pub struct MemoryRef(_);
Expand description
Reference to a memory (See MemoryInstance
for details).
This reference has a reference-counting semantics.
Methods from Deref<Target = MemoryInstance>§
sourcepub fn maximum(&self) -> Option<Pages>
pub fn maximum(&self) -> Option<Pages>
Returns maximum amount of pages this MemoryInstance
can grow to.
Returns None
if there is no limit set.
Maximum memory size cannot exceed 65536
pages or 4GiB.
sourcepub fn lowest_used(&self) -> u32
pub fn lowest_used(&self) -> u32
Returns lowest offset ever written or u32::max_value()
if none.
sourcepub fn reset_lowest_used(&self, addr: u32)
pub fn reset_lowest_used(&self, addr: u32)
Resets tracked lowest offset.
sourcepub fn current_size(&self) -> Pages
pub fn current_size(&self) -> Pages
Returns current linear memory size.
Maximum memory size cannot exceed 65536
pages or 4GiB.
Example
To convert number of pages to number of bytes you can use the following code:
use wasmi::MemoryInstance;
use wasmi::memory_units::*;
let memory = MemoryInstance::alloc(Pages(1), None).unwrap();
let byte_size: Bytes = memory.current_size().into();
assert_eq!(
byte_size,
Bytes(65536),
);
sourcepub fn used_size(&self) -> Bytes
pub fn used_size(&self) -> Bytes
Returns current used memory size in bytes. This is the highest memory address that had been written to.
sourcepub fn get_value<T: LittleEndianConvert>(&self, offset: u32) -> Result<T, Error>
pub fn get_value<T: LittleEndianConvert>(&self, offset: u32) -> Result<T, Error>
Get value from memory at given offset.
sourcepub fn get(&self, offset: u32, size: usize) -> Result<Vec<u8>, Error>
pub fn get(&self, offset: u32, size: usize) -> Result<Vec<u8>, Error>
Copy data from memory at given offset.
This will allocate vector for you.
If you can provide a mutable slice you can use get_into
.
sourcepub fn get_into(&self, offset: u32, target: &mut [u8]) -> Result<(), Error>
pub fn get_into(&self, offset: u32, target: &mut [u8]) -> Result<(), Error>
Copy data from given offset in the memory into target
slice.
Errors
Returns Err
if the specified region is out of bounds.
sourcepub fn set(&self, offset: u32, value: &[u8]) -> Result<(), Error>
pub fn set(&self, offset: u32, value: &[u8]) -> Result<(), Error>
Copy data in the memory at given offset.
sourcepub fn set_value<T: LittleEndianConvert>(
&self,
offset: u32,
value: T
) -> Result<(), Error>
pub fn set_value<T: LittleEndianConvert>(
&self,
offset: u32,
value: T
) -> Result<(), Error>
Copy value in the memory at given offset.
sourcepub fn grow(&self, additional: Pages) -> Result<Pages, Error>
pub fn grow(&self, additional: Pages) -> Result<Pages, Error>
Increases the size of the linear memory by given number of pages. Returns previous memory size if succeeds.
Errors
Returns Err
if attempted to allocate more memory than permited by the limit.
sourcepub fn copy(
&self,
src_offset: usize,
dst_offset: usize,
len: usize
) -> Result<(), Error>
pub fn copy(
&self,
src_offset: usize,
dst_offset: usize,
len: usize
) -> Result<(), Error>
Copy contents of one memory region to another.
Semantically equivalent to memmove
.
Errors
Returns Err
if either of specified regions is out of bounds.
sourcepub fn copy_nonoverlapping(
&self,
src_offset: usize,
dst_offset: usize,
len: usize
) -> Result<(), Error>
pub fn copy_nonoverlapping(
&self,
src_offset: usize,
dst_offset: usize,
len: usize
) -> Result<(), Error>
Copy contents of one memory region to another (non-overlapping version).
Semantically equivalent to memcpy
.
but returns Error if source overlaping with destination.
Errors
Returns Err
if:
- either of specified regions is out of bounds,
- these regions overlaps.
sourcepub fn clear(&self, offset: usize, new_val: u8, len: usize) -> Result<(), Error>
pub fn clear(&self, offset: usize, new_val: u8, len: usize) -> Result<(), Error>
Fill the memory region with the specified value.
Semantically equivalent to memset
.
Errors
Returns Err
if the specified region is out of bounds.
sourcepub fn zero(&self, offset: usize, len: usize) -> Result<(), Error>
pub fn zero(&self, offset: usize, len: usize) -> Result<(), Error>
Fill the specified memory region with zeroes.
Errors
Returns Err
if the specified region is out of bounds.