Add locator for expiration events

src/storage/KeyLocators.hh

@@ -31,11 +31,13 @@
 namespace quarkdb {
 
 using KeyBuffer = SmartBuffer<512>;
+using ClockValue = uint64_t;
 
 enum class InternalKeyType : char {
   kInternal = '_',
   kConfiguration = '~',
-  kDescriptor = '!'
+  kDescriptor = '!',
+  kExpirationEvent = '@'
 };
 
 class DescriptorLocator {
@@ -264,6 +266,28 @@ private:
   KeyBuffer keyBuffer;
 };
 
+class ExpirationEventLocator {
+public:
+  ExpirationEventLocator(ClockValue deadline, const std::string &redisKey) {
+    reset(deadline, redisKey);
+  }
+
+  void reset(ClockValue deadline, const std::string &redisKey) {
+    keyBuffer.resize(1 + sizeof(ClockValue) + redisKey.size());
+    keyBuffer[0] = char(InternalKeyType::kExpirationEvent);
+
+    unsignedIntToBinaryString(deadline, keyBuffer.data() + 1);
+    memcpy(keyBuffer.data()+1+sizeof(ClockValue), redisKey.data(), redisKey.size());
+  }
+
+  rocksdb::Slice toSlice() {
+    return keyBuffer.toSlice();
+  }
+
+private:
+  KeyBuffer keyBuffer;
+};
+
 }
 
 #endif

test/state-machine.cc

@@ -881,6 +881,11 @@ TEST(LeaseLocator, BasicSanity) {
   ASSERT_EQ(locator2.toSlice().ToString(), "fmy#key");
 }
 
+TEST(ExpirationEventLocator, BasicSanity) {
+  ExpirationEventLocator locator1(ClockValue(123u), "some-key");
+  ASSERT_EQ(locator1.toSlice().ToString(), SSTR("@" << unsignedIntToBinaryString(123u) << "some-key"));
+}
+
 TEST(PatternMatching, BasicSanity) {
   ASSERT_EQ(extractPatternPrefix("abc*"), "abc");
   ASSERT_EQ(extractPatternPrefix("abc"), "abc");