Factor out common cache testing code.

- To be used for pipeline cache testing.
- Plumbs overriding the platform to the adapters for testing.
- Restructures build a little bit so that the test infrastructure can have full access to dawn native internals. Also differentiates end2end and white_box a bit more to make it clear that end2end should not have access to dawn native internals.

Bug: dawn:549, dawn:1374
Change-Id: Ibcc6c44a116c7967ee2317c74409f613e896eb0a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86841
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Loko Kung <lokokung@google.com>

include/dawn/native/DawnNative.h

@@ -164,6 +164,7 @@ namespace dawn::native {
         // Enable debug capture on Dawn startup
         void EnableBeginCaptureOnStartup(bool beginCaptureOnStartup);
 
+        // TODO(dawn:1374) Deprecate this once it is passed via the descriptor.
         void SetPlatform(dawn::platform::Platform* platform);
 
         // Returns the underlying WGPUInstance object.

src/dawn/native/DawnNative.cpp

@@ -240,6 +240,7 @@ namespace dawn::native {
         mImpl->EnableBeginCaptureOnStartup(beginCaptureOnStartup);
     }
 
+    // TODO(dawn:1374) Deprecate this once it is passed via the descriptor.
     void Instance::SetPlatform(dawn::platform::Platform* platform) {
         mImpl->SetPlatform(platform);
     }

src/dawn/native/Instance.cpp

@@ -422,15 +422,12 @@ namespace dawn::native {
         mBlobCache = std::make_unique<BlobCache>(GetCachingInterface(platform));
     }
 
-    dawn::platform::Platform* InstanceBase::GetPlatform() {
+    void InstanceBase::SetPlatformForTesting(dawn::platform::Platform* platform) {
-        if (mPlatform != nullptr) {
+        SetPlatform(platform);
-            return mPlatform;
+    }
-        }
 
-        if (mDefaultPlatform == nullptr) {
+    dawn::platform::Platform* InstanceBase::GetPlatform() {
-            mDefaultPlatform = std::make_unique<dawn::platform::Platform>();
+        return mPlatform;
-        }
-        return mDefaultPlatform.get();
     }
 
     BlobCache* InstanceBase::GetBlobCache() {

src/dawn/native/Instance.h

@@ -77,9 +77,10 @@ namespace dawn::native {
         void EnableBeginCaptureOnStartup(bool beginCaptureOnStartup);
         bool IsBeginCaptureOnStartupEnabled() const;
 
-        // TODO(dawn:1374): SetPlatform should become a private helper, and a NOT thread-safe
+        // TODO(dawn:1374): SetPlatform should become a private helper, and SetPlatformForTesting
-        // testing version exposed for special testing cases.
+        // will become the NOT thread-safe testing version exposed for special testing cases.
         void SetPlatform(dawn::platform::Platform* platform);
+        void SetPlatformForTesting(dawn::platform::Platform* platform);
         dawn::platform::Platform* GetPlatform();
         BlobCache* GetBlobCache();
 

src/dawn/tests/BUILD.gn

@@ -330,32 +330,76 @@ dawn_test("dawn_unittests") {
 }
 
 ###############################################################################
-# Dawn end2end tests targets
+# Dawn test infrastructure targets
 ###############################################################################
 
-source_set("end2end_tests_sources") {
+source_set("test_infra_sources") {
-  configs += [ "${dawn_root}/src/dawn/common:internal_config" ]
+  configs += [ "${dawn_root}/src/dawn/native:internal" ]
   testonly = true
 
   deps = [
-    ":gmock_and_gtest",
     "${dawn_root}/src/dawn:cpp",
     "${dawn_root}/src/dawn:proc",
     "${dawn_root}/src/dawn/common",
-
+    "${dawn_root}/src/dawn/native:sources",
-    # Statically linked because the end2end white_box tests use Dawn internals.
     "${dawn_root}/src/dawn/native:static",
-    "${dawn_root}/src/dawn/platform:platform",
     "${dawn_root}/src/dawn/utils",
     "${dawn_root}/src/dawn/wire",
   ]
 
