Server rewrite

CONTRIBUTING.md

@@ -22,6 +22,8 @@ Now you can open the codebase in [IDEA](https://www.jetbrains.com/idea/download/
 
 ### Java (server)
 
+Before contributing to the server, read [server/README.md](server/README.md) for an overview of its architecture and design guidelines.
+
 The Java code is built with `gradle`, a CLI tool that manages java projects and their
 dependencies.
 - You can run the server by running `./gradlew run` in your IDE's terminal.

README.md

@@ -22,6 +22,8 @@ Latest setup instructions are [in our docs](https://docs.slimevr.dev/server/inde
 ## Building & Contributing
 For information on building and contributing to the codebase, see [CONTRIBUTING.md](CONTRIBUTING.md).
 
+For an overview of the server architecture and design guidelines, see [server/README.md](server/README.md).
+
 ## Translating
 
 Translation is done via Pontoon at [i18n.slimevr.dev](https://i18n.slimevr.dev/). Please join our [Discord translation forum](https://discord.com/channels/817184208525983775/1050413434249949235) to coordinate.

flake.nix

@@ -12,8 +12,10 @@
 
       perSystem = { pkgs, ... }:
         let
+          java = pkgs.javaPackages.compiler.temurin-bin.jdk-24;
+
           runtimeLibs = pkgs: (with pkgs; [
-            jdk17
+            java
 
             alsa-lib at-spi2-atk at-spi2-core cairo cups dbus expat
             gdk-pixbuf glib gtk3 libdrm libgbm libglvnd libnotify
@@ -33,8 +35,8 @@
             name = "slimevr-env";
             targetPkgs = runtimeLibs;
             profile = ''
-              export JAVA_HOME=${pkgs.jdk17}
-              export PATH="${pkgs.jdk17}/bin:$PATH"
+              export JAVA_HOME=${java}
+              export PATH="${java}/bin:$PATH"
 
               # Tell electron-builder to use system tools instead of downloading them
               export USE_SYSTEM_FPM=true

gradle.properties

@@ -20,3 +20,4 @@ buildconfigVersion=6.0.7
 # We should probably stop using grgit, see:
 # https://andrewoberstar.com/posts/2024-04-02-dont-commit-to-grgit/
 grgitVersion=5.3.3
+wireVersion=5.3.1

server/android/build.gradle.kts

@@ -22,12 +22,12 @@ plugins {
 
 kotlin {
 	jvmToolchain {
-		languageVersion.set(JavaLanguageVersion.of(17))
+		languageVersion.set(JavaLanguageVersion.of(24))
 	}
 }
 java {
 	toolchain {
-		languageVersion.set(JavaLanguageVersion.of(17))
+		languageVersion.set(JavaLanguageVersion.of(24))
 	}
 }
 
@@ -83,7 +83,7 @@ val deleteTempKeyStore = tasks.register<Delete>("deleteTempKeyStore") {
 
 tasks.withType<KotlinCompile> {
 	compilerOptions {
-		jvmTarget.set(JvmTarget.JVM_17)
+		jvmTarget.set(JvmTarget.JVM_22)
 		freeCompilerArgs.set(listOf("-Xvalue-classes"))
 	}
 }
@@ -217,7 +217,7 @@ android {
 	}
 
 	compileOptions {
-		sourceCompatibility = JavaVersion.VERSION_17
-		targetCompatibility = JavaVersion.VERSION_17
+		sourceCompatibility = JavaVersion.VERSION_24
+		targetCompatibility = JavaVersion.VERSION_24
 	}
 }

