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enforceUpdateGuards

@totemsdk/omnia

@totemsdk/omnia / enforceUpdateGuards

Function: enforceUpdateGuards()

enforceUpdateGuards(channelId, newSequence, payloadHash, pendingProposal?): "CAPACITY_NEAR_EXHAUSTION" | null

Enforce all per-update invariants that must hold for every state transition regardless of whether the caller is updateState, addHTLC, fulfillHTLC, or timeoutHTLC.

Specifically:

  1. WOTS capacity check: throws ChannelCapacityError at 100%, returns 'CAPACITY_NEAR_EXHAUSTION' at 95% (caller must NOT advance watermark).
  2. Stale-sequence guard (SequenceError): rejects any attempt to sign a sequence that is behind the module-level watermark.
  3. Double-sign guard (DoubleSignError): rejects a different payload at a sequence already committed by this process.
  4. Watermark advance: after all guards pass, records (newSequence, payloadHash) synchronously — before any async work — so no concurrent call can slip in between the guard and the WOTS reservation.

Parameters​

channelId​

string

Channel identifier for the watermark map key.

newSequence​

number

Proposed next sequence number.

payloadHash​

string

Hex-encoded SHA3-256 of the full off-chain state commitment (sequence + balances + pending HTLCs).

pendingProposal?​

payloadHash​

string

sequence​

number

Returns​

"CAPACITY_NEAR_EXHAUSTION" | null

'CAPACITY_NEAR_EXHAUSTION' when signing is blocked at the 95% threshold; null when signing may proceed.