Documentation
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Overview ¶
Package record provides topic recording, deterministic replay, and fault injection for go-DDS applications.
Recording captures all samples delivered to a set of subscribers and writes them to an io.Writer as newline-delimited JSON (JSONL). Each line is a RecordedSample object.
Replay reads a JSONL recording and re-publishes the samples through a Participant, preserving original timing (or scaling it).
Fault injection wraps any Publisher and injects configurable faults — packet loss, delay, payload corruption, and duplication — to stress-test DDS consumers without modifying the network or transport.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type FaultOptions ¶
type FaultOptions struct {
// LossRate is the probability that a Write call is silently dropped.
LossRate float64
// DelayMin and DelayMax bound the random additional latency added before
// forwarding a sample. DelayMin == DelayMax imposes a fixed delay.
// Both zero means no added latency.
DelayMin time.Duration
DelayMax time.Duration
// CorruptRate is the probability that one byte of the payload is bit-flipped
// before forwarding.
CorruptRate float64
// DuplicateRate is the probability that a sample is forwarded twice.
DuplicateRate float64
// ReorderWindow, when > 1, buffers up to ReorderWindow samples and emits
// them in randomised order when the window fills, simulating out-of-order
// delivery. Samples buffered at Close are flushed in shuffled order.
ReorderWindow int
}
FaultOptions configures the fault injection behaviour of a FaultPublisher. All probability fields are in [0.0, 1.0]; values outside that range are clamped at call time.
type FaultPublisher ¶
type FaultPublisher struct {
// contains filtered or unexported fields
}
FaultPublisher wraps a dds.Publisher and injects faults on Write according to the given FaultOptions. It satisfies the dds.Publisher interface.
func NewFaultPublisher ¶
func NewFaultPublisher(pub dds.Publisher, opts FaultOptions, seed int64) *FaultPublisher
NewFaultPublisher wraps pub with fault injection configured by opts. seed is passed to the internal PRNG; pass 0 for a time-derived seed.
func (*FaultPublisher) Close ¶
func (f *FaultPublisher) Close() error
Close flushes any buffered reorder window, then closes the underlying publisher.
func (*FaultPublisher) Write ¶
func (f *FaultPublisher) Write(payload []byte) error
Write applies configured faults and then forwards to the underlying publisher. The call may block if DelayMin > 0.
type Player ¶
type Player struct {
// contains filtered or unexported fields
}
Player reads a JSONL recording written by Recorder and replays all samples through freshly created publishers on a Participant.
func NewPlayer ¶
func NewPlayer(r io.Reader, p dds.Participant) *Player
NewPlayer returns a Player that reads from r and creates publishers on p.
func (*Player) Play ¶
Play replays the recording at 1× speed (real-time). The first sample is published immediately; subsequent samples are delayed to match the original inter-sample timing recorded by the Recorder.
func (*Player) PlayFiltered ¶
PlayFiltered replays only samples whose topic is in the allow-list. A nil or empty allow-list plays all topics.
type RecordedSample ¶
type RecordedSample struct {
Topic string `json:"topic"`
Payload []byte `json:"payload"`
Timestamp time.Time `json:"timestamp"`
RecordedAt time.Time `json:"recorded_at"`
}
RecordedSample is the JSON-line format written by Recorder. Payload is base64-encoded when marshalled to JSON (standard encoding/json behaviour for []byte fields).
type Recorder ¶
type Recorder struct {
// contains filtered or unexported fields
}
Recorder subscribes to one or more topics and writes all received samples to an io.Writer as JSONL. Each call to AddTopic registers a subscriber whose channel will be drained into the recording.
func NewRecorder ¶
NewRecorder returns a Recorder that writes JSONL to w.
func (*Recorder) AddTopic ¶
func (r *Recorder) AddTopic(sub dds.Subscriber) *Recorder
AddTopic registers sub for recording. Must be called before Start. Returns r for chaining.
Source Files