Documentation
¶
Overview ¶
Package cmd defines the commands that drive an execution. A command is a request (start, complete a task, deliver a signal, fire a timer, …) published on the execution's partition of the command stream; the engine decides which events it produces. Every command carries an id: the stream deduplicates on it (Nats-Msg-Id) and the decision is idempotent, so redelivery is harmless.
The JSON encoding is the wire protocol shared by every SDK.
Index ¶
Constants ¶
const ( HeaderMsgID = "Nats-Msg-Id" HeaderType = "Pt-Cmd-Type" HeaderTraceparent = "traceparent" )
Headers.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type CancelData ¶
type CancelData struct {
Reason string `json:"reason,omitempty"`
}
CancelData is the payload of Cancel.
type ChildDoneData ¶
type ChildDoneData struct {
ChildID string `json:"child_id"`
Status string `json:"status"`
Output json.RawMessage `json:"output,omitempty"`
Error string `json:"error,omitempty"`
Counters map[string]float64 `json:"counters,omitempty"`
}
ChildDoneData is the payload of ChildDone, sent to the parent.
type Command ¶
type Command struct {
ID string `json:"id"`
Type Type `json:"type"`
ExecID string `json:"exec_id"`
Time time.Time `json:"time,omitzero"`
Data json.RawMessage `json:"data,omitempty"`
// Reply, when set, is a subject the engine answers on once the command is
// decided (stored, a no-op, or rejected): wire.Reply.
Reply string `json:"reply,omitempty"`
}
Command is the envelope of every command.
type CompleteData ¶
type CompleteData struct {
TaskRef
Output json.RawMessage `json:"output,omitempty"`
Writes map[string]json.RawMessage `json:"writes,omitempty"`
Next string `json:"next,omitempty"`
Usage map[string]float64 `json:"usage,omitempty"`
CacheKey string `json:"cache_key,omitempty"`
Cached bool `json:"cached,omitempty"`
}
CompleteData is the payload of Complete.
type FailData ¶
type FailData struct {
TaskRef
Error string `json:"error"`
Retryable bool `json:"retryable"`
Reason string `json:"reason,omitempty"`
Usage map[string]float64 `json:"usage,omitempty"`
}
FailData is the payload of Fail.
type ForkData ¶
type ForkData struct {
From string `json:"from"`
Seq uint64 `json:"seq"`
// Writes edit the fork's channels (through their reducers) before it
// resumes: LangGraph's update_state then continue.
Writes map[string]json.RawMessage `json:"writes,omitempty"`
}
ForkData is the payload of Fork: create ExecID from the state of From at sequence Seq (the end of a decision).
type InterruptData ¶
type InterruptData struct {
TaskRef
Payload json.RawMessage `json:"payload,omitempty"`
Usage map[string]float64 `json:"usage,omitempty"`
}
InterruptData is the payload of Interrupt.
type ResumeData ¶
type ResumeData struct {
Node string `json:"node"`
Key string `json:"key,omitempty"`
Value json.RawMessage `json:"value,omitempty"`
}
ResumeData is the payload of Resume: re-run the interrupted node with Value available to the worker as `resume`.
type SignalData ¶
type SignalData struct {
Name string `json:"name"`
Payload json.RawMessage `json:"payload,omitempty"`
}
SignalData is the payload of Signal. The command id is the signal id.
type StartData ¶
type StartData struct {
Flow string `json:"flow"`
// Version pins a flow hash; empty means the latest registered version.
Version string `json:"version,omitempty"`
Input json.RawMessage `json:"input,omitempty"`
Parent *event.ParentRef `json:"parent,omitempty"`
}
StartData is the payload of Start.
type TaskRef ¶
type TaskRef struct {
Key string `json:"key"`
Generation int `json:"generation"`
Attempt int `json:"attempt"`
}
TaskRef identifies one attempt of a task instance; a completion for any other attempt is stale and ignored.
type TimerData ¶
type TimerData struct {
TimerID string `json:"timer_id"`
}
TimerData is the payload of Timer (published by a JetStream schedule).
type Type ¶
type Type string
Type names a command.
const ( Start Type = "start" Fork Type = "fork" Complete Type = "complete" Fail Type = "fail" Interrupt Type = "interrupt" Resume Type = "resume" Signal Type = "signal" Cancel Type = "cancel" // Update writes channels of a running execution (synchronous: the // command carries a reply subject). Update Type = "update" Timer Type = "timer" ChildDone Type = "child_done" Archive Type = "archive" // Redispatch lifts the quarantine of an execution (dispatcher replay). Redispatch Type = "redispatch" )
Command types.
type UpdateData ¶
type UpdateData struct {
Writes map[string]json.RawMessage `json:"writes"`
}
UpdateData is the payload of Update. The command id is the update id: an update is applied once, however often it is delivered.
Source Files