Struct Leb128Reader 

pub struct Leb128Reader<R, P = NonStrict> { /* private fields */ }

Reader wrapper for LEB128 integers.

The decoding policy is selected by the P type parameter. Use Leb128Reader<R, NonStrict> for permissive decoding and Leb128Reader<R, Strict> for canonical-only decoding.

Target-width integers

usize and isize methods use the current Rust target’s pointer width. Prefer fixed-width integer methods such as read_u64 or read_i64 for persistent files and cross-platform protocols.

Implementations

impl<R, P> Leb128Reader<R, P>

where P: DecodePolicy,

pub const fn new(inner: R) -> Self

Creates a LEB128 reader.

pub const fn is_strict(&self) -> bool

Returns whether this reader rejects non-canonical encodings.

pub const fn get_ref(&self) -> &R

Returns a shared reference to the underlying reader.

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

Returns an exclusive reference to the underlying reader.

pub fn into_inner(self) -> R

Consumes this wrapper and returns the underlying reader.

impl<R> Leb128Reader<R, NonStrict>

where R: Read,

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

Reads an unsigned LEB128 u8.

pub fn read_u16(&mut self) -> Result<u16>

Reads an unsigned LEB128 u16.

pub fn read_u32(&mut self) -> Result<u32>

Reads an unsigned LEB128 u32.

pub fn read_u64(&mut self) -> Result<u64>

Reads an unsigned LEB128 u64.

pub fn read_u128(&mut self) -> Result<u128>

Reads an unsigned LEB128 u128.

pub fn read_usize(&mut self) -> Result<usize>

Reads an unsigned LEB128 usize.

pub fn read_i8(&mut self) -> Result<i8>

Reads a signed LEB128 i8.

pub fn read_i16(&mut self) -> Result<i16>

Reads a signed LEB128 i16.

pub fn read_i32(&mut self) -> Result<i32>

Reads a signed LEB128 i32.

pub fn read_i64(&mut self) -> Result<i64>

Reads a signed LEB128 i64.

pub fn read_i128(&mut self) -> Result<i128>

Reads a signed LEB128 i128.

pub fn read_isize(&mut self) -> Result<isize>

Reads a signed LEB128 isize.

pub fn read_utf8_string(&mut self, max_len: usize) -> Result<String>

Reads a UTF-8 string prefixed by an unsigned LEB128 byte length.

The length prefix is decoded as usize, so this format is target-width dependent. Prefer a fixed-width length prefix for persistent files and cross-platform protocols.

Parameters

• max_len: Maximum accepted UTF-8 payload length in bytes.

Returns

Returns the decoded UTF-8 string.

Errors

Returns an I/O error for length or payload reads, std::io::ErrorKind::InvalidData when the encoded length exceeds max_len, or std::io::ErrorKind::InvalidData when the payload is not valid UTF-8.

impl<R> Leb128Reader<R, Strict>

where R: Read,

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

Reads an unsigned LEB128 u8.

pub fn read_u16(&mut self) -> Result<u16>

Reads an unsigned LEB128 u16.

pub fn read_u32(&mut self) -> Result<u32>

Reads an unsigned LEB128 u32.

pub fn read_u64(&mut self) -> Result<u64>

Reads an unsigned LEB128 u64.

pub fn read_u128(&mut self) -> Result<u128>

Reads an unsigned LEB128 u128.

pub fn read_usize(&mut self) -> Result<usize>

Reads an unsigned LEB128 usize.

pub fn read_i8(&mut self) -> Result<i8>

Reads a signed LEB128 i8.

pub fn read_i16(&mut self) -> Result<i16>

Reads a signed LEB128 i16.

pub fn read_i32(&mut self) -> Result<i32>

Reads a signed LEB128 i32.

pub fn read_i64(&mut self) -> Result<i64>

Reads a signed LEB128 i64.

pub fn read_i128(&mut self) -> Result<i128>

Reads a signed LEB128 i128.

pub fn read_isize(&mut self) -> Result<isize>

Reads a signed LEB128 isize.

pub fn read_utf8_string(&mut self, max_len: usize) -> Result<String>

Reads a UTF-8 string prefixed by an unsigned LEB128 byte length.

The length prefix is decoded as usize, so this format is target-width dependent. Prefer a fixed-width length prefix for persistent files and cross-platform protocols.

Parameters

• max_len: Maximum accepted UTF-8 payload length in bytes.

Returns

Returns the decoded UTF-8 string.

Errors

Returns an I/O error for length or payload reads, std::io::ErrorKind::InvalidData when the encoded length exceeds max_len, or std::io::ErrorKind::InvalidData when the payload is not valid UTF-8.

Trait Implementations

impl<R, P> Read for Leb128Reader<R, P>

where R: Read,

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

Reads bytes from the wrapped reader.

Parameters

• buffer: Destination byte buffer.

Returns

Returns the number of bytes read.

Errors

Returns the I/O error reported by the wrapped reader.

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

Like read, except that it reads into a slice of buffers.

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.

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.

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

Reads all bytes until EOF in this source, appending them to buf.

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

Reads the exact number of bytes required to fill buf.

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.

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.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

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.

impl<R, P> Seek for Leb128Reader<R, P>

where R: Seek,

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

Seeks the wrapped reader.

Parameters

• position: Target seek position.

Returns

Returns the new stream position.

Errors

Returns the seek error reported by the wrapped reader.

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

Rewind to the beginning of a stream.

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).

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

Returns the current seek position from the start of the stream.

fn seek_relative(&mut self, offset: i64) -> Result<(), Error>

Seeks relative to the current position.