inode;
use crate::AyaFS;
use indexmap::IndexMap;
use libc::{c_int, ENOENT, ENOSPC};
use log::debug;
use std::ffi::{OsStr, OsString};
use std::os::unix::ffi::OsStrExt;
impl AyaFS {
pub(crate) fn init_direntry_map(&mut self, index: usize) {
let direntry_map: IndexMap<OsString, DirectoryEntry> = IndexMap::new();
if let Some((old_inode_index, old_dir_entry_map)) =
self.dir_entry_map.push(index, direntry_map)
{
if let Some(old_inode) = self.get_inode(old_inode_index) {
let mut old_inode = old_inode.clone();
self.write_back_direntry(old_inode_index, &mut old_inode, old_dir_entry_map)
.unwrap();
self.update_inode(old_inode_index, old_inode);
}
}
}
pub(crate) fn load_direntry_map(&mut self, index: usize, inode: &Inode) -> Result<(), c_int> {
if self.dir_entry_map.contains(&index) {
debug!("load_direntry_map(ino: {}) already in cache", index);
return Ok(());
}
debug!("load_direntry_map(ino: {}) loading", index);
let mut dir_entry_map: IndexMap<OsString, DirectoryEntry> = IndexMap::new();
let mut entry_index: usize = 0;
loop {
let block_index_within_inode = entry_index / 15;
let entry_index_within_block = entry_index % 15;
match self.access_block::<DirectoryBlock>(inode, block_index_within_inode) {
Some(directory_block) => {
if directory_block.block.query(entry_index_within_block) {
let dir_entry = &directory_block.block.entries[entry_index_within_block];
let name = dir_entry.name();
dir_entry_map.insert(name, dir_entry.clone());
} else {
break;
}
}
None => break,
}
entry_index += 1;
}
if let Some((old_inode_index, old_dir_entry_map)) =
self.dir_entry_map.push(index, dir_entry_map)
{
if let Some(old_inode) = self.get_inode(old_inode_index) {
let mut old_inode = old_inode.clone();
self.write_back_direntry(old_inode_index, &mut old_inode, old_dir_entry_map)?;
self.update_inode(old_inode_index, old_inode);
}
}
Ok(())
}
pub(crate) fn write_back_direntry(
&mut self,
_parent_index: usize,
parent_inode: &mut Inode,
dir_entry_map: IndexMap<OsString, DirectoryEntry>,
) -> Result<(), c_int> {
for (entry_index, (_, dir_entry)) in dir_entry_map.into_iter().enumerate() {
let block_index_within_inode = entry_index / 15;
let entry_index_within_block = entry_index % 15;
// 不够就新分配
if self
.get_block_index(parent_inode, block_index_within_inode)
.is_none()
{
match self.allocate_block_for(parent_inode) {
Some((_, block_index_within)) => {
assert_eq!(block_index_within, block_index_within_inode);
}
None => {
return Err(ENOSPC);
}
}
}
match self.access_block_mut::<DirectoryBlock>(parent_inode, block_index_within_inode) {
Some(directory_block) => {
directory_block.block.allocate(entry_index_within_block);
directory_block.block.entries[entry_index_within_block] = dir_entry;
}
None => {
return Err(ENOENT);
}
}
}
Ok(())
}
/// 删除第 entry_index 个 dir entry
pub(crate) fn remove_direntry(
&mut self,
parent_index: usize,
parent_inode: &mut Inode,
name: &OsStr,
_entry_index: u32,
) -> Result<(), c_int> {
self.load_direntry_map(parent_index, parent_inode)?;
if let Some(dir_entry_map) = self.dir_entry_map.get_mut(&parent_index) {
debug!(" remove_direntry(ino: {}) using hashmap", parent_index);
if dir_entry_map.shift_remove(name).is_some() {
Ok(())
} else {
Err(ENOENT)
}
} else {
Err(ENOENT)
}
}
pub(crate) fn add_direntry<T: AsRef<OsStr>>(
&mut self,
parent_index: usize,
parent_inode: &mut Inode,
child_inode_index: usize,
child_inode_name: T,
file_type: u8,
) -> Result<u32, c_int> {
let child_inode_name = child_inode_name.as_ref();
self.load_direntry_map(parent_index, parent_inode)?;
if let Some(dir_entry_map) = self.dir_entry_map.get_mut(&parent_index) {
let name_len = child_inode_name.len() as u8;
let mut name = [0u8; 256];
(&mut name[0..child_inode_name.len()]).copy_from_slice(child_inode_name.as_bytes());
let dir_entry = DirectoryEntry {
inode: child_inode_index as u32,
record_len: 264,
name_len,
file_type,
name,
};
let (entry_index, _) =
dir_entry_map.insert_full(child_inode_name.to_os_string(), dir_entry);
debug!(
" add_direntry(ino: {}) using hashmap, entry {}",
parent_index, entry_index
);
parent_inode.size += 1;
Ok(entry_index as u32)
} else {
Err(ENOENT)
}
}
pub(crate) fn get_direntry(
&mut self,
parent_index: usize,
parent_inode: &Inode,
entry_index: u32,
) -> Result<DirectoryEntry, c_int> {
self.load_direntry_map(parent_index, parent_inode)?;
if let Some(dir_entry_map) = self.dir_entry_map.get(&parent_index) {
debug!(
" get_direntry(ino: {}, entry_index: {}) using hashmap",
parent_index, entry_index
);
dir_entry_map
.iter()
.skip(entry_index as usize)
.next()
.map(|entry| entry.1.clone())
.ok_or(ENOENT)
} else {
Err(ENOENT)
}
}
/// 返回 inode_index, inode 在 parent 里的 index, inode 本身
pub fn lookup_name(
&mut self,
parent_index: usize,
parent_inode: &Inode,
name: &OsStr,
) -> Result<(u32, u32, Inode), c_int> {
self.load_direntry_map(parent_index, parent_inode)?;
if let Some(dir_entry_map) = self.dir_entry_map.get(&parent_index) {
if let Some((entry_index, _, dir_entry)) = dir_entry_map.get_full(name) {
let inode_index = dir_entry.inode;
let inode = self.get_inode(inode_index as usize).unwrap().clone();
Ok((inode_index, entry_index as u32, inode))
} else {
Err(ENOENT)
}
} else {
let mut entry_index = 0;
while entry_index < parent_inode.size {
if let Ok(entry) = self.get_direntry(parent_index, parent_inode, entry_index) {
if entry.name() == name {
let inode = self.get_inode(entry.inode as usize).unwrap().clone();
return Ok((entry.inode, entry_index, inode));
}
}
entry_index += 1;
}
Err(ENOENT)
}
}
}
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