From b6b04fa6c56e0804c3b4b31efbaf1a7bb640ec67 Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Sun, 31 Jul 2022 13:11:57 +0100
Subject: [PATCH] Use small_vector for VMM TranslateRange results

This was the source of a lot of heap allocs, moving to small_vector helps to avoid most of them
---
 app/src/main/cpp/skyline/common/address_space.h   | 5 ++++-
 app/src/main/cpp/skyline/common/address_space.inc | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/app/src/main/cpp/skyline/common/address_space.h b/app/src/main/cpp/skyline/common/address_space.h
index e3f1965c..39cf2b39 100644
--- a/app/src/main/cpp/skyline/common/address_space.h
+++ b/app/src/main/cpp/skyline/common/address_space.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <boost/container/small_vector.hpp>
 #include <concepts>
 #include <common.h>
 
@@ -10,6 +11,8 @@ namespace skyline {
     template<typename VaType, size_t AddressSpaceBits>
     concept AddressSpaceValid = std::is_unsigned_v<VaType> && sizeof(VaType) * 8 >= AddressSpaceBits;
 
+    using TranslatedAddressRange = boost::container::small_vector<span<u8>, 1>;
+
     struct EmptyStruct {};
 
     /**
@@ -116,7 +119,7 @@ namespace skyline {
         /**
          * @return A vector of all physical ranges inside of the given virtual range
          */
-        std::vector<span<u8>> TranslateRange(VaType virt, VaType size, std::function<void(span<u8>)> cpuAccessCallback = {});
+        TranslatedAddressRange TranslateRange(VaType virt, VaType size, std::function<void(span<u8>)> cpuAccessCallback = {});
 
         void Read(u8 *destination, VaType virt, VaType size, std::function<void(span<u8>)> cpuAccessCallback = {});
 
diff --git a/app/src/main/cpp/skyline/common/address_space.inc b/app/src/main/cpp/skyline/common/address_space.inc
index bec53a73..00607a04 100644
--- a/app/src/main/cpp/skyline/common/address_space.inc
+++ b/app/src/main/cpp/skyline/common/address_space.inc
@@ -233,7 +233,7 @@ namespace skyline {
         munmap(sparseMap, SparseMapSize);
     }
 
-    MM_MEMBER(std::vector<span<u8>>)::TranslateRange(VaType virt, VaType size, std::function<void(span<u8>)> cpuAccessCallback) {
+    MM_MEMBER(TranslatedAddressRange)::TranslateRange(VaType virt, VaType size, std::function<void(span<u8>)> cpuAccessCallback) {
         TRACE_EVENT("containers", "FlatMemoryManager::TranslateRange");
 
         std::scoped_lock lock(this->blockMutex);
@@ -247,7 +247,7 @@ namespace skyline {
         u8 *blockPhys{predecessor->phys + (virt - predecessor->virt)};
         VaType blockSize{std::min(successor->virt - virt, size)};
 
-        std::vector<span<u8>> ranges;
+        TranslatedAddressRange ranges;
 
         while (size) {
             // Return a zeroed out map to emulate sparse mappings