Module delta_buffer 

Delta buffering for sync scenarios (Invariant I6).

When a snapshot sync is in progress, incoming deltas are buffered so they can be replayed after the snapshot completes. This ensures that:

1. Deltas arriving during sync aren’t lost (Invariant I6 - Liveness Guarantee)
2. Event handlers can execute for buffered deltas after context is initialized

Delivery Contract

• Buffer size: Configurable, default 10,000 deltas per context
• Drop policy: Oldest-first when buffer full (with metric increment)
• Backpressure: None (fire-and-forget from network layer)
• Metrics: drops counter MUST be observable

Minimum Capacity Warning

If buffer capacity is set below MIN_RECOMMENDED_CAPACITY, a warning should be logged at startup. Zero capacity is valid but will drop ALL deltas.

Structs

BufferedDelta

A single buffered delta.

DeltaBuffer

Buffer for storing deltas during snapshot sync.

Enums

PushResult

Result of pushing a delta to the buffer.

Constants

DEFAULT_BUFFER_CAPACITY

Default buffer capacity (10,000 deltas per context).

MIN_RECOMMENDED_CAPACITY

Minimum recommended buffer capacity.