Merge pull request #37 from maticnetwork/plasma-exit-counter

plasma exit counter introduced so that we know the queue position for…

root/schema.graphql

@@ -38,6 +38,7 @@ type StateRegistration @entity {
 type PlasmaExit @entity {
   # id always created using `plasma-exit-${exitId}`
   id: ID!
+  counter: BigInt! # this field can be used to know where the exitStarted transaction happened.
   exitId: BigInt!
   exitInitiator: Bytes
   exitCompleter: Bytes
@@ -108,6 +109,12 @@ type GlobalDelegatorCounter @entity {
   current: BigInt!
 }
 
+# This can be used to get the count of the plasma exits and till where have the process exits been processed.
+type GlobalPlasmaExitCounter @entity {
+  id: ID!
+  current: BigInt!
+}
+
 type Delegator @entity {
   id: ID!
   counter: BigInt! # this field can be used for traversing through large number of delegator list

root/src/mappings/staking-info.ts

@@ -198,7 +198,6 @@ export function handleUpdateCommissionRate(event: UpdateCommissionRate): void {
 // Sole purpose of this entity is to keep a global state variable
 // which can be used when new delegator comes into picture
 function getGlobalDelegatorCounter(): GlobalDelegatorCounter {
-
   // Only one entry will be kept in this entity
   let id = 'global-delegator-counter'
   let entity = GlobalDelegatorCounter.load(id)
@@ -208,9 +207,7 @@ function getGlobalDelegatorCounter(): GlobalDelegatorCounter {
     entity.current = BigInt.fromI32(0)
 
   }
-
   return entity as GlobalDelegatorCounter
-
 }
 
 function loadDelegator(validatorId: BigInt, delegator: Address): Delegator {

root/src/mappings/withdraw-manager.ts

@@ -1,14 +1,36 @@
+import { BigInt } from '@graphprotocol/graph-ts'
 import { ExitStarted, ExitCancelled, Withdraw } from '../../generated/WithdrawManager/WithdrawManager'
-import { PlasmaExit } from '../../generated/schema'
+import { PlasmaExit, GlobalPlasmaExitCounter } from '../../generated/schema'
 
+function getGlobalPlasmaExitCounter(): GlobalPlasmaExitCounter {
+  // Only one entry will be kept in this entity
+  let id = 'global-plasma-exit-counter'
+  let entity = GlobalPlasmaExitCounter.load(id)
+  if (entity == null) {
+
+    entity = new GlobalPlasmaExitCounter(id)
+    entity.current = BigInt.fromI32(0)
+
+  }
+  return entity as GlobalPlasmaExitCounter
+}
 
 export function handleExitStarted(event: ExitStarted): void {
   let id = 'plasma-exit-' + event.params.exitId.toHexString()
+
+  // Try to get what's current global plasma counter's state
+  // when called for very first time, it'll be `0`
+  let counter = getGlobalPlasmaExitCounter()
+  let updated = counter.current.plus(BigInt.fromI32(1))
+
+  // Updating global counter's state
+  counter.current = updated
+  counter.save()
 
   // this is first time this entity being created i.e. during plasma
   // exit start step
   let entity = new PlasmaExit(id)
-
+  entity.counter = updated
   entity.exitId = event.params.exitId
   entity.exitInitiator = event.params.exitor
   entity.token = event.params.token