Struct ic_cdk::api::stable::StableReader

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pub struct StableReader<M: StableMemory = CanisterStableMemory>(/* private fields */);
Expand description

Keeps an offset and reads off stable memory consecutively.

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impl<M: StableMemory> StableReader<M>

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pub fn with_memory(memory: M, offset: usize) -> Self

Creates a new StableReader which reads from the selected memory

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pub fn offset(&self) -> usize

Returns the offset of the reader

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

Reads data from the stable memory location specified by an offset.

Note: The stable memory size is cached on creation of the StableReader. Therefore, in following scenario, it will get an OutOfBounds error:

  1. Create a StableReader
  2. Write some data to the stable memory which causes it grow
  3. call read() to read the newly written bytes

Trait Implementations§

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impl<M: Debug + StableMemory> Debug for StableReader<M>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl Default for StableReader

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fn default() -> Self

Returns the “default value” for a type. Read more
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impl<M: StableMemory> From<StableIO<M>> for StableReader<M>

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fn from(io: StableIO<M>) -> Self

Converts to this type from the input type.
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impl<M: StableMemory> Read for StableReader<M>

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

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>

Read 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>

Read 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>

Read 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)
Read 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” adaptor for this instance of Read. Read more
1.0.0 · source§

fn bytes(self) -> Bytes<Self>
where Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more
1.0.0 · source§

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
1.0.0 · source§

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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impl<M: StableMemory> Seek for StableReader<M>

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fn seek(&mut self, pos: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in a stream. Read more
1.55.0 · source§

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream. Read more
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fn stream_len(&mut self) -> Result<u64, Error>

🔬This is a nightly-only experimental API. (seek_stream_len)
Returns the length of this stream (in bytes). Read more
1.51.0 · source§

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream. Read more
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fn seek_relative(&mut self, offset: i64) -> Result<(), Error>

🔬This is a nightly-only experimental API. (seek_seek_relative)
Seeks relative to the current position. Read more

Auto Trait Implementations§

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impl<M> RefUnwindSafe for StableReader<M>
where M: RefUnwindSafe,

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impl<M> Send for StableReader<M>
where M: Send,

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impl<M> Sync for StableReader<M>
where M: Sync,

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impl<M> Unpin for StableReader<M>
where M: Unpin,

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impl<M> UnwindSafe for StableReader<M>
where M: UnwindSafe,

Blanket Implementations§

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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<R> BinReaderExt for R
where R: Read + Seek,

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fn read_type<T>(&mut self, endian: Endian) -> Result<T, Error>
where T: BinRead,

Read the given type from the reader using the given endianness.
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fn read_be<T>(&mut self) -> Result<T, Error>
where T: BinRead,

Read the given type from the reader with big endian byteorder
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fn read_le<T>(&mut self) -> Result<T, Error>
where T: BinRead,

Read the given type from the reader with little endian byteorder
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fn read_ne<T>(&mut self) -> Result<T, Error>
where T: BinRead,

Read the given type from the reader with the native byteorder
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fn read_type_args<T>( &mut self, endian: Endian, args: <T as BinRead>::Args ) -> Result<T, Error>
where T: BinRead,

Read T from the reader with the given byte order and arguments.
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fn read_be_args<T>(&mut self, args: <T as BinRead>::Args) -> Result<T, Error>
where T: BinRead,

Read T from the reader, assuming big-endian byte order, using the given arguments.
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fn read_le_args<T>(&mut self, args: <T as BinRead>::Args) -> Result<T, Error>
where T: BinRead,

Read T from the reader, assuming little-endian byte order, using the given arguments.
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fn read_ne_args<T>(&mut self, args: <T as BinRead>::Args) -> Result<T, Error>
where T: BinRead,

Read T from the reader, assuming native-endian byte order, using the given arguments.
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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<R> ReadBytesExt for R
where R: Read + ?Sized,

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fn read_u8(&mut self) -> Result<u8, Error>

Reads an unsigned 8 bit integer from the underlying reader. Read more
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fn read_i8(&mut self) -> Result<i8, Error>

Reads a signed 8 bit integer from the underlying reader. Read more
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fn read_u16<T>(&mut self) -> Result<u16, Error>
where T: ByteOrder,

Reads an unsigned 16 bit integer from the underlying reader. Read more
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fn read_i16<T>(&mut self) -> Result<i16, Error>
where T: ByteOrder,

Reads a signed 16 bit integer from the underlying reader. Read more
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fn read_u24<T>(&mut self) -> Result<u32, Error>
where T: ByteOrder,

Reads an unsigned 24 bit integer from the underlying reader. Read more
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fn read_i24<T>(&mut self) -> Result<i32, Error>
where T: ByteOrder,