+  public_deps = [ ":gmock_and_gtest" ]
+
+  if (dawn_supports_glfw_for_windowing || dawn_enable_opengl) {
+    assert(dawn_supports_glfw_for_windowing)
+    public_deps += [ "${dawn_root}/src/dawn/utils:glfw" ]
+  }
+
   sources = [
+    "DawnTest.cpp",
     "DawnTest.h",
     "MockCallback.h",
     "ParamGenerator.h",
     "ToggleParser.cpp",
     "ToggleParser.h",
+  ]
+}
+
+###############################################################################
+# Dawn end2end tests targets
+###############################################################################
+
+# Source code for mocks used for end2end testing are separated from the rest of
+# sources so that they aren't included in non-test builds.
+source_set("end2end_mocks_sources") {
+  configs += [ "${dawn_root}/src/dawn/native:internal" ]
+  testonly = true
+
+  deps = [
+    ":gmock_and_gtest",
+    "${dawn_root}/src/dawn/platform",
+  ]
+
+  sources = [
+    "end2end/mocks/CachingInterfaceMock.cpp",
+    "end2end/mocks/CachingInterfaceMock.h",
+  ]
+}
+
+source_set("end2end_tests_sources") {
+  testonly = true
+
+  deps = [
+    ":end2end_mocks_sources",
+    ":test_infra_sources",
+    "${dawn_root}/src/dawn:cpp",
+    "${dawn_root}/src/dawn:proc",
+    "${dawn_root}/src/dawn/common",
+    "${dawn_root}/src/dawn/native:headers",
+    "${dawn_root}/src/dawn/utils",
+    "${dawn_root}/src/dawn/wire",
+  ]
+
+  sources = [
     "end2end/AdapterDiscoveryTests.cpp",
     "end2end/BasicTests.cpp",
     "end2end/BindGroupTests.cpp",
@@ -461,17 +505,12 @@ source_set("end2end_tests_sources") {
     frameworks = [ "IOSurface.framework" ]
   }
 
-  if (dawn_enable_opengl) {
-    assert(dawn_supports_glfw_for_windowing)
-  }
-
   if (dawn_supports_glfw_for_windowing) {
     sources += [
       "end2end/SwapChainTests.cpp",
       "end2end/SwapChainValidationTests.cpp",
       "end2end/WindowSurfaceTests.cpp",
     ]
-    deps += [ "${dawn_root}/src/dawn/utils:glfw" ]
   }
 
   if (dawn_enable_d3d12 || (dawn_enable_vulkan && is_chromeos) ||
@@ -492,23 +531,19 @@ source_set("white_box_tests_sources") {
   testonly = true
 
   deps = [
-    ":gmock_and_gtest",
+    ":test_infra_sources",
     "${dawn_root}/src/dawn:cpp",
     "${dawn_root}/src/dawn:proc",
     "${dawn_root}/src/dawn/common",
-    "${dawn_root}/src/dawn/native:sources",
 
-    # Statically linked because the end2end white_box tests use Dawn internals.
+    # Statically linked and with sources because the end2end white_box tests use Dawn internals.
+    "${dawn_root}/src/dawn/native:sources",
     "${dawn_root}/src/dawn/native:static",
     "${dawn_root}/src/dawn/utils",
     "${dawn_root}/src/dawn/wire",
   ]
 
-  sources = [
+  sources = []
-    "DawnTest.h",
-    "ParamGenerator.h",
-    "ToggleParser.h",
-  ]
 
   if (dawn_enable_vulkan) {
     deps += [ "${dawn_vulkan_headers_dir}:vulkan_headers" ]
@@ -552,10 +587,6 @@ source_set("white_box_tests_sources") {
     sources += [ "white_box/MetalAutoreleasePoolTests.mm" ]
   }
 
-  if (dawn_enable_opengl) {
-    deps += [ "${dawn_root}/src/dawn/utils:glfw" ]
-  }
-
   if (dawn_enable_opengles && defined(dawn_angle_dir)) {
     sources += [ "white_box/EGLImageWrappingTests.cpp" ]
     deps += [ "${dawn_angle_dir}:libEGL" ]
@@ -567,22 +598,11 @@ source_set("white_box_tests_sources") {
 dawn_test("dawn_end2end_tests") {
   deps = [
     ":end2end_tests_sources",
-    ":gmock_and_gtest",
+    ":test_infra_sources",
     ":white_box_tests_sources",
-    "${dawn_root}/src/dawn:cpp",
-    "${dawn_root}/src/dawn:proc",
-    "${dawn_root}/src/dawn/common",
-    "${dawn_root}/src/dawn/native:static",
-    "${dawn_root}/src/dawn/platform:platform",
-    "${dawn_root}/src/dawn/utils",
-    "${dawn_root}/src/dawn/wire",
-  ]
-
-  sources = [
-    "DawnTest.cpp",
-    "DawnTest.h",
   ]
 
+  sources = []
   libs = []
 
