commit 25700b452535ce7ae838bfe832392b46ed555ed2
author Chia-I Wu <olv@google.com> Thu Apr 28 06:36:09 2016 +0800
committer Chia-I Wu <olv@google.com> Thu Apr 28 08:52:40 2016 +0800
tree 0971ec44d2461cc073186422e7a3aab9a06a1c69
parent 6cfb89c0bfe11c2ee513fe4df339ad753d4ad4ff

vulkan: refactor layer enumeration

Replace Enumerate*Layers by a set of new functions that do not distinguish
instance and device layers.  The new functions are also careful not to
pollute the rest of the loader with std containers.

There should be no user-visible change.

Bug: 27911856
Change-Id: I4790fadc1aa2ea934a4628bce55dd45892f15e0b

vulkan/libvulkan/api.cpp

diff --git a/vulkan/libvulkan/api.cpp b/vulkan/libvulkan/api.cpp
index e7f10b3..e3f69fe 100644
--- a/vulkan/libvulkan/api.cpp
+++ b/vulkan/libvulkan/api.cpp
@@ -1098,13 +1098,19 @@
     if (!EnsureInitialized())
         return VK_ERROR_INITIALIZATION_FAILED;
 
-    uint32_t count =
-        EnumerateInstanceLayers(pProperties ? *pPropertyCount : 0, pProperties);
+    uint32_t count = GetLayerCount();
 
-    if (!pProperties || *pPropertyCount > count)
+    if (!pProperties) {
         *pPropertyCount = count;
+        return VK_SUCCESS;
+    }
 
-    return *pPropertyCount < count ? VK_INCOMPLETE : VK_SUCCESS;
+    uint32_t copied = std::min(*pPropertyCount, count);
+    for (uint32_t i = 0; i < copied; i++)
+        pProperties[i] = GetLayerProperties(GetLayer(i));
+    *pPropertyCount = copied;
+
+    return (copied == count) ? VK_SUCCESS : VK_INCOMPLETE;
 }
 
 VkResult EnumerateInstanceExtensionProperties(
@@ -1137,13 +1143,34 @@
                                         VkLayerProperties* pProperties) {
     (void)physicalDevice;
 
-    uint32_t count =
-        EnumerateDeviceLayers(pProperties ? *pPropertyCount : 0, pProperties);
+    uint32_t total_count = GetLayerCount();
 
-    if (!pProperties || *pPropertyCount > count)
+    if (!pProperties) {
+        uint32_t count = 0;
+        for (uint32_t i = 0; i < total_count; i++) {
+            if (IsLayerGlobal(GetLayer(i)))
+                count++;
+        }
+
         *pPropertyCount = count;
+        return VK_SUCCESS;
+    }
 
-    return *pPropertyCount < count ? VK_INCOMPLETE : VK_SUCCESS;
+    uint32_t count = 0;
+    uint32_t copied = 0;
+    for (uint32_t i = 0; i < total_count; i++) {
+        const Layer& layer = GetLayer(i);
+        if (!IsLayerGlobal(layer))
+            continue;
+
+        count++;
+        if (copied < *pPropertyCount)
+            pProperties[copied++] = GetLayerProperties(layer);
+    }
+
+    *pPropertyCount = copied;
+
+    return (copied == count) ? VK_SUCCESS : VK_INCOMPLETE;
 }
 
 VkResult EnumerateDeviceExtensionProperties(

vulkan/libvulkan/layers_extensions.cpp

diff --git a/vulkan/libvulkan/layers_extensions.cpp b/vulkan/libvulkan/layers_extensions.cpp
index 4cf1c2a..4363dd8 100644
--- a/vulkan/libvulkan/layers_extensions.cpp
+++ b/vulkan/libvulkan/layers_extensions.cpp
@@ -50,6 +50,7 @@
     VkLayerProperties properties;
     size_t library_idx;
 
+    // true if the layer intercepts vkCreateDevice and device commands
     bool is_global;
 
     std::vector<VkExtensionProperties> instance_extensions;
@@ -359,29 +360,20 @@
         DiscoverLayersInDirectory(LoaderData::GetInstance().layer_path.c_str());
 }
 
-uint32_t EnumerateInstanceLayers(uint32_t count,
-                                 VkLayerProperties* properties) {
-    uint32_t n =
-        std::min(count, static_cast<uint32_t>(g_instance_layers.size()));
-    for (uint32_t i = 0; i < n; i++)
-        properties[i] = g_instance_layers[i].properties;
-
+uint32_t GetLayerCount() {
     return static_cast<uint32_t>(g_instance_layers.size());
 }
 
-uint32_t EnumerateDeviceLayers(uint32_t count, VkLayerProperties* properties) {
-    uint32_t n = 0;
-    for (const auto& layer : g_instance_layers) {
-        // ignore non-global layers
-        if (!layer.is_global)
-            continue;
+const Layer& GetLayer(uint32_t index) {
+    return g_instance_layers[index];
+}
 
-        if (n < count)
-            properties[n] = layer.properties;
-        n++;
-    }
+const VkLayerProperties& GetLayerProperties(const Layer& layer) {
+    return layer.properties;
+}
 
-    return n;
+bool IsLayerGlobal(const Layer& layer) {
+    return layer.is_global;
 }
 
 void GetInstanceLayerExtensions(const char* name,

vulkan/libvulkan/layers_extensions.h

diff --git a/vulkan/libvulkan/layers_extensions.h b/vulkan/libvulkan/layers_extensions.h
index e2eb32b..ee85f00 100644
--- a/vulkan/libvulkan/layers_extensions.h
+++ b/vulkan/libvulkan/layers_extensions.h
@@ -23,6 +23,7 @@
 namespace api {
 
 struct Layer;
+
 class LayerRef {
    public:
     LayerRef(const Layer* layer, bool is_instance);
@@ -48,8 +49,13 @@
 };
 
 void DiscoverLayers();
-uint32_t EnumerateInstanceLayers(uint32_t count, VkLayerProperties* properties);
-uint32_t EnumerateDeviceLayers(uint32_t count, VkLayerProperties* properties);
+
+uint32_t GetLayerCount();
+const Layer& GetLayer(uint32_t index);
+
+const VkLayerProperties& GetLayerProperties(const Layer& layer);
+bool IsLayerGlobal(const Layer& layer);
+
 void GetInstanceLayerExtensions(const char* name,
                                 const VkExtensionProperties** properties,
                                 uint32_t* count);