From 1db50f245b419a8d1ce59e4cf4964098a97b5f22 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Fri, 3 Jan 2025 19:10:42 +0100
Subject: [PATCH 01/17] First stab at CurrentReferenceCacheClient

---
 .../CurrentReferenceCacheClient.swift         | 70 +++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
new file mode 100644
index 000000000..f412212ec
--- /dev/null
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -0,0 +1,70 @@
+// Copyright Dave Verwer, Sven A. Schmidt, and other contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import Dependencies
+import DependenciesMacros
+import NIOCore
+import Redis
+
+
+@DependencyClient
+struct CurrentReferenceCacheClient {
+    var set: @Sendable (_ owner: String, _ repository: String, _ reference: String) async -> Void
+    var get: @Sendable (_ owner: String, _ repository: String) async -> String?
+}
+
+
+extension CurrentReferenceCacheClient: DependencyKey {
+    static var liveValue: CurrentReferenceCacheClient {
+        .init(
+            set: { owner, repository, reference async in
+                await Self.redis?.set(owner: owner, repository: repository, reference: reference)
+            },
+            get: { owner, repository in
+                await Self.redis?.get(owner: owner, repository: repository)
+            }
+        )
+    }
+}
+
+
+extension CurrentReferenceCacheClient {
+    @MainActor
+    static var redis: Redis?
+
+    @MainActor
+    static func setRedis(_ client: sending RedisClient) { redis = .init(client: client) }
+
+    actor Redis {
+        var client: RedisClient
+        init(client: RedisClient) {
+            self.client = client
+        }
+
+        static let expirationInSeconds = 5*60
+
+        func set(owner: String, repository: String, reference: String) async -> Void {
+            let key = "\(owner)/\(repository)".lowercased()
+            let buffer = ByteBuffer(string: reference)
+            try? await client.setex(.init(key),
+                                    to: RESPValue.bulkString(buffer),
+                                    expirationInSeconds: Self.expirationInSeconds).get()
+        }
+
+        func get(owner: String, repository: String) async -> String? {
+            let key = "\(owner)/\(repository)".lowercased()
+            return try? await client.get(.init(key)).map(\.string).get()
+        }
+    }
+}

From 65f83354c79cde74b003f01407a751b44857caf7 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 15:48:30 +0100
Subject: [PATCH 02/17] Tweak setup

---
 .../CurrentReferenceCacheClient.swift           | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index f412212ec..9e33c4e41 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -39,17 +39,28 @@ extension CurrentReferenceCacheClient: DependencyKey {
 }
 
 
+@preconcurrency import RediStack
+
+
 extension CurrentReferenceCacheClient {
     @MainActor
     static var redis: Redis?
 
     @MainActor
-    static func setRedis(_ client: sending RedisClient) { redis = .init(client: client) }
+    static func bootstrap(hostname: String) async throws {
+#warning("Add retry")
+        redis = try await Redis(hostname: hostname)
+    }
 
     actor Redis {
         var client: RedisClient
-        init(client: RedisClient) {
-            self.client = client
+
+        init(hostname: String) async throws {
+            let connection = RedisConnection.make(
+                configuration: try .init(hostname: hostname),
+                boundEventLoop: NIOSingletons.posixEventLoopGroup.any()
+            )
+            self.client = try await connection.get()
         }
 
         static let expirationInSeconds = 5*60

From 87bdbf8b0410f3b1daa667d6f26dac2f4c1908db Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:00:35 +0100
Subject: [PATCH 03/17] More tweaks

---
 .../CurrentReferenceCacheClient.swift         | 38 ++++++++++---------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 9e33c4e41..329b14d49 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -15,7 +15,7 @@
 import Dependencies
 import DependenciesMacros
 import NIOCore
-import Redis
+@preconcurrency import RediStack
 
 
 @DependencyClient
@@ -29,41 +29,45 @@ extension CurrentReferenceCacheClient: DependencyKey {
     static var liveValue: CurrentReferenceCacheClient {
         .init(
             set: { owner, repository, reference async in
-                await Self.redis?.set(owner: owner, repository: repository, reference: reference)
+                await Redis.shared.set(owner: owner, repository: repository, reference: reference)
             },
             get: { owner, repository in
-                await Self.redis?.get(owner: owner, repository: repository)
+                await Redis.shared.get(owner: owner, repository: repository)
             }
         )
     }
 }
 
 
-@preconcurrency import RediStack
-
-
 extension CurrentReferenceCacheClient {
-    @MainActor
-    static var redis: Redis?
-
-    @MainActor
-    static func bootstrap(hostname: String) async throws {
-#warning("Add retry")
-        redis = try await Redis(hostname: hostname)
-    }
-
     actor Redis {
         var client: RedisClient
+        static private var task: Task<Redis, Never>?
+
+        static var shared: Redis {
+            get async {
+                if let task {
+                    return await task.value
+                }
+                let task = Task {
+#warning("Add retry")
+                    return try! await Redis()
+                }
+                self.task = task
+                return await task.value
+            }
+        }
 
-        init(hostname: String) async throws {
+        private init() async throws {
             let connection = RedisConnection.make(
-                configuration: try .init(hostname: hostname),
+                configuration: try .init(hostname: Redis.hostname),
                 boundEventLoop: NIOSingletons.posixEventLoopGroup.any()
             )
             self.client = try await connection.get()
         }
 
         static let expirationInSeconds = 5*60
+        static let hostname = "redis"
 
         func set(owner: String, repository: String, reference: String) async -> Void {
             let key = "\(owner)/\(repository)".lowercased()

