refactor(quartz): encapsulate interning as InternedEventStore decorator

Replaces the ctor-injected interner inside SQLiteEventStore /
QueryBuilder / EventStore / FsEventStore with a standalone
InternedEventStore decorator in nip01Core/cache/.

Composition is now explicit at the call site:

  val sqlite = EventStore(...)
  val cached = InternedEventStore(sqlite)
  val observable = ObservableEventStore(cached)

Each layer has one job: EventStore persists, InternedEventStore
canonicalises read results, ObservableEventStore publishes the bus.
Stores no longer carry an interner field; passing one through three
layers of constructor params is gone.

InternedEventStore wraps every IEventStore.query variant (list +
streaming, single filter + multi) and pipes results through
interner.intern. Writes (insert, transaction, delete*,
deleteExpiredEvents) and counts pass through untouched.

assertQuery test helpers generalized from EventStore /
SQLiteEventStore to IEventStore so the decorator works with the
existing fixtures.

BaseDBTest reverts to plain EventStore — the basic store tests
don't read through the projection / interning layer, so they don't
need decoration. Tests that DO want canonical-instance reads can
wrap explicitly: `InternedEventStore(eventStore)`.

7/7 interner + 240/240 store + projection tests still pass.

https://claude.ai/code/session_01Jny85MTu1ynKgFBgysfWu5

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/cache/InternedEventStore.kt

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip01Core.cache
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.store.IEventStore
+
+/**
+ * Decorator that canonicalises every [Event] returned by the inner
+ * store through an [EventInterner], so all consumers of read paths
+ * share a single object reference per event id.
+ *
+ * Wrap any [IEventStore] (SQLite, FS, in-memory test fake) when you
+ * want event-identity sharing across the read paths:
+ *
+ * ```
+ * val sqlite = EventStore(...)
+ * val cached = InternedEventStore(sqlite)
+ * val observable = ObservableEventStore(cached)
+ * ```
+ *
+ * Writes (`insert`, `transaction`, `delete*`) pass through unchanged
+ * — the decorator never substitutes the caller's event for a cached
+ * one on the way in (sigs may differ across "same id, different
+ * decode" cases). Canonicalisation only happens on results coming
+ * back out of the store.
+ *
+ * The default [interner] is [EventInterner.Default]; pass a fresh
+ * instance for tests or any context that needs isolation.
+ */
+class InternedEventStore(
+    private val inner: IEventStore,
+    private val interner: EventInterner = EventInterner.Default,
+) : IEventStore {
+    override suspend fun insert(event: Event) = inner.insert(event)
+
+    override suspend fun transaction(body: IEventStore.ITransaction.() -> Unit) = inner.transaction(body)
+
+    @Suppress("UNCHECKED_CAST")
+    override suspend fun <T : Event> query(filter: Filter): List<T> = inner.query<T>(filter).map { interner.intern(it) as T }
+
+    @Suppress("UNCHECKED_CAST")
+    override suspend fun <T : Event> query(filters: List<Filter>): List<T> = inner.query<T>(filters).map { interner.intern(it) as T }
+
+    @Suppress("UNCHECKED_CAST")
+    override suspend fun <T : Event> query(
+        filter: Filter,
+        onEach: (T) -> Unit,
+    ) = inner.query<T>(filter) { onEach(interner.intern(it) as T) }
+
+    @Suppress("UNCHECKED_CAST")
+    override suspend fun <T : Event> query(
+        filters: List<Filter>,
+        onEach: (T) -> Unit,
+    ) = inner.query<T>(filters) { onEach(interner.intern(it) as T) }
+
+    override suspend fun count(filter: Filter): Int = inner.count(filter)
+
+    override suspend fun count(filters: List<Filter>): Int = inner.count(filters)
+
+    override suspend fun delete(filter: Filter) = inner.delete(filter)
+
+    override suspend fun delete(filters: List<Filter>) = inner.delete(filters)
+
+    override suspend fun deleteExpiredEvents() = inner.deleteExpiredEvents()
+
+    override fun close() = inner.close()
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/EventStore.kt

@@ -21,7 +21,6 @@
 package com.vitorpamplona.quartz.nip01Core.store.sqlite
 
 import androidx.sqlite.driver.bundled.BundledSQLiteDriver
-import com.vitorpamplona.quartz.nip01Core.cache.EventInterner
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
@@ -37,9 +36,8 @@ class EventStore(
     dbName: String? = "events.db",
     val relay: NormalizedRelayUrl? = "wss://quartz.local/".normalizeRelayUrl(),
     val indexStrategy: IndexingStrategy = DefaultIndexingStrategy(),
-    val interner: EventInterner = EventInterner.Default,
 ) : IEventStore {
-    val store = SQLiteEventStore(BundledSQLiteDriver(), dbName, relay, indexStrategy, interner = interner)
+    val store = SQLiteEventStore(BundledSQLiteDriver(), dbName, relay, indexStrategy)
 
     override suspend fun insert(event: Event) = store.insertEvent(event)
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/QueryBuilder.kt

