sharded dicts

Author: sid42

contracts/TopShotIPFSResolver.cdc

@@ -3,8 +3,12 @@ access(all) contract TopShotIPFSResolver {
     access(all) event CIDSet(setID: UInt32, playID: UInt32, subeditionID: UInt32, mediaType: String, cid: String)
     access(all) event GatewayUpdated(gateway: String)
 
-    // Composite key "setID_playID_subeditionID" → { mediaType: CID }
-    access(contract) let cids: {String: {String: String}}
+    // Number of buckets to split CID entries across
+    access(all) let numBuckets: UInt64
+
+    // Sharded storage: bucket index -> composite key -> { mediaType: CID }
+    // Let's us store 32 * 100 k= 3,200 CID entries
+    access(contract) let shards: {UInt64: {String: {String: String}}}
 
     // IPFS gateway base URL (e.g., "https://ipfs.dapperlabs.com/ipfs/")
     access(all) var gateway: String
@@ -14,9 +18,12 @@ access(all) contract TopShotIPFSResolver {
     access(all) resource Admin {
         access(all) fun setCID(setID: UInt32, playID: UInt32, subeditionID: UInt32, mediaType: String, cid: String) {
             let key = TopShotIPFSResolver.buildKey(setID: setID, playID: playID, subeditionID: subeditionID)
-            var inner = TopShotIPFSResolver.cids[key] ?? {}
+            let bucket = TopShotIPFSResolver.getBucket(setID: setID, playID: playID, subeditionID: subeditionID)
+            var shard = TopShotIPFSResolver.shards[bucket] ?? {}
+            var inner = shard[key] ?? {}
             inner[mediaType] = cid
-            TopShotIPFSResolver.cids[key] = inner
+            shard[key] = inner
+            TopShotIPFSResolver.shards[bucket] = shard
             emit CIDSet(setID: setID, playID: playID, subeditionID: subeditionID, mediaType: mediaType, cid: cid)
         }
 
@@ -28,7 +35,13 @@ access(all) contract TopShotIPFSResolver {
 
     access(all) view fun getCIDs(setID: UInt32, playID: UInt32, subeditionID: UInt32): {String: String}? {
         let key = self.buildKey(setID: setID, playID: playID, subeditionID: subeditionID)
-        return self.cids[key]
+        let bucket = self.getBucket(setID: setID, playID: playID, subeditionID: subeditionID)
+        let shard = self.shards[bucket] ?? {}
+        return shard[key]
+    }
+
+    access(all) view fun getBucket(setID: UInt32, playID: UInt32, subeditionID: UInt32): UInt64 {
+        return (UInt64(setID) + UInt64(playID) + UInt64(subeditionID)) % self.numBuckets
     }
 
     access(all) view fun buildKey(setID: UInt32, playID: UInt32, subeditionID: UInt32): String {
@@ -40,7 +53,8 @@ access(all) contract TopShotIPFSResolver {
     }
 
     init() {
-        self.cids = {}
+        self.numBuckets = 10
+        self.shards = {}
         self.gateway = "https://ipfs.dapperlabs.com/ipfs/"
         self.AdminStoragePath = /storage/TopShotIPFSResolverAdmin
         self.account.storage.save<@Admin>(<- create Admin(), to: self.AdminStoragePath)