From 382852418be0fd14fb0290d7b0ff86644685b59b Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Thu, 23 Aug 2018 15:38:57 -0400
Subject: [PATCH] video_core: Add RasterizerCache class for common cache
 management code.

---
 src/video_core/CMakeLists.txt     |   1 +
 src/video_core/rasterizer_cache.h | 116 ++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)
 create mode 100644 src/video_core/rasterizer_cache.h

diff --git a/src/video_core/CMakeLists.txt b/src/video_core/CMakeLists.txt
index c6431e722c..c9822f0d8d 100644
--- a/src/video_core/CMakeLists.txt
+++ b/src/video_core/CMakeLists.txt
@@ -18,6 +18,7 @@ add_library(video_core STATIC
     macro_interpreter.h
     memory_manager.cpp
     memory_manager.h
+    rasterizer_cache.h
     rasterizer_interface.h
     renderer_base.cpp
     renderer_base.h
diff --git a/src/video_core/rasterizer_cache.h b/src/video_core/rasterizer_cache.h
new file mode 100644
index 0000000000..7a0492a4e0
--- /dev/null
+++ b/src/video_core/rasterizer_cache.h
@@ -0,0 +1,116 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <unordered_map>
+#include <boost/icl/interval_map.hpp>
+#include <boost/range/iterator_range.hpp>
+
+#include "common/common_types.h"
+#include "core/memory.h"
+#include "video_core/memory_manager.h"
+
+template <class T>
+class RasterizerCache : NonCopyable {
+public:
+    /// Mark the specified region as being invalidated
+    void InvalidateRegion(Tegra::GPUVAddr region_addr, size_t region_size) {
+        for (auto iter = cached_objects.cbegin(); iter != cached_objects.cend();) {
+            const auto& object{iter->second};
+
+            ++iter;
+
+            if (object->GetAddr() <= (region_addr + region_size) &&
+                region_addr <= (object->GetAddr() + object->GetSizeInBytes())) {
+                // Regions overlap, so invalidate
+                Unregister(object);
+            }
+        }
+    }
+
+protected:
+    /// Tries to get an object from the cache with the specified address
+    T TryGet(Tegra::GPUVAddr addr) const {
+        const auto& search{cached_objects.find(addr)};
+        if (search != cached_objects.end()) {
+            return search->second;
+        }
+
+        return nullptr;
+    }
+
+    /// Gets a reference to the cache
+    const std::unordered_map<Tegra::GPUVAddr, T>& GetCache() const {
+        return cached_objects;
+    }
+
+    /// Register an object into the cache
+    void Register(const T& object) {
+        const auto& search{cached_objects.find(object->GetAddr())};
+        if (search != cached_objects.end()) {
+            // Registered already
+            return;
+        }
+
+        cached_objects[object->GetAddr()] = object;
+        UpdatePagesCachedCount(object->GetAddr(), object->GetSizeInBytes(), 1);
+    }
+
+    /// Unregisters an object from the cache
+    void Unregister(const T& object) {
+        const auto& search{cached_objects.find(object->GetAddr())};
+        if (search == cached_objects.end()) {
+            // Unregistered already
+            return;
+        }
+
+        UpdatePagesCachedCount(object->GetAddr(), object->GetSizeInBytes(), -1);
+        cached_objects.erase(search);
+    }
+
+private:
+    using PageMap = boost::icl::interval_map<u64, int>;
+
+    template <typename Map, typename Interval>
+    constexpr auto RangeFromInterval(Map& map, const Interval& interval) {
+        return boost::make_iterator_range(map.equal_range(interval));
+    }
+
+    /// Increase/decrease the number of object in pages touching the specified region
+    void UpdatePagesCachedCount(Tegra::GPUVAddr addr, u64 size, int delta) {
+        const u64 page_start{addr >> Tegra::MemoryManager::PAGE_BITS};
+        const u64 page_end{(addr + size) >> Tegra::MemoryManager::PAGE_BITS};
+
+        // Interval maps will erase segments if count reaches 0, so if delta is negative we have to
+        // subtract after iterating
+        const auto pages_interval = PageMap::interval_type::right_open(page_start, page_end);
+        if (delta > 0)
+            cached_pages.add({pages_interval, delta});
+
+        for (const auto& pair : RangeFromInterval(cached_pages, pages_interval)) {
+            const auto interval = pair.first & pages_interval;
+            const int count = pair.second;
+
+            const Tegra::GPUVAddr interval_start_addr = boost::icl::first(interval)
+                                                        << Tegra::MemoryManager::PAGE_BITS;
+            const Tegra::GPUVAddr interval_end_addr = boost::icl::last_next(interval)
+                                                      << Tegra::MemoryManager::PAGE_BITS;
+            const u64 interval_size = interval_end_addr - interval_start_addr;
+
+            if (delta > 0 && count == delta)
+                Memory::RasterizerMarkRegionCached(interval_start_addr, interval_size, true);
+            else if (delta < 0 && count == -delta)
+                Memory::RasterizerMarkRegionCached(interval_start_addr, interval_size, false);
+            else
+                ASSERT(count >= 0);
+        }
+
+        if (delta < 0)
+            cached_pages.add({pages_interval, delta});
+    }
+
+    std::unordered_map<Tegra::GPUVAddr, T> cached_objects;
+    PageMap cached_pages;
+};