Avoids allocating Strings for the JSON conversion when checking if a filter has changed.

app/src/main/java/com/vitorpamplona/amethyst/service/NostrDataSource.kt

@@ -221,7 +221,7 @@ abstract class NostrDataSource(val debugName: String) {
         // saves the channels that are currently active
         val activeSubscriptions = subscriptions.values.filter { it.typedFilters != null }
         // saves the current content to only update if it changes
-        val currentFilters = activeSubscriptions.associate { it.id to it.toJson() }
+        val currentFilters = activeSubscriptions.associate { it.id to it.typedFilters }
 
         changingFilters.getAndSet(true)
 
@@ -245,7 +245,7 @@ abstract class NostrDataSource(val debugName: String) {
                         Client.close(updatedSubscription.id)
                     } else {
                         // was active and is still active, check if it has changed.
-                        if (updatedSubscription.toJson() != currentFilters[updatedSubscription.id]) {
+                        if (updatedSubscription.hasChangedFiltersFrom(currentFilters[updatedSubscription.id])) {
                             Client.close(updatedSubscription.id)
                             if (active) {
                                 Client.sendFilter(updatedSubscription.id, updatedSubscriptionNewFilters)
@@ -265,7 +265,7 @@ abstract class NostrDataSource(val debugName: String) {
                         // was not active and is still not active, does nothing
                     } else {
                         // was not active and becomes active, sends the filter.
-                        if (updatedSubscription.toJson() != currentFilters[updatedSubscription.id]) {
+                        if (updatedSubscription.hasChangedFiltersFrom(currentFilters[updatedSubscription.id])) {
                             if (active) {
                                 Log.d(
                                     this@NostrDataSource.javaClass.simpleName,

app/src/main/java/com/vitorpamplona/amethyst/service/relays/Subscription.kt

@@ -20,8 +20,6 @@
  */
 package com.vitorpamplona.amethyst.service.relays
 
-import com.fasterxml.jackson.databind.JsonNode
-import com.vitorpamplona.quartz.events.Event
 import java.util.UUID
 
 data class Subscription(
@@ -37,23 +35,36 @@ data class Subscription(
         onEOSE?.let { it(time, relay) }
     }
 
-    fun toJson(): String {
-        return Event.mapper.writeValueAsString(toJsonObject())
-    }
+    fun hasChangedFiltersFrom(otherFilters: List<TypedFilter>?): Boolean {
+        if (typedFilters == null && otherFilters == null) return false
+        if (typedFilters?.size != otherFilters?.size) return true
 
-    fun toJsonObject(): JsonNode {
-        val factory = Event.mapper.nodeFactory
+        typedFilters?.forEachIndexed { index, typedFilter ->
+            val otherFilter = otherFilters?.getOrNull(index) ?: return true
 
-        return factory.objectNode().apply {
-            put("id", id)
-            typedFilters?.also { filters ->
-                replace(
-                    "typedFilters",
-                    factory.arrayNode(filters.size).apply {
-                        filters.forEach { filter -> add(filter.toJsonObject()) }
-                    },
-                )
+            // Does not check SINCE on purpose. Avoids replacing the filter if SINCE was all that changed.
+            // fast check
+            if (typedFilter.filter.authors?.size != otherFilter.filter.authors?.size ||
+                typedFilter.filter.ids?.size != otherFilter.filter.ids?.size ||
+                typedFilter.filter.tags?.size != otherFilter.filter.tags?.size ||
+                typedFilter.filter.kinds?.size != otherFilter.filter.kinds?.size ||
+                typedFilter.filter.limit != otherFilter.filter.limit ||
+                typedFilter.filter.search?.length != otherFilter.filter.search?.length ||
+                typedFilter.filter.until != otherFilter.filter.until
+            ) {
+                return true
+            }
+
+            // deep check
+            if (typedFilter.filter.ids != otherFilter.filter.ids ||
+                typedFilter.filter.authors != otherFilter.filter.authors ||
+                typedFilter.filter.tags != otherFilter.filter.tags ||
+                typedFilter.filter.kinds != otherFilter.filter.kinds ||
+                typedFilter.filter.search != otherFilter.filter.search
+            ) {
+                return true
             }
         }
+        return false
     }
 }

app/src/main/java/com/vitorpamplona/amethyst/service/relays/TypedFilter.kt

@@ -20,73 +20,7 @@
  */
 package com.vitorpamplona.amethyst.service.relays
 
-import com.fasterxml.jackson.databind.JsonNode
-import com.fasterxml.jackson.databind.node.ArrayNode
-import com.vitorpamplona.quartz.events.Event
-
 class TypedFilter(
     val types: Set<FeedType>,
     val filter: JsonFilter,
-) {
-    fun toJson(): String {
-        return Event.mapper.writeValueAsString(toJsonObject())
-    }
-
-    fun toJsonObject(): JsonNode {
-        val factory = Event.mapper.nodeFactory
-
-        return factory.objectNode().apply {
-            replace("types", typesToJson(types))
-            replace("filter", filterToJson(filter))
-        }
-    }
-
-    fun typesToJson(types: Set<FeedType>): ArrayNode {
-        val factory = Event.mapper.nodeFactory
-        return factory.arrayNode(types.size).apply { types.forEach { add(it.name.lowercase()) } }
-    }
-
-    fun filterToJson(filter: JsonFilter): JsonNode {
-        val factory = Event.mapper.nodeFactory
-        return factory.objectNode().apply {
-            filter.ids?.run {
-                replace(
-                    "ids",
-                    factory.arrayNode(filter.ids.size).apply { filter.ids.forEach { add(it) } },
-                )
-            }
-            filter.authors?.run {
-                replace(
-                    "authors",
-                    factory.arrayNode(filter.authors.size).apply { filter.authors.forEach { add(it) } },
-                )
-            }
-            filter.kinds?.run {
-                replace(
-                    "kinds",
-                    factory.arrayNode(filter.kinds.size).apply { filter.kinds.forEach { add(it) } },
-                )
-            }
-            filter.tags?.run {
-                entries.forEach { kv ->
-                    replace(
-                        "#${kv.key}",
-                        factory.arrayNode(kv.value.size).apply { kv.value.forEach { add(it) } },
-                    )
-                }
-            }
-      /*
-      Does not include since in the json comparison
-      filter.since?.run {
-          val jsonObjectSince = JsonObject()
-          entries.forEach { sincePairs ->
-              jsonObjectSince.addProperty(sincePairs.key, "${sincePairs.value}")
-          }
-          jsonObject.add("since", jsonObjectSince)
-      }*/
-            filter.until?.run { put("until", filter.until) }
-            filter.limit?.run { put("limit", filter.limit) }
-            filter.search?.run { put("search", filter.search) }
-        }
-    }
-}
+)

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/FeedView.kt

@@ -58,7 +58,6 @@ import com.vitorpamplona.amethyst.ui.note.NoteCompose
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.theme.FeedPadding
 import com.vitorpamplona.amethyst.ui.theme.StdVertSpacer
-import kotlin.time.ExperimentalTime
 
 @Composable
 fun RefresheableFeedView(
@@ -205,7 +204,7 @@ private fun WatchScrollToTop(
     }
 }
 
-@OptIn(ExperimentalFoundationApi::class, ExperimentalTime::class)
+@OptIn(ExperimentalFoundationApi::class)
 @Composable
 private fun FeedLoaded(
     state: FeedState.Loaded,