From d2f240ff0ca0d27f417f837e706c781a98c31311 Mon Sep 17 00:00:00 2001 From: Linnea Gräf Date: Wed, 28 Aug 2024 19:04:24 +0200 Subject: Refactor source layout Introduce compat source sets and move all kotlin sources to the main directory [no changelog] --- src/main/kotlin/util/MutableMapWithMaxSize.kt | 38 +++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 src/main/kotlin/util/MutableMapWithMaxSize.kt (limited to 'src/main/kotlin/util/MutableMapWithMaxSize.kt') diff --git a/src/main/kotlin/util/MutableMapWithMaxSize.kt b/src/main/kotlin/util/MutableMapWithMaxSize.kt new file mode 100644 index 0000000..067e652 --- /dev/null +++ b/src/main/kotlin/util/MutableMapWithMaxSize.kt @@ -0,0 +1,38 @@ + +package moe.nea.firmament.util + +fun mutableMapWithMaxSize(maxSize: Int): MutableMap = object : LinkedHashMap() { + override fun removeEldestEntry(eldest: MutableMap.MutableEntry): Boolean { + return size > maxSize + } +} + +fun ((T) -> R).memoizeIdentity(maxCacheSize: Int): (T) -> R { + val memoized = { it: IdentityCharacteristics -> + this(it.value) + }.memoize(maxCacheSize) + return { memoized(IdentityCharacteristics(it)) } +} + +@PublishedApi +internal val SENTINEL_NULL = java.lang.Object() + +/** + * Requires the map to only contain values of type [R] or [SENTINEL_NULL]. This is ensured if the map is only ever + * accessed via this function. + */ +inline fun MutableMap.computeNullableFunction(key: T, crossinline func: () -> R): R { + val value = this.getOrPut(key) { + func() ?: SENTINEL_NULL + } + @Suppress("UNCHECKED_CAST") + return if (value === SENTINEL_NULL) null as R + else value as R +} + +fun ((T) -> R).memoize(maxCacheSize: Int): (T) -> R { + val map = mutableMapWithMaxSize(maxCacheSize) + return { + map.computeNullableFunction(it) { this@memoize(it) } + } +} -- cgit