Remove the functionality to erase data updated 62 days before.

This restriction is no longer required.

PiperOrigin-RevId: 802837210

Author: taku910

src/rewriter/user_boundary_history_rewriter.cc

@@ -271,10 +271,7 @@ UserBoundaryHistoryRewriter::CheckResizeSegmentsRequest(
   return std::nullopt;
 }
 
-bool UserBoundaryHistoryRewriter::Sync() {
-  storage_.DeleteElementsUntouchedFor62Days();
-  return true;
-}
+bool UserBoundaryHistoryRewriter::Sync() { return true; }
 
 bool UserBoundaryHistoryRewriter::Reload() {
   const std::string filename = ConfigFileStream::GetFileName(kFileName);

src/rewriter/user_segment_history_rewriter.cc

@@ -803,12 +803,7 @@ void UserSegmentHistoryRewriter::Finish(const ConversionRequest& request,
   revert_cache_.Insert(segments.revert_id(), revert_entries);
 }
 
-bool UserSegmentHistoryRewriter::Sync() {
-  if (storage_) {
-    storage_->DeleteElementsUntouchedFor62Days();
-  }
-  return true;
-}
+bool UserSegmentHistoryRewriter::Sync() { return true; }
 
 bool UserSegmentHistoryRewriter::Reload() {
   const std::string filename = ConfigFileStream::GetFileName(kFileName);

src/storage/lru_storage.cc

@@ -72,8 +72,6 @@ constexpr size_t kMaxValueSize = 1024;   // 1024 byte
 // * 4 bytes for fingerprint seed
 constexpr size_t kFileHeaderSize = 12;
 
-constexpr uint64_t k62DaysInSec = 62 * 24 * 60 * 60;
-
 uint64_t GetFP(const char* ptr) { return LoadUnaligned<uint64_t>(ptr); }
 
 uint32_t GetTimeStamp(const char* ptr) {
@@ -97,11 +95,6 @@ void Update(char* ptr, uint64_t fp, const char* value, size_t value_size) {
   std::copy_n(value, value_size, ptr);
 }
 
-bool IsOlderThan62Days(uint64_t timestamp) {
-  const uint64_t now = absl::ToUnixSeconds(Clock::GetAbslTime());
-  return (timestamp + k62DaysInSec < now);
-}
-
 class CompareByTimeStamp {
  public:
   bool operator()(const char* a, const char* b) const {
@@ -382,16 +375,10 @@ bool LruStorage::Open(char* ptr, size_t ptr_size) {
   next_item_ = (next != nullptr) ? next : end_;
   DCHECK_LE(next_item_, end_);
 
-  // At the time file is opened, perform clean up.
-  DeleteElementsUntouchedFor62Days();
-
   return true;
 }
 
 void LruStorage::Close() {
-  // Perform clean up before closing the file.
-  DeleteElementsUntouchedFor62Days();
-
   filename_.clear();
   mmap_.Close();
   lru_list_.clear();
@@ -406,9 +393,6 @@ const char* absl_nullable LruStorage::Lookup(const absl::string_view key,
     return nullptr;
   }
   const uint32_t timestamp = GetTimeStamp(*it->second);
-  if (IsOlderThan62Days(timestamp)) {
-    return nullptr;
-  }
   *last_access_time = timestamp;
   return GetValue(*it->second);
 }
@@ -419,10 +403,6 @@ void LruStorage::GetAllValues(std::vector<std::string>* values) const {
   // Iterate data from the most recently used element to the least recently used
   // element.
   for (const char* ptr : lru_list_) {
-    const uint32_t timestamp = GetTimeStamp(ptr);
-    if (IsOlderThan62Days(timestamp)) {
-      break;
-    }
     // Default constructor of string is not applicable
     // because value's size() must return value_size_.
     DCHECK(ptr);
@@ -436,10 +416,6 @@ bool LruStorage::Touch(const absl::string_view key) {
   if (it == lru_map_.end()) {
     return false;
   }
-  const uint32_t timestamp = GetTimeStamp(*it->second);
-  if (IsOlderThan62Days(timestamp)) {
-    return false;
-  }
   Update(*it->second);
   // Move the node pointed to by it->second to the front.
   lru_list_.splice(lru_list_.begin(), lru_list_, it->second);
@@ -566,13 +542,6 @@ int LruStorage::DeleteElementsBefore(uint32_t timestamp) {
   return num_deleted;
 }
 
