Trait bytecodec::Decode
[−]
[src]
pub trait Decode { type Item; fn decode(
&mut self,
buf: &[u8],
eos: Eos
) -> Result<(usize, Option<Self::Item>)>; fn requiring_bytes(&self) -> ByteCount; }
This trait allows for decoding items from a byte sequence incrementally.
Associated Types
type Item
The type of items to be decoded.
Required Methods
fn decode(
&mut self,
buf: &[u8],
eos: Eos
) -> Result<(usize, Option<Self::Item>)>
&mut self,
buf: &[u8],
eos: Eos
) -> Result<(usize, Option<Self::Item>)>
Consumes the given buffer (a part of a byte sequence), and decodes an item from it.
The first element of a succeeded result is the number of bytes consumed
from buf
by the decoding process.
If an item is successfully decoded, the decoder will return Ok((_, Some(..)))
.
If the buffer does not contain enough bytes to decode the next item,
the decoder will return Ok((_, None))
.
In this case, the decoder must consume as many bytes in the buffer as possible.
If an item is not yet decoded but the number of consumed bytes in the last decode
invocation
is smaller than the length of buf
, it means the decoder has been suspended its work in any reasons.
In that case the decoder may require some instructions from clients to resume the work,
but its concrete method is beyond the scope of this trait.
Errors
Decoders return the following kinds of errors as necessary:
ErrorKind::DecoderTerminated
:- If all decodable items have been decoded,
the decoder must return this kind of error when
decode
method is called.
- If all decodable items have been decoded,
the decoder must return this kind of error when
ErrorKind::UnexpectedEos
:- The invocation of
eos.is_reached()
returnstrue
despite of the decoder requires more bytes to decode the next item.
- The invocation of
ErrorKind::InvalidInput
:- Decoded items have invalid values
- Invalid parameters were given to decoders
ErrorKind::Error
:- Other errors
fn requiring_bytes(&self) -> ByteCount
Returns the lower bound of the number of bytes needed to decode the next item.
If the decoder does not know the value, it will return ByteCount::Unknown
(e.g., null-terminated strings have no pre-estimable length).
If the decoder returns ByteCount::Finite(0)
, it means one of the followings:
- (a) There is an already decoded item
- The next invocation of
decode()
will return it without consuming any bytes
- The next invocation of
- (b) There are no decodable items
- All decodable items have been decoded, and the decoder cannot do any further works
Implementations on Foreign Types
impl<'a, D: ?Sized + Decode> Decode for &'a mut D
[src]
impl<D: ?Sized + Decode> Decode for Box<D>
[src]
Implementors
impl<T> Decode for BincodeDecoder<T> where
T: for<'de> Deserialize<'de>, type Item = T;impl<B: AsRef<[u8]> + AsMut<[u8]> + Copy> Decode for CopyableBytesDecoder<B> type Item = B;
impl<B: AsRef<[u8]> + AsMut<[u8]>> Decode for BytesDecoder<B> type Item = B;
impl Decode for RemainingBytesDecoder type Item = Vec<u8>;
impl<D> Decode for Utf8Decoder<D> where
D: Decode<Item = Vec<u8>>, type Item = String;impl<D, T, F> Decode for Map<D, T, F> where
D: Decode,
F: Fn(D::Item) -> T, type Item = T;impl<D, F, E> Decode for MapErr<D, F, E> where
D: Decode,
F: Fn(Error) -> E,
Error: From<E>, type Item = D::Item;impl<D0, D1, F> Decode for AndThen<D0, D1, F> where
D0: Decode,
D1: Decode,
F: Fn(D0::Item) -> D1, type Item = D1::Item;impl<D: Decode> Decode for Omittable<D> type Item = Option<D::Item>;
impl<D, T: Default> Decode for Collect<D, T> where
D: Decode,
T: Extend<D::Item>, type Item = T;impl<D: Decode> Decode for Length<D> type Item = D::Item;
impl<D, T> Decode for CollectN<D, T> where
D: Decode,
T: Default + Extend<D::Item>, type Item = T;impl<D, F, T, E> Decode for TryMap<D, F, T, E> where
D: Decode,
F: Fn(D::Item) -> Result<T, E>,
Error: From<E>, type Item = T;impl<D: Decode> Decode for SkipRemaining<D> type Item = D::Item;
impl<D: Decode> Decode for MaxBytes<D> type Item = D::Item;
impl<D: Decode, F> Decode for Assert<D, F> where
F: for<'a> Fn(&'a D::Item) -> bool, type Item = D::Item;impl<D: Decode> Decode for Slice<D> type Item = D::Item;
impl<D: Decode> Decode for MaybeEos<D> type Item = D::Item;
impl Decode for U8Decoder type Item = u8;