From a95aba989aab8ea3da7b6da28f97045b0bbe6181 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:24:49 +0100
Subject: [PATCH 04/17] Add connection retry

---
 .../CurrentReferenceCacheClient.swift         | 24 +++++++++++++------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 329b14d49..7990e8e9e 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -29,10 +29,10 @@ extension CurrentReferenceCacheClient: DependencyKey {
     static var liveValue: CurrentReferenceCacheClient {
         .init(
             set: { owner, repository, reference async in
-                await Redis.shared.set(owner: owner, repository: repository, reference: reference)
+                await Redis.shared?.set(owner: owner, repository: repository, reference: reference)
             },
             get: { owner, repository in
-                await Redis.shared.get(owner: owner, repository: repository)
+                await Redis.shared?.get(owner: owner, repository: repository)
             }
         )
     }
@@ -42,16 +42,25 @@ extension CurrentReferenceCacheClient: DependencyKey {
 extension CurrentReferenceCacheClient {
     actor Redis {
         var client: RedisClient
-        static private var task: Task<Redis, Never>?
+        static private var task: Task<Redis?, Never>?
 
-        static var shared: Redis {
+        static var shared: Redis? {
             get async {
                 if let task {
                     return await task.value
                 }
-                let task = Task {
-#warning("Add retry")
-                    return try! await Redis()
+                let task = Task<Redis?, Never> {
+                    var attemptsLeft = maxConnectionAttempts
+                    while attemptsLeft > 0 {
+                        do {
+                            return try await Redis()
+                        } catch {
+                            attemptsLeft -= 1
+                            print("Redis connection failed, \(attemptsLeft) attempts left. Error: \(error)")
+                            try? await Task.sleep(for: .milliseconds(500))
+                        }
+                    }
+                    return nil
                 }
                 self.task = task
                 return await task.value
@@ -68,6 +77,7 @@ extension CurrentReferenceCacheClient {
 
         static let expirationInSeconds = 5*60
         static let hostname = "redis"
+        static let maxConnectionAttempts = 3
 
         func set(owner: String, repository: String, reference: String) async -> Void {
             let key = "\(owner)/\(repository)".lowercased()

From 1c5ca6d0a9c4e5caf1fe15fd9621761f5e3bfce3 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:25:55 +0100
Subject: [PATCH 05/17] Log error

---
 Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 7990e8e9e..0c2373e14 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -56,7 +56,7 @@ extension CurrentReferenceCacheClient {
                             return try await Redis()
                         } catch {
                             attemptsLeft -= 1
-                            print("Redis connection failed, \(attemptsLeft) attempts left. Error: \(error)")
+                            Current.logger().warning("Redis connection failed, \(attemptsLeft) attempts left. Error: \(error)")
                             try? await Task.sleep(for: .milliseconds(500))
                         }
                     }

From 1aa5b2143ec5372f0c56818985d95a0ee5db0360 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:29:08 +0100
Subject: [PATCH 06/17] Finish dependency system setup

---
 .../Dependencies/CurrentReferenceCacheClient.swift  | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 0c2373e14..069db041a 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -39,6 +39,19 @@ extension CurrentReferenceCacheClient: DependencyKey {
 }
 
 
+extension CurrentReferenceCacheClient: TestDependencyKey {
+    static var testValue: Self { Self() }
+}
+
+
+extension DependencyValues {
+    var currentReferenceCache: CurrentReferenceCacheClient {
+        get { self[CurrentReferenceCacheClient.self] }
+        set { self[CurrentReferenceCacheClient.self] = newValue }
+    }
+}
+
+
 extension CurrentReferenceCacheClient {
     actor Redis {
         var client: RedisClient

From d8f22caeb98655bf08b7901ba26593018ae51c76 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:46:51 +0100
Subject: [PATCH 07/17] Accept `nil` reference, deleting the key if set

---
 .../CurrentReferenceCacheClient.swift            | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 069db041a..ffb4a5dd2 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -20,7 +20,7 @@ import NIOCore
 
 @DependencyClient
 struct CurrentReferenceCacheClient {
-    var set: @Sendable (_ owner: String, _ repository: String, _ reference: String) async -> Void
+    var set: @Sendable (_ owner: String, _ repository: String, _ reference: String?) async -> Void
     var get: @Sendable (_ owner: String, _ repository: String) async -> String?
 }
 
@@ -92,12 +92,16 @@ extension CurrentReferenceCacheClient {
         static let hostname = "redis"
         static let maxConnectionAttempts = 3
 
-        func set(owner: String, repository: String, reference: String) async -> Void {
+        func set(owner: String, repository: String, reference: String?) async -> Void {
             let key = "\(owner)/\(repository)".lowercased()
-            let buffer = ByteBuffer(string: reference)
-            try? await client.setex(.init(key),
-                                    to: RESPValue.bulkString(buffer),
-                                    expirationInSeconds: Self.expirationInSeconds).get()
+            if let reference {
+                let buffer = ByteBuffer(string: reference)
+                try? await client.setex(.init(key),
+                                        to: RESPValue.bulkString(buffer),
+                                        expirationInSeconds: Self.expirationInSeconds).get()
+            } else {
+                _ = try? await client.delete([.init(key)]).get()
+            }
         }
 
         func get(owner: String, repository: String) async -> String? {

From fbcb232609891be1f819009cde280966765c84b5 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:47:24 +0100
Subject: [PATCH 08/17] Update current cache to also write key/value pair to
 redis