Reads a signed 24 bit integer from the underlying reader. Read more
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fn read_u32<T>(&mut self) -> Result<u32, Error>
where T: ByteOrder,

Reads an unsigned 32 bit integer from the underlying reader. Read more
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fn read_i32<T>(&mut self) -> Result<i32, Error>
where T: ByteOrder,

Reads a signed 32 bit integer from the underlying reader. Read more
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fn read_u48<T>(&mut self) -> Result<u64, Error>
where T: ByteOrder,

Reads an unsigned 48 bit integer from the underlying reader. Read more
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fn read_i48<T>(&mut self) -> Result<i64, Error>
where T: ByteOrder,

Reads a signed 48 bit integer from the underlying reader. Read more
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fn read_u64<T>(&mut self) -> Result<u64, Error>
where T: ByteOrder,

Reads an unsigned 64 bit integer from the underlying reader. Read more
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fn read_i64<T>(&mut self) -> Result<i64, Error>
where T: ByteOrder,

Reads a signed 64 bit integer from the underlying reader. Read more
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fn read_u128<T>(&mut self) -> Result<u128, Error>
where T: ByteOrder,

Reads an unsigned 128 bit integer from the underlying reader. Read more
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fn read_i128<T>(&mut self) -> Result<i128, Error>
where T: ByteOrder,

Reads a signed 128 bit integer from the underlying reader. Read more
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fn read_uint<T>(&mut self, nbytes: usize) -> Result<u64, Error>
where T: ByteOrder,

Reads an unsigned n-bytes integer from the underlying reader. Read more
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fn read_int<T>(&mut self, nbytes: usize) -> Result<i64, Error>
where T: ByteOrder,

Reads a signed n-bytes integer from the underlying reader. Read more
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fn read_uint128<T>(&mut self, nbytes: usize) -> Result<u128, Error>
where T: ByteOrder,

Reads an unsigned n-bytes integer from the underlying reader.
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fn read_int128<T>(&mut self, nbytes: usize) -> Result<i128, Error>
where T: ByteOrder,

Reads a signed n-bytes integer from the underlying reader.
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fn read_f32<T>(&mut self) -> Result<f32, Error>
where T: ByteOrder,

Reads a IEEE754 single-precision (4 bytes) floating point number from the underlying reader. Read more
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fn read_f64<T>(&mut self) -> Result<f64, Error>
where T: ByteOrder,

Reads a IEEE754 double-precision (8 bytes) floating point number from the underlying reader. Read more
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fn read_u16_into<T>(&mut self, dst: &mut [u16]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of unsigned 16 bit integers from the underlying reader. Read more
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fn read_u32_into<T>(&mut self, dst: &mut [u32]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of unsigned 32 bit integers from the underlying reader. Read more
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fn read_u64_into<T>(&mut self, dst: &mut [u64]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of unsigned 64 bit integers from the underlying reader. Read more
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fn read_u128_into<T>(&mut self, dst: &mut [u128]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of unsigned 128 bit integers from the underlying reader. Read more
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fn read_i8_into(&mut self, dst: &mut [i8]) -> Result<(), Error>

Reads a sequence of signed 8 bit integers from the underlying reader. Read more
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fn read_i16_into<T>(&mut self, dst: &mut [i16]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of signed 16 bit integers from the underlying reader. Read more
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fn read_i32_into<T>(&mut self, dst: &mut [i32]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of signed 32 bit integers from the underlying reader. Read more
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fn read_i64_into<T>(&mut self, dst: &mut [i64]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of signed 64 bit integers from the underlying reader. Read more
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fn read_i128_into<T>(&mut self, dst: &mut [i128]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of signed 128 bit integers from the underlying reader. Read more
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fn read_f32_into<T>(&mut self, dst: &mut [f32]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of IEEE754 single-precision (4 bytes) floating point numbers from the underlying reader. Read more
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fn read_f32_into_unchecked<T>(&mut self, dst: &mut [f32]) -> Result<(), Error>
where T: ByteOrder,

👎Deprecated since 1.2.0: please use read_f32_into instead
DEPRECATED. Read more
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fn read_f64_into<T>(&mut self, dst: &mut [f64]) -> Result<(), Error>
where T: ByteOrder,

Reads a sequence of IEEE754 double-precision (8 bytes) floating point numbers from the underlying reader. Read more
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fn read_f64_into_unchecked<T>(&mut self, dst: &mut [f64]) -> Result<(), Error>
where T: ByteOrder,

👎Deprecated since 1.2.0: please use read_f64_into instead
DEPRECATED. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> StreamPosition for T
where T: Seek,

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fn stream_pos(&mut self) -> Result<u64, Error>

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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.