impl Decode for I8Decoder type Item = i8;
impl Decode for U16beDecoder type Item = u16;
impl Decode for U16leDecoder type Item = u16;
impl Decode for I16beDecoder type Item = i16;
impl Decode for I16leDecoder type Item = i16;
impl Decode for U24beDecoder type Item = u32;
impl Decode for U24leDecoder type Item = u32;
impl Decode for U32beDecoder type Item = u32;
impl Decode for U32leDecoder type Item = u32;
impl Decode for I32beDecoder type Item = i32;
impl Decode for I32leDecoder type Item = i32;
impl Decode for U40beDecoder type Item = u64;
impl Decode for U40leDecoder type Item = u64;
impl Decode for U48beDecoder type Item = u64;
impl Decode for U48leDecoder type Item = u64;
impl Decode for U56beDecoder type Item = u64;
impl Decode for U56leDecoder type Item = u64;
impl Decode for U64beDecoder type Item = u64;
impl Decode for U64leDecoder type Item = u64;
impl Decode for I64beDecoder type Item = i64;
impl Decode for I64leDecoder type Item = i64;
impl Decode for F32beDecoder type Item = f32;
impl Decode for F32leDecoder type Item = f32;
impl Decode for F64beDecoder type Item = f64;
impl Decode for F64leDecoder type Item = f64;
impl<T> Decode for JsonDecoder<T> where
T: for<'de> Deserialize<'de>, type Item = T;impl<D: MonolithicDecode> Decode for MonolithicDecoder<D> type Item = D::Item;
impl<D0, D1> Decode for Tuple2Decoder<D0, D1> where
D0: Decode,
D1: Decode, type Item = (D0::Item, D1::Item);impl<D0, D1, D2> Decode for Tuple3Decoder<D0, D1, D2> where
D0: Decode,
D1: Decode,
D2: Decode, type Item = (D0::Item, D1::Item, D2::Item);impl<D0, D1, D2, D3> Decode for Tuple4Decoder<D0, D1, D2, D3> where
D0: Decode,
D1: Decode,
D2: Decode,
D3: Decode, type Item = (D0::Item, D1::Item, D2::Item, D3::Item);impl<D0, D1, D2, D3, D4> Decode for Tuple5Decoder<D0, D1, D2, D3, D4> where
D0: Decode,
D1: Decode,
D2: Decode,
D3: Decode,
D4: Decode, type Item = (D0::Item, D1::Item, D2::Item, D3::Item, D4::Item);impl<D0, D1, D2, D3, D4, D5> Decode for Tuple6Decoder<D0, D1, D2, D3, D4, D5> where
D0: Decode,
D1: Decode,
D2: Decode,
D3: Decode,
D4: Decode,
D5: Decode, type Item = (D0::Item, D1::Item, D2::Item, D3::Item, D4::Item, D5::Item);impl<D0, D1, D2, D3, D4, D5, D6> Decode for Tuple7Decoder<D0, D1, D2, D3, D4, D5, D6> where
D0: Decode,
D1: Decode,
D2: Decode,
D3: Decode,
D4: Decode,
D5: Decode,
D6: Decode, type Item = (D0::Item, D1::Item, D2::Item, D3::Item, D4::Item, D5::Item, D6::Item);impl<D0, D1, D2, D3, D4, D5, D6, D7> Decode for Tuple8Decoder<D0, D1, D2, D3, D4, D5, D6, D7> where
D0: Decode,
D1: Decode,
D2: Decode,
D3: Decode,
D4: Decode,
D5: Decode,
D6: Decode,
D7: Decode, type Item = (D0::Item, D1::Item, D2::Item, D3::Item, D4::Item, D5::Item, D6::Item, D7::Item);impl<T> Decode for DecodedValue<T> type Item = T;
impl Decode for NullDecoder type Item = ();
impl Decode for StartDecoderChain type Item = ();
impl<D> Decode for DecoderChain<StartDecoderChain, D, ()> where
D: Decode, type Item = (D::Item,);impl<D0, D1, T0> Decode for DecoderChain<D0, D1, (T0,)> where
D0: Decode<Item = (T0,)>,
D1: Decode, type Item = (T0, D1::Item);impl<D0, D1, T0, T1> Decode for DecoderChain<D0, D1, (T0, T1)> where
D0: Decode<Item = (T0, T1)>,
D1: Decode, type Item = (T0, T1, D1::Item);impl<D0, D1, T0, T1, T2> Decode for DecoderChain<D0, D1, (T0, T1, T2)> where
D0: Decode<Item = (T0, T1, T2)>,
D1: Decode, type Item = (T0, T1, T2, D1::Item);impl<D0, D1, T0, T1, T2, T3> Decode for DecoderChain<D0, D1, (T0, T1, T2, T3)> where
D0: Decode<Item = (T0, T1, T2, T3)>,
D1: Decode, type Item = (T0, T1, T2, T3, D1::Item);impl<D0, D1, T0, T1, T2, T3, T4> Decode for DecoderChain<D0, D1, (T0, T1, T2, T3, T4)> where
D0: Decode<Item = (T0, T1, T2, T3, T4)>,
D1: Decode, type Item = (T0, T1, T2, T3, T4, D1::Item);impl<D0, D1, T0, T1, T2, T3, T4, T5> Decode for DecoderChain<D0, D1, (T0, T1, T2, T3, T4, T5)> where
D0: Decode<Item = (T0, T1, T2, T3, T4, T5)>,
D1: Decode, type Item = (T0, T1, T2, T3, T4, T5, D1::Item);impl<D0, D1, T0, T1, T2, T3, T4, T5, T6> Decode for DecoderChain<D0, D1, (T0, T1, T2, T3, T4, T5, T6)> where
D0: Decode<Item = (T0, T1, T2, T3, T4, T5, T6)>,
D1: Decode, type Item = (T0, T1, T2, T3, T4, T5, T6, D1::Item);impl<D: Decode> Decode for Buffered<D> type Item = D::Item;