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MemoryAccess

wasm_dbms_memory

Trait MemoryAccess 

Source 
pub trait MemoryAccess {
    // Required methods
    fn page_size(&self) -> u64;
    fn allocate_page(&mut self) -> MemoryResult<Page>;
    fn read_at<D>(&self, page: Page, offset: PageOffset) -> MemoryResult<D>
       where D: Encode;
    fn write_at<E>(
        &mut self,
        page: Page,
        offset: PageOffset,
        data: &E,
    ) -> MemoryResult<()>
       where E: Encode;
    fn zero<E>(
        &mut self,
        page: Page,
        offset: PageOffset,
        data: &E,
    ) -> MemoryResult<()>
       where E: Encode;
    fn read_at_raw(
        &self,
        page: Page,
        offset: PageOffset,
        buf: &mut [u8],
    ) -> MemoryResult<usize>;
}
Expand description

Abstraction over page-level memory operations.

All table-registry and ledger functions are generic over this trait so that callers can transparently add write-ahead journaling or other interceptors without modifying the memory crate.

Required Methods§

Source

fn page_size(&self) -> u64

Returns the size of a single memory page.

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fn allocate_page(&mut self) -> MemoryResult<Page>

Allocates an additional page in memory and returns its number.

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fn read_at<D>(&self, page: Page, offset: PageOffset) -> MemoryResult<D>
where D: Encode,

Reads a typed value from the specified page and offset.

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fn write_at<E>( &mut self, page: Page, offset: PageOffset, data: &E, ) -> MemoryResult<()>
where E: Encode,

Writes a typed value at the specified page and offset.

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fn zero<E>( &mut self, page: Page, offset: PageOffset, data: &E, ) -> MemoryResult<()>
where E: Encode,

Zeros out the region occupied by data at the specified page and offset.

Source

fn read_at_raw( &self, page: Page, offset: PageOffset, buf: &mut [u8], ) -> MemoryResult<usize>

Reads raw bytes into buf at the specified page and offset.

Returns the number of bytes actually read.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§