From 910e14b4417e22adb2491a9694bcf5e56df67780 Mon Sep 17 00:00:00 2001
From: Brent Simmons <brent@ranchero.com>
Date: Thu, 19 Mar 2020 22:22:58 -0700
Subject: [PATCH] =?UTF-8?q?Use=20a=20serial=20queue=20for=20RSImage.scaled?=
 =?UTF-8?q?ForIcon,=20so=20we=20don=E2=80=99t=20end=20up=20having=20a=20to?=
 =?UTF-8?q?n=20of=20threads=20and=20doing=20too=20much=20at=20once,=20whic?=
 =?UTF-8?q?h=20hurts=20performance.=20Fix=20#1489.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Shared/Extensions/RSImage-Extensions.swift | 33 +++++++++++++++++-----
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/Shared/Extensions/RSImage-Extensions.swift b/Shared/Extensions/RSImage-Extensions.swift
index e6f515270..94ae44892 100644
--- a/Shared/Extensions/RSImage-Extensions.swift
+++ b/Shared/Extensions/RSImage-Extensions.swift
@@ -6,6 +6,7 @@
 //  Copyright © 2019 Ranchero Software. All rights reserved.
 //
 
+import RSCore
 #if os(macOS)
 import AppKit
 #else
@@ -18,13 +19,8 @@ extension RSImage {
 	
 	static let maxIconSize = 48
 	
-	static func scaledForIcon(_ data: Data, imageResultBlock: @escaping (RSImage?) -> Void) {
-		DispatchQueue.global(qos: .default).async {
-			let image = RSImage.scaledForIcon(data)
-			DispatchQueue.main.async {
-				imageResultBlock(image)
-			}
-		}
+	static func scaledForIcon(_ data: Data, imageResultBlock: @escaping ImageResultBlock) {
+		IconScalerQueue.shared.scaledForIcon(data, imageResultBlock)
 	}
 
 	static func scaledForIcon(_ data: Data) -> RSImage? {
@@ -41,3 +37,26 @@ extension RSImage {
 		#endif		
 	}
 }
+
+// MARK: - IconScalerQueue
+
+private class IconScalerQueue {
+
+	static let shared = IconScalerQueue()
+
+	private let queue: DispatchQueue = {
+		let q = DispatchQueue(label: "IconScaler", attributes: .initiallyInactive)
+		q.setTarget(queue: DispatchQueue.global(qos: .default))
+		q.activate()
+		return q
+	}()
+
+	func scaledForIcon(_ data: Data, _ imageResultBlock: @escaping ImageResultBlock) {
+		queue.async {
+			let image = RSImage.scaledForIcon(data)
+			DispatchQueue.main.async {
+				imageResultBlock(image)
+			}
+		}
+	}
+}