pub struct DecodeReaderBytes<R, B> { /* private fields */ }
Expand description
An implementation of io::Read
that transcodes to UTF-8 in a streaming
fashion.
The high level goal of this decoder is to provide access to byte streams that are assumed to be UTF-8 unless an encoding is otherwise specified (either via a BOM or via an explicit designation of an encoding).
When no explicit source encoding is specified (via
DecodeReaderBytesBuilder
), the source encoding is determined by
inspecting the BOM from the stream read from R
, if one exists. If a
UTF-16 BOM exists, then the source stream is transcoded to UTF-8 with
invalid UTF-16 sequences translated to the Unicode replacement character.
Similarly if a UTF-8 BOM is seen. In all other cases, the source of the
underlying reader is passed through unchanged as if it were UTF-8.
Since this particular reader does not guarantee providing valid UTF-8 to the caller, the caller must be prepared to handle invalid UTF-8 itself.
R
is the type of the underlying reader and B
is the type of an internal
buffer used to store the results of transcoding. Callers may elect to reuse
the internal buffer via the DecodeReaderBytesBuilder::build_with_buffer
constructor.
Implementations§
Source§impl<R: Read> DecodeReaderBytes<R, Vec<u8>>
impl<R: Read> DecodeReaderBytes<R, Vec<u8>>
Sourcepub fn new(rdr: R) -> DecodeReaderBytes<R, Vec<u8>> ⓘ
pub fn new(rdr: R) -> DecodeReaderBytes<R, Vec<u8>> ⓘ
Create a new transcoder that converts a source stream to valid UTF-8 via BOM sniffing.
To explicitly control the encoding, UTF-8 passthru or amortize
allocation, use the
DecodeReaderBytesBuilder
constructor.
When a BOM is found (which must correspond to UTF-8, UTF-16LE or UTF-16BE), then transcoding to UTF-8 is performed and any invalid sequences in the source data are seamlessly replaced by the Unicode replacement character.
When no BOM is found (and no other encoding is specified via the builder), the underlying bytes are passed through as-is.
Trait Implementations§
Source§impl<R: Read, B: AsMut<[u8]>> Read for DecodeReaderBytes<R, B>
impl<R: Read, B: AsMut<[u8]>> Read for DecodeReaderBytes<R, B>
Source§fn read(&mut self, buf: &mut [u8]) -> Result<usize>
fn read(&mut self, buf: &mut [u8]) -> Result<usize>
1.36.0 · Source§fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>
read
, except that it reads into a slice of buffers. Read moreSource§fn is_read_vectored(&self) -> bool
fn is_read_vectored(&self) -> bool
can_vector
)1.0.0 · Source§fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>
buf
. Read more1.0.0 · Source§fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>
fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>
buf
. Read more1.6.0 · Source§fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>
fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>
buf
. Read moreSource§fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>
fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>
read_buf
)Source§fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>
fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>
read_buf
)cursor
. Read more1.0.0 · Source§fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
Read
. Read more