Add Env::Remove{File,Dir} which obsolete Env::Delete{File,Dir}.

The "DeleteFile" method name causes pain for Windows developers, because
<windows.h> #defines a DeleteFile macro to DeleteFileW or DeleteFileA.
Current code uses workarounds, like #undefining DeleteFile everywhere an
Env is declared, implemented, or used.

This CL removes the need for workarounds by renaming Env::DeleteFile to
Env::RemoveFile. For consistency, Env::DeleteDir is also renamed to
Env::RemoveDir. A few internal methods are also renamed for consistency.
Software that supports Windows is expected to migrate any Env
implementations and usage to Remove{File,Dir}, and never use the name
Env::Delete{File,Dir} in its code.

The renaming is done in a backwards-compatible way, at the risk of
making it slightly more difficult to build a new correct Env
implementation. The backwards compatibility is achieved using the
following hacks:

1) Env::Remove{File,Dir} methods are added, with a default
    implementation that calls into Env::Delete{File,Dir}. This makes old
    Env implementations compatible with code that calls into the updated
    API.
2) The Env::Delete{File,Dir} methods are no longer pure virtuals.
    Instead, they gain a default implementation that calls into
    Env::Remove{File,Dir}. This makes updated Env implementations
    compatible with code that calls into the old API.

The cost of this approach is that it's possible to write an Env without
overriding either Rename{File,Dir} or Delete{File,Dir}, without getting
a compiler warning. However, attempting to run the test suite will
immediately fail with an infinite call stack ending in
{Remove,Delete}{File,Dir}, making developers aware of the problem.

PiperOrigin-RevId: 288710907

benchmarks/db_bench.cc

@@ -414,7 +414,7 @@ class Benchmark {
     g_env->GetChildren(FLAGS_db, &files);
     for (size_t i = 0; i < files.size(); i++) {
       if (Slice(files[i]).starts_with("heap-")) {
-        g_env->DeleteFile(std::string(FLAGS_db) + "/" + files[i]);
+        g_env->RemoveFile(std::string(FLAGS_db) + "/" + files[i]);
       }
     }
     if (!FLAGS_use_existing_db) {
@@ -912,7 +912,7 @@ class Benchmark {
     delete file;
     if (!ok) {
       fprintf(stderr, "heap profiling not supported\n");
-      g_env->DeleteFile(fname);
+      g_env->RemoveFile(fname);
     }
   }
 };

benchmarks/db_bench_sqlite3.cc

@@ -328,7 +328,7 @@ class Benchmark {
           std::string file_name(test_dir);
           file_name += "/";
           file_name += files[i];
-          Env::Default()->DeleteFile(file_name.c_str());
+          Env::Default()->RemoveFile(file_name.c_str());
         }
       }
     }

benchmarks/db_bench_tree_db.cc

@@ -301,7 +301,7 @@ class Benchmark {
           std::string file_name(test_dir);
           file_name += "/";
           file_name += files[i];
-          Env::Default()->DeleteFile(file_name.c_str());
+          Env::Default()->RemoveFile(file_name.c_str());
         }
       }
     }

db/builder.cc

@@ -71,7 +71,7 @@ Status BuildTable(const std::string& dbname, Env* env, const Options& options,
   if (s.ok() && meta->file_size > 0) {
     // Keep it
   } else {
-    env->DeleteFile(fname);
+    env->RemoveFile(fname);
   }
   return s;
 }

db/db_impl.cc

@@ -206,7 +206,7 @@ Status DBImpl::NewDB() {
     // Make "CURRENT" file that points to the new manifest file.
     s = SetCurrentFile(env_, dbname_, 1);
   } else {
-    env_->DeleteFile(manifest);
+    env_->RemoveFile(manifest);
   }
   return s;
 }
@@ -220,7 +220,7 @@ void DBImpl::MaybeIgnoreError(Status* s) const {
   }
 }
 
-void DBImpl::DeleteObsoleteFiles() {
+void DBImpl::RemoveObsoleteFiles() {
   mutex_.AssertHeld();
 
