Struct Memory 

pub struct Memory { /* private fields */ }

A sequential memory. It uses Rust’s Vec for internal representation.

Implementations

impl Memory

pub const fn new(limit: usize) -> Self

Create a new memory with the given limit.

pub const fn limit(&self) -> usize

Memory limit.

pub fn len(&self) -> usize

Get the length of the current memory range.

pub const fn effective_len(&self) -> usize

Get the effective length.

pub fn is_empty(&self) -> bool

Return true if current effective memory range is zero.

pub const fn data(&self) -> &Vec<u8>

Return the full memory.

pub fn resize_offset( &mut self, offset: usize, len: usize, ) -> Result<(), ExitError>

Resize the memory, making it cover the memory region of offset..offset + len, with 32 bytes as the step. If the length is zero, this function does nothing.

Errors

Return ExitError::InvalidRange if offset + len is overflow.

pub fn resize_end(&mut self, end: usize) -> Result<(), ExitError>

Resize the memory, making it cover to end, with 32 bytes as the step.

Errors

Return ExitError::InvalidRange if end value is overflow in next_multiple_of_32 call.

pub fn get(&self, offset: usize, size: usize) -> Vec<u8>

Get memory region at given offset.

Panics

Value of size is considered trusted. If they’re too large, the program can run out of memory, or it can overflow.

pub fn get_h256(&self, offset: usize) -> H256

Get H256 value from a specific offset in memory.

pub fn set( &mut self, offset: usize, value: &[u8], target_size: usize, ) -> Result<(), ExitFatal>

Set memory region at given offset. The offset and value is considered untrusted.

Errors

Return ExitFatal::NotSupported if offset + target_size is out of memory limit or overflow.

pub fn copy( &mut self, src_offset: usize, dst_offset: usize, length: usize, ) -> Result<(), ExitFatal>

Copy memory region form src to dst with length. copy_within uses memmove to avoid DoS attacks.

Errors

Return ExitFatal::Other:

• OverflowOnCopy if offset + length is overflow
• OutOfGasOnCopy if offst_length out of memory limit

pub fn copy_data( &mut self, memory_offset: usize, data_offset: U256, length: usize, data: &[u8], ) -> Result<(), ExitFatal>

Copy data into the memory, for the given length.

Copies min(length, available_source_bytes) from the source data starting at data_offset, into self.data starting at memory_offset. If length is greater than the number of bytes copied from source, the remaining bytes in the destination range (up to length) are filled with zeros.

Errors

Returns ExitFatal::NotSupported if the destination range memory_offset..memory_offset + length exceeds the memory limit or causes usize overflow.

Trait Implementations

impl Clone for Memory

fn clone(&self) -> Memory

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Memory

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

Formats the value using the given formatter.