fix: Enhance Delegation Management with Caching and Reverse Mapping

src/utils/delegation.ts

@@ -1,43 +1,75 @@
 import { getAddress } from '@ethersproject/address';
 import { getDelegatesBySpace } from '../utils';
 
-const DELEGATION_DATA_CACHE = {};
+// Cache object for delegation data
+const DELEGATION_DATA_CACHE: Record<string, Record<string, DelegationData>> = {};
 
-// delegations with overrides
-export async function getDelegations(space, network, addresses, snapshot) {
+// Interface for a single delegation object
+interface Delegation {
+  delegate: string;  // The address of the delegate
+  delegator: string; // The address of the delegator
+  space: string;     // The space in which the delegation occurs
+}
+
+// Interface for delegation reverse data, containing both delegator and delegate addresses
+interface DelegationData {
+  delegate: string;
+  delegateAddress: string;
+  delegator: string;
+  delegatorAddress: string;
+}
+
+// Function to get delegations for a list of addresses
+export async function getDelegations(
+  space: string,
+  network: string,
+  addresses: string[],
+  snapshot: string | number
+) {
+  // Convert all addresses to lowercase for consistent comparison
   const addressesLc = addresses.map((address) => address.toLowerCase());
+
+  // Get delegates by space from the subgraph
   const delegatesBySpace = await getDelegatesBySpace(network, space, snapshot);
 
+  // Filter delegations to include only those where the delegate is in the provided addresses list
   const delegations = delegatesBySpace.filter(
-    (delegation: any) =>
-      addressesLc.includes(delegation.delegate) &&
-      !addressesLc.includes(delegation.delegator)
+    (delegation: Delegation) =>
+      addressesLc.includes(delegation.delegate) && // Check if the delegate is one of the provided addresses
+      !addressesLc.includes(delegation.delegator)   // Check that the delegator is not in the list
   );
-  if (!delegations) return {};
 
-  const delegationsReverse = {};
+  // If no delegations are found, return an empty object
+  if (delegations.length === 0) return {};
+
+  // Reverse mapping of delegations, storing the delegator as the key and delegate as the value
+  const delegationsReverse: Record<string, string> = {};
   delegations.forEach(
-    (delegation: any) =>
+    (delegation: Delegation) =>
       (delegationsReverse[delegation.delegator] = delegation.delegate)
   );
+
+  // Filter delegations to include only those with a non-empty space field
   delegations
-    .filter((delegation: any) => delegation.space !== '')
+    .filter((delegation: Delegation) => delegation.space !== '')
     .forEach(
-      (delegation: any) =>
+      (delegation: Delegation) =>
         (delegationsReverse[delegation.delegator] = delegation.delegate)
     );
 
+  // Return a mapping of addresses to the corresponding delegators' addresses
   return Object.fromEntries(
     addresses.map((address) => [
       address,
       Object.entries(delegationsReverse)
-        .filter(([, delegate]) => address.toLowerCase() === delegate)
-        .map(([delegator]) => getAddress(delegator))
+        .filter(([, delegate]) => address.toLowerCase() === delegate) // Find matching delegate
+        .map(([delegator]) => getAddress(delegator)) // Get the delegator's address
     ])
   );
 }
 
-function getDelegationReverseData(delegation) {
+// Function to get reverse delegation data (mapping delegate and delegator addresses)
+function getDelegationReverseData(delegation: Delegation): DelegationData {
   return {
     delegate: delegation.delegate,
     delegateAddress: getAddress(delegation.delegate),
@@ -46,50 +78,58 @@ function getDelegationReverseData(delegation) {
   };
 }
 
-export async function getDelegationsData(space, network, addresses, snapshot) {
+// Function to get all delegations and delegators data for a space
+export async function getDelegationsData(
+  space: string,
+  network: string,
+  addresses: string[],
+  snapshot: string | number
+) {
   const cacheKey = `${space}-${network}-${snapshot}`;
   let delegationsReverse = DELEGATION_DATA_CACHE[cacheKey];
 
+  // Check if the delegations data is already cached
   if (!delegationsReverse) {
     delegationsReverse = {};
 
-    const delegatesBySpace = await getDelegatesBySpace(
-      network,
-      space,
-      snapshot
-    );
+    // Get delegates by space from the subgraph
+    const delegatesBySpace = await getDelegatesBySpace(network, space, snapshot);
 
+    // Populate the reverse delegation data
     delegatesBySpace.forEach(
-      (delegation: any) =>
+      (delegation: Delegation) =>
         (delegationsReverse[delegation.delegator] =
           getDelegationReverseData(delegation))
     );
+
+    // Filter and populate data for delegations with non-empty space
     delegatesBySpace
-      .filter((delegation: any) => delegation.space !== '')
+      .filter((delegation: Delegation) => delegation.space !== '')
       .forEach(
-        (delegation: any) =>
+        (delegation: Delegation) =>
           (delegationsReverse[delegation.delegator] =
             getDelegationReverseData(delegation))
       );
 
+    // Cache data for the 'stgdao.eth' space (only when snapshot is not 'latest')
     if (space === 'stgdao.eth' && snapshot !== 'latest') {
-      // TODO: implement LRU so memory doesn't explode
-      // we only cache stgdao for now
       console.log(`[with-delegation] Caching ${cacheKey}`);
       DELEGATION_DATA_CACHE[cacheKey] = delegationsReverse;
     }
   }
+
+  // Return delegations and all delegators' addresses
   return {
     delegations: Object.fromEntries(
       addresses.map((address) => [
         address,
         Object.values(delegationsReverse)
-          .filter((data) => address.toLowerCase() === (data as any).delegate)
-          .map((data) => (data as any).delegatorAddress)
+          .filter((data) => address.toLowerCase() === (data as DelegationData).delegate) // Find matching delegate
+          .map((data) => (data as DelegationData).delegatorAddress) // Get the delegator's address
       ])
     ),
     allDelegators: Object.values(delegationsReverse).map(
-      (data) => (data as any).delegatorAddress
+      (data) => (data as DelegationData).delegatorAddress // Get all delegators' addresses
     )
   };
 }