   # When building inside Chromium, use their gtest main function because it is
@@ -593,10 +613,6 @@ dawn_test("dawn_end2end_tests") {
     sources += [ "End2EndTestsMain.cpp" ]
   }
 
-  if (dawn_enable_opengl) {
-    deps += [ "${dawn_root}/src/dawn/utils:glfw" ]
-  }
-
   if (is_chromeos) {
     libs += [ "gbm" ]
   }
@@ -608,22 +624,16 @@ dawn_test("dawn_end2end_tests") {
 
 dawn_test("dawn_perf_tests") {
   deps = [
-    ":gmock_and_gtest",
+    ":test_infra_sources",
     "${dawn_root}/src/dawn:cpp",
     "${dawn_root}/src/dawn:proc",
     "${dawn_root}/src/dawn/common",
-    "${dawn_root}/src/dawn/native",
     "${dawn_root}/src/dawn/platform",
     "${dawn_root}/src/dawn/utils",
     "${dawn_root}/src/dawn/wire",
   ]
 
   sources = [
-    "DawnTest.cpp",
-    "DawnTest.h",
-    "ParamGenerator.h",
-    "ToggleParser.cpp",
-    "ToggleParser.h",
     "perf_tests/BufferUploadPerf.cpp",
     "perf_tests/DawnPerfTest.cpp",
     "perf_tests/DawnPerfTest.h",
@@ -648,8 +658,4 @@ dawn_test("dawn_perf_tests") {
   if (dawn_enable_metal) {
     frameworks = [ "IOSurface.framework" ]
   }
-
-  if (dawn_enable_opengl) {
-    deps += [ "${dawn_root}/src/dawn/utils:glfw" ]
-  }
 }

src/dawn/tests/DawnTest.cpp

@@ -30,6 +30,8 @@
 #include "dawn/common/Platform.h"
 #include "dawn/common/SystemUtils.h"
 #include "dawn/dawn_proc.h"
+#include "dawn/native/Instance.h"
+#include "dawn/native/dawn_platform.h"
 #include "dawn/utils/ComboRenderPipelineDescriptor.h"
 #include "dawn/utils/PlatformDebugLogger.h"
 #include "dawn/utils/SystemUtils.h"
@@ -921,9 +923,11 @@ void DawnTestBase::SetUp() {
         mBackendAdapter = *it;
     }
 
-    // Setup the per-test platform. Tests can provide one by overloading CreateTestPlatform.
+    // Setup the per-test platform. Tests can provide one by overloading CreateTestPlatform. This is
+    // NOT a thread-safe operation and is allowed here for testing only.
     mTestPlatform = CreateTestPlatform();
-    gTestEnv->GetInstance()->SetPlatform(mTestPlatform.get());
+    dawn::native::FromAPI(gTestEnv->GetInstance()->Get())
+        ->SetPlatformForTesting(mTestPlatform.get());
 
     // Create the device from the adapter
     for (const char* forceEnabledWorkaround : mParam.forceEnabledWorkarounds) {

src/dawn/tests/end2end/D3D12CachingTests.cpp

@@ -13,97 +13,30 @@
 // limitations under the License.
 
 #include <memory>
-#include <string>
 #include <unordered_map>
 #include <utility>
-#include <vector>
 
 #include "dawn/tests/DawnTest.h"
+#include "dawn/tests/end2end/mocks/CachingInterfaceMock.h"
 #include "dawn/utils/ComboRenderPipelineDescriptor.h"
 #include "dawn/utils/WGPUHelpers.h"
 