---
 Sources/App/Core/CurrentReferenceCache.swift  | 21 +++++++++++--------
 Sources/App/routes+documentation.swift        |  4 ++--
 .../PackageController+routesTests.swift       |  2 +-
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/Sources/App/Core/CurrentReferenceCache.swift b/Sources/App/Core/CurrentReferenceCache.swift
index f7de4336d..37b2316e3 100644
--- a/Sources/App/Core/CurrentReferenceCache.swift
+++ b/Sources/App/Core/CurrentReferenceCache.swift
@@ -13,20 +13,23 @@
 // limitations under the License.
 
 @preconcurrency import Cache
+import Dependencies
+
 
 typealias CurrentReferenceCache = ExpiringCache<String, String>
 
 extension CurrentReferenceCache {
     static let live = CurrentReferenceCache(duration: .minutes(5))
 
-    subscript(owner owner: String, repository repository: String) -> String? {
-        get {
-            let key = "\(owner)/\(repository)".lowercased()
-            return self[key]
-        }
-        set {
-            let key = "\(owner)/\(repository)".lowercased()
-            self[key] = newValue
-        }
+    func get(owner: String, repository: String) -> String? {
+        let key = "\(owner)/\(repository)".lowercased()
+        return self[key]
+    }
+
+    func set(owner: String, repository: String, reference: String?) async {
+        let key = "\(owner)/\(repository)".lowercased()
+        self[key] = reference
+        @Dependency(\.currentReferenceCache) var currentReferenceCache
+        await currentReferenceCache.set(owner: owner, repository: repository, reference: reference)
     }
 }
diff --git a/Sources/App/routes+documentation.swift b/Sources/App/routes+documentation.swift
index aef2fa664..af28a7be5 100644
--- a/Sources/App/routes+documentation.swift
+++ b/Sources/App/routes+documentation.swift
@@ -178,14 +178,14 @@ extension Request {
 
         let docVersion = try await { () -> DocVersion in
             if reference == String.current {
-                if let ref = environment.currentReferenceCache()?[owner: owner, repository: repository] {
+                if let ref = environment.currentReferenceCache()?.get(owner: owner, repository: repository) {
                     return .current(referencing: ref)
                 }
 
                 guard let params = try await DocumentationTarget.query(on: db, owner: owner, repository: repository)?.internal
                 else { throw Abort(.notFound) }
 
-                environment.currentReferenceCache()?[owner: owner, repository: repository] = "\(params.docVersion)"
+                await environment.currentReferenceCache()?.set(owner: owner, repository: repository, reference: "\(params.docVersion)")
                 return .current(referencing: "\(params.docVersion)")
             } else {
                 return .reference(reference)
diff --git a/Tests/AppTests/PackageController+routesTests.swift b/Tests/AppTests/PackageController+routesTests.swift
index eed792c9e..e7fe01f6e 100644
--- a/Tests/AppTests/PackageController+routesTests.swift
+++ b/Tests/AppTests/PackageController+routesTests.swift
@@ -1576,7 +1576,7 @@ class PackageController_routesTests: SnapshotTestCase {
                 XCTFail("unexpected error: \(error)")
             }
 
-            cache[owner: "owner", repository: "repo"] = "1.2.3"
+            await cache.set(owner: "owner", repository: "repo", reference: "1.2.3")
 
             do { // Now with the cache in place this resolves
                 let route = try await req.getDocRoute(fragment: .documentation)

From a61478ab76ffd998f14359da4011fa248fa2e92d Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sat, 4 Jan 2025 16:59:21 +0100
Subject: [PATCH 09/17] Update tests

---
 .../Core/Dependencies/CurrentReferenceCacheClient.swift  | 9 +++++++++
 Tests/AppTests/PackageController+routesTests.swift       | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index ffb4a5dd2..4d595472c 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -110,3 +110,12 @@ extension CurrentReferenceCacheClient {
         }
     }
 }
+
+
+#if DEBUG
+extension CurrentReferenceCacheClient {
+    static var disabled: Self {
+        .init(set: { _, _, _ in }, get: { _, _ in nil })
+    }
+}
+#endif
diff --git a/Tests/AppTests/PackageController+routesTests.swift b/Tests/AppTests/PackageController+routesTests.swift
index e7fe01f6e..de40f4214 100644
--- a/Tests/AppTests/PackageController+routesTests.swift
+++ b/Tests/AppTests/PackageController+routesTests.swift
@@ -1479,6 +1479,7 @@ class PackageController_routesTests: SnapshotTestCase {
         // Ensures default branch updates don't introduce a "documentation gap"
         // https://github.com/SwiftPackageIndex/SwiftPackageIndex-Server/issues/2288
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
             $0.environment.currentReferenceCache = { .live }
             $0.httpClient.fetchDocumentation = { @Sendable _ in .init(status: .ok, body: .mockIndexHTML()) }
@@ -1558,6 +1559,7 @@ class PackageController_routesTests: SnapshotTestCase {
     func test_getDocRoute_documentation_current() async throws {
         nonisolated(unsafe) let cache = CurrentReferenceCache()
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.currentReferenceCache = { cache }
         } operation: {
             // owner/repo/~/documentation/archive

