libs/ui: Remove isStable() flag from DisplayId

There are currently no clients of DisplayId who use isStable().

This CL removes the parsing and serving of "stableness" of a DisplayId
by removing the isStable() API, and all associated tests.

See: go/edid-display-ids-al13

Flag: com.android.graphics.surfaceflinger.flags.stable_edid_ids
Bug: 352320847
Test: Display{Id|Identification} & libsurfaceflinger_unittest
Change-Id: I903fae86085001d32f77f34286c9f03ee481093b

Author: stagadish

libs/ui/include/ui/DisplayId.h

@@ -20,7 +20,6 @@
 #include <ostream>
 #include <string>
 
-#include <ftl/hash.h>
 #include <ftl/optional.h>
 
 namespace android {
@@ -31,16 +30,12 @@ struct DisplayId {
     // Flag indicating that the display is virtual.
     static constexpr uint64_t FLAG_VIRTUAL = 1ULL << 63;
 
-    // Flag indicating that the ID is stable across reboots.
-    static constexpr uint64_t FLAG_STABLE = 1ULL << 62;
-
     // TODO(b/162612135) Remove default constructor
     DisplayId() = default;
     constexpr DisplayId(const DisplayId&) = default;
     DisplayId& operator=(const DisplayId&) = default;
 
     constexpr bool isVirtual() const { return value & FLAG_VIRTUAL; }
-    constexpr bool isStable() const { return value & FLAG_STABLE; }
 
     uint64_t value;
 
@@ -106,6 +101,9 @@ struct PhysicalDisplayId : DisplayId {
     constexpr uint8_t getPort() const { return static_cast<uint8_t>(value); }
 
 private:
+    // Flag indicating that the ID is stable across reboots.
+    static constexpr uint64_t FLAG_STABLE = 1ULL << 62;
+
     constexpr PhysicalDisplayId(uint64_t flags, uint8_t port, uint16_t manufacturerId,
                                 uint32_t modelHash)
           : DisplayId(flags | (static_cast<uint64_t>(manufacturerId) << 40) |
@@ -149,13 +147,6 @@ struct HalVirtualDisplayId : VirtualDisplayId {
 struct GpuVirtualDisplayId : VirtualDisplayId {
     explicit constexpr GpuVirtualDisplayId(BaseId baseId) : VirtualDisplayId(FLAG_GPU | baseId) {}
 
-    static constexpr std::optional<GpuVirtualDisplayId> fromUniqueId(const std::string& uniqueId) {
-        if (const auto hashOpt = ftl::stable_hash(uniqueId)) {
-            return GpuVirtualDisplayId(HashTag{}, *hashOpt);
-        }
-        return {};
-    }
-
     static constexpr std::optional<GpuVirtualDisplayId> tryCast(DisplayId id) {
         if (id.isVirtual() && (id.value & FLAG_GPU)) {
             return GpuVirtualDisplayId(id);
@@ -164,10 +155,6 @@ struct GpuVirtualDisplayId : VirtualDisplayId {
     }
 
 private:
-    struct HashTag {}; // Disambiguate with BaseId constructor.
-    constexpr GpuVirtualDisplayId(HashTag, uint64_t hash)
-          : VirtualDisplayId(FLAG_STABLE | FLAG_GPU | hash) {}
-
     explicit constexpr GpuVirtualDisplayId(DisplayId other) : VirtualDisplayId(other) {}
 };
 

libs/ui/tests/DisplayId_test.cpp

@@ -75,21 +75,6 @@ TEST(DisplayIdTest, createVirtualIdFromGpuVirtualId) {
     EXPECT_EQ((id.isVirtual() && isGpuVirtualId), GpuVirtualDisplayId::tryCast(id).has_value());
 }
 
-TEST(DisplayIdTest, createGpuVirtualIdFromUniqueId) {
-    static const std::string kUniqueId("virtual:ui:DisplayId_test");
-    const auto idOpt = GpuVirtualDisplayId::fromUniqueId(kUniqueId);
-    ASSERT_TRUE(idOpt.has_value());
-    const GpuVirtualDisplayId id = idOpt.value();
-    EXPECT_TRUE(VirtualDisplayId::tryCast(id));
-    EXPECT_TRUE(GpuVirtualDisplayId::tryCast(id));
-    EXPECT_FALSE(HalVirtualDisplayId::tryCast(id));
-    EXPECT_FALSE(PhysicalDisplayId::tryCast(id));
-    EXPECT_FALSE(HalDisplayId::tryCast(id));
-
-    EXPECT_EQ(id, DisplayId::fromValue(id.value));
-    EXPECT_EQ(id, DisplayId::fromValue<GpuVirtualDisplayId>(id.value));
-}
-
 TEST(DisplayIdTest, createHalVirtualId) {
     const HalVirtualDisplayId id(42);
     EXPECT_TRUE(VirtualDisplayId::tryCast(id));