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
use super::{ObjectError, ObjectId, Result, WriteObject};
use crate::{
backends::Backend,
compress,
crypto::{ChunkKey, CryptoProvider, Digest},
ChunkPointer,
};
use std::sync::Arc;
pub trait Writer: Send {
fn write_chunk(&mut self, hash: &Digest, data: &[u8]) -> Result<ChunkPointer>;
fn flush(&mut self) -> Result<()>;
}
pub struct AEADWriter {
backend: Arc<dyn Backend>,
crypto: ChunkKey,
object: WriteObject,
}
impl AEADWriter {
pub fn new(backend: Arc<dyn Backend>, crypto: ChunkKey) -> Self {
let mut object = WriteObject::default();
object.reset_id(&crypto);
AEADWriter {
backend,
crypto,
object,
}
}
}
impl Clone for AEADWriter {
fn clone(&self) -> Self {
let mut object = self.object.clone();
object.set_id(ObjectId::new(&self.crypto));
AEADWriter {
object,
backend: self.backend.clone(),
crypto: self.crypto.clone(),
}
}
}
impl Drop for AEADWriter {
fn drop(&mut self) {
if self.object.position() > 0 {
self.flush().unwrap();
}
}
}
impl Writer for AEADWriter {
fn write_chunk(&mut self, hash: &Digest, data: &[u8]) -> Result<ChunkPointer> {
let size = {
let buffer = self.object.tail_mut();
match compress::compress_into(data, buffer) {
Ok(size) => size,
Err(_e) => {
self.flush()?;
let buffer = self.object.tail_mut();
compress::compress_into(data, buffer).map_err(|_| {
ObjectError::ChunkTooLarge {
size: data.len(),
max_size: ((self.object.capacity() - 16 - 4) as f64 / 1.1) as usize,
}
})?
}
}
};
let oid = *self.object.id();
let (size, tag) = {
let buffer = self.object.tail_mut();
let tag = self.crypto.encrypt_chunk(&oid, hash, &mut buffer[..size]);
(size, tag)
};
let offs = self.object.position();
*self.object.position_mut() += size;
Ok(ChunkPointer::new(offs as u32, size as u32, oid, *hash, tag))
}
fn flush(&mut self) -> Result<()> {
self.object.finalize(&self.crypto);
self.backend.write_object(&self.object)?;
self.object.reset_id(&self.crypto);
self.object.reset_cursor();
Ok(())
}
}