From 3edf3e54e8b820f0ec4ef0cb59590ab3861cfa06 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 11:06:34 +0100
Subject: [PATCH 10/17] Move Redis to own file

---
 .../CurrentReferenceCacheClient.swift         | 62 ---------------
 .../App/Core/Dependencies/RedisClient.swift   | 75 +++++++++++++++++++
 2 files changed, 75 insertions(+), 62 deletions(-)
 create mode 100644 Sources/App/Core/Dependencies/RedisClient.swift

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 4d595472c..1752f055c 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -14,8 +14,6 @@
 
 import Dependencies
 import DependenciesMacros
-import NIOCore
-@preconcurrency import RediStack
 
 
 @DependencyClient
@@ -52,66 +50,6 @@ extension DependencyValues {
 }
 
 
-extension CurrentReferenceCacheClient {
-    actor Redis {
-        var client: RedisClient
-        static private var task: Task<Redis?, Never>?
-
-        static var shared: Redis? {
-            get async {
-                if let task {
-                    return await task.value
-                }
-                let task = Task<Redis?, Never> {
-                    var attemptsLeft = maxConnectionAttempts
-                    while attemptsLeft > 0 {
-                        do {
-                            return try await Redis()
-                        } catch {
-                            attemptsLeft -= 1
-                            Current.logger().warning("Redis connection failed, \(attemptsLeft) attempts left. Error: \(error)")
-                            try? await Task.sleep(for: .milliseconds(500))
-                        }
-                    }
-                    return nil
-                }
-                self.task = task
-                return await task.value
-            }
-        }
-
-        private init() async throws {
-            let connection = RedisConnection.make(
-                configuration: try .init(hostname: Redis.hostname),
-                boundEventLoop: NIOSingletons.posixEventLoopGroup.any()
-            )
-            self.client = try await connection.get()
-        }
-
-        static let expirationInSeconds = 5*60
-        static let hostname = "redis"
-        static let maxConnectionAttempts = 3
-
-        func set(owner: String, repository: String, reference: String?) async -> Void {
-            let key = "\(owner)/\(repository)".lowercased()
-            if let reference {
-                let buffer = ByteBuffer(string: reference)
-                try? await client.setex(.init(key),
-                                        to: RESPValue.bulkString(buffer),
-                                        expirationInSeconds: Self.expirationInSeconds).get()
-            } else {
-                _ = try? await client.delete([.init(key)]).get()
-            }
-        }
-
-        func get(owner: String, repository: String) async -> String? {
-            let key = "\(owner)/\(repository)".lowercased()
-            return try? await client.get(.init(key)).map(\.string).get()
-        }
-    }
-}
-
-
 #if DEBUG
 extension CurrentReferenceCacheClient {
     static var disabled: Self {
diff --git a/Sources/App/Core/Dependencies/RedisClient.swift b/Sources/App/Core/Dependencies/RedisClient.swift
new file mode 100644
index 000000000..12d1a186a
--- /dev/null
+++ b/Sources/App/Core/Dependencies/RedisClient.swift
@@ -0,0 +1,75 @@
+// Copyright Dave Verwer, Sven A. Schmidt, and other contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import NIOCore
+@preconcurrency import RediStack
+
+
+actor Redis {
+    var client: RedisClient
+    static private var task: Task<Redis?, Never>?
+
+    static var shared: Redis? {
+        get async {
+            if let task {
+                return await task.value
+            }
+            let task = Task<Redis?, Never> {
+                var attemptsLeft = maxConnectionAttempts
+                while attemptsLeft > 0 {
+                    do {
+                        return try await Redis()
+                    } catch {
+                        attemptsLeft -= 1
+                        Current.logger().warning("Redis connection failed, \(attemptsLeft) attempts left. Error: \(error)")
+                        try? await Task.sleep(for: .milliseconds(500))
+                    }
+                }
+                return nil
+            }
+            self.task = task
+            return await task.value
+        }
+    }
+
+    private init() async throws {
+        let connection = RedisConnection.make(
+            configuration: try .init(hostname: Redis.hostname),
+            boundEventLoop: NIOSingletons.posixEventLoopGroup.any()
+        )
+        self.client = try await connection.get()
+    }
+
+    static let expirationInSeconds = 5*60
+    static let hostname = "redis"
+    static let maxConnectionAttempts = 3
+
+    func set(owner: String, repository: String, reference: String?) async -> Void {
+        let key = "\(owner)/\(repository)".lowercased()
+        if let reference {
+            let buffer = ByteBuffer(string: reference)
+            try? await client.setex(.init(key),
+                                    to: RESPValue.bulkString(buffer),
+                                    expirationInSeconds: Self.expirationInSeconds).get()
+        } else {
+            _ = try? await client.delete([.init(key)]).get()
+        }
+    }
+
+    func get(owner: String, repository: String) async -> String? {
+        let key = "\(owner)/\(repository)".lowercased()
+        return try? await client.get(.init(key)).map(\.string).get()
+    }
+}
+

From 90e3a501de8b39ad7c9e0c3d02ec8975107f29cf Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 11:22:04 +0100
Subject: [PATCH 11/17] Make Redis actor private