server/architecture.dot

@@ -0,0 +1,123 @@
+digraph module_architecture {
+    rankdir=TB
+    splines=false
+    nodesep=0.8
+    ranksep=0.8
+    forcelabels=true
+    fontname="monospace"
+    node [fontname="monospace", fontsize=11, style="filled,rounded", shape=box, margin="0.3,0.2"]
+    edge [fontname="monospace", fontsize=10]
+
+    ext [
+        label="external events\n(packets · messages)"
+        shape=ellipse fillcolor="#dae8fc" color="#6c8ebf"
+    ]
+
+    subgraph cluster_A {
+        label="Module A"
+        style="rounded" bgcolor="#fafafa" color="#999999" penwidth=1.5
+
+        subgraph cluster_A_beh {
+            label="Behaviours"
+            style="dashed" color="#aaaaaa" bgcolor="#fffff8"
+
+            bA1 [label="BehaviourA1\n────────────────────\nobserve(receiver)\n  subscribes to flows\n  calls dispatch()\n────────────────────\nreduce(state, action)\n  pure: State -> State"
+                fillcolor="#fff9db" color="#d6ae00"]
+
+            bA2 [label="BehaviourA2\n────────────────────\nobserve(receiver)\n  ...\n────────────────────\nreduce(state, action)\n  ..."
+                fillcolor="#fff9db" color="#d6ae00"]
+
+            bAmore [label="···\n────────────────────\nobserve(receiver)\n  ...\n────────────────────\nreduce(state, action)\n  ..."
+                fillcolor="#fff9db" color="#d6ae00"]
+        }
+
+        foldA [
+            label="reduce fold\n──────────────────────────────────\nstate = BehaviourA1.reduce(state, a)\nstate = BehaviourA2.reduce(state, a)\nstate = ···"
+            fillcolor="#d5e8d4" color="#82b366"
+        ]
+
+        sfA [
+            label="StateFlow<StateA>"
+            shape=cylinder fillcolor="#dae8fc" color="#6c8ebf"
+        ]
+
+    }
+
+    subgraph cluster_B {
+        label="Module B"
+        style="rounded" bgcolor="#fafafa" color="#999999" penwidth=1.5
+
+        subgraph cluster_B_beh {
+            label="Behaviours"
+            style="dashed" color="#aaaaaa" bgcolor="#fffff8"
+
+            bBmore [label="···\n────────────────────\nobserve(receiver)\n  ...\n────────────────────\nreduce(state, action)\n  ..."
+                fillcolor="#fff9db" color="#d6ae00"]
+        }
+
+        foldB [
+            label="reduce fold"
+            fillcolor="#d5e8d4" color="#82b366"
+        ]
+
+        sfB [
+            label="StateFlow<StateB>"
+            shape=cylinder fillcolor="#dae8fc" color="#6c8ebf"
+        ]
+    }
+
+    subgraph cluster_C {
+        label="Module C"
+        style="rounded" bgcolor="#fafafa" color="#999999" penwidth=1.5
+
+        subgraph cluster_C_beh {
+            label="Behaviours"
+            style="dashed" color="#aaaaaa" bgcolor="#fffff8"
+
+            bCmore [label="···\n────────────────────\nobserve(receiver)\n  ...\n────────────────────\nreduce(state, action)\n  ..."
+                fillcolor="#fff9db" color="#d6ae00"]
+        }
+
+        foldC [
+            label="reduce fold"
+            fillcolor="#d5e8d4" color="#82b366"
+        ]
+
+        sfC [
+            label="StateFlow<StateC>"
+            shape=cylinder fillcolor="#dae8fc" color="#6c8ebf"
+        ]
+
+    }
+
+    // ext -> all modules
+    ext -> bA1    [color="#6c8ebf" fontcolor="#6c8ebf" weight=1]
+    ext -> bA2    [color="#6c8ebf" weight=1]
+    ext -> bAmore [color="#6c8ebf" weight=1]
+    ext -> bBmore [color="#6c8ebf" weight=1]
+    ext -> bCmore [color="#6c8ebf" weight=1]
+
+    // Module A internal flow
+    bA1    -> foldA  [xlabel="dispatch(action)" color="#d6ae00" fontcolor="#d6ae00"]
+    bA2    -> foldA  [xlabel="dispatch(action)" color="#d6ae00" fontcolor="#d6ae00"]
+    bAmore -> foldA  [xlabel="dispatch(action)" color="#d6ae00" fontcolor="#d6ae00"]
+    foldA  -> sfA    [xlabel="new state" color="#82b366" fontcolor="#82b366"]
+
+    // Module B internal flow
+    bBmore -> foldB  [xlabel="dispatch(action)" color="#d6ae00" fontcolor="#d6ae00"]
+    foldB  -> sfB    [color="#82b366"]
+
+    // Module C internal flow
+    bCmore -> foldC  [xlabel="dispatch(action)" color="#d6ae00" fontcolor="#d6ae00"]
+    foldC  -> sfC    [color="#82b366"]
+    // Within-module feedback (gray)
+    bA1 -> sfA       [xlabel="collect()" dir=back style=dashed color="#888888" fontcolor="#888888" constraint=true]
+    bBmore -> sfB    [xlabel="collect()" dir=back style=dashed color="#888888" fontcolor="#888888" constraint=true]
+    bCmore -> sfC    [xlabel="collect()" dir=back style=dashed color="#888888" fontcolor="#888888" constraint=true]
+
+
+    // Cross-module: routed via waypoints at rank 4 — exits downward, travels below all modules
+    bBmore -> sfA [xlabel="collect()" dir=back style=dashed color="#FF0000" fontcolor="#FF0000" constraint=false]
+    bCmore -> sfA [xlabel="collect()" dir=back style=dashed color="#FF0000" fontcolor="#FF0000" constraint=false]
+    bCmore -> sfB [xlabel="collect()" dir=back style=dashed color="#FF0000" fontcolor="#FF0000" constraint=false]
+}