-#define EXPECT_CACHE_HIT(N, statement)              \
+namespace {
-    do {                                            \
+    using ::testing::NiceMock;
-        size_t before = mPersistentCache.mHitCount; \
+}  // namespace
-        statement;                                  \
-        FlushWire();                                \
-        size_t after = mPersistentCache.mHitCount;  \
-        EXPECT_EQ(N, after - before);               \
-    } while (0)
-
-// FakePersistentCache implements a in-memory persistent cache.
-class FakePersistentCache : public dawn::platform::CachingInterface {
-  public:
-    // PersistentCache API
-    void StoreData(const WGPUDevice device,
-                   const void* key,
-                   size_t keySize,
-                   const void* value,
-                   size_t valueSize) override {
-        if (mIsDisabled)
-            return;
-        const std::string keyStr(reinterpret_cast<const char*>(key), keySize);
-
-        const uint8_t* value_start = reinterpret_cast<const uint8_t*>(value);
-        std::vector<uint8_t> entry_value(value_start, value_start + valueSize);
-
-        EXPECT_TRUE(mCache.insert({keyStr, std::move(entry_value)}).second);
-    }
-
-    size_t LoadData(const WGPUDevice device,
-                    const void* key,
-                    size_t keySize,
-                    void* value,
-                    size_t valueSize) override {
-        const std::string keyStr(reinterpret_cast<const char*>(key), keySize);
-        auto entry = mCache.find(keyStr);
-        if (entry == mCache.end()) {
-            return 0;
-        }
-        if (valueSize >= entry->second.size()) {
-            memcpy(value, entry->second.data(), entry->second.size());
-        }
-        mHitCount++;
-        return entry->second.size();
-    }
-
-    using Blob = std::vector<uint8_t>;
-    using FakeCache = std::unordered_map<std::string, Blob>;
-
-    FakeCache mCache;
-
-    size_t mHitCount = 0;
-    bool mIsDisabled = false;
-};
-
-// Test platform that only supports caching.
-class DawnTestPlatform : public dawn::platform::Platform {
-  public:
-    explicit DawnTestPlatform(dawn::platform::CachingInterface* cachingInterface)
-        : mCachingInterface(cachingInterface) {
-    }
-    ~DawnTestPlatform() override = default;
-
-    dawn::platform::CachingInterface* GetCachingInterface(const void* fingerprint,
-                                                          size_t fingerprintSize) override {
-        return mCachingInterface;
-    }
-
-    dawn::platform::CachingInterface* mCachingInterface = nullptr;
-};
 
 class D3D12CachingTests : public DawnTest {
   protected:
     std::unique_ptr<dawn::platform::Platform> CreateTestPlatform() override {
-        return std::make_unique<DawnTestPlatform>(&mPersistentCache);
+        return std::make_unique<DawnCachingMockPlatform>(&mMockCache);
     }
 
-    FakePersistentCache mPersistentCache;
+    NiceMock<CachingInterfaceMock> mMockCache;
 };
 
-// Test that duplicate WGSL still re-compiles HLSL even when the cache is not enabled.
+// Test that duplicate WGSL still works (and re-compiles HLSL) when the cache is not enabled.
 TEST_P(D3D12CachingTests, SameShaderNoCache) {
-    mPersistentCache.mIsDisabled = true;
+    mMockCache.Disable();
 
     wgpu::ShaderModule module = utils::CreateShaderModule(device, R"(
         @stage(vertex) fn vertex_main() -> @builtin(position) vec4<f32> {
@@ -122,11 +55,9 @@ TEST_P(D3D12CachingTests, SameShaderNoCache) {
         desc.vertex.entryPoint = "vertex_main";
         desc.cFragment.module = module;
         desc.cFragment.entryPoint = "fragment_main";
-
+        EXPECT_CACHE_HIT(mMockCache, 0u, device.CreateRenderPipeline(&desc));
-        EXPECT_CACHE_HIT(0u, device.CreateRenderPipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 0u);
-    EXPECT_EQ(mPersistentCache.mCache.size(), 0u);
 
     // Load the same WGSL shader from the cache.
     {
@@ -135,11 +66,9 @@ TEST_P(D3D12CachingTests, SameShaderNoCache) {
         desc.vertex.entryPoint = "vertex_main";
         desc.cFragment.module = module;
         desc.cFragment.entryPoint = "fragment_main";
-
+        EXPECT_CACHE_HIT(mMockCache, 0u, device.CreateRenderPipeline(&desc));
-        EXPECT_CACHE_HIT(0u, device.CreateRenderPipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 0u);
-    EXPECT_EQ(mPersistentCache.mCache.size(), 0u);
 }
 
 // Test creating a pipeline from two entrypoints in multiple stages will cache the correct number
@@ -163,11 +92,9 @@ TEST_P(D3D12CachingTests, ReuseShaderWithMultipleEntryPointsPerStage) {
         desc.vertex.entryPoint = "vertex_main";
         desc.cFragment.module = module;
         desc.cFragment.entryPoint = "fragment_main";
-
+        EXPECT_CACHE_HIT(mMockCache, 0u, device.CreateRenderPipeline(&desc));
-        EXPECT_CACHE_HIT(0u, device.CreateRenderPipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 2u);
-    EXPECT_EQ(mPersistentCache.mCache.size(), 2u);
 
