From aaf3e7438cf4f6e73411a5bb9409f09c3a82f7fa Mon Sep 17 00:00:00 2001
From: Robbert van der Helm <mail@robbertvanderhelm.nl>
Date: Fri, 11 Jun 2021 14:48:28 +0200
Subject: [PATCH] Use unordered maps for VST3 plugin instances

The better algorithmic time complexity should help when using many (say,
hundreds) of instances of a single VST3 plugin.
---
 CHANGELOG.md                                 | 2 ++
 src/common/communication/common.h            | 2 +-
 src/common/communication/vst3.h              | 3 ++-
 src/plugin/bridges/vst3-impls/plugin-proxy.h | 2 +-
 src/plugin/bridges/vst3.h                    | 2 +-
 src/wine-host/bridges/vst3.h                 | 2 +-
 6 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ee80ca98..dcf7c7df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,8 @@ Versioning](https://semver.org/spec/v2.0.0.html).
   completely rewritten to use both shared memory and message passing to reduce
   expensive memory copies to a minimum. With this change the DSP load overhead
   during audio processing should now be about as low as it's going to get.
+- Optimized the management of VST3 plugin instances to reduce the overhead when
+  using many instances of a VST3 plugin.
 - Prevented some more potential unnecessary memory operations during yabridge's
   communication. The underlying serialization library was recreating some
   objects even when that wasn't needed, which could in theory result in memory
diff --git a/src/common/communication/common.h b/src/common/communication/common.h
index bf4be761..53e84f9e 100644
--- a/src/common/communication/common.h
+++ b/src/common/communication/common.h
@@ -744,7 +744,7 @@ class AdHocSocketHandler {
 
         // This works the exact same was as `active_plugins` and
         // `next_plugin_id` in `GroupBridge`
-        std::map<size_t, Thread> active_secondary_requests{};
+        std::unordered_map<size_t, Thread> active_secondary_requests{};
         std::atomic_size_t next_request_id{};
         std::mutex active_secondary_requests_mutex{};
         accept_requests(
diff --git a/src/common/communication/vst3.h b/src/common/communication/vst3.h
index a40f1165..991b884b 100644
--- a/src/common/communication/vst3.h
+++ b/src/common/communication/vst3.h
@@ -526,7 +526,8 @@ class Vst3Sockets final : public Sockets {
      * would have one dedicated thread for handling function calls to these
      * interfaces, and then another dedicated thread just idling around.
      */
-    std::map<size_t, Vst3MessageHandler<Thread, AudioProcessorRequest>>
+    std::unordered_map<size_t,
+                       Vst3MessageHandler<Thread, AudioProcessorRequest>>
         audio_processor_sockets;
     std::mutex audio_processor_sockets_mutex;
 };
diff --git a/src/plugin/bridges/vst3-impls/plugin-proxy.h b/src/plugin/bridges/vst3-impls/plugin-proxy.h
index 7b7118e3..47db1806 100644
--- a/src/plugin/bridges/vst3-impls/plugin-proxy.h
+++ b/src/plugin/bridges/vst3-impls/plugin-proxy.h
@@ -529,7 +529,7 @@ class Vst3PluginProxyImpl : public Vst3PluginProxy {
         /**
          * Memoizes `IEditController::getParameterInfo()`.
          */
-        std::map<int32, Steinberg::Vst::ParameterInfo> parameter_info;
+        std::unordered_map<int32, Steinberg::Vst::ParameterInfo> parameter_info;
     };
 
     /**
diff --git a/src/plugin/bridges/vst3.h b/src/plugin/bridges/vst3.h
index 1fed94f9..e8a2f31f 100644
--- a/src/plugin/bridges/vst3.h
+++ b/src/plugin/bridges/vst3.h
@@ -204,7 +204,7 @@ class Vst3PluginBridge : PluginBridge<Vst3Sockets<std::jthread>> {
      * `register_plugin_proxy()` in the constractor, and an instance is then
      * removed through a call to `unregister_plugin_proxy()` in the destructor.
      */
-    std::map<size_t, std::reference_wrapper<Vst3PluginProxyImpl>>
+    std::unordered_map<size_t, std::reference_wrapper<Vst3PluginProxyImpl>>
         plugin_proxies;
 
    private:
diff --git a/src/wine-host/bridges/vst3.h b/src/wine-host/bridges/vst3.h
index 94f920f3..b499ce10 100644
--- a/src/wine-host/bridges/vst3.h
+++ b/src/wine-host/bridges/vst3.h
@@ -440,7 +440,7 @@ class Vst3Bridge : public HostBridge {
      * will cause all pointers to it to get dropped and the object to be cleaned
      * up.
      */
-    std::map<size_t, InstanceInterfaces> object_instances;
+    std::unordered_map<size_t, InstanceInterfaces> object_instances;
     std::mutex object_instances_mutex;
 
     /**