---
 .../CurrentReferenceCacheClient.swift         | 10 +++-
 .../App/Core/Dependencies/RedisClient.swift   | 47 +++++++++++++++----
 2 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 1752f055c..0725dbc5d 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -27,13 +27,19 @@ extension CurrentReferenceCacheClient: DependencyKey {
     static var liveValue: CurrentReferenceCacheClient {
         .init(
             set: { owner, repository, reference async in
-                await Redis.shared?.set(owner: owner, repository: repository, reference: reference)
+                @Dependency(\.redis) var redis
+                await redis.set(key: getKey(owner: owner, repository: repository), value: reference)
             },
             get: { owner, repository in
-                await Redis.shared?.get(owner: owner, repository: repository)
+                @Dependency(\.redis) var redis
+                return await redis.get(key: getKey(owner: owner, repository: repository))
             }
         )
     }
+
+    static func getKey(owner: String, repository: String) -> String {
+        "\(owner)/\(repository)".lowercased()
+    }
 }
 
 
diff --git a/Sources/App/Core/Dependencies/RedisClient.swift b/Sources/App/Core/Dependencies/RedisClient.swift
index 12d1a186a..888064576 100644
--- a/Sources/App/Core/Dependencies/RedisClient.swift
+++ b/Sources/App/Core/Dependencies/RedisClient.swift
@@ -14,10 +14,42 @@
 
 import NIOCore
 @preconcurrency import RediStack
+import Dependencies
+import DependenciesMacros
 
 
-actor Redis {
-    var client: RedisClient
+@DependencyClient
+struct RedisClient {
+    var set: @Sendable (_ key: String, _ value: String?) async -> Void
+    var get: @Sendable (_ key: String) async -> String?
+}
+
+
+extension RedisClient: DependencyKey {
+    static var liveValue: RedisClient {
+        .init(
+            set: { key, value in await Redis.shared?.set(key: key, value: value) },
+            get: { key in await Redis.shared?.get(key: key) }
+        )
+    }
+}
+
+
+extension RedisClient: TestDependencyKey {
+    static var testValue: Self { Self() }
+}
+
+
+extension DependencyValues {
+    var redis: RedisClient {
+        get { self[RedisClient.self] }
+        set { self[RedisClient.self] = newValue }
+    }
+}
+
+
+private actor Redis {
+    var client: RediStack.RedisClient
     static private var task: Task<Redis?, Never>?
 
     static var shared: Redis? {
@@ -51,14 +83,14 @@ actor Redis {
         self.client = try await connection.get()
     }
 
+#warning("move expiry to interface")
     static let expirationInSeconds = 5*60
     static let hostname = "redis"
     static let maxConnectionAttempts = 3
 
-    func set(owner: String, repository: String, reference: String?) async -> Void {
-        let key = "\(owner)/\(repository)".lowercased()
-        if let reference {
-            let buffer = ByteBuffer(string: reference)
+    func set(key: String, value: String?) async -> Void {
+        if let value {
+            let buffer = ByteBuffer(string: value)
             try? await client.setex(.init(key),
                                     to: RESPValue.bulkString(buffer),
                                     expirationInSeconds: Self.expirationInSeconds).get()
@@ -67,8 +99,7 @@ actor Redis {
         }
     }
 
-    func get(owner: String, repository: String) async -> String? {
-        let key = "\(owner)/\(repository)".lowercased()
+    func get(key: String) async -> String? {
         return try? await client.get(.init(key)).map(\.string).get()
     }
 }

From 1a975b2184435d13981200ef67ed676bcf9696a9 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 11:28:36 +0100
Subject: [PATCH 12/17] Add static `RedisClient.disabled`

---
 Sources/App/Core/Dependencies/RedisClient.swift | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Sources/App/Core/Dependencies/RedisClient.swift b/Sources/App/Core/Dependencies/RedisClient.swift
index 888064576..988676cd3 100644
--- a/Sources/App/Core/Dependencies/RedisClient.swift
+++ b/Sources/App/Core/Dependencies/RedisClient.swift
@@ -48,6 +48,15 @@ extension DependencyValues {
 }
 
 
+#if DEBUG
+extension RedisClient {
+    static var disabled: Self {
+        .init(set: { _, _ in }, get: { _ in nil })
+    }
+}
+#endif
+
+
 private actor Redis {
     var client: RediStack.RedisClient
     static private var task: Task<Redis?, Never>?

From 519b256caf5c76743897c006b781a415a20f6a52 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 11:28:53 +0100
Subject: [PATCH 13/17] Remove outdated RedisConfiguration setup

---
 Sources/App/configure.swift | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/Sources/App/configure.swift b/Sources/App/configure.swift
index e1846a1b9..06828ecdf 100644
--- a/Sources/App/configure.swift
+++ b/Sources/App/configure.swift
@@ -78,13 +78,6 @@ public func configure(_ app: Application) async throws -> String {
                                 sqlLogLevel: .debug),
                       as: .psql)
 
-    // Setup Redis connection
-    do {
-        app.redis.configuration = try RedisConfiguration(hostname: "redis")
-    } catch {
-        app.logger.warning("Failed to configure Redis, caching disabled. Error: \(error)")
-    }
-
     do {  // Migration 001 - schema 1.0
         app.migrations.add(CreatePackage())
         app.migrations.add(CreateRepository())

From 8efbace52bb74b54ca2c87cf13299171c819f6cd Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 12:08:37 +0100
Subject: [PATCH 14/17] Remove old cache