     // Load the same WGSL shader from the cache.
     {
@@ -176,13 +103,9 @@ TEST_P(D3D12CachingTests, ReuseShaderWithMultipleEntryPointsPerStage) {
         desc.vertex.entryPoint = "vertex_main";
         desc.cFragment.module = module;
         desc.cFragment.entryPoint = "fragment_main";
-
+        EXPECT_CACHE_HIT(mMockCache, 2u, device.CreateRenderPipeline(&desc));
-        // Cached HLSL shader calls LoadData twice (once to peek, again to get), so check 2 x
-        // kNumOfShaders hits.
-        EXPECT_CACHE_HIT(4u, device.CreateRenderPipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 2u);
-    EXPECT_EQ(mPersistentCache.mCache.size(), 2u);
 
     // Modify the WGSL shader functions and make sure it doesn't hit.
     wgpu::ShaderModule newModule = utils::CreateShaderModule(device, R"(
@@ -201,12 +124,9 @@ TEST_P(D3D12CachingTests, ReuseShaderWithMultipleEntryPointsPerStage) {
         desc.vertex.entryPoint = "vertex_main";
         desc.cFragment.module = newModule;
         desc.cFragment.entryPoint = "fragment_main";
-        EXPECT_CACHE_HIT(0u, device.CreateRenderPipeline(&desc));
+        EXPECT_CACHE_HIT(mMockCache, 0u, device.CreateRenderPipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 4u);
-    // Cached HLSL shader calls LoadData twice (once to peek, again to get), so check 2 x
-    // kNumOfShaders hits.
-    EXPECT_EQ(mPersistentCache.mCache.size(), 4u);
 }
 
 // Test creating a WGSL shader with two entrypoints in the same stage will cache the correct number
@@ -232,33 +152,26 @@ TEST_P(D3D12CachingTests, ReuseShaderWithMultipleEntryPoints) {
         wgpu::ComputePipelineDescriptor desc;
         desc.compute.module = module;
         desc.compute.entryPoint = "write1";
-        EXPECT_CACHE_HIT(0u, device.CreateComputePipeline(&desc));
+        EXPECT_CACHE_HIT(mMockCache, 0u, device.CreateComputePipeline(&desc));
 
         desc.compute.module = module;
         desc.compute.entryPoint = "write42";
-        EXPECT_CACHE_HIT(0u, device.CreateComputePipeline(&desc));
+        EXPECT_CACHE_HIT(mMockCache, 0u, device.CreateComputePipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 2u);
-    EXPECT_EQ(mPersistentCache.mCache.size(), 2u);
 
     // Load the same WGSL shader from the cache.
     {
         wgpu::ComputePipelineDescriptor desc;
         desc.compute.module = module;
         desc.compute.entryPoint = "write1";
-
+        EXPECT_CACHE_HIT(mMockCache, 1u, device.CreateComputePipeline(&desc));
-        // Cached HLSL shader calls LoadData twice (once to peek, again to get), so check 2 x
-        // kNumOfShaders hits.
-        EXPECT_CACHE_HIT(2u, device.CreateComputePipeline(&desc));
 
         desc.compute.module = module;
         desc.compute.entryPoint = "write42";
-
+        EXPECT_CACHE_HIT(mMockCache, 1u, device.CreateComputePipeline(&desc));
-        // Cached HLSL shader calls LoadData twice, so check 2 x kNumOfShaders hits.
-        EXPECT_CACHE_HIT(2u, device.CreateComputePipeline(&desc));
     }
-
+    EXPECT_EQ(mMockCache.GetNumEntries(), 2u);
-    EXPECT_EQ(mPersistentCache.mCache.size(), 2u);
 }
 
 DAWN_INSTANTIATE_TEST(D3D12CachingTests, D3D12Backend());

