From 51e98ef62d3ac5d896014af5b28c6bad5cccc15f Mon Sep 17 00:00:00 2001
From: Him188 <Him188@mamoe.net>
Date: Sun, 1 Mar 2020 14:37:24 +0800
Subject: [PATCH] Improve iteration performance
---
.../message/data/CombinedMessage.kt | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/data/CombinedMessage.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/data/CombinedMessage.kt
index c29b85149..f632f790b 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/data/CombinedMessage.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/data/CombinedMessage.kt
@@ -16,6 +16,10 @@ import kotlin.jvm.JvmMultifileClass
import kotlin.jvm.JvmName
/**
+ * 链接的两个消息.
+ *
+ * @see Message.plus
+ *
* Left-biased list
*/
class CombinedMessage(
@@ -27,11 +31,19 @@ class CombinedMessage(
private suspend fun SequenceScope<Message>.yieldCombinedOrElements(message: Message) {
when (message) {
is CombinedMessage -> {
+ // fast path, 避免创建新的 iterator, 也不会挂起协程
yieldCombinedOrElements(message.element)
yieldCombinedOrElements(message.left)
}
- is MessageChain -> message.forEach { yieldCombinedOrElements(it) }
- else -> yield(message)
+ is MessageChain -> {
+ // 更好的性能, 因为协程不会挂起.
+ // 这可能会导致爆栈 (十万个元素), 但作为消息序列足够了.
+ message.forEach { yieldCombinedOrElements(it) }
+ }
+ else -> {
+ check(message is SingleMessage) { "unsupported Message type. DO NOT CREATE YOUR OWN Message TYPE!" }
+ yield(message)
+ }
}
}