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MemoryProvider

wasm_dbms_memory

Trait MemoryProvider 

Source 
pub trait MemoryProvider {
    const PAGE_SIZE: u64;

    // Required methods
    fn size(&self) -> u64;
    fn pages(&self) -> u64;
    fn grow(&mut self, new_pages: u64) -> MemoryResult<u64>;
    fn read(&self, offset: u64, buf: &mut [u8]) -> MemoryResult<()>;
    fn write(&mut self, offset: u64, buf: &[u8]) -> MemoryResult<()>;
}
Expand description

Memory Provider trait defines the interface for interacting with the underlying memory.

Abstracting memory access allows different implementations for production (e.g. stable memory) and testing (heap-based).

Required Associated Constants§

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const PAGE_SIZE: u64

The size of a memory page in bytes.

Required Methods§

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fn size(&self) -> u64

Gets the current size of the memory in bytes.

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fn pages(&self) -> u64

Gets the amount of pages currently allocated.

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fn grow(&mut self, new_pages: u64) -> MemoryResult<u64>

Attempts to grow the memory by new_pages (added pages).

Returns an error if it wasn’t possible. Otherwise, returns the previous size that was reserved.

Actual reserved size after the growth will be previous_size + (new_pages * PAGE_SIZE).

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fn read(&self, offset: u64, buf: &mut [u8]) -> MemoryResult<()>

Reads data from memory starting at offset into the provided buffer buf.

Returns an error if offset + buf.len() exceeds the current memory size.

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fn write(&mut self, offset: u64, buf: &[u8]) -> MemoryResult<()>

Writes data from the provided buffer buf into memory starting at offset.

Returns an error if offset + buf.len() exceeds the current memory size.

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§