src/proc/bin/starnix/fs/xattr.rs

// Copyright 2022 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

use std::collections::hash_map::Entry;
use std::collections::HashMap;

use super::*;
use crate::lock::Mutex;
use crate::types::*;

#[derive(Default)]
pub struct MemoryXattrStorage {
    xattrs: Mutex<HashMap<FsString, FsString>>,
}
impl MemoryXattrStorage {
    pub fn get_xattr(&self, name: &FsStr) -> Result<FsString, Errno> {
        let xattrs = self.xattrs.lock();
        Ok(xattrs.get(name).ok_or(errno!(ENODATA))?.clone())
    }

    pub fn set_xattr(&self, name: &FsStr, value: &FsStr, op: XattrOp) -> Result<(), Errno> {
        let mut xattrs = self.xattrs.lock();
        match xattrs.entry(name.to_owned()) {
            Entry::Vacant(_) if op == XattrOp::Replace => return error!(ENODATA),
            Entry::Occupied(_) if op == XattrOp::Create => return error!(EEXIST),
            Entry::Vacant(v) => {
                v.insert(value.to_owned());
            }
            Entry::Occupied(mut o) => {
                let s = o.get_mut();
                s.clear();
                s.extend_from_slice(value);
            }
        };
        Ok(())
    }

    pub fn remove_xattr(&self, name: &FsStr) -> Result<(), Errno> {
        let mut xattrs = self.xattrs.lock();
        if xattrs.remove(name).is_none() {
            return error!(ENODATA);
        }
        Ok(())
    }

    pub fn list_xattrs(&self) -> Result<Vec<FsString>, Errno> {
        let xattrs = self.xattrs.lock();
        Ok(xattrs.keys().map(|k| k.to_vec()).collect())
    }
}