use crate::memory::{LinearMemory, MemoryCreator};
use crate::store::{InstanceId, StoreOpaque};
use crate::trampoline::create_handle;
use crate::{Limits, MemoryType};
use anyhow::{anyhow, Result};
use wasmtime_environ::entity::PrimaryMap;
use wasmtime_environ::{wasm, MemoryPlan, MemoryStyle, Module, WASM_PAGE_SIZE};
use wasmtime_runtime::{RuntimeLinearMemory, RuntimeMemoryCreator, VMMemoryDefinition};
use std::sync::Arc;
pub fn create_memory(store: &mut StoreOpaque<'_>, memory: &MemoryType) -> Result<InstanceId> {
let mut module = Module::new();
let memory = wasm::Memory {
minimum: memory.limits().min(),
maximum: memory.limits().max(),
shared: false, };
let memory_plan =
wasmtime_environ::MemoryPlan::for_memory(memory, &store.engine().config().tunables);
let memory_id = module.memory_plans.push(memory_plan);
module
.exports
.insert(String::new(), wasm::EntityIndex::Memory(memory_id));
create_handle(module, store, PrimaryMap::new(), Box::new(()), &[], None)
}
struct LinearMemoryProxy {
mem: Box<dyn LinearMemory>,
}
impl RuntimeLinearMemory for LinearMemoryProxy {
fn size(&self) -> u32 {
self.mem.size()
}
fn maximum(&self) -> Option<u32> {
self.mem.maximum()
}
fn grow(&mut self, delta: u32) -> Option<u32> {
self.mem.grow(delta)
}
fn vmmemory(&self) -> VMMemoryDefinition {
VMMemoryDefinition {
base: self.mem.as_ptr(),
current_length: self.mem.size() as usize * WASM_PAGE_SIZE as usize,
}
}
}
#[derive(Clone)]
pub(crate) struct MemoryCreatorProxy(pub Arc<dyn MemoryCreator>);
impl RuntimeMemoryCreator for MemoryCreatorProxy {
fn new_memory(&self, plan: &MemoryPlan) -> Result<Box<dyn RuntimeLinearMemory>> {
let ty = MemoryType::new(Limits::new(plan.memory.minimum, plan.memory.maximum));
let reserved_size_in_bytes = match plan.style {
MemoryStyle::Static { bound } => Some(bound as u64 * WASM_PAGE_SIZE as u64),
MemoryStyle::Dynamic => None,
};
self.0
.new_memory(ty, reserved_size_in_bytes, plan.offset_guard_size)
.map(|mem| Box::new(LinearMemoryProxy { mem }) as Box<dyn RuntimeLinearMemory>)
.map_err(|e| anyhow!(e))
}
}