tfio 0.3.0

A library that provides a Transaction-like interface traditionally used in databases, applied to FileIO operations.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178

use std::fs;
use std::{
    env,
    io,
    path::{Path, PathBuf},
};

use crate::{copy_dir, DirectoryOperation, RollbackableOperation, SingleFileOperation};

/// Deletes a file (backed up so it can be restored on rollback).
pub struct DeleteFile {
    source: PathBuf,
    temp_dir: PathBuf,
    backup_path: PathBuf,
}

impl DeleteFile {
    /// Constructs a new `DeleteFile` operation, using the OS temp directory for backups.
    pub fn new<S: AsRef<Path>>(source: S) -> Self {
        Self::with_temp_dir(source, env::temp_dir())
    }

    /// Constructs a new `DeleteFile` operation with a custom backup directory.
    pub fn with_temp_dir<S: AsRef<Path>, T: AsRef<Path>>(source: S, temp_dir: T) -> Self {
        Self {
            source: source.as_ref().into(),
            temp_dir: temp_dir.as_ref().into(),
            backup_path: PathBuf::new(),
        }
    }
}

impl RollbackableOperation for DeleteFile {
    fn execute(&mut self) -> io::Result<()> {
        self.create_backup_file()?;
        fs::remove_file(self.get_path())
    }

    fn rollback(&mut self) -> io::Result<()> {
        if self.backup_path.as_os_str().is_empty() {
            return Ok(());
        }
        fs::copy(self.get_backup_path(), self.get_path()).map(|_| ())
    }
}

impl SingleFileOperation for DeleteFile {
    fn get_path(&self) -> &Path {
        &self.source
    }

    fn get_backup_path(&self) -> &Path {
        &self.backup_path
    }

    fn set_backup_path<S: AsRef<Path>>(&mut self, path: S) {
        self.backup_path = path.as_ref().into();
    }

    fn get_temp_dir(&self) -> &Path {
        &self.temp_dir
    }
}

impl Drop for DeleteFile {
    fn drop(&mut self) {
        if let Err(e) = self.dispose() {
            eprintln!("{}", e);
        }
    }
}

/// Deletes a directory (backed up so it can be restored on rollback).
pub struct DeleteDirectory {
    source: PathBuf,
    backup_path: PathBuf,
    temp_dir: PathBuf,
}

impl DeleteDirectory {
    /// Constructs a new `DeleteDirectory` operation, using the OS temp directory for backups.
    pub fn new<S: AsRef<Path>>(source: S) -> Self {
        Self::with_temp_dir(source, env::temp_dir())
    }

    /// Constructs a new `DeleteDirectory` operation with a custom backup directory.
    pub fn with_temp_dir<S: AsRef<Path>, T: AsRef<Path>>(source: S, temp_dir: T) -> Self {
        Self {
            source: source.as_ref().into(),
            temp_dir: temp_dir.as_ref().into(),
            backup_path: PathBuf::new(),
        }
    }
}

impl RollbackableOperation for DeleteDirectory {
    fn execute(&mut self) -> io::Result<()> {
        self.create_backup_folder()?;
        fs::remove_dir_all(&self.source)
    }

    fn rollback(&mut self) -> io::Result<()> {
        if self.backup_path.as_os_str().is_empty() {
            return Ok(());
        }
        match fs::rename(self.get_backup_path(), &self.source) {
            Ok(()) => Ok(()),
            Err(e) if e.kind() == io::ErrorKind::CrossesDevices => {
                copy_dir(self.get_backup_path(), &self.source)?;
                fs::remove_dir_all(self.get_backup_path())
            }
            Err(e) => Err(e),
        }
    }
}

impl DirectoryOperation for DeleteDirectory {
    fn get_path(&self) -> &Path {
        &self.source
    }

    fn get_backup_path(&self) -> &Path {
        &self.backup_path
    }

    fn set_backup_path<S: AsRef<Path>>(&mut self, path: S) {
        self.backup_path = path.as_ref().into();
    }

    fn get_temp_dir(&self) -> &Path {
        &self.temp_dir
    }
}

impl Drop for DeleteDirectory {
    fn drop(&mut self) {
        if let Err(e) = self.dispose() {
            eprintln!("{}", e);
        }
    }
}

#[cfg(test)]
mod tests {
    use std::fs;

    use tempfile::tempdir;

    use super::*;

    #[test]
    fn delete_file_works() {
        let dir = tempdir().unwrap();
        let file_path = dir.path().join("delete_me.txt");
        fs::write(&file_path, b"data").unwrap();

        let mut op = DeleteFile::with_temp_dir(&file_path, dir.path());
        assert!(file_path.exists());
        op.execute().unwrap();
        assert!(!file_path.exists());
        op.rollback().unwrap();
        assert!(file_path.exists());
    }

    #[test]
    fn delete_dir_works() {
        let dir = tempdir().unwrap();
        let target_dir = dir.path().join("delete_me_dir");
        fs::create_dir(&target_dir).unwrap();

        let mut op = DeleteDirectory::with_temp_dir(&target_dir, dir.path());
        assert!(target_dir.exists());
        op.execute().unwrap();
        assert!(!target_dir.exists());
        op.rollback().unwrap();
        assert!(target_dir.exists());
    }
}