Revert "Caching between SF and HWC for BufferStateLayers"

This reverts commit b28f007e51fb84ff78ce8b053d80efb0efdbce20.

Reason for revert: Causing pre-submit failure b/126704033

Change-Id: I17c99cd410b3fa3825d01fedd21a52451368b5c0
diff --git a/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp b/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp
index d4bbf6d..f2a1aad 100644
--- a/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp
@@ -22,78 +22,60 @@
 namespace android::compositionengine {
 namespace {
 
-class TestableHwcBufferCache : public impl::HwcBufferCache {
-public:
-    void getHwcBuffer(const sp<GraphicBuffer>& buffer, uint32_t* outSlot,
-                      sp<GraphicBuffer>* outBuffer) {
-        HwcBufferCache::getHwcBuffer(buffer, outSlot, outBuffer);
-    }
-    int getSlot(const sp<GraphicBuffer>& buffer) { return HwcBufferCache::getSlot(buffer); }
-    int getLeastRecentlyUsedSlot() { return HwcBufferCache::getLeastRecentlyUsedSlot(); }
-};
-
 class HwcBufferCacheTest : public testing::Test {
 public:
     ~HwcBufferCacheTest() override = default;
 
-    TestableHwcBufferCache mCache;
+    void testSlot(const int inSlot, const uint32_t expectedSlot) {
+        uint32_t outSlot;
+        sp<GraphicBuffer> outBuffer;
+
+        // The first time, the output  is the same as the input
+        mCache.getHwcBuffer(inSlot, mBuffer1, &outSlot, &outBuffer);
+        EXPECT_EQ(expectedSlot, outSlot);
+        EXPECT_EQ(mBuffer1, outBuffer);
+
+        // The second time with the same buffer, the outBuffer is nullptr.
+        mCache.getHwcBuffer(inSlot, mBuffer1, &outSlot, &outBuffer);
+        EXPECT_EQ(expectedSlot, outSlot);
+        EXPECT_EQ(nullptr, outBuffer.get());
+
+        // With a new buffer, the outBuffer is the input.
+        mCache.getHwcBuffer(inSlot, mBuffer2, &outSlot, &outBuffer);
+        EXPECT_EQ(expectedSlot, outSlot);
+        EXPECT_EQ(mBuffer2, outBuffer);
+
+        // Again, the second request with the same buffer sets outBuffer to nullptr.
+        mCache.getHwcBuffer(inSlot, mBuffer2, &outSlot, &outBuffer);
+        EXPECT_EQ(expectedSlot, outSlot);
+        EXPECT_EQ(nullptr, outBuffer.get());
+
+        // Setting a slot to use nullptr lookslike works, but note that
+        // the output values make it look like no new buffer is being set....
+        mCache.getHwcBuffer(inSlot, sp<GraphicBuffer>(), &outSlot, &outBuffer);
+        EXPECT_EQ(expectedSlot, outSlot);
+        EXPECT_EQ(nullptr, outBuffer.get());
+    }
+
+    impl::HwcBufferCache mCache;
     sp<GraphicBuffer> mBuffer1{new GraphicBuffer(1, 1, HAL_PIXEL_FORMAT_RGBA_8888, 1, 0)};
     sp<GraphicBuffer> mBuffer2{new GraphicBuffer(1, 1, HAL_PIXEL_FORMAT_RGBA_8888, 1, 0)};
 };
 
-TEST_F(HwcBufferCacheTest, testSlot) {
-    uint32_t outSlot;
-    sp<GraphicBuffer> outBuffer;
-
-    // The first time, the output  is the same as the input
-    mCache.getHwcBuffer(mBuffer1, &outSlot, &outBuffer);
-    EXPECT_EQ(0, outSlot);
-    EXPECT_EQ(mBuffer1, outBuffer);
-
-    // The second time with the same buffer, the outBuffer is nullptr.
-    mCache.getHwcBuffer(mBuffer1, &outSlot, &outBuffer);
-    EXPECT_EQ(0, outSlot);
-    EXPECT_EQ(nullptr, outBuffer.get());
-
-    // With a new buffer, the outBuffer is the input.
-    mCache.getHwcBuffer(mBuffer2, &outSlot, &outBuffer);
-    EXPECT_EQ(1, outSlot);
-    EXPECT_EQ(mBuffer2, outBuffer);
-
-    // Again, the second request with the same buffer sets outBuffer to nullptr.
-    mCache.getHwcBuffer(mBuffer2, &outSlot, &outBuffer);
-    EXPECT_EQ(1, outSlot);
-    EXPECT_EQ(nullptr, outBuffer.get());
-
-    // Setting a slot to use nullptr lookslike works, but note that
-    // the output values make it look like no new buffer is being set....
-    mCache.getHwcBuffer(sp<GraphicBuffer>(), &outSlot, &outBuffer);
-    EXPECT_EQ(2, outSlot);
-    EXPECT_EQ(nullptr, outBuffer.get());
+TEST_F(HwcBufferCacheTest, cacheWorksForSlotZero) {
+    testSlot(0, 0);
 }
 
-TEST_F(HwcBufferCacheTest, testGetLeastRecentlyUsedSlot) {
-    int slot;
-    uint32_t outSlot;
-    sp<GraphicBuffer> outBuffer;
+TEST_F(HwcBufferCacheTest, cacheWorksForMaxSlot) {
+    testSlot(BufferQueue::NUM_BUFFER_SLOTS - 1, BufferQueue::NUM_BUFFER_SLOTS - 1);
+}
 
-    // fill up cache
-    for (int i = 0; i < BufferQueue::NUM_BUFFER_SLOTS; i++) {
-        sp<GraphicBuffer> buf{new GraphicBuffer(1, 1, HAL_PIXEL_FORMAT_RGBA_8888, 1, 0)};
-        mCache.getHwcBuffer(buf, &outSlot, &outBuffer);
-        EXPECT_EQ(buf, outBuffer);
-        EXPECT_EQ(i, outSlot);
-    }
+TEST_F(HwcBufferCacheTest, cacheMapsNegativeSlotToZero) {
+    testSlot(-123, 0);
+}
 
-    slot = mCache.getLeastRecentlyUsedSlot();
-    EXPECT_EQ(0, slot);
-
-    mCache.getHwcBuffer(mBuffer1, &outSlot, &outBuffer);
-    EXPECT_EQ(0, outSlot);
-    EXPECT_EQ(mBuffer1, outBuffer);
-
-    slot = mCache.getLeastRecentlyUsedSlot();
-    EXPECT_EQ(1, slot);
+TEST_F(HwcBufferCacheTest, cacheMapsInvalidBufferSlotToZero) {
+    testSlot(BufferQueue::INVALID_BUFFER_SLOT, 0);
 }
 
 } // namespace