vfs/directory/
helper.rs

1// Copyright 2020 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::directory::entry::DirectoryEntry;
6use crate::directory::entry_container::Directory;
7use crate::name::Name;
8use std::sync::Arc;
9use thiserror::Error;
10use zx_status::Status;
11
12/// An entry with the same name already exists in the directory.
13#[derive(Error, Debug)]
14#[error("An entry with the same name already exists in the directory")]
15pub struct AlreadyExists;
16
17impl Into<Status> for AlreadyExists {
18    fn into(self) -> Status {
19        Status::ALREADY_EXISTS
20    }
21}
22
23/// The entry identified by `name` is not a directory.
24#[derive(Error, Debug)]
25#[error("The specified entry is not a directory")]
26pub struct NotDirectory;
27
28impl Into<Status> for NotDirectory {
29    fn into(self) -> Status {
30        Status::NOT_DIR
31    }
32}
33
34/// `DirectlyMutable` is a superset of `MutableDirectory` which also allows server-side management
35/// of directory entries (via `add_entry` and `remove_entry`).
36pub trait DirectlyMutable: Directory + Send + Sync {
37    /// Adds a child entry to this directory.
38    ///
39    /// Possible errors are:
40    ///   * `ZX_ERR_INVALID_ARGS` or `ZX_ERR_BAD_PATH` if `name` is not a valid [`Name`].
41    ///   * `ZX_ERR_ALREADY_EXISTS` if an entry with the same name is already present in the
42    ///     directory.
43    fn add_entry<NameT>(&self, name: NameT, entry: Arc<dyn DirectoryEntry>) -> Result<(), Status>
44    where
45        NameT: Into<String>,
46        Self: Sized,
47    {
48        self.add_entry_may_overwrite(name, entry, false)
49    }
50
51    /// Adds a child entry to this directory. If `overwrite` is true, this function may overwrite
52    /// an existing entry.
53    ///
54    /// Possible errors are:
55    ///   * `ZX_ERR_INVALID_ARGS` or `ZX_ERR_BAD_PATH` if `name` is not a valid [`Name`].
56    ///   * `ZX_ERR_ALREADY_EXISTS` if an entry with the same name is already present in the
57    ///     directory and `overwrite` is false.
58    fn add_entry_may_overwrite<NameT>(
59        &self,
60        name: NameT,
61        entry: Arc<dyn DirectoryEntry>,
62        overwrite: bool,
63    ) -> Result<(), Status>
64    where
65        NameT: Into<String>,
66        Self: Sized,
67    {
68        let name: String = name.into();
69        let name: Name = name.try_into()?;
70        self.add_entry_impl(name, entry, overwrite)
71            .map_err(|_: AlreadyExists| Status::ALREADY_EXISTS)
72    }
73
74    /// Adds a child entry to this directory.
75    fn add_entry_impl(
76        &self,
77        name: Name,
78        entry: Arc<dyn DirectoryEntry>,
79        overwrite: bool,
80    ) -> Result<(), AlreadyExists>;
81
82    /// Removes a child entry from this directory.  In case an entry with the matching name was
83    /// found, the entry will be returned to the caller.  If `must_be_directory` is true, an error
84    /// is returned if the entry is not a directory.
85    ///
86    /// Possible errors are:
87    ///   * `ZX_ERR_INVALID_ARGS` or `ZX_ERR_BAD_PATH` if `name` is not a valid [`Name`].
88    ///   * `ZX_ERR_NOT_DIR` if the entry identified by `name` is not a directory and
89    ///     `must_be_directory` is true.
90    fn remove_entry<NameT>(
91        &self,
92        name: NameT,
93        must_be_directory: bool,
94    ) -> Result<Option<Arc<dyn DirectoryEntry>>, Status>
95    where
96        NameT: Into<String>,
97        Self: Sized,
98    {
99        let name: String = name.into();
100        let name: Name = name.try_into()?;
101        let entry = self
102            .remove_entry_impl(name, must_be_directory)
103            .map_err(|_: NotDirectory| Status::NOT_DIR)?;
104        Ok(entry)
105    }
106
107    /// Removes a child entry from this directory.  In case an entry with the matching name was
108    /// found, the entry will be returned to the caller.
109    fn remove_entry_impl(
110        &self,
111        name: Name,
112        must_be_directory: bool,
113    ) -> Result<Option<Arc<dyn DirectoryEntry>>, NotDirectory>;
114}
vfs/directory/helper.rs

vfs/directory/
helper.rs