@@ -22,7 +22,6 @@ package com.vitorpamplona.quartz.nip01Core.store.sqlite
 
 import androidx.sqlite.SQLiteConnection
 import androidx.sqlite.SQLiteStatement
-import com.vitorpamplona.quartz.nip01Core.cache.EventInterner
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Kind
@@ -36,7 +35,6 @@ class QueryBuilder(
     val fts: FullTextSearchModule,
     val hasher: (db: SQLiteConnection) -> TagNameValueHasher,
     val indexStrategy: IndexingStrategy,
-    val interner: EventInterner = EventInterner.Default,
 ) {
     // ------------
     // Main methods
@@ -234,23 +232,16 @@ class QueryBuilder(
         }
     }
 
-    @Suppress("UNCHECKED_CAST")
-    private fun <T : Event> SQLiteStatement.toEvent(): T {
-        val event =
-            EventFactory.create<T>(
-                getText(0),
-                getText(1),
-                getLong(2),
-                getInt(3),
-                OptimizedJsonMapper.fromJsonToTagArray(getText(4)),
-                getText(5),
-                getText(6),
-            )
-        // Events read from durable storage were valid when written, so
-        // interning their reconstruction is safe. Multiple projections
-        // re-querying the same id end up sharing one Event instance.
-        return interner.intern(event) as T
-    }
+    private fun <T : Event> SQLiteStatement.toEvent(): T =
+        EventFactory.create<T>(
+            getText(0),
+            getText(1),
+            getLong(2),
+            getInt(3),
+            OptimizedJsonMapper.fromJsonToTagArray(getText(4)),
+            getText(5),
+            getText(6),
+        )
 
     private fun SQLiteStatement.toRawEvent() =
         RawEvent(

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/SQLiteEventStore.kt

@@ -24,7 +24,6 @@ import androidx.sqlite.SQLiteConnection
 import androidx.sqlite.SQLiteDriver
 import androidx.sqlite.SQLiteException
 import androidx.sqlite.driver.bundled.BundledSQLiteDriver
-import com.vitorpamplona.quartz.nip01Core.cache.EventInterner
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Kind
@@ -42,7 +41,6 @@ class SQLiteEventStore(
     val relay: NormalizedRelayUrl? = null,
     val indexStrategy: IndexingStrategy = DefaultIndexingStrategy(),
     val numReaders: Int = 4,
-    val interner: EventInterner = EventInterner.Default,
 ) {
     companion object {
         const val DATABASE_VERSION = 2
@@ -70,7 +68,6 @@ class SQLiteEventStore(
             fullTextSearchModule,
             seedModule::hasher,
             indexStrategy,
-            interner,
         )
 
     val modules =

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/AssertUtils.kt

@@ -22,9 +22,10 @@ package com.vitorpamplona.quartz.nip01Core.store.sqlite
 
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.store.IEventStore
 import kotlin.test.assertEquals
 
-suspend fun <T : Event> EventStore.assertQuery(
+suspend fun <T : Event> IEventStore.assertQuery(
     expected: T?,
     filter: Filter,
 ) {
@@ -40,7 +41,7 @@ suspend fun <T : Event> EventStore.assertQuery(
     }
 }
 
-suspend fun <T : Event> EventStore.assertQuery(
+suspend fun <T : Event> IEventStore.assertQuery(
     expected: List<T>,
     filter: Filter,
 ) {

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/BaseDBTest.kt

@@ -20,7 +20,6 @@
  */
 package com.vitorpamplona.quartz.nip01Core.store.sqlite
 
-import com.vitorpamplona.quartz.nip01Core.cache.EventInterner
 import com.vitorpamplona.quartz.utils.Secp256k1Instance
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -64,12 +63,6 @@ open class BaseDBTest {
                             EventStore(
                                 dbName = null,
                                 indexStrategy = indexStrategy,
-                                // Each store gets its own interner so
-                                // parallel forEachDB runs don't share a
-                                // canonical Event for the same id —
-                                // tests sign with random sigs that
-                                // would otherwise cross-pollinate.
-                                interner = EventInterner(),
                             )
                     }
                 }

quartz/src/jvmMain/kotlin/com/vitorpamplona/quartz/nip01Core/store/fs/FsEventStore.kt

@@ -20,7 +20,6 @@
  */
 package com.vitorpamplona.quartz.nip01Core.store.fs
 
-import com.vitorpamplona.quartz.nip01Core.cache.EventInterner
 import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
@@ -76,7 +75,6 @@ open class FsEventStore(
      * verification re-canonicalises — so format is purely a UX choice.
      */
     private val eventToJson: (Event) -> String = Event::toJson,
-    private val interner: EventInterner = EventInterner.Default,
 ) : IEventStore {
     private val layout = FsLayout(root)
     private val hasher: TagNameValueHasher
@@ -510,10 +508,7 @@ open class FsEventStore(
         val p = layout.canonical(id)
         if (!p.exists()) return null
         return try {
-            // Events on disk were valid when written, so interning
-            // their reconstruction is safe and lets multiple readers
-            // of the same id share one Event instance.
-            interner.intern(Event.fromJson(p.readText()))
+            Event.fromJson(p.readText())
         } catch (_: java.nio.file.NoSuchFileException) {
             null
         }