1 files changed, 134 insertions, 0 deletions
diff --git a/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp b/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp
new file mode 100644
index 000000000..72b1dbb32
--- /dev/null
+++ b/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp
@@ -0,0 +1,134 @@
+// SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <array>
+#include <memory>
+#include <span>
+
+#include <glad/glad.h>
+
+#include "common/alignment.h"
+#include "common/assert.h"
+#include "video_core/renderer_opengl/gl_staging_buffer_pool.h"
+
+namespace OpenGL {
+
+StagingBufferMap::~StagingBufferMap() {
+    if (sync) {
+        sync->Create();
+    }
+}
+
+StagingBuffers::StagingBuffers(GLenum storage_flags_, GLenum map_flags_)
+    : storage_flags{storage_flags_}, map_flags{map_flags_} {}
+
+StagingBuffers::~StagingBuffers() = default;
+
+StagingBufferMap StagingBuffers::RequestMap(size_t requested_size, bool insert_fence) {
+    const size_t index = RequestBuffer(requested_size);
+    OGLSync* const sync = insert_fence ? &syncs[index] : nullptr;
+    return StagingBufferMap{
+        .mapped_span = std::span(maps[index], requested_size),
+        .sync = sync,
+        .buffer = buffers[index].handle,
+    };
+}
+
+size_t StagingBuffers::RequestBuffer(size_t requested_size) {
+    if (const std::optional<size_t> index = FindBuffer(requested_size); index) {
+        return *index;
+    }
+
+    OGLBuffer& buffer = buffers.emplace_back();
+    buffer.Create();
+    glNamedBufferStorage(buffer.handle, requested_size, nullptr,
+                         storage_flags | GL_MAP_PERSISTENT_BIT);
+    maps.push_back(static_cast<u8*>(glMapNamedBufferRange(buffer.handle, 0, requested_size,
+                                                          map_flags | GL_MAP_PERSISTENT_BIT)));
+
+    syncs.emplace_back();
+    sizes.push_back(requested_size);
+
+    ASSERT(syncs.size() == buffers.size() && buffers.size() == maps.size() &&
+           maps.size() == sizes.size());
+
+    return buffers.size() - 1;
+}
+
+std::optional<size_t> StagingBuffers::FindBuffer(size_t requested_size) {
+    size_t smallest_buffer = std::numeric_limits<size_t>::max();
+    std::optional<size_t> found;
+    const size_t num_buffers = sizes.size();
+    for (size_t index = 0; index < num_buffers; ++index) {
+        const size_t buffer_size = sizes[index];
+        if (buffer_size < requested_size || buffer_size >= smallest_buffer) {
+            continue;
+        }
+        if (syncs[index].handle != 0) {
+            if (!syncs[index].IsSignaled()) {
+                continue;
+            }
+            syncs[index].Release();
+        }
+        smallest_buffer = buffer_size;
+        found = index;
+    }
+    return found;
+}
+
+StreamBuffer::StreamBuffer() {
+    static constexpr GLenum flags = GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT;
+    buffer.Create();
+    glObjectLabel(GL_BUFFER, buffer.handle, -1, "Stream Buffer");
+    glNamedBufferStorage(buffer.handle, STREAM_BUFFER_SIZE, nullptr, flags);
+    mapped_pointer =
+        static_cast<u8*>(glMapNamedBufferRange(buffer.handle, 0, STREAM_BUFFER_SIZE, flags));
+    for (OGLSync& sync : fences) {
+        sync.Create();
+    }
+}
+
+std::pair<std::span<u8>, size_t> StreamBuffer::Request(size_t size) noexcept {
+    ASSERT(size < REGION_SIZE);
+    for (size_t region = Region(used_iterator), region_end = Region(iterator); region < region_end;
+         ++region) {
+        fences[region].Create();
+    }
+    used_iterator = iterator;
+
+    for (size_t region = Region(free_iterator) + 1,
+                region_end = std::min(Region(iterator + size) + 1, NUM_SYNCS);
+         region < region_end; ++region) {
+        glClientWaitSync(fences[region].handle, 0, GL_TIMEOUT_IGNORED);
+        fences[region].Release();
+    }
+    if (iterator + size >= free_iterator) {
+        free_iterator = iterator + size;
+    }
+    if (iterator + size > STREAM_BUFFER_SIZE) {
+        for (size_t region = Region(used_iterator); region < NUM_SYNCS; ++region) {
+            fences[region].Create();
+        }
+        used_iterator = 0;
+        iterator = 0;
+        free_iterator = size;
+
+        for (size_t region = 0, region_end = Region(size); region <= region_end; ++region) {
+            glClientWaitSync(fences[region].handle, 0, GL_TIMEOUT_IGNORED);
+            fences[region].Release();
+        }
+    }
+    const size_t offset = iterator;
+    iterator = Common::AlignUp(iterator + size, MAX_ALIGNMENT);
+    return {std::span(mapped_pointer + offset, size), offset};
+}
+
+StagingBufferMap StagingBufferPool::RequestUploadBuffer(size_t size) {
+    return upload_buffers.RequestMap(size, true);
+}
+
+StagingBufferMap StagingBufferPool::RequestDownloadBuffer(size_t size) {
+    return download_buffers.RequestMap(size, false);
+}
+
+} // namespace OpenGL