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Reader

Struct Reader 

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pub struct Reader<R, D> {
    reader: R,
    operation: D,
    state: State,
    single_frame: bool,
    finished_frame: bool,
}
Expand description

Implements the Read API around an Operation.

This can be used to wrap a raw in-memory operation in a read-focused API.

It can wrap either a compression or decompression operation, and pulls input data from a wrapped Read.

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§reader: R§operation: D§state: State§single_frame: bool§finished_frame: bool

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impl<R, D> Reader<R, D>

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pub fn new(reader: R, operation: D) -> Self

Creates a new Reader.

reader will be used to pull input data for the given operation.

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pub fn set_single_frame(&mut self)

Sets self to stop after the first decoded frame.

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pub fn operation_mut(&mut self) -> &mut D

Returns a mutable reference to the underlying operation.

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pub fn reader_mut(&mut self) -> &mut R

Returns a mutable reference to the underlying reader.

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pub fn reader(&self) -> &R

Returns a reference to the underlying reader.

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pub fn into_inner(self) -> R

Returns the inner reader.

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pub fn flush(&mut self, output: &mut [u8]) -> Result<usize>
where D: Operation,

Flush any internal buffer.

For encoders, this ensures all input consumed so far is compressed.

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impl<R, D> Reader<R, D>
where R: BufRead, D: Operation,

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pub fn finish_frame(&mut self) -> Result<()>

Consume the rest of the current frame from the underlying reader.

Once all the decoded data has been read, zstd may still not have consumed the tail of the frame: it can produce the last of the output before reading the frame epilogue. The underlying reader is then left pointing somewhere inside the frame rather than just after it.

This feeds zstd the input it still needs, with no room for output, so the reader ends up positioned exactly at the end of the frame.

It stops there: it will not start decoding whatever follows, so a stream of concatenated frames keeps its remaining frames, and trailing non-zstd data is left untouched.

This is a no-op if the current frame is already complete, so it will not read from the underlying reader in that case.

Trait Implementations§

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impl<R, D> Read for Reader<R, D>
where R: BufRead, D: Operation,

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fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
1.36.0 · Source§

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers. Read more
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fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)
Determines if this Reader has an efficient read_vectored implementation. Read more
1.0.0 · Source§

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf. Read more
1.0.0 · Source§

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf. Read more
1.6.0 · Source§

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf. Read more
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fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)
Pull some bytes from this source into the specified buffer. Read more
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fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)
Reads the exact number of bytes required to fill cursor. Read more
1.0.0 · Source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Creates a “by reference” adapter for this instance of Read. Read more
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fn bytes(self) -> Bytes<Self>
where Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more
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fn chain<R>(self, next: R) -> Chain<Self, R>
where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another. Read more
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fn take(self, limit: u64) -> Take<Self>
where Self: Sized,

Creates an adapter which will read at most limit bytes from it. Read more
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fn read_array<const N: usize>(&mut self) -> Result<[u8; N], Error>
where Self: Sized,

🔬This is a nightly-only experimental API. (read_array)
Read and return a fixed array of bytes from this source. Read more

Auto Trait Implementations§

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impl<R, D> Freeze for Reader<R, D>
where R: Freeze, D: Freeze,

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impl<R, D> RefUnwindSafe for Reader<R, D>

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impl<R, D> Send for Reader<R, D>
where R: Send, D: Send,

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impl<R, D> Sync for Reader<R, D>
where R: Sync, D: Sync,

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impl<R, D> Unpin for Reader<R, D>
where R: Unpin, D: Unpin,

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impl<R, D> UnsafeUnpin for Reader<R, D>
where R: UnsafeUnpin, D: UnsafeUnpin,

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impl<R, D> UnwindSafe for Reader<R, D>
where R: UnwindSafe, D: UnwindSafe,

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.