   if (!bg_error_.ok()) {
@@ -282,7 +282,7 @@ void DBImpl::DeleteObsoleteFiles() {
   // are therefore safe to delete while allowing other threads to proceed.
   mutex_.Unlock();
   for (const std::string& filename : files_to_delete) {
-    env_->DeleteFile(dbname_ + "/" + filename);
+    env_->RemoveFile(dbname_ + "/" + filename);
   }
   mutex_.Lock();
 }
@@ -569,7 +569,7 @@ void DBImpl::CompactMemTable() {
     imm_->Unref();
     imm_ = nullptr;
     has_imm_.store(false, std::memory_order_release);
-    DeleteObsoleteFiles();
+    RemoveObsoleteFiles();
   } else {
     RecordBackgroundError(s);
   }
@@ -729,7 +729,7 @@ void DBImpl::BackgroundCompaction() {
     // Move file to next level
     assert(c->num_input_files(0) == 1);
     FileMetaData* f = c->input(0, 0);
-    c->edit()->DeleteFile(c->level(), f->number);
+    c->edit()->RemoveFile(c->level(), f->number);
     c->edit()->AddFile(c->level() + 1, f->number, f->file_size, f->smallest,
                        f->largest);
     status = versions_->LogAndApply(c->edit(), &mutex_);
@@ -749,7 +749,7 @@ void DBImpl::BackgroundCompaction() {
     }
     CleanupCompaction(compact);
     c->ReleaseInputs();
-    DeleteObsoleteFiles();
+    RemoveObsoleteFiles();
   }
   delete c;
 
@@ -1506,7 +1506,7 @@ Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
     s = impl->versions_->LogAndApply(&edit, &impl->mutex_);
   }
   if (s.ok()) {
-    impl->DeleteObsoleteFiles();
+    impl->RemoveObsoleteFiles();
     impl->MaybeScheduleCompaction();
   }
   impl->mutex_.Unlock();
@@ -1539,15 +1539,15 @@ Status DestroyDB(const std::string& dbname, const Options& options) {
     for (size_t i = 0; i < filenames.size(); i++) {
       if (ParseFileName(filenames[i], &number, &type) &&
           type != kDBLockFile) {  // Lock file will be deleted at end
-        Status del = env->DeleteFile(dbname + "/" + filenames[i]);
+        Status del = env->RemoveFile(dbname + "/" + filenames[i]);
         if (result.ok() && !del.ok()) {
           result = del;
         }
       }
     }
     env->UnlockFile(lock);  // Ignore error since state is already gone
-    env->DeleteFile(lockname);
-    env->DeleteDir(dbname);  // Ignore error in case dir contains other files
+    env->RemoveFile(lockname);
+    env->RemoveDir(dbname);  // Ignore error in case dir contains other files
   }
   return result;
 }

db/db_impl.h

@@ -116,7 +116,7 @@ class DBImpl : public DB {
   void MaybeIgnoreError(Status* s) const;
 
   // Delete any unneeded files and stale in-memory entries.
-  void DeleteObsoleteFiles() EXCLUSIVE_LOCKS_REQUIRED(mutex_);
+  void RemoveObsoleteFiles() EXCLUSIVE_LOCKS_REQUIRED(mutex_);
 
   // Compact the in-memory write buffer to disk.  Switches to a new
   // log-file/memtable and writes a new descriptor iff successful.

db/db_test.cc

@@ -509,7 +509,7 @@ class DBTest : public testing::Test {
     FileType type;
     for (size_t i = 0; i < filenames.size(); i++) {
       if (ParseFileName(filenames[i], &number, &type) && type == kTableFile) {
-        EXPECT_LEVELDB_OK(env_->DeleteFile(TableFileName(dbname_, number)));
+        EXPECT_LEVELDB_OK(env_->RemoveFile(TableFileName(dbname_, number)));
         return true;
       }
     }
@@ -1666,7 +1666,7 @@ TEST_F(DBTest, DBOpen_Options) {
 TEST_F(DBTest, DestroyEmptyDir) {
   std::string dbname = testing::TempDir() + "db_empty_dir";
   TestEnv env(Env::Default());
-  env.DeleteDir(dbname);
+  env.RemoveDir(dbname);
   ASSERT_TRUE(!env.FileExists(dbname));
 
   Options opts;
@@ -1693,7 +1693,7 @@ TEST_F(DBTest, DestroyEmptyDir) {
 
 TEST_F(DBTest, DestroyOpenDB) {
   std::string dbname = testing::TempDir() + "open_db_dir";
-  env_->DeleteDir(dbname);
+  env_->RemoveDir(dbname);
   ASSERT_TRUE(!env_->FileExists(dbname));
 
