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Overview

The SDK data layer includes record() and replay() utilities that let you capture live samples to disk and replay them later. Replayed samples flow through the same backend as live data, re-triggering any active hooks and subscribers.

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Quick start

from cyberwave.data import get_backend
from cyberwave.data.recording import record, replay

backend = get_backend()

# Record live samples
with record(backend, ["frames/default", "depth"], "/tmp/session1"):
    # ... samples flow through the backend while this block runs
    pass

# Replay recorded samples
result = replay(backend, "/tmp/session1", speed=1.0)
print(f"Replayed {result.samples_published} samples")

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Recording

record() returns a RecordingSession context manager. It subscribes to the specified channels using policy="fifo" and writes every incoming sample to per-channel .bin files inside the target directory. 
# Record with limits
session = record(
    backend,
    channels=["frames/default", "joint_states"],
    path="/data/recordings/session_001",
    max_samples=1000,       # stop after 1000 samples
    max_duration_s=60.0,    # or after 60 seconds
)
# ... later
manifest = session.stop()
The recording directory contains:
FileContents
manifest.jsonVersion, channels, timestamps, sample count
<channel>.binBinary stream of timestamped sample entries

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Replay

replay() reads a recording directory and publishes each sample back through the backend, preserving inter-sample timing. 
from cyberwave.data.recording import replay

# Real-time replay
replay(backend, "/data/recordings/session_001", speed=1.0)

# 2x speed
replay(backend, "/data/recordings/session_001", speed=2.0)

# As fast as possible (no sleep between samples)
replay(backend, "/data/recordings/session_001", speed=0)

# Replay specific channels only
replay(backend, "/data/recordings/session_001", channels=["frames/default"])

# Loop continuously
replay(backend, "/data/recordings/session_001", loop=True)

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Portability

Recordings are plain files with no backend-specific data. You can record on one backend (e.g. Zenoh) and replay on another (e.g. filesystem), or transfer recordings between machines.