wasm

type ByteMeter interface {
	AddIn(n int64)
	AddOut(n int64)
}

type Capabilities struct {
	Env           map[string]string `json:"env,omitempty"`
	Preopens      []Preopen         `json:"preopens,omitempty"`
	Args          []string          `json:"args,omitempty"`
	MemoryMB      int               `json:"memory_mb,omitempty"`
	WallTimeoutNs int64             `json:"wall_timeout_ns,omitempty"`
	// WASIListenPort enables wasip1 pre-open TCP listeners when >= 0 (0 = ephemeral).
	// When unset, use -1 to disable.
	WASIListenPort int    `json:"wasi_listen_port,omitempty"`
	WASIListenHost string `json:"wasi_listen_host,omitempty"`
}

type Engine interface {
	// LoadModule compiles bytes from path. Idempotent per path within one engine.
	LoadModule(ctx context.Context, path string, opts LoadOptions) error
	// Instantiate creates a runnable instance with the given capabilities.
	Instantiate(ctx context.Context, caps Capabilities) error
	// InvokeExport calls an exported function by name.
	InvokeExport(ctx context.Context, name string) error
	// Run re-instantiates with caps, invokes export, and captures stdout/stderr.
	Run(ctx context.Context, caps Capabilities, export string) (RunResult, error)
	// StopInstance tears down the active instance but keeps the compiled module.
	StopInstance(ctx context.Context) error
	// CaptureSnapshot exports linear memory from the active instance.
	CaptureSnapshot(ctx context.Context) (SnapshotCapture, error)
	// RestoreSnapshot re-instantiates and loads memory from a capture.
	RestoreSnapshot(ctx context.Context, snap SnapshotRestoreInput, caps Capabilities) error
	// Close releases compiled module and any active instance.
	Close(ctx context.Context) error
	// ResolvedListenPort returns the host port for an ephemeral wasip1 listener (0 in caps).
	ResolvedListenPort() (int, bool)
	// SupportsListen reports whether the engine can host a wasip1 TCP listener
	// (the HTTP ingress / expose_port path). wazero can; the wasmtime backend
	// cannot yet (see plans/wasm-runtime.md "Still open"). Callers must reject
	// listen requests up front rather than silently failing to resolve a port.
	SupportsListen() bool
}

type LoadOptions struct {
	MemoryMB int
}

type NetByteCounter struct {
	// contains filtered or unexported fields
}

type NetDialer interface {
	DialContext(ctx context.Context, network, address string) (net.Conn, error)
}

type NetworkAwareEngine interface {
	Engine
	SetNetworkHook(hook *NetworkHook)
	ClearNetworkHook()
}

type NetworkHook struct {
	SandboxID string
	Dial      NetDialer
	// Meter receives wasip1 sock_accept/recv/send and host-module socket bytes.
	Meter ByteMeter
}

type Preopen struct {
	GuestPath string `json:"guest_path"`
	HostPath  string `json:"host_path"`
}

type RunResult struct {
	ExitCode int        `json:"exit_code"`
	Stdout   string     `json:"stdout,omitempty"`
	Stderr   string     `json:"stderr,omitempty"`
	Usage    UsageStats `json:"usage,omitempty"`
}

type SnapshotBaseModule struct {
	Digest string `json:"digest"`
	Size   int64  `json:"size"`
}

type SnapshotCapture struct {
	Config    SnapshotConfig
	Memory    []byte
	Globals   []byte
	WASIState []byte
}

type SnapshotConfig struct {
	SchemaVersion     int                `json:"schema_version"`
	Engine            string             `json:"engine"`
	EngineVersion     string             `json:"engine_version"`
	WASIVersion       string             `json:"wasi_version"`
	BaseModule        SnapshotBaseModule `json:"base_module"`
	Entrypoint        string             `json:"entrypoint"`
	Durability        string             `json:"durability"`
	CapturedAt        string             `json:"captured_at"`
	CloneGeneration   string             `json:"clone_generation"`
	MemoryChecksum    string             `json:"memory_checksum"`
	WASIStateChecksum string             `json:"wasi_state_checksum"`
	GlobalsCount      int                `json:"globals_count"`
}

type SnapshotRestoreInput struct {
	Config    SnapshotConfig
	Memory    []byte
	Globals   []byte
	WASIState []byte
}

type UsageStats struct {
	WallDurationMs int64 `json:"wall_duration_ms"`
	// Instructions is populated only on the wasmtime engine seam (UC-42b).
	Instructions int64 `json:"instructions,omitempty"`
}