package engine import ( "context" "io" "git.defalsify.org/vise/persist" "git.defalsify.org/vise/resource" ) // RunPersisted performs a single vm execution from client input using a persisted state. // // State is first loaded from storage. The vm is initialized with the state and executed. The new state is then saved to storage. // // The resulting output of the execution will be written to the provided writer. // // The state is identified by the SessionId member of the Config. Before first execution, the caller must ensure that an // initialized state actually is available for the identifier, otherwise the method will fail. // // It will also fail if execution by the underlying Engine fails. func RunPersisted(cfg Config, rs resource.Resource, pr persist.Persister, input []byte, w io.Writer, ctx context.Context) error { err := pr.Load(cfg.SessionId) if err != nil { return err } en, err := NewEngine(cfg, pr.GetState(), rs, pr.GetMemory(), ctx) if err != nil { return err } c, err := en.WriteResult(w, ctx) if err != nil { return err } err = pr.Save(cfg.SessionId) if err != nil { return err } if c > 0 { return err } _, err = en.Exec(input, ctx) if err != nil { return err } _, err = en.WriteResult(w, ctx) if err != nil { return err } return pr.Save(cfg.SessionId) }