Struct SbeCursor 

pub struct SbeCursor<'a> { /* private fields */ }

Zero-copy SBE byte cursor for sequential decoding.

Wraps a byte slice and tracks position, providing typed read methods that automatically advance the cursor.

Implementations

impl<'a> SbeCursor<'a>

pub const fn new(buf: &'a [u8]) -> SbeCursor<'a>

Creates a new cursor at position 0.

pub const fn new_at(buf: &'a [u8], pos: usize) -> SbeCursor<'a>

Creates a cursor starting at a specific offset.

pub const fn pos(&self) -> usize

Current position in the buffer.

pub const fn remaining(&self) -> usize

Remaining bytes from current position.

pub const fn buffer(&self) -> &'a [u8]

Returns the underlying buffer.

pub fn peek(&self) -> &'a [u8]

Returns remaining bytes as a slice.

pub fn require(&self, n: usize) -> Result<(), SbeDecodeError>

Ensures at least n bytes remain.

Errors

Returns BufferTooShort if fewer than n bytes remain.

pub fn advance(&mut self, n: usize) -> Result<(), SbeDecodeError>

Advances position by n bytes.

Errors

Returns BufferTooShort if fewer than n bytes remain.

pub fn skip(&mut self, n: usize)

Skips n bytes without bounds checking.

Caller must ensure n bytes are available.

pub fn reset(&mut self)

Resets cursor to start of buffer.

pub fn set_pos(&mut self, pos: usize)

Sets cursor to a specific position.

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

Reads a u8 and advances by 1 byte.

Errors

Returns BufferTooShort if fewer than 1 byte remains.

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

Reads an i8 and advances by 1 byte.

Errors

Returns BufferTooShort if fewer than 1 byte remains.

pub fn read_u16_le(&mut self) -> Result<u16, SbeDecodeError>

Reads a u16 little-endian and advances by 2 bytes.

Errors

Returns BufferTooShort if fewer than 2 bytes remain.

pub fn read_i16_le(&mut self) -> Result<i16, SbeDecodeError>

Reads an i16 little-endian and advances by 2 bytes.

Errors

Returns BufferTooShort if fewer than 2 bytes remain.

pub fn read_u32_le(&mut self) -> Result<u32, SbeDecodeError>

Reads a u32 little-endian and advances by 4 bytes.

Errors

Returns BufferTooShort if fewer than 4 bytes remain.

pub fn read_i32_le(&mut self) -> Result<i32, SbeDecodeError>

Reads an i32 little-endian and advances by 4 bytes.

Errors

Returns BufferTooShort if fewer than 4 bytes remain.

pub fn read_u64_le(&mut self) -> Result<u64, SbeDecodeError>

Reads a u64 little-endian and advances by 8 bytes.

Errors

Returns BufferTooShort if fewer than 8 bytes remain.

pub fn read_i64_le(&mut self) -> Result<i64, SbeDecodeError>

Reads an i64 little-endian and advances by 8 bytes.

Errors

Returns BufferTooShort if fewer than 8 bytes remain.

pub fn read_u128_le(&mut self) -> Result<u128, SbeDecodeError>

Reads a u128 little-endian and advances by 16 bytes.

Errors

Returns BufferTooShort if fewer than 16 bytes remain.

pub fn read_i128_le(&mut self) -> Result<i128, SbeDecodeError>

Reads an i128 little-endian and advances by 16 bytes.

Errors

Returns BufferTooShort if fewer than 16 bytes remain.

pub fn read_optional_i64_le(&mut self) -> Result<Option<i64>, SbeDecodeError>

Reads an optional i64 where i64::MIN represents None.

Errors

Returns BufferTooShort if fewer than 8 bytes remain.

pub fn read_bytes(&mut self, n: usize) -> Result<&'a [u8], SbeDecodeError>

Reads N bytes and advances.

Errors

Returns BufferTooShort if fewer than n bytes remain.

pub fn read_var_string8(&mut self) -> Result<String, SbeDecodeError>

Reads a varString8 (1-byte length prefix + UTF-8 data).

Returns empty string if length is 0.

Errors

Returns BufferTooShort if the buffer is too short, or InvalidUtf8 if the data is not valid UTF-8.

pub fn read_var_string8_ref(&mut self) -> Result<&'a str, SbeDecodeError>

Reads a varString8 as a &str (zero-copy).

Errors

Returns BufferTooShort if the buffer is too short, or InvalidUtf8 if the data is not valid UTF-8.

pub fn read_var_string16(&mut self) -> Result<String, SbeDecodeError>

Reads a varString16 (2-byte length prefix + UTF-8 data).

Returns empty string if length is 0.

Errors

Returns BufferTooShort if the buffer is too short, or InvalidUtf8 if the data is not valid UTF-8.

pub fn read_var_string16_ref(&mut self) -> Result<&'a str, SbeDecodeError>

Reads a varString16 as a &str (zero-copy).

Errors

Returns BufferTooShort if the buffer is too short, or InvalidUtf8 if the data is not valid UTF-8.

pub fn skip_var_data8(&mut self) -> Result<(), SbeDecodeError>

Skips a varData8 field (1-byte length prefix + binary data).

Used for skipping binary fields that should not be decoded as UTF-8.

Errors

Returns BufferTooShort if the buffer is too short.

pub fn read_var_bytes8(&mut self) -> Result<Vec<u8>, SbeDecodeError>

Reads a varData8 field (1-byte length prefix + binary data).

Returns the raw bytes without UTF-8 decoding.

Errors

Returns BufferTooShort if the buffer is too short.

pub fn skip_var_data16(&mut self) -> Result<(), SbeDecodeError>

Skips a varData16 field (2-byte length prefix + binary data).

Errors

Returns BufferTooShort if the buffer is too short.

pub fn read_var_bytes16(&mut self) -> Result<Vec<u8>, SbeDecodeError>

Reads a varData16 field (2-byte length prefix + binary data).

Returns the raw bytes without UTF-8 decoding.

Errors

Returns BufferTooShort if the buffer is too short.

pub fn read_group_header(&mut self) -> Result<(u16, u32), SbeDecodeError>

Reads group header (u16 block_length + u32 num_in_group).

Returns (block_length, num_in_group).

Errors

Returns BufferTooShort if fewer than 6 bytes are available and GroupSizeTooLarge if num_in_group exceeds MAX_GROUP_SIZE.

pub fn read_group_header_16(&mut self) -> Result<(u16, u16), SbeDecodeError>

Reads compact group header (u16 block_length + u16 num_in_group).

Returns (block_length, num_in_group).

Errors

Returns BufferTooShort if fewer than 4 bytes are available and GroupSizeTooLarge if num_in_group exceeds MAX_GROUP_SIZE.

pub fn read_group<T, F>( &mut self, block_length: u16, num_in_group: u32, decode_item: F, ) -> Result<Vec<T>, SbeDecodeError>

where F: FnMut(&mut SbeCursor<'a>) -> Result<T, SbeDecodeError>,

Iterates over a group, calling decode_item for each element.

The decoder function receives a cursor positioned at the start of each item and should decode the item without advancing past block_length bytes.

Errors

Returns BufferTooShort if the buffer does not contain all group entries, or any error returned by decode_item.

Trait Implementations

impl<'a> Clone for SbeCursor<'a>

fn clone(&self) -> SbeCursor<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for SbeCursor<'a>

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

Formats the value using the given formatter.