   Options opts;
@@ -2279,7 +2279,7 @@ void BM_LogAndApply(int iters, int num_base_files) {
 
   for (int i = 0; i < iters; i++) {
     VersionEdit vedit;
-    vedit.DeleteFile(2, fnum);
+    vedit.RemoveFile(2, fnum);
     InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
     InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
     vedit.AddFile(2, fnum++, 1 /* file size */, start, limit);

db/fault_injection_test.cc

@@ -77,7 +77,7 @@ Status Truncate(const std::string& filename, uint64_t length) {
       if (s.ok()) {
         s = env->RenameFile(tmp_name, filename);
       } else {
-        env->DeleteFile(tmp_name);
+        env->RemoveFile(tmp_name);
       }
     }
   }
@@ -138,12 +138,12 @@ class FaultInjectionTestEnv : public EnvWrapper {
                          WritableFile** result) override;
   Status NewAppendableFile(const std::string& fname,
                            WritableFile** result) override;
-  Status DeleteFile(const std::string& f) override;
+  Status RemoveFile(const std::string& f) override;
   Status RenameFile(const std::string& s, const std::string& t) override;
 
   void WritableFileClosed(const FileState& state);
   Status DropUnsyncedFileData();
-  Status DeleteFilesCreatedAfterLastDirSync();
+  Status RemoveFilesCreatedAfterLastDirSync();
   void DirWasSynced();
   bool IsFileCreatedSinceLastDirSync(const std::string& filename);
   void ResetState();
@@ -303,8 +303,8 @@ void FaultInjectionTestEnv::UntrackFile(const std::string& f) {
   new_files_since_last_dir_sync_.erase(f);
 }
 
-Status FaultInjectionTestEnv::DeleteFile(const std::string& f) {
-  Status s = EnvWrapper::DeleteFile(f);
+Status FaultInjectionTestEnv::RemoveFile(const std::string& f) {
+  Status s = EnvWrapper::RemoveFile(f);
   EXPECT_LEVELDB_OK(s);
   if (s.ok()) {
     UntrackFile(f);
@@ -340,17 +340,17 @@ void FaultInjectionTestEnv::ResetState() {
   SetFilesystemActive(true);
 }
 
-Status FaultInjectionTestEnv::DeleteFilesCreatedAfterLastDirSync() {
-  // Because DeleteFile access this container make a copy to avoid deadlock
+Status FaultInjectionTestEnv::RemoveFilesCreatedAfterLastDirSync() {
+  // Because RemoveFile access this container make a copy to avoid deadlock
   mutex_.Lock();
   std::set<std::string> new_files(new_files_since_last_dir_sync_.begin(),
                                   new_files_since_last_dir_sync_.end());
   mutex_.Unlock();
   Status status;
   for (const auto& new_file : new_files) {
-    Status delete_status = DeleteFile(new_file);
-    if (!delete_status.ok() && status.ok()) {
-      status = std::move(delete_status);
+    Status remove_status = RemoveFile(new_file);
+    if (!remove_status.ok() && status.ok()) {
+      status = std::move(remove_status);
     }
   }
   return status;
@@ -482,7 +482,7 @@ class FaultInjectionTest : public testing::Test {
         ASSERT_LEVELDB_OK(env_->DropUnsyncedFileData());
         break;
       case RESET_DELETE_UNSYNCED_FILES:
-        ASSERT_LEVELDB_OK(env_->DeleteFilesCreatedAfterLastDirSync());
+        ASSERT_LEVELDB_OK(env_->RemoveFilesCreatedAfterLastDirSync());
         break;
       default:
         assert(false);

db/filename.cc

@@ -133,7 +133,7 @@ Status SetCurrentFile(Env* env, const std::string& dbname,
     s = env->RenameFile(tmp, CurrentFileName(dbname));
   }
   if (!s.ok()) {
-    env->DeleteFile(tmp);
+    env->RemoveFile(tmp);
   }
   return s;
 }

db/recovery_test.cc

@@ -100,19 +100,19 @@ class RecoveryTest : public testing::Test {
 
   std::string LogName(uint64_t number) { return LogFileName(dbname_, number); }
 
-  size_t DeleteLogFiles() {
+  size_t RemoveLogFiles() {
     // Linux allows unlinking open files, but Windows does not.
     // Closing the db allows for file deletion.
     Close();
     std::vector<uint64_t> logs = GetFiles(kLogFile);
     for (size_t i = 0; i < logs.size(); i++) {
-      EXPECT_LEVELDB_OK(env_->DeleteFile(LogName(logs[i]))) << LogName(logs[i]);
+      EXPECT_LEVELDB_OK(env_->RemoveFile(LogName(logs[i]))) << LogName(logs[i]);
     }
     return logs.size();
   }
 
