raft_engine/env/
obfuscated.rs

1// Copyright (c) 2017-present, PingCAP, Inc. Licensed under Apache-2.0.
2
3use std::io::{Read, Result as IoResult, Seek, SeekFrom, Write};
4use std::path::Path;
5use std::sync::atomic::{AtomicUsize, Ordering};
6use std::sync::Arc;
7
8use crate::env::{DefaultFileSystem, FileSystem, Permission, WriteExt};
9
10pub struct ObfuscatedReader(<DefaultFileSystem as FileSystem>::Reader);
11
12impl Read for ObfuscatedReader {
13    fn read(&mut self, buf: &mut [u8]) -> IoResult<usize> {
14        if !buf.is_empty() {
15            let len = self.0.read(&mut buf[..1])?;
16            if len == 1 {
17                buf[0] = buf[0].wrapping_sub(1);
18            }
19            Ok(len)
20        } else {
21            Ok(0)
22        }
23    }
24}
25
26impl Seek for ObfuscatedReader {
27    fn seek(&mut self, pos: SeekFrom) -> IoResult<u64> {
28        self.0.seek(pos)
29    }
30}
31
32pub struct ObfuscatedWriter(<DefaultFileSystem as FileSystem>::Writer);
33
34impl Write for ObfuscatedWriter {
35    fn write(&mut self, buf: &[u8]) -> IoResult<usize> {
36        if !buf.is_empty() {
37            let tmp_vec = vec![buf[0].wrapping_add(1)];
38            self.0.write(&tmp_vec)
39        } else {
40            Ok(0)
41        }
42    }
43
44    fn flush(&mut self) -> IoResult<()> {
45        self.0.flush()
46    }
47}
48
49impl Seek for ObfuscatedWriter {
50    fn seek(&mut self, pos: SeekFrom) -> IoResult<u64> {
51        self.0.seek(pos)
52    }
53}
54
55impl WriteExt for ObfuscatedWriter {
56    fn truncate(&mut self, offset: usize) -> IoResult<()> {
57        self.0.truncate(offset)
58    }
59
60    fn allocate(&mut self, offset: usize, size: usize) -> IoResult<()> {
61        self.0.allocate(offset, size)
62    }
63}
64
65/// `[ObfuscatedFileSystem]` is a special implementation of `[FileSystem]`,
66/// which is used for constructing and simulating an abnormal file system for
67/// `[Read]` and `[Write]`.
68pub struct ObfuscatedFileSystem {
69    inner: DefaultFileSystem,
70    files: AtomicUsize,
71}
72
73impl Default for ObfuscatedFileSystem {
74    fn default() -> Self {
75        ObfuscatedFileSystem {
76            inner: DefaultFileSystem,
77            files: AtomicUsize::new(0),
78        }
79    }
80}
81
82impl ObfuscatedFileSystem {
83    pub fn file_count(&self) -> usize {
84        self.files.load(Ordering::Relaxed)
85    }
86}
87
88impl FileSystem for ObfuscatedFileSystem {
89    type Handle = <DefaultFileSystem as FileSystem>::Handle;
90    type Reader = ObfuscatedReader;
91    type Writer = ObfuscatedWriter;
92
93    fn create<P: AsRef<Path>>(&self, path: P) -> IoResult<Self::Handle> {
94        let r = self.inner.create(path);
95        if r.is_ok() {
96            self.files.fetch_add(1, Ordering::Relaxed);
97        }
98        r
99    }
100
101    fn open<P: AsRef<Path>>(&self, path: P, perm: Permission) -> IoResult<Self::Handle> {
102        self.inner.open(path, perm)
103    }
104
105    fn delete<P: AsRef<Path>>(&self, path: P) -> IoResult<()> {
106        let r = self.inner.delete(path);
107        if r.is_ok() {
108            self.files.fetch_sub(1, Ordering::Relaxed);
109        }
110        r
111    }
112
113    fn rename<P: AsRef<Path>>(&self, src_path: P, dst_path: P) -> IoResult<()> {
114        self.inner.rename(src_path, dst_path)
115    }
116
117    fn reuse<P: AsRef<Path>>(&self, src_path: P, dst_path: P) -> IoResult<()> {
118        self.delete(src_path)?;
119        self.create(dst_path)?;
120        Ok(())
121    }
122
123    fn new_reader(&self, handle: Arc<Self::Handle>) -> IoResult<Self::Reader> {
124        Ok(ObfuscatedReader(self.inner.new_reader(handle)?))
125    }
126
127    fn new_writer(&self, handle: Arc<Self::Handle>) -> IoResult<Self::Writer> {
128        Ok(ObfuscatedWriter(self.inner.new_writer(handle)?))
129    }
130}
raft_engine/env/obfuscated.rs

raft_engine/env/
obfuscated.rs
