Enum MemoryPointerLength 

pub enum MemoryPointerLength {
    X32b,
    X64b,
}

An enum deciding the amount of bytes required to point to a location in memory. If the extra memory is not needed, using a smaller MemoryPointerLength can be file size optimization.

Pointing to the max memory index

X32b => [0xFF, 0xFF, 0xFF, 0xFF]
X64b => [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]

Variants

X32b

32 bit memory pointers - (4 bytes).

X64b

64 bit memory pointers - (8 bytes).

Implementations

impl MemoryPointerLength

pub fn extract(&self, index: usize, pool: &[u8]) -> usize

Extract a usize from the memory pool at the given start index, until this MemoryPointerLength’s span is satisfied.

See Self::get_span(), [Self::to_usize(&[u8])].

pub fn to_usize(&self, input: &[u8]) -> usize

Convert the given input to a usize.

Panics if this length cannot be fit into a usize.

pub fn fit(&self, mem_ptr_index: usize) -> Vec<u8>

Convert a memory pointer index to its little-endian byte representation.

pub fn get_span(&self) -> usize

Get the byte size of this memory size.

X32b => 4 bytes, X64b => 8 bytes.

pub fn get_byte_identifier(&self) -> u8

Get the this memory pointer length’s byte identifier. This will be placed into the bytecode header.

See [options::header_format_doc] for a full guide regarding the ivm bytecode format.

pub fn from_byte_identifier(byte: u8) -> Option<Self>

Match the memory pointer length from the given byte.

See MemoryPointerLength::get_byte_identifier().