-  void DeleteManifestFile() {
-    ASSERT_LEVELDB_OK(env_->DeleteFile(ManifestFileName()));
+  void RemoveManifestFile() {
+    ASSERT_LEVELDB_OK(env_->RemoveFile(ManifestFileName()));
   }
 
   uint64_t FirstLogFile() { return GetFiles(kLogFile)[0]; }
@@ -212,7 +212,7 @@ TEST_F(RecoveryTest, LargeManifestCompacted) {
 
 TEST_F(RecoveryTest, NoLogFiles) {
   ASSERT_LEVELDB_OK(Put("foo", "bar"));
-  ASSERT_EQ(1, DeleteLogFiles());
+  ASSERT_EQ(1, RemoveLogFiles());
   Open();
   ASSERT_EQ("NOT_FOUND", Get("foo"));
   Open();
@@ -327,7 +327,7 @@ TEST_F(RecoveryTest, MultipleLogFiles) {
 TEST_F(RecoveryTest, ManifestMissing) {
   ASSERT_LEVELDB_OK(Put("foo", "bar"));
   Close();
-  DeleteManifestFile();
+  RemoveManifestFile();
 
   Status status = OpenWithStatus();
   ASSERT_TRUE(status.IsCorruption());

db/repair.cc

@@ -341,7 +341,7 @@ class Repairer {
       }
     }
     if (!s.ok()) {
-      env_->DeleteFile(copy);
+      env_->RemoveFile(copy);
     }
   }
 
@@ -386,7 +386,7 @@ class Repairer {
     file = nullptr;
 
     if (!status.ok()) {
-      env_->DeleteFile(tmp);
+      env_->RemoveFile(tmp);
     } else {
       // Discard older manifests
       for (size_t i = 0; i < manifests_.size(); i++) {
@@ -398,7 +398,7 @@ class Repairer {
       if (status.ok()) {
         status = SetCurrentFile(env_, dbname_, 1);
       } else {
-        env_->DeleteFile(tmp);
+        env_->RemoveFile(tmp);
       }
     }
     return status;

db/version_edit.cc

@@ -232,7 +232,7 @@ std::string VersionEdit::DebugString() const {
     r.append(compact_pointers_[i].second.DebugString());
   }
   for (const auto& deleted_files_kvp : deleted_files_) {
-    r.append("\n  DeleteFile: ");
+    r.append("\n  RemoveFile: ");
     AppendNumberTo(&r, deleted_files_kvp.first);
     r.append(" ");
     AppendNumberTo(&r, deleted_files_kvp.second);

db/version_edit.h

@@ -71,7 +71,7 @@ class VersionEdit {
   }
 
   // Delete the specified "file" from the specified "level".
-  void DeleteFile(int level, uint64_t file) {
+  void RemoveFile(int level, uint64_t file) {
     deleted_files_.insert(std::make_pair(level, file));
   }
 

db/version_edit_test.cc

@@ -27,7 +27,7 @@ TEST(VersionEditTest, EncodeDecode) {
     edit.AddFile(3, kBig + 300 + i, kBig + 400 + i,
                  InternalKey("foo", kBig + 500 + i, kTypeValue),
                  InternalKey("zoo", kBig + 600 + i, kTypeDeletion));
-    edit.DeleteFile(4, kBig + 700 + i);
+    edit.RemoveFile(4, kBig + 700 + i);
     edit.SetCompactPointer(i, InternalKey("x", kBig + 900 + i, kTypeValue));
   }
 

db/version_set.cc

@@ -853,7 +853,7 @@ Status VersionSet::LogAndApply(VersionEdit* edit, port::Mutex* mu) {
       delete descriptor_file_;
       descriptor_log_ = nullptr;
       descriptor_file_ = nullptr;
-      env_->DeleteFile(new_manifest_file);
+      env_->RemoveFile(new_manifest_file);
     }
   }
 
@@ -1502,7 +1502,7 @@ bool Compaction::IsTrivialMove() const {
 void Compaction::AddInputDeletions(VersionEdit* edit) {
   for (int which = 0; which < 2; which++) {
     for (size_t i = 0; i < inputs_[which].size(); i++) {
-      edit->DeleteFile(level_ + which, inputs_[which][i]->number);
+      edit->RemoveFile(level_ + which, inputs_[which][i]->number);
     }
   }
 }

doc/impl.md

@@ -166,7 +166,7 @@ So maybe even the sharding is not necessary on modern filesystems?
 
 ## Garbage collection of files
 
-`DeleteObsoleteFiles()` is called at the end of every compaction and at the end
+`RemoveObsoleteFiles()` is called at the end of every compaction and at the end
 of recovery. It finds the names of all files in the database. It deletes all log
 files that are not the current log file. It deletes all table files that are not
 referenced from some level and are not the output of an active compaction.