-int LruStorage::DeleteElementsUntouchedFor62Days() {
-  const uint64_t now = absl::ToUnixSeconds(Clock::GetAbslTime());
-  const uint32_t timestamp =
-      static_cast<uint32_t>((now > k62DaysInSec) ? now - k62DaysInSec : 0);
-  return DeleteElementsBefore(timestamp);
-}
-
 void LruStorage::Write(size_t i, uint64_t fp, const absl::string_view value,
                        uint32_t last_access_time) {
   DCHECK_LT(i, size_);

src/storage/lru_storage.h

@@ -107,10 +107,6 @@ class LruStorage {
   // elements.
   int DeleteElementsBefore(uint32_t timestamp);
 
-  // Deletes all the elements that are not accessed for 62 days.
-  // Returns the number of deleted elements.
-  int DeleteElementsUntouchedFor62Days();
-
   // Returns the byte length of each item, which is the user specified value
   // size + 12 bytes.  Here, 12 bytes is used for fingerprint (8 bytes) and
   // timestamp (4 bytes).

src/storage/lru_storage_test.cc

@@ -483,79 +483,5 @@ TEST_F(LruStorageTest, DeleteElementsBefore) {
   EXPECT_EQ(values, kExpectedAfterDelete);
 }
 
-TEST_F(LruStorageTest, DeleteElementsUntouchedFor62Days) {
-  ScopedClockMock clock(absl::FromUnixSeconds(1));
-
-  constexpr size_t kValueSize = 4;
-  constexpr size_t kNumElements = 4;
-  LruStorage storage;
-  TempFile file(testing::MakeTempFileOrDie());
-  ASSERT_TRUE(storage.OpenOrCreate(file.path().c_str(), kValueSize,
-                                   kNumElements, kSeed));
-
-  // Auto advance clock after opening the file; otherwise OpenOrCreate()
-  // advances the clock.
-  clock->Advance(absl::Seconds(1));
-
-  storage.Insert("1111", "aaaa");
-  storage.Insert("2222", "bbbb");
-
-  // Advance clock for 63 days.
-  clock->Advance(absl::Hours(63 * 24));
-
-  // Insert newer elements.
-  storage.Insert("3333", "cccc");
-  storage.Insert("4444", "dddd");
-
-  EXPECT_EQ(storage.DeleteElementsUntouchedFor62Days(), 2);
-
-  std::vector<std::string> values;
-  storage.GetAllValues(&values);
-  const std::vector<std::string> kExpectedAfterDelete = {
-      "dddd",
-      "cccc",
-  };
-  EXPECT_EQ(values, kExpectedAfterDelete);
-}
-
-TEST_F(LruStorageTest, OldDataAreNotLookedUp) {
-  ScopedClockMock clock(absl::FromUnixSeconds(1));
-
-  constexpr size_t kValueSize = 4;
-  constexpr size_t kNumElements = 4;
-  LruStorage storage;
-  TempFile file(testing::MakeTempFileOrDie());
-  ASSERT_TRUE(storage.OpenOrCreate(file.path().c_str(), kValueSize,
-                                   kNumElements, kSeed));
-
-  EXPECT_TRUE(storage.Insert("1111", "aaaa"));
-  EXPECT_TRUE(storage.Insert("2222", "bbbb"));
-
-  // The two elements can be looked up as they are still not 62-day old.
-  EXPECT_EQ(storage.LookupAsString("1111"), "aaaa");
-  EXPECT_EQ(storage.LookupAsString("2222"), "bbbb");
-  EXPECT_TRUE(storage.Touch("1111"));
-  EXPECT_TRUE(storage.Touch("2222"));
-
-  // Advance clock for 63 days.
-  clock->Advance(absl::Hours(63 * 24));
-
-  // Insert new elements.
-  EXPECT_TRUE(storage.Insert("3333", "cccc"));
-  EXPECT_TRUE(storage.Insert("4444", "dddd"));
-
-  // The old two cannot be looked up.
-  EXPECT_TRUE(storage.Lookup("1111") == nullptr);
-  EXPECT_TRUE(storage.Lookup("2222") == nullptr);
-  EXPECT_FALSE(storage.Touch("1111"));
-  EXPECT_FALSE(storage.Touch("2222"));
-
-  // But the new ones are accessible.
-  EXPECT_EQ(storage.LookupAsString("3333"), "cccc");
-  EXPECT_EQ(storage.LookupAsString("4444"), "dddd");
-  EXPECT_TRUE(storage.Touch("3333"));
-  EXPECT_TRUE(storage.Touch("4444"));
-}
-
 }  // namespace storage
 }  // namespace mozc