sevenz_rust/writer/
seq_reader.rs

1use std::{
2    fs::File,
3    io::{self, Read},
4    ops::Deref,
5    path::{Path, PathBuf},
6};
7#[derive(Default)]
8pub struct SeqReader<R> {
9    readers: Vec<R>,
10    current: usize,
11}
12
13impl<R> From<Vec<R>> for SeqReader<R> {
14    fn from(value: Vec<R>) -> Self {
15        Self::new(value)
16    }
17}
18
19impl<R> Deref for SeqReader<R> {
20    type Target = [R];
21
22    fn deref(&self) -> &Self::Target {
23        &self.readers
24    }
25}
26
27impl<R> AsRef<[R]> for SeqReader<R> {
28    fn as_ref(&self) -> &[R] {
29        &self.readers
30    }
31}
32
33#[cfg(not(target_arch = "wasm32"))]
34impl SeqReader<File> {
35    pub fn from_path_iter<'a>(paths: impl Iterator<Item = &'a Path>) -> std::io::Result<Self> {
36        let mut readers = Vec::new();
37        for path in paths {
38            readers.push(File::open(path)?);
39        }
40        Ok(Self::new(readers))
41    }
42}
43
44impl<R> SeqReader<R> {
45    pub fn new(readers: Vec<R>) -> Self {
46        Self {
47            readers,
48            current: 0,
49        }
50    }
51
52    pub fn reader_len(&self) -> usize {
53        self.readers.len()
54    }
55}
56
57impl<R: Read> Read for SeqReader<R> {
58    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
59        let mut i = 0;
60        while self.current < self.readers.len() {
61            let r = &mut self.readers[self.current];
62            i = r.read(buf)?;
63            if i == 0 {
64                self.current += 1;
65            } else {
66                break;
67            }
68        }
69
70        Ok(i)
71    }
72}
73
74pub struct SourceReader<R> {
75    reader: R,
76    size: usize,
77    crc: crc::Digest<'static, u32>,
78    crc_value: u32,
79}
80
81impl<R> From<R> for SourceReader<R> {
82    fn from(value: R) -> Self {
83        Self::new(value)
84    }
85}
86
87impl<R: Read> Read for SourceReader<R> {
88    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
89        let n = self.reader.read(buf)?;
90        if self.crc_value == 0 {
91            if n > 0 {
92                self.size += n;
93                self.crc.update(&buf[..n]);
94            } else {
95                let crc = std::mem::replace(&mut self.crc, crate::reader::CRC32.digest());
96                self.crc_value = crc.finalize();
97            }
98        }
99        Ok(n)
100    }
101}
102
103impl<R> SourceReader<R> {
104    pub fn new(reader: R) -> Self {
105        Self {
106            reader,
107            size: 0,
108            crc: crate::reader::CRC32.digest(),
109            crc_value: 0,
110        }
111    }
112
113    pub fn read_count(&self) -> usize {
114        self.size
115    }
116    pub fn crc_value(&self) -> u32 {
117        self.crc_value
118    }
119}
120
121pub(crate) struct LazyFileReader {
122    path: PathBuf,
123    reader: Option<File>,
124    end: bool,
125}
126
127impl LazyFileReader {
128    pub fn new(path: PathBuf) -> Self {
129        Self {
130            path,
131            reader: None,
132            end: false,
133        }
134    }
135}
136
137impl Read for LazyFileReader {
138    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
139        if self.end {
140            return Ok(0);
141        }
142        if self.reader.is_none() {
143            self.reader = Some(File::open(&self.path)?);
144        }
145        let n = self.reader.as_mut().unwrap().read(buf)?;
146        if n == 0 {
147            self.end = true;
148            self.reader = None;
149        }
150        Ok(n)
151    }
152}
sevenz_rust/writer/seq_reader.rs

sevenz_rust/writer/
seq_reader.rs
