51 lines
1.6 KiB
Go
51 lines
1.6 KiB
Go
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package experimental
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import (
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"context"
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"github.com/tetratelabs/wazero/internal/expctxkeys"
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)
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// MemoryAllocator is a memory allocation hook,
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// invoked to create a LinearMemory.
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type MemoryAllocator interface {
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// Allocate should create a new LinearMemory with the given specification:
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// cap is the suggested initial capacity for the backing []byte,
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// and max the maximum length that will ever be requested.
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//
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// Notes:
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// - To back a shared memory, the address of the backing []byte cannot
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// change. This is checked at runtime. Implementations should document
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// if the returned LinearMemory meets this requirement.
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Allocate(cap, max uint64) LinearMemory
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}
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// MemoryAllocatorFunc is a convenience for defining inlining a MemoryAllocator.
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type MemoryAllocatorFunc func(cap, max uint64) LinearMemory
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// Allocate implements MemoryAllocator.Allocate.
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func (f MemoryAllocatorFunc) Allocate(cap, max uint64) LinearMemory {
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return f(cap, max)
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}
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// LinearMemory is an expandable []byte that backs a Wasm linear memory.
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type LinearMemory interface {
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// Reallocates the linear memory to size bytes in length.
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//
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// Notes:
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// - To back a shared memory, Reallocate can't change the address of the
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// backing []byte (only its length/capacity may change).
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Reallocate(size uint64) []byte
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// Free the backing memory buffer.
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Free()
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}
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// WithMemoryAllocator registers the given MemoryAllocator into the given
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// context.Context.
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func WithMemoryAllocator(ctx context.Context, allocator MemoryAllocator) context.Context {
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if allocator != nil {
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return context.WithValue(ctx, expctxkeys.MemoryAllocatorKey{}, allocator)
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}
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return ctx
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}
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