49 lines
2.0 KiB
Go
49 lines
2.0 KiB
Go
package experimental
|
|
|
|
import (
|
|
"context"
|
|
|
|
"github.com/tetratelabs/wazero/internal/expctxkeys"
|
|
)
|
|
|
|
// Snapshot holds the execution state at the time of a Snapshotter.Snapshot call.
|
|
type Snapshot interface {
|
|
// Restore sets the Wasm execution state to the capture. Because a host function
|
|
// calling this is resetting the pointer to the executation stack, the host function
|
|
// will not be able to return values in the normal way. ret is a slice of values the
|
|
// host function intends to return from the restored function.
|
|
Restore(ret []uint64)
|
|
}
|
|
|
|
// Snapshotter allows host functions to snapshot the WebAssembly execution environment.
|
|
type Snapshotter interface {
|
|
// Snapshot captures the current execution state.
|
|
Snapshot() Snapshot
|
|
}
|
|
|
|
// EnableSnapshotterKey is a context key to indicate that snapshotting should be enabled.
|
|
// The context.Context passed to a exported function invocation should have this key set
|
|
// to a non-nil value, and host functions will be able to retrieve it using SnapshotterKey.
|
|
//
|
|
// Deprecated: use WithSnapshotter to enable snapshots.
|
|
type EnableSnapshotterKey = expctxkeys.EnableSnapshotterKey
|
|
|
|
// WithSnapshotter enables snapshots.
|
|
// Passing the returned context to a exported function invocation enables snapshots,
|
|
// and allows host functions to retrieve the Snapshotter using GetSnapshotter.
|
|
func WithSnapshotter(ctx context.Context) context.Context {
|
|
return context.WithValue(ctx, expctxkeys.EnableSnapshotterKey{}, struct{}{})
|
|
}
|
|
|
|
// SnapshotterKey is a context key to access a Snapshotter from a host function.
|
|
// It is only present if EnableSnapshotter was set in the function invocation context.
|
|
//
|
|
// Deprecated: use GetSnapshotter to get the snapshotter.
|
|
type SnapshotterKey = expctxkeys.SnapshotterKey
|
|
|
|
// GetSnapshotter gets the Snapshotter from a host function.
|
|
// It is only present if WithSnapshotter was called with the function invocation context.
|
|
func GetSnapshotter(ctx context.Context) Snapshotter {
|
|
return ctx.Value(expctxkeys.SnapshotterKey{}).(Snapshotter)
|
|
}
|