tower_web/util/buf_stream/
from.rs

1use super::SizeHint;
2
3use bytes::{Buf, BufMut, Bytes, BytesMut};
4
5/// Conversion from a `BufStream`.
6///
7/// By implementing `FromBufStream` for a type, you define how it will be
8/// created from a buf stream. This is common for types which describe byte
9/// storage of some kind.
10///
11/// `FromBufStream` is rarely called explicitly, and it is instead used through
12/// `BufStream`'s `collect` method.
13pub trait FromBufStream {
14    /// Type that is used to build `Self` while the `BufStream` is being
15    /// consumed.
16    type Builder;
17
18    /// Create a new, empty, builder. The provided `hint` can be used to inform
19    /// reserving capacity.
20    fn builder(hint: &SizeHint) -> Self::Builder;
21
22    /// Extend the builder with the `Buf`.
23    ///
24    /// This method is called whenever a new `Buf` value is obtained from the
25    /// buf stream.
26    fn extend<T: Buf>(builder: &mut Self::Builder, buf: &mut T);
27
28    /// Finalize the building of `Self`.
29    ///
30    /// Called once the buf stream is fully consumed.
31    fn build(builder: Self::Builder) -> Self;
32}
33
34impl FromBufStream for Vec<u8> {
35    type Builder = Vec<u8>;
36
37    fn builder(hint: &SizeHint) -> Vec<u8> {
38        Vec::with_capacity(hint.lower())
39    }
40
41    fn extend<T: Buf>(builder: &mut Self, buf: &mut T) {
42        builder.put(buf);
43    }
44
45    fn build(builder: Self) -> Self {
46        builder
47    }
48}
49
50impl FromBufStream for Bytes {
51    type Builder = BytesMut;
52
53    fn builder(hint: &SizeHint) -> BytesMut {
54        BytesMut::with_capacity(hint.lower())
55    }
56
57    fn extend<T: Buf>(builder: &mut Self::Builder, buf: &mut T) {
58        builder.put(buf);
59    }
60
61    fn build(builder: Self::Builder) -> Self {
62        builder.freeze()
63    }
64}
tower_web/util/buf_stream/from.rs

tower_web/util/buf_stream/
from.rs
