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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/hyper/src/common/buf.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/hyper/src/common/buf.rs')
-rw-r--r-- | third_party/rust/hyper/src/common/buf.rs | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/third_party/rust/hyper/src/common/buf.rs b/third_party/rust/hyper/src/common/buf.rs new file mode 100644 index 0000000000..64e9333ead --- /dev/null +++ b/third_party/rust/hyper/src/common/buf.rs @@ -0,0 +1,151 @@ +use std::collections::VecDeque; +use std::io::IoSlice; + +use bytes::{Buf, BufMut, Bytes, BytesMut}; + +pub(crate) struct BufList<T> { + bufs: VecDeque<T>, +} + +impl<T: Buf> BufList<T> { + pub(crate) fn new() -> BufList<T> { + BufList { + bufs: VecDeque::new(), + } + } + + #[inline] + pub(crate) fn push(&mut self, buf: T) { + debug_assert!(buf.has_remaining()); + self.bufs.push_back(buf); + } + + #[inline] + #[cfg(feature = "http1")] + pub(crate) fn bufs_cnt(&self) -> usize { + self.bufs.len() + } +} + +impl<T: Buf> Buf for BufList<T> { + #[inline] + fn remaining(&self) -> usize { + self.bufs.iter().map(|buf| buf.remaining()).sum() + } + + #[inline] + fn chunk(&self) -> &[u8] { + self.bufs.front().map(Buf::chunk).unwrap_or_default() + } + + #[inline] + fn advance(&mut self, mut cnt: usize) { + while cnt > 0 { + { + let front = &mut self.bufs[0]; + let rem = front.remaining(); + if rem > cnt { + front.advance(cnt); + return; + } else { + front.advance(rem); + cnt -= rem; + } + } + self.bufs.pop_front(); + } + } + + #[inline] + fn chunks_vectored<'t>(&'t self, dst: &mut [IoSlice<'t>]) -> usize { + if dst.is_empty() { + return 0; + } + let mut vecs = 0; + for buf in &self.bufs { + vecs += buf.chunks_vectored(&mut dst[vecs..]); + if vecs == dst.len() { + break; + } + } + vecs + } + + #[inline] + fn copy_to_bytes(&mut self, len: usize) -> Bytes { + // Our inner buffer may have an optimized version of copy_to_bytes, and if the whole + // request can be fulfilled by the front buffer, we can take advantage. + match self.bufs.front_mut() { + Some(front) if front.remaining() == len => { + let b = front.copy_to_bytes(len); + self.bufs.pop_front(); + b + } + Some(front) if front.remaining() > len => front.copy_to_bytes(len), + _ => { + assert!(len <= self.remaining(), "`len` greater than remaining"); + let mut bm = BytesMut::with_capacity(len); + bm.put(self.take(len)); + bm.freeze() + } + } + } +} + +#[cfg(test)] +mod tests { + use std::ptr; + + use super::*; + + fn hello_world_buf() -> BufList<Bytes> { + BufList { + bufs: vec![Bytes::from("Hello"), Bytes::from(" "), Bytes::from("World")].into(), + } + } + + #[test] + fn to_bytes_shorter() { + let mut bufs = hello_world_buf(); + let old_ptr = bufs.chunk().as_ptr(); + let start = bufs.copy_to_bytes(4); + assert_eq!(start, "Hell"); + assert!(ptr::eq(old_ptr, start.as_ptr())); + assert_eq!(bufs.chunk(), b"o"); + assert!(ptr::eq(old_ptr.wrapping_add(4), bufs.chunk().as_ptr())); + assert_eq!(bufs.remaining(), 7); + } + + #[test] + fn to_bytes_eq() { + let mut bufs = hello_world_buf(); + let old_ptr = bufs.chunk().as_ptr(); + let start = bufs.copy_to_bytes(5); + assert_eq!(start, "Hello"); + assert!(ptr::eq(old_ptr, start.as_ptr())); + assert_eq!(bufs.chunk(), b" "); + assert_eq!(bufs.remaining(), 6); + } + + #[test] + fn to_bytes_longer() { + let mut bufs = hello_world_buf(); + let start = bufs.copy_to_bytes(7); + assert_eq!(start, "Hello W"); + assert_eq!(bufs.remaining(), 4); + } + + #[test] + fn one_long_buf_to_bytes() { + let mut buf = BufList::new(); + buf.push(b"Hello World" as &[_]); + assert_eq!(buf.copy_to_bytes(5), "Hello"); + assert_eq!(buf.chunk(), b" World"); + } + + #[test] + #[should_panic(expected = "`len` greater than remaining")] + fn buf_to_bytes_too_many() { + hello_world_buf().copy_to_bytes(42); + } +} |