Merge PR #228: ICS 4 refactors

Author: cwgoes

spec.pdf

@@ -466,13 +466,19 @@ function sendPacket(packet: Packet) {
  assert(packet.destPort === channel.counterpartyPortIdentifier)
  assert(packet.destChannel === channel.counterpartyChannelIdentifier)
  connection = provableStore.get(connectionPath(packet.connectionHops[0]))
+
  // optimistic sends are permitted once the handshake has started
  assert(connection.state !== CLOSED)
  assert(packet.connectionHops === channel.connectionHops)
+
  consensusState = provableStore.get(consensusStatePath(connection.clientIdentifier))
  assert(consensusState.getHeight() < packet.timeoutHeight)
+
  nextSequenceSend = provableStore.get(nextSequenceSendPath(packet.sourcePort, packet.sourceChannel))
  assert(packet.sequence === nextSequenceSend)
+
+ // all assertions passed, we can alter state
+
  nextSequenceSend = nextSequenceSend + 1
  provableStore.set(nextSequenceSendPath(packet.sourcePort, packet.sourceChannel), nextSequenceSend)
  provableStore.set(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, sequence), commit(packet.data))
@@ -507,10 +513,13 @@ function recvPacket(
  assert(authenticate(provableStore.get(portPath(packet.destPort))))
  assert(packet.sourcePort === channel.counterpartyPortIdentifier)
  assert(packet.sourceChannel === channel.counterpartyChannelIdentifier)
+
  connection = provableStore.get(connectionPath(channel.connectionHops[0]))
  assert(connection.state === OPEN)
  assert(packet.connectionHops === channel.connectionHops)
+
  assert(proofHeight < packet.timeoutHeight)
+
  client = queryClient(connection.clientIdentifier)
  assert(client.verifyMembership(
  proofHeight,
@@ -519,6 +528,8 @@ function recvPacket(
  commit(packet.data)
  ))
 
+ // all assertions passed (except sequence check), we can alter state
+
  if (acknowledgement.length > 0 || channel.order === UNORDERED)
  provableStore.set(
  packetAcknowledgementPath(packet.destPort, packet.destChannel, packet.sequence),
@@ -556,6 +567,7 @@ function acknowledgePacket(
  assert(channel.state === OPEN)
  assert(authenticate(provableStore.get(portPath(packet.sourcePort))))
  assert(packet.sourceChannel === channel.counterpartyChannelIdentifier)
+
  connection = provableStore.get(connectionPath(channel.connectionHops[0]))
  assert(packet.sourcePort === channel.counterpartyPortIdentifier)
  assert(packet.connectionHops === channel.connectionHops)
@@ -574,6 +586,8 @@ function acknowledgePacket(
  commit(acknowledgement)
  ))
 
+ // all assertions passed, we can alter state
+
  // delete our commitment so we can't "acknowledge" again
  provableStore.delete(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
 
@@ -606,9 +620,11 @@ function timeoutPacketOrdered(
  proof: CommitmentProof,
  proofHeight: uint64,
  nextSequenceRecv: uint64): Packet {
+
  channel = provableStore.get(channelPath(packet.sourcePort, packet.sourceChannel))
  assert(channel.state === OPEN)
  assert(channel.order === ORDERED)
+
  assert(authenticate(provableStore.get(portPath(packet.sourcePort))))
  assert(packet.destChannel === channel.counterpartyChannelIdentifier)
 
@@ -636,6 +652,8 @@ function timeoutPacketOrdered(
  nextSequenceRecv
  ))
 
+ // all assertions passed, we can alter state
+
  // delete our commitment
  provableStore.delete(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
 
@@ -685,6 +703,8 @@ function timeoutPacketUnordered(
  proof,
  packetAcknowledgementPath(packet.sourcePort, packet.sourceChannel, packet.sequence)
  ))
+ 
+ // all assertions passed, we can alter state
 
  // delete our commitment
  provableStore.delete(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
@@ -732,6 +752,8 @@ function timeoutClose(
  commit(packet.data)
  ))
 
+ // all assertions passed, we can alter state
+
  channel.state = CLOSED
  provableStore.set(channelPath(packet.destPort, packet.destChannel), channel)
 
@@ -784,6 +806,8 @@ function timeoutOnClose(
  packetAcknowledgementPath(packet.sourcePort, packet.sourceChannel, packet.sequence)
  ))
 
+ // all assertions passed, we can alter state
+
  // delete our commitment
  provableStore.delete(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
 
@@ -818,6 +842,10 @@ function cleanupPacketOrdered(
  // assert packet has been received on the other end
  assert(nextSequenceRecv > packet.sequence)
 
+ // verify we actually sent the packet, check the store
+ assert(provableStore.get(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
+ === commit(packet.data))
+
  // check that the recv sequence is as claimed
  client = queryClient(connection.clientIdentifier)
  assert(client.verifyMembership(
@@ -827,9 +855,7 @@ function cleanupPacketOrdered(
  nextSequenceRecv
  ))
 
- // verify we actually sent the packet, check the store
- assert(provableStore.get(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
- === commit(packet.data))
+ // all assertions passed, we can alter state
 
  // clear the store
  provableStore.delete(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
@@ -871,6 +897,8 @@ function cleanupPacketUnordered(
  assert(provableStore.get(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))
  === commit(packet.data))
 
+ // all assertions passed, we can alter state
+
  // clear the store
  provableStore.delete(packetCommitmentPath(packet.sourcePort, packet.sourceChannel, packet.sequence))