src/dawn/tests/end2end/mocks/CachingInterfaceMock.cpp

@@ -0,0 +1,89 @@
+// Copyright 2022 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "dawn/tests/end2end/mocks/CachingInterfaceMock.h"
+
+using ::testing::Invoke;
+
+CachingInterfaceMock::CachingInterfaceMock() {
+    ON_CALL(*this, LoadData).WillByDefault(Invoke([=](auto&&... args) {
+        return LoadDataDefault(args...);
+    }));
+    ON_CALL(*this, StoreData).WillByDefault(Invoke([=](auto&&... args) {
+        return StoreDataDefault(args...);
+    }));
+}
+
+void CachingInterfaceMock::Enable() {
+    mEnabled = true;
+}
+
+void CachingInterfaceMock::Disable() {
+    mEnabled = false;
+}
+
+size_t CachingInterfaceMock::GetHitCount() const {
+    return mHitCount;
+}
+
+size_t CachingInterfaceMock::GetNumEntries() const {
+    return mCache.size();
+}
+
+size_t CachingInterfaceMock::LoadDataDefault(const WGPUDevice device,
+                                             const void* key,
+                                             size_t keySize,
+                                             void* value,
+                                             size_t valueSize) {
+    if (!mEnabled) {
+        return 0;
+    }
+
+    const std::string keyStr(reinterpret_cast<const char*>(key), keySize);
+    auto entry = mCache.find(keyStr);
+    if (entry == mCache.end()) {
+        return 0;
+    }
+    if (valueSize >= entry->second.size()) {
+        // Only consider a cache-hit on the memcpy, since peeks are implementation detail.
+        memcpy(value, entry->second.data(), entry->second.size());
+        mHitCount++;
+    }
+    return entry->second.size();
+}
+
+void CachingInterfaceMock::StoreDataDefault(const WGPUDevice device,
+                                            const void* key,
+                                            size_t keySize,
+                                            const void* value,
+                                            size_t valueSize) {
+    if (!mEnabled) {
+        return;
+    }
+
+    const std::string keyStr(reinterpret_cast<const char*>(key), keySize);
+    const uint8_t* it = reinterpret_cast<const uint8_t*>(value);
+    std::vector<uint8_t> entry(it, it + valueSize);
+    mCache.insert_or_assign(keyStr, entry);
+}
+
+DawnCachingMockPlatform::DawnCachingMockPlatform(dawn::platform::CachingInterface* cachingInterface)
+    : mCachingInterface(cachingInterface) {
+}
+
+dawn::platform::CachingInterface* DawnCachingMockPlatform::GetCachingInterface(
+    const void* fingerprint,
+    size_t fingerprintSize) {
+    return mCachingInterface;
+}

src/dawn/tests/end2end/mocks/CachingInterfaceMock.h

@@ -0,0 +1,87 @@
+// Copyright 2022 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_DAWN_TESTS_END2END_MOCKS_CACHINGINTERFACEMOCK_H_
+#define SRC_DAWN_TESTS_END2END_MOCKS_CACHINGINTERFACEMOCK_H_
+
+#include <dawn/platform/DawnPlatform.h>
+#include <gmock/gmock.h>
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#define EXPECT_CACHE_HIT(cache, N, statement) \
+    do {                                      \
+        FlushWire();                          \
+        size_t before = cache.GetHitCount();  \
+        statement;                            \
+        FlushWire();                          \
+        size_t after = cache.GetHitCount();   \
+        EXPECT_EQ(N, after - before);         \
+    } while (0)
+
+// A mock caching interface class that also supplies an in memory cache for testing.
+class CachingInterfaceMock : public dawn::platform::CachingInterface {
+  public:
+    CachingInterfaceMock();
+
+    // Toggles to disable/enable caching.
+    void Disable();
+    void Enable();
+
+    // Returns the number of cache hits up to this point.
+    size_t GetHitCount() const;
+
+    // Returns the number of entries in the cache.
+    size_t GetNumEntries() const;
+
+    MOCK_METHOD(size_t,
+                LoadData,
+                (const WGPUDevice, const void*, size_t, void*, size_t),
+                (override));
+    MOCK_METHOD(void,
+                StoreData,
+                (const WGPUDevice, const void*, size_t, const void*, size_t),
+                (override));
+
+  private:
+    size_t LoadDataDefault(const WGPUDevice device,
+                           const void* key,
+                           size_t keySize,
+                           void* value,
+                           size_t valueSize);
+    void StoreDataDefault(const WGPUDevice device,
+                          const void* key,
+                          size_t keySize,
+                          const void* value,
+                          size_t valueSize);
+
+    bool mEnabled = true;
+    size_t mHitCount = 0;
+    std::unordered_map<std::string, std::vector<uint8_t>> mCache;
+};
+
+// Dawn platform used for testing with a mock caching interface.
+class DawnCachingMockPlatform : public dawn::platform::Platform {
+  public:
+    explicit DawnCachingMockPlatform(dawn::platform::CachingInterface* cachingInterface);
+    dawn::platform::CachingInterface* GetCachingInterface(const void* fingerprint,
+                                                          size_t fingerprintSize) override;
+
+  private:
+    dawn::platform::CachingInterface* mCachingInterface = nullptr;
+};
+
+#endif  // SRC_DAWN_TESTS_END2END_MOCKS_CACHINGINTERFACEMOCK_H_