# tokio_util::codec::LinesCodec - Rust
API documentation for the Rust `LinesCodec` struct in crate `tokio_util`.
Keywords: rust, rustlang, rust-lang, LinesCodec

# Struct tokio_util::codec::LinesCodec [−] [src]

    pub struct LinesCodec { /* fields omitted */ }

A simple `Decoder` and `Encoder` implementation that splits up data into lines.

## Implementations

### `impl LinesCodec` [src]

#### `pub fn new() -> LinesCodec` [src]

Returns a `LinesCodec` for splitting up data into lines.

# Note

The returned `LinesCodec` will not have an upper bound on the length of a buffered line. See the documentation for `new_with_max_length` for information on why this could be a potential security risk.

#### `pub fn new_with_max_length(max_length: usize) -> Self` [src]

Returns a `LinesCodec` with a maximum line length limit.

If this is set, calls to `LinesCodec::decode` will return a `LinesCodecError` when a line exceeds the length limit. Subsequent calls will discard up to `limit` bytes from that line until a newline character is reached, returning `None` until the line over the limit has been fully discarded. After that point, calls to `decode` will function as normal.

# Note

Setting a length limit is highly recommended for any `LinesCodec` which will be exposed to untrusted input. Otherwise, the size of the buffer that holds the line currently being read is unbounded. An attacker could exploit this unbounded buffer by sending an unbounded amount of input without any `\n` characters, causing unbounded memory consumption.

#### `pub fn max_length(&self) -> usize` [src]

Returns the maximum line length when decoding.

    use std::usize;
    use tokio_util::codec::LinesCodec;

    let codec = LinesCodec::new();
    assert_eq!(codec.max_length(), usize::MAX);

    use tokio_util::codec::LinesCodec;

    let codec = LinesCodec::new_with_max_length(256);
    assert_eq!(codec.max_length(), 256);

## Trait Implementations

### `impl Clone for LinesCodec` [src]

#### `fn clone(&self) -> LinesCodec` [src]

Returns a copy of the value. Read more

#### `pub fn clone_from(&mut self, source: &Self)`1.0.0 [src]

Performs copy-assignment from `source`. Read more

### `impl Debug for LinesCodec` [src]

#### `fn fmt(&self, f: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl Decoder for LinesCodec` [src]

#### `type Item = String`

The type of decoded frames.

#### `type Error = LinesCodecError`

The type of unrecoverable frame decoding errors. Read more

#### `fn decode(
&mut self,
buf: &mut BytesMut
) -> Result<Option<String>, LinesCodecError>` [src]

Attempts to decode a frame from the provided buffer of bytes. Read more

#### `fn decode_eof(
&mut self,
buf: &mut BytesMut
) -> Result<Option<String>, LinesCodecError>` [src]

A default method available to be called when there are no more bytes available to be read from the underlying I/O. Read more

#### `fn framed<T: AsyncRead + AsyncWrite + Sized>(self, io: T) -> Framed<T, Self> where
Self: Sized,` [src]

Provides a `Stream` and `Sink` interface for reading and writing to this `Io` object, using `Decode` and `Encode` to read and write the raw data. Read more

### `impl Default for LinesCodec` [src]

#### `fn default() -> Self` [src]

Returns the "default value" for a type. Read more

### `impl<T> Encoder<T> for LinesCodec where
T: AsRef<str>,` [src]

#### `type Error = LinesCodecError`

The type of encoding errors. Read more

#### `fn encode(&mut self, line: T, buf: &mut BytesMut) -> Result<(), LinesCodecError>` [src]

Encodes a frame into the buffer provided. Read more

### `impl Eq for LinesCodec` [src]

### `impl Hash for LinesCodec` [src]

#### `fn hash<__H: Hasher>(&self, state: &mut __H)` [src]

Feeds this value into the given `Hasher`. Read more

#### `pub fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,` 1.3.0 [src]

Feeds a slice of this type into the given `Hasher`. Read more

### `impl Ord for LinesCodec` [src]

#### `fn cmp(&self, other: &LinesCodec) -> Ordering` [src]

This method returns an `Ordering` between `self` and `other`. Read more

#### `#[must_use]pub fn max(self, other: Self) -> Self` 1.21.0 [src]

Compares and returns the maximum of two values. Read more

#### `#[must_use]pub fn min(self, other: Self) -> Self` 1.21.0 [src]

Compares and returns the minimum of two values. Read more

#### `#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self` 1.50.0 [src]

Restrict a value to a certain interval. Read more

### `impl PartialEq<LinesCodec> for LinesCodec` [src]

#### `fn eq(&self, other: &LinesCodec) -> bool` [src]

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &LinesCodec) -> bool` [src]

This method tests for `!=`.

### `impl PartialOrd<LinesCodec> for LinesCodec` [src]

#### `fn partial_cmp(&self, other: &LinesCodec) -> Option<Ordering>` [src]

This method returns an ordering between `self` and `other` values if one exists. Read more

#### `fn lt(&self, other: &LinesCodec) -> bool` [src]

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more

#### `fn le(&self, other: &LinesCodec) -> bool` [src]

This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more

#### `fn gt(&self, other: &LinesCodec) -> bool` [src]

This method tests greater than (for `self` and `other`) and is used by the `>` operator. Read more

#### `fn ge(&self, other: &LinesCodec) -> bool` [src]

This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more

### `impl StructuralEq for LinesCodec` [src]

### `impl StructuralPartialEq for LinesCodec` [src]

## Auto Trait Implementations

### `impl RefUnwindSafe for LinesCodec` [src]

### `impl Send for LinesCodec` [src]

### `impl Sync for LinesCodec` [src]

### `impl Unpin for LinesCodec` [src]

### `impl UnwindSafe for LinesCodec` [src]

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `pub fn to_owned(&self) -> T` [src]

Creates owned data from borrowed data, usually by cloning. Read more

#### `pub fn clone_into(&self, target: &mut T)` [src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into`)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.