Merge pull request #6 from sksamuel/feature/bulk_load

Added buildAll method
sksamuel · Apr 2, 2023 · fe466a6 · fe466a6
2 parents 2cdf4b5 + a550677
commit fe466a6
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diff --git a/aedile-core/src/main/kotlin/com/sksamuel/aedile/core/caffeine.kt b/aedile-core/src/main/kotlin/com/sksamuel/aedile/core/caffeine.kt
@@ -1,5 +1,6 @@
 package com.sksamuel.aedile.core
 
+import com.github.benmanes.caffeine.cache.AsyncCacheLoader
 import com.github.benmanes.caffeine.cache.Caffeine
 import com.github.benmanes.caffeine.cache.Expiry
 import com.github.benmanes.caffeine.cache.RemovalCause
@@ -12,6 +13,8 @@ import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.async
 import kotlinx.coroutines.future.asCompletableFuture
 import kotlinx.coroutines.launch
+import java.util.concurrent.CompletableFuture
+import java.util.concurrent.Executor
 import kotlin.time.Duration
 import kotlin.time.toJavaDuration
 
@@ -170,5 +173,33 @@ class Builder<K, V>(
    fun build(compute: suspend (K) -> V): LoadingCache<K, V> {
       return LoadingCache(scope, caffeine.buildAsync { key, _ -> scope.async { compute(key) }.asCompletableFuture() })
    }
+
+   /**
+    * Returns a [Cache] which suspends when requesting values.
+    *
+    * If a requested key does not exist, then the suspendable [compute] function is invoked
+    * to compute the required values.
+    *
+    * If the suspendable computation throws or computes a null value then the
+    * entry will be automatically removed.
+    *
+    */
+   fun buildAll(compute: suspend (Set<K>) -> Map<K, V>): LoadingCache<K, V> {
+      return LoadingCache(
+         scope,
+         caffeine.buildAsync(object : AsyncCacheLoader<K, V> {
+            override fun asyncLoad(key: K, executor: Executor?): CompletableFuture<V> {
+               return asyncLoadAll(setOf(key), executor).thenApply { results -> results[key] }
+            }
+
+            override fun asyncLoadAll(
+               keys: Set<K>,
+               executor: Executor?,
+            ): CompletableFuture<Map<K, V>> {
+               return scope.async { compute(keys) }.asCompletableFuture()
+            }
+         })
+      )
+   }
 }
 
diff --git a/aedile-core/src/test/kotlin/com/sksamuel/aedile/core/LoadingCacheTest.kt b/aedile-core/src/test/kotlin/com/sksamuel/aedile/core/LoadingCacheTest.kt
@@ -16,6 +16,15 @@ class LoadingCacheTest : FunSpec() {
          cache.get("else") shouldBe "bar"
       }
 
+      test("LoadingCache should use support suspendable multiple keys loading function") {
+         val cache = caffeineBuilder<String, String>().buildAll {
+            delay(1)
+            mapOf("tweedle" to "dee", "twuddle" to "dum")
+         }
+         cache.get("tweedle") shouldBe "dee"
+         cache.get("twuddle") shouldBe "dum"
+      }
+
       test("LoadingCache should support simple puts") {
          val cache = caffeineBuilder<String, String>().build()
          cache.put("foo", "bar")