---
 Package.resolved                              | 11 +-----
 Package.swift                                 |  2 --
 Sources/App/Core/CurrentReferenceCache.swift  | 35 -------------------
 .../CurrentReferenceCacheClient.swift         | 17 +++++++++
 .../Core/Dependencies/EnvironmentClient.swift |  2 --
 Sources/App/routes+documentation.swift        |  5 +--
 .../PackageController+routesTests.swift       | 20 +++++------
 7 files changed, 30 insertions(+), 62 deletions(-)
 delete mode 100644 Sources/App/Core/CurrentReferenceCache.swift

diff --git a/Package.resolved b/Package.resolved
index c1d729ef6..be2aefffa 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -1,5 +1,5 @@
 {
-  "originHash" : "522f8d8b891d1a65e94cabb612d629f37de0bf6025993255871335482d355051",
+  "originHash" : "c68e60d7c703a8fa9fb0a3a11024cf6b2304fb294ba9f124de1d41f024b11cc9",
   "pins" : [
     {
       "identity" : "async-http-client",
@@ -28,15 +28,6 @@
         "version" : "2.0.2"
       }
     },
-    {
-      "identity" : "cache",
-      "kind" : "remoteSourceControl",
-      "location" : "https://github.com/0xLeif/Cache.git",
-      "state" : {
-        "revision" : "a535c68aab7bf0b42bda7a5de66b04f86e48c6e6",
-        "version" : "2.1.0"
-      }
-    },
     {
       "identity" : "canonicalpackageurl",
       "kind" : "remoteSourceControl",
diff --git a/Package.swift b/Package.swift
index bc6225c79..9adebaf27 100644
--- a/Package.swift
+++ b/Package.swift
@@ -27,7 +27,6 @@ let package = Package(
         .library(name: "S3Store", targets: ["S3Store"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/0xLeif/Cache.git", from: "2.1.0"),
         .package(url: "https://github.com/JohnSundell/Ink.git", from: "0.5.1"),
         .package(url: "https://github.com/swift-server/swift-prometheus.git", from: "1.0.0"),
         .package(url: "https://github.com/SwiftPackageIndex/Plot.git", branch: "main"),
@@ -63,7 +62,6 @@ let package = Package(
                     .product(name: "SPIManifest", package: "SPIManifest"),
                     .product(name: "SemanticVersion", package: "SemanticVersion"),
                     .product(name: "SwiftSoup", package: "SwiftSoup"),
-                    .product(name: "Cache", package: "cache"),
                     .product(name: "CanonicalPackageURL", package: "CanonicalPackageURL"),
                     .product(name: "CustomDump", package: "swift-custom-dump"),
                     .product(name: "Dependencies", package: "swift-dependencies"),
diff --git a/Sources/App/Core/CurrentReferenceCache.swift b/Sources/App/Core/CurrentReferenceCache.swift
deleted file mode 100644
index 37b2316e3..000000000
--- a/Sources/App/Core/CurrentReferenceCache.swift
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright Dave Verwer, Sven A. Schmidt, and other contributors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-@preconcurrency import Cache
-import Dependencies
-
-
-typealias CurrentReferenceCache = ExpiringCache<String, String>
-
-extension CurrentReferenceCache {
-    static let live = CurrentReferenceCache(duration: .minutes(5))
-
-    func get(owner: String, repository: String) -> String? {
-        let key = "\(owner)/\(repository)".lowercased()
-        return self[key]
-    }
-
-    func set(owner: String, repository: String, reference: String?) async {
-        let key = "\(owner)/\(repository)".lowercased()
-        self[key] = reference
-        @Dependency(\.currentReferenceCache) var currentReferenceCache
-        await currentReferenceCache.set(owner: owner, repository: repository, reference: reference)
-    }
-}
diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 0725dbc5d..721ac2350 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -61,5 +61,22 @@ extension CurrentReferenceCacheClient {
     static var disabled: Self {
         .init(set: { _, _, _ in }, get: { _, _ in nil })
     }
+
+    static var inMemory: Self {
+        .init(
+            set: { owner, repository, reference in
+                _cache.withValue {
+                    $0[getKey(owner: owner, repository: repository)] = reference
+                }
+            },
+            get: { owner, repository in
+                _cache.withValue {
+                    $0[getKey(owner: owner, repository: repository)]
+                }
+            }
+        )
+    }
+
+    nonisolated(unsafe) static var _cache = LockIsolated<[String: String]>([:])
 }
 #endif
diff --git a/Sources/App/Core/Dependencies/EnvironmentClient.swift b/Sources/App/Core/Dependencies/EnvironmentClient.swift
index 67ee40016..371b570bf 100644
--- a/Sources/App/Core/Dependencies/EnvironmentClient.swift
+++ b/Sources/App/Core/Dependencies/EnvironmentClient.swift
@@ -39,7 +39,6 @@ struct EnvironmentClient {
     var collectionSigningCertificateChain: @Sendable () -> [URL] = { XCTFail("collectionSigningCertificateChain"); return [] }
     var collectionSigningPrivateKey: @Sendable () -> Data?
     var current: @Sendable () -> Environment = { XCTFail("current"); return .development }
-    var currentReferenceCache: @Sendable () -> CurrentReferenceCache?
     var dbId: @Sendable () -> String?
     var mastodonCredentials: @Sendable () -> Mastodon.Credentials?
     var random: @Sendable (_ range: ClosedRange<Double>) -> Double = { XCTFail("random"); return Double.random(in: $0) }
@@ -102,7 +101,6 @@ extension EnvironmentClient: DependencyKey {
                 Environment.get("COLLECTION_SIGNING_PRIVATE_KEY").map { Data($0.utf8) }
             },
             current: { (try? Environment.detect()) ?? .development },
-            currentReferenceCache: { .live },
             dbId: { Environment.get("DATABASE_ID") },
             mastodonCredentials: {
                 Environment.get("MASTODON_ACCESS_TOKEN")
diff --git a/Sources/App/routes+documentation.swift b/Sources/App/routes+documentation.swift
index af28a7be5..595d4171f 100644
--- a/Sources/App/routes+documentation.swift
+++ b/Sources/App/routes+documentation.swift
@@ -178,14 +178,15 @@ extension Request {
 
