1 files changed, 74 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go b/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go
new file mode 100644
index 000000000..a809ff120
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go
@@ -0,0 +1,74 @@
+package wasm
+
+import (
+	"context"
+
+	"github.com/tetratelabs/wazero/api"
+	"github.com/tetratelabs/wazero/experimental"
+)
+
+type snapshotskey struct{}
+
+// withSetjmpLongjmp updates the context to contain wazero/experimental.Snapshotter{} support,
+// and embeds the necessary snapshots map required for later calls to Setjmp() / Longjmp().
+func withSetjmpLongjmp(ctx context.Context) context.Context {
+	snapshots := make(map[uint32]experimental.Snapshot, 10)
+	ctx = experimental.WithSnapshotter(ctx)
+	ctx = context.WithValue(ctx, snapshotskey{}, snapshots)
+	return ctx
+}
+
+func getSnapshots(ctx context.Context) map[uint32]experimental.Snapshot {
+	v, _ := ctx.Value(snapshotskey{}).(map[uint32]experimental.Snapshot)
+	return v
+}
+
+// setjmp implements the C function: setjmp(env jmp_buf)
+func setjmp(ctx context.Context, mod api.Module, stack []uint64) {
+
+	// Input arguments.
+	envptr := api.DecodeU32(stack[0])
+
+	// Take snapshot of current execution environment.
+	snapshotter := experimental.GetSnapshotter(ctx)
+	snapshot := snapshotter.Snapshot()
+
+	// Get stored snapshots map.
+	snapshots := getSnapshots(ctx)
+	if snapshots == nil {
+		panic("setjmp / longjmp not supported")
+	}
+
+	// Set latest snapshot in map.
+	snapshots[envptr] = snapshot
+
+	// Set return.
+	stack[0] = 0
+}
+
+// longjmp implements the C function: int longjmp(env jmp_buf, value int)
+func longjmp(ctx context.Context, mod api.Module, stack []uint64) {
+
+	// Input arguments.
+	envptr := api.DecodeU32(stack[0])
+	// val := stack[1]
+
+	// Get stored snapshots map.
+	snapshots := getSnapshots(ctx)
+	if snapshots == nil {
+		panic("setjmp / longjmp not supported")
+	}
+
+	// Get snapshot stored in map.
+	snapshot := snapshots[envptr]
+	if snapshot == nil {
+		panic("must first call setjmp")
+	}
+
+	// Set return.
+	stack[0] = 0
+
+	// Restore execution and
+	// return passed value arg.
+	snapshot.Restore(stack[1:])
+}