1 | use std::collections::VecDeque; |
2 | use std::io::IoSlice; |
3 | |
4 | use bytes::{Buf, BufMut, Bytes, BytesMut}; |
5 | |
6 | pub(crate) struct BufList<T> { |
7 | bufs: VecDeque<T>, |
8 | } |
9 | |
10 | impl<T: Buf> BufList<T> { |
11 | pub(crate) fn new() -> BufList<T> { |
12 | BufList { |
13 | bufs: VecDeque::new(), |
14 | } |
15 | } |
16 | |
17 | #[inline ] |
18 | pub(crate) fn push(&mut self, buf: T) { |
19 | debug_assert!(buf.has_remaining()); |
20 | self.bufs.push_back(buf); |
21 | } |
22 | |
23 | #[inline ] |
24 | #[cfg (feature = "http1" )] |
25 | pub(crate) fn bufs_cnt(&self) -> usize { |
26 | self.bufs.len() |
27 | } |
28 | } |
29 | |
30 | impl<T: Buf> Buf for BufList<T> { |
31 | #[inline ] |
32 | fn remaining(&self) -> usize { |
33 | self.bufs.iter().map(|buf| buf.remaining()).sum() |
34 | } |
35 | |
36 | #[inline ] |
37 | fn chunk(&self) -> &[u8] { |
38 | self.bufs.front().map(Buf::chunk).unwrap_or_default() |
39 | } |
40 | |
41 | #[inline ] |
42 | fn advance(&mut self, mut cnt: usize) { |
43 | while cnt > 0 { |
44 | { |
45 | let front = &mut self.bufs[0]; |
46 | let rem = front.remaining(); |
47 | if rem > cnt { |
48 | front.advance(cnt); |
49 | return; |
50 | } else { |
51 | front.advance(rem); |
52 | cnt -= rem; |
53 | } |
54 | } |
55 | self.bufs.pop_front(); |
56 | } |
57 | } |
58 | |
59 | #[inline ] |
60 | fn chunks_vectored<'t>(&'t self, dst: &mut [IoSlice<'t>]) -> usize { |
61 | if dst.is_empty() { |
62 | return 0; |
63 | } |
64 | let mut vecs = 0; |
65 | for buf in &self.bufs { |
66 | vecs += buf.chunks_vectored(&mut dst[vecs..]); |
67 | if vecs == dst.len() { |
68 | break; |
69 | } |
70 | } |
71 | vecs |
72 | } |
73 | |
74 | #[inline ] |
75 | fn copy_to_bytes(&mut self, len: usize) -> Bytes { |
76 | // Our inner buffer may have an optimized version of copy_to_bytes, and if the whole |
77 | // request can be fulfilled by the front buffer, we can take advantage. |
78 | match self.bufs.front_mut() { |
79 | Some(front) if front.remaining() == len => { |
80 | let b = front.copy_to_bytes(len); |
81 | self.bufs.pop_front(); |
82 | b |
83 | } |
84 | Some(front) if front.remaining() > len => front.copy_to_bytes(len), |
85 | _ => { |
86 | assert!(len <= self.remaining(), "`len` greater than remaining" ); |
87 | let mut bm = BytesMut::with_capacity(len); |
88 | bm.put(self.take(len)); |
89 | bm.freeze() |
90 | } |
91 | } |
92 | } |
93 | } |
94 | |
95 | #[cfg (test)] |
96 | mod tests { |
97 | use std::ptr; |
98 | |
99 | use super::*; |
100 | |
101 | fn hello_world_buf() -> BufList<Bytes> { |
102 | BufList { |
103 | bufs: vec![Bytes::from("Hello" ), Bytes::from(" " ), Bytes::from("World" )].into(), |
104 | } |
105 | } |
106 | |
107 | #[test ] |
108 | fn to_bytes_shorter() { |
109 | let mut bufs = hello_world_buf(); |
110 | let old_ptr = bufs.chunk().as_ptr(); |
111 | let start = bufs.copy_to_bytes(4); |
112 | assert_eq!(start, "Hell" ); |
113 | assert!(ptr::eq(old_ptr, start.as_ptr())); |
114 | assert_eq!(bufs.chunk(), b"o" ); |
115 | assert!(ptr::eq(old_ptr.wrapping_add(4), bufs.chunk().as_ptr())); |
116 | assert_eq!(bufs.remaining(), 7); |
117 | } |
118 | |
119 | #[test ] |
120 | fn to_bytes_eq() { |
121 | let mut bufs = hello_world_buf(); |
122 | let old_ptr = bufs.chunk().as_ptr(); |
123 | let start = bufs.copy_to_bytes(5); |
124 | assert_eq!(start, "Hello" ); |
125 | assert!(ptr::eq(old_ptr, start.as_ptr())); |
126 | assert_eq!(bufs.chunk(), b" " ); |
127 | assert_eq!(bufs.remaining(), 6); |
128 | } |
129 | |
130 | #[test ] |
131 | fn to_bytes_longer() { |
132 | let mut bufs = hello_world_buf(); |
133 | let start = bufs.copy_to_bytes(7); |
134 | assert_eq!(start, "Hello W" ); |
135 | assert_eq!(bufs.remaining(), 4); |
136 | } |
137 | |
138 | #[test ] |
139 | fn one_long_buf_to_bytes() { |
140 | let mut buf = BufList::new(); |
141 | buf.push(b"Hello World" as &[_]); |
142 | assert_eq!(buf.copy_to_bytes(5), "Hello" ); |
143 | assert_eq!(buf.chunk(), b" World" ); |
144 | } |
145 | |
146 | #[test ] |
147 | #[should_panic (expected = "`len` greater than remaining" )] |
148 | fn buf_to_bytes_too_many() { |
149 | hello_world_buf().copy_to_bytes(42); |
150 | } |
151 | } |
152 | |