diff options
Diffstat (limited to 'buffered-reader/src/generic.rs')
| -rw-r--r-- | buffered-reader/src/generic.rs | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/buffered-reader/src/generic.rs b/buffered-reader/src/generic.rs index eed96d5e..f54fe6b2 100644 --- a/buffered-reader/src/generic.rs +++ b/buffered-reader/src/generic.rs @@ -12,9 +12,11 @@ use super::*; /// [`Memory`]. Both are more efficient than `Generic`. /// pub struct Generic<T: io::Read + Send + Sync, C: fmt::Debug + Sync + Send> { - buffer: Option<Box<[u8]>>, + buffer: Option<Vec<u8>>, // The next byte to read in the buffer. cursor: usize, + /// Currently unused buffer. + unused_buffer: Option<Vec<u8>>, // The preferred chunk size. This is just a hint. preferred_chunk_size: usize, // The wrapped reader. @@ -71,6 +73,7 @@ impl<T: io::Read + Send + Sync, C: fmt::Debug + Sync + Send> Generic<T, C> { Generic { buffer: None, cursor: 0, + unused_buffer: None, preferred_chunk_size: if let Some(s) = preferred_chunk_size { s } else { DEFAULT_BUF_SIZE }, @@ -135,7 +138,12 @@ impl<T: io::Read + Send + Sync, C: fmt::Debug + Sync + Send> Generic<T, C> { DEFAULT_BUF_SIZE, 2 * self.preferred_chunk_size), amount); - let mut buffer_new : Vec<u8> = vec![0u8; capacity]; + let mut buffer_new = self.unused_buffer.take() + .map(|mut v| { + vec_resize(&mut v, capacity); + v + }) + .unwrap_or_else(|| vec![0u8; capacity]); let mut amount_read = 0; while amount_buffered + amount_read < amount { @@ -170,9 +178,9 @@ impl<T: io::Read + Send + Sync, C: fmt::Debug + Sync + Send> Generic<T, C> { } vec_truncate(&mut buffer_new, amount_buffered + amount_read); - buffer_new.shrink_to_fit(); - self.buffer = Some(buffer_new.into_boxed_slice()); + self.unused_buffer = self.buffer.take(); + self.buffer = Some(buffer_new); self.cursor = 0; } } |