         let docVersion = try await { () -> DocVersion in
             if reference == String.current {
-                if let ref = environment.currentReferenceCache()?.get(owner: owner, repository: repository) {
+                @Dependency(\.currentReferenceCache) var currentReferenceCache
+                if let ref = await currentReferenceCache.get(owner: owner, repository: repository) {
                     return .current(referencing: ref)
                 }
 
                 guard let params = try await DocumentationTarget.query(on: db, owner: owner, repository: repository)?.internal
                 else { throw Abort(.notFound) }
 
-                await environment.currentReferenceCache()?.set(owner: owner, repository: repository, reference: "\(params.docVersion)")
+                await currentReferenceCache.set(owner: owner, repository: repository, reference: "\(params.docVersion)")
                 return .current(referencing: "\(params.docVersion)")
             } else {
                 return .reference(reference)
diff --git a/Tests/AppTests/PackageController+routesTests.swift b/Tests/AppTests/PackageController+routesTests.swift
index de40f4214..4d0d8c672 100644
--- a/Tests/AppTests/PackageController+routesTests.swift
+++ b/Tests/AppTests/PackageController+routesTests.swift
@@ -566,8 +566,8 @@ class PackageController_routesTests: SnapshotTestCase {
         // Test the current (~) documentation routes:
         //   /owner/package/documentation/~ + various path elements
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil }
             $0.httpClient.fetchDocumentation = { @Sendable _ in .init(status: .ok, body: .mockIndexHTML()) }
         } operation: {
             // setup
@@ -649,8 +649,8 @@ class PackageController_routesTests: SnapshotTestCase {
         // Test the current (~) documentation routes with baseURL rewriting:
         //   /owner/package/documentation/~ + various path elements
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil }
             $0.httpClient.fetchDocumentation = { @Sendable _ in .init(status: .ok, body: .mockIndexHTML(baseURL: "/owner/package/1.0.0")) }
         } operation: {
             // setup
@@ -941,8 +941,8 @@ class PackageController_routesTests: SnapshotTestCase {
 
     func test_documentation_current_css() async throws {
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil }
             $0.httpClient.fetchDocumentation = App.HTTPClient.echoURL()
         } operation: {
             // setup
@@ -996,8 +996,8 @@ class PackageController_routesTests: SnapshotTestCase {
 
     func test_documentation_current_js() async throws {
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil }
             $0.httpClient.fetchDocumentation = App.HTTPClient.echoURL()
         } operation: {
             // setup
@@ -1051,8 +1051,8 @@ class PackageController_routesTests: SnapshotTestCase {
 
     func test_documentation_current_data() async throws {
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil }
             $0.httpClient.fetchDocumentation = App.HTTPClient.echoURL()
         } operation: {
             // setup
@@ -1156,8 +1156,8 @@ class PackageController_routesTests: SnapshotTestCase {
         // https://github.com/SwiftPackageIndex/SwiftPackageIndex-Server/issues/2287
         // Ensure references are path encoded
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil }
             $0.httpClient.fetchDocumentation = { @Sendable _ in .init(status: .ok, body: .mockIndexHTML()) }
         } operation: {
             // setup
@@ -1220,8 +1220,8 @@ class PackageController_routesTests: SnapshotTestCase {
 
     func test_documentation_routes_tutorials() async throws {
         try await withDependencies {
+            $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { nil  }
             $0.environment.dbId = { nil }
             $0.httpClient.fetchDocumentation = { @Sendable _ in .init(status: .ok, body: .mockIndexHTML()) }
         } operation: {
@@ -1481,7 +1481,6 @@ class PackageController_routesTests: SnapshotTestCase {
         try await withDependencies {
             $0.currentReferenceCache = .disabled
             $0.environment.awsDocsBucket = { "docs-bucket" }
-            $0.environment.currentReferenceCache = { .live }
             $0.httpClient.fetchDocumentation = { @Sendable _ in .init(status: .ok, body: .mockIndexHTML()) }
         } operation: {
             // setup
@@ -1557,10 +1556,8 @@ class PackageController_routesTests: SnapshotTestCase {
     }
 
     func test_getDocRoute_documentation_current() async throws {
-        nonisolated(unsafe) let cache = CurrentReferenceCache()
         try await withDependencies {
-            $0.currentReferenceCache = .disabled
-            $0.environment.currentReferenceCache = { cache }
+            $0.currentReferenceCache = .inMemory
         } operation: {
             // owner/repo/~/documentation/archive
             let req = Request(application: app, url: "", on: app.eventLoopGroup.next())
@@ -1578,6 +1575,7 @@ class PackageController_routesTests: SnapshotTestCase {
                 XCTFail("unexpected error: \(error)")
             }
 
