Aleksei/prevent constant db calls (#304)

* add validator addresses to db

* linted

* ignore in local dev

* revert

* fixed fetch

* comment

* refactored db into constructor

* cleanup

* prevent constant db interaction

* stored object structure changed

* remove nesting in validators

* filter validators list

Co-authored-by: Fabian <frznhope@gmail.com>

lib/block-listeners/cosmos-node-subscription.js

@@ -21,6 +21,7 @@ class CosmosNodeSubscription {
     this.network = network
     this.cosmosAPI = new CosmosApiClass(network)
     this.store = store
+    this.validators = []
     const networkSchemaName = this.network.id.replace(/-/g, '_')
     this.db = new database(config)(networkSchemaName)
     this.chainHangup = undefined
@@ -120,7 +121,30 @@ class CosmosNodeSubscription {
 
   // this adds all the validator addresses to the database so we can easily check in the database which ones have an image and which ones don't
   async updateDBValidatorProfiles(validators) {
-    const validatorRows = validators.map(({ operatorAddress, name }) => ({
+    // filter only new validators
+    let newValidators = validators.filter(
+      validator =>
+        !this.validators.find(
+          v =>
+            v.address == validator.operatorAddress && v.name == validator.name // in case if validator name was changed
+        )
+    )
+    // save all new validators to an array
+    this.validators = [
+      ...this.validators.filter(
+        ({ operatorAddress }) =>
+          !newValidators.find(
+            ({ operatorAddress: newValidatorOperatorAddress }) =>
+              newValidatorOperatorAddress === operatorAddress
+          )
+      ),
+      ...newValidators.map(v => ({
+        address: v.operatorAddress,
+        name: v.name
+      }))
+    ]
+    // update only new onces
+    const validatorRows = newValidators.map(({ operatorAddress, name }) => ({
       operator_address: operatorAddress,
       name
     }))