+            @Dependency(\.currentReferenceCache) var cache
             await cache.set(owner: "owner", repository: "repo", reference: "1.2.3")
 
             do { // Now with the cache in place this resolves

From 6ba350c2027a175081c18d7258a81c80a6b62a48 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 12:28:03 +0100
Subject: [PATCH 15/17] Move hard coded expiry from Redis to
 CurrentReferenceCacheClient

---
 .../CurrentReferenceCacheClient.swift         |  6 +++-
 .../App/Core/Dependencies/RedisClient.swift   | 29 +++++++++++++------
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
index 721ac2350..793a65f8b 100644
--- a/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
+++ b/Sources/App/Core/Dependencies/CurrentReferenceCacheClient.swift
@@ -24,11 +24,15 @@ struct CurrentReferenceCacheClient {
 
 
 extension CurrentReferenceCacheClient: DependencyKey {
+    static let timeToLive: Duration = .seconds(5*60)
+
     static var liveValue: CurrentReferenceCacheClient {
         .init(
             set: { owner, repository, reference async in
                 @Dependency(\.redis) var redis
-                await redis.set(key: getKey(owner: owner, repository: repository), value: reference)
+                await redis.set(key: getKey(owner: owner, repository: repository),
+                                value: reference,
+                                expiresIn: timeToLive)
             },
             get: { owner, repository in
                 @Dependency(\.redis) var redis
diff --git a/Sources/App/Core/Dependencies/RedisClient.swift b/Sources/App/Core/Dependencies/RedisClient.swift
index 988676cd3..35c704a18 100644
--- a/Sources/App/Core/Dependencies/RedisClient.swift
+++ b/Sources/App/Core/Dependencies/RedisClient.swift
@@ -20,15 +20,24 @@ import DependenciesMacros
 
 @DependencyClient
 struct RedisClient {
-    var set: @Sendable (_ key: String, _ value: String?) async -> Void
+    var set: @Sendable (_ key: String, _ value: String?, Duration?) async -> Void
     var get: @Sendable (_ key: String) async -> String?
 }
 
 
+extension RedisClient {
+    func set(key: String, value: String?, expiresIn: Duration? = nil) async {
+        await set(key: key, value: value, expiresIn)
+    }
+}
+
+
 extension RedisClient: DependencyKey {
     static var liveValue: RedisClient {
         .init(
-            set: { key, value in await Redis.shared?.set(key: key, value: value) },
+            set: { key, value, expiresIn in
+                await Redis.shared?.set(key: key, value: value, expiresIn: expiresIn)
+            },
             get: { key in await Redis.shared?.get(key: key) }
         )
     }
@@ -51,7 +60,7 @@ extension DependencyValues {
 #if DEBUG
 extension RedisClient {
     static var disabled: Self {
-        .init(set: { _, _ in }, get: { _ in nil })
+        .init(set: { _, _, _ in }, get: { _ in nil })
     }
 }
 #endif
@@ -92,17 +101,19 @@ private actor Redis {
         self.client = try await connection.get()
     }
 
-#warning("move expiry to interface")
-    static let expirationInSeconds = 5*60
     static let hostname = "redis"
     static let maxConnectionAttempts = 3
 
-    func set(key: String, value: String?) async -> Void {
+    func set(key: String, value: String?, expiresIn: Duration?) async -> Void {
         if let value {
             let buffer = ByteBuffer(string: value)
-            try? await client.setex(.init(key),
-                                    to: RESPValue.bulkString(buffer),
-                                    expirationInSeconds: Self.expirationInSeconds).get()
+            let value = RESPValue.bulkString(buffer)
+            if let expiresIn {
+                let ttl = Int(expiresIn.components.seconds)
+                try? await client.setex(.init(key), to: value, expirationInSeconds: ttl).get()
+            } else {
+                try? await client.set(.init(key), to: value).get()
+            }
         } else {
             _ = try? await client.delete([.init(key)]).get()
         }

From 8eead6b1c76c2d4454f08496763d327846456e66 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 14:39:02 +0100
Subject: [PATCH 16/17] Add comment regarding hostname

---
 Sources/App/Core/Dependencies/RedisClient.swift | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Sources/App/Core/Dependencies/RedisClient.swift b/Sources/App/Core/Dependencies/RedisClient.swift
index 35c704a18..c4582b4f6 100644
--- a/Sources/App/Core/Dependencies/RedisClient.swift
+++ b/Sources/App/Core/Dependencies/RedisClient.swift
@@ -101,6 +101,7 @@ private actor Redis {
         self.client = try await connection.get()
     }
 
+    // This hostname has to match the redir service name in app.yml.
     static let hostname = "redis"
     static let maxConnectionAttempts = 3
 

From 1e40561bbbe0cb275be822fabda1f50927373472 Mon Sep 17 00:00:00 2001
From: "Sven A. Schmidt" <sas@finestructure.co>
Date: Sun, 5 Jan 2025 14:55:49 +0100
Subject: [PATCH 17/17] Remove import

---
 Sources/App/configure.swift | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Sources/App/configure.swift b/Sources/App/configure.swift
index 06828ecdf..c8a65988a 100644
--- a/Sources/App/configure.swift
+++ b/Sources/App/configure.swift
@@ -14,7 +14,6 @@
 
 import Fluent
 import FluentPostgresDriver
-import Redis
 import Vapor