Move the blob file format related classes to the main namespace, rename reader/writer (#7086)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7086

Test Plan: `make check`

Reviewed By: zhichao-cao

Differential Revision: D22395420

Pulled By: ltamasi

fbshipit-source-id: 088a20097bd6b73b0c433cd79725779f97ec04f2

db/blob/blob_log_format.cc

@@ -11,7 +11,6 @@
 #include "util/crc32c.h"
 
 namespace ROCKSDB_NAMESPACE {
-namespace blob_db {
 
 void BlobLogHeader::EncodeTo(std::string* dst) {
   assert(dst != nullptr);
@@ -144,6 +143,5 @@ Status BlobLogRecord::CheckBlobCRC() const {
   return Status::OK();
 }
 
-}  // namespace blob_db
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // ROCKSDB_LITE

db/blob/blob_log_format.h

@@ -18,7 +18,6 @@
 #include "rocksdb/types.h"
 
 namespace ROCKSDB_NAMESPACE {
-namespace blob_db {
 
 constexpr uint32_t kMagicNumber = 2395959;  // 0x00248f37
 constexpr uint32_t kVersion1 = 1;
@@ -126,6 +125,5 @@ struct BlobLogRecord {
   Status CheckBlobCRC() const;
 };
 
-}  // namespace blob_db
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // ROCKSDB_LITE

db/blob/blob_log_reader.cc

@@ -14,9 +14,9 @@
 #include "util/stop_watch.h"
 
 namespace ROCKSDB_NAMESPACE {
-namespace blob_db {
 
-Reader::Reader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
+BlobLogReader::BlobLogReader(
+    std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
     Statistics* statistics)
     : file_(std::move(file_reader)),
       env_(env),
@@ -24,7 +24,7 @@ Reader::Reader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
       buffer_(),
       next_byte_(0) {}
 
-Status Reader::ReadSlice(uint64_t size, Slice* slice, char* buf) {
+Status BlobLogReader::ReadSlice(uint64_t size, Slice* slice, char* buf) {
   StopWatch read_sw(env_, statistics_, BLOB_DB_BLOB_FILE_READ_MICROS);
   Status s = file_->Read(IOOptions(), next_byte_, static_cast<size_t>(size),
                          slice, buf, nullptr);
@@ -39,7 +39,7 @@ Status Reader::ReadSlice(uint64_t size, Slice* slice, char* buf) {
   return s;
 }
 
-Status Reader::ReadHeader(BlobLogHeader* header) {
+Status BlobLogReader::ReadHeader(BlobLogHeader* header) {
   assert(file_.get() != nullptr);
   assert(next_byte_ == 0);
   Status s = ReadSlice(BlobLogHeader::kSize, &buffer_, header_buf_);
@@ -54,7 +54,7 @@ Status Reader::ReadHeader(BlobLogHeader* header) {
   return header->DecodeFrom(buffer_);
 }
 
-Status Reader::ReadRecord(BlobLogRecord* record, ReadLevel level,
+Status BlobLogReader::ReadRecord(BlobLogRecord* record, ReadLevel level,
                                  uint64_t* blob_offset) {
   Status s = ReadSlice(BlobLogRecord::kHeaderSize, &buffer_, header_buf_);
   if (!s.ok()) {
@@ -101,6 +101,5 @@ Status Reader::ReadRecord(BlobLogRecord* record, ReadLevel level,
   return s;
 }
 
-}  // namespace blob_db
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // ROCKSDB_LITE

db/blob/blob_log_reader.h

@@ -22,15 +22,14 @@ namespace ROCKSDB_NAMESPACE {
 class SequentialFileReader;
 class Logger;
 
-namespace blob_db {
-
 /**
- * Reader is a general purpose log stream reader implementation. The actual job
- * of reading from the device is implemented by the SequentialFile interface.
+ * BlobLogReader is a general purpose log stream reader implementation. The
+ * actual job of reading from the device is implemented by the SequentialFile
+ * interface.
  *
  * Please see Writer for details on the file and record layout.
  */
-class Reader {
+class BlobLogReader {
  public:
   enum ReadLevel {
     kReadHeader,
@@ -39,14 +38,14 @@ class Reader {
   };
 
   // Create a reader that will return log records from "*file".
-  // "*file" must remain live while this Reader is in use.
-  Reader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
+  // "*file" must remain live while this BlobLogReader is in use.
+  BlobLogReader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
                 Statistics* statistics);
   // No copying allowed
-  Reader(const Reader&) = delete;
-  Reader& operator=(const Reader&) = delete;
+  BlobLogReader(const BlobLogReader&) = delete;
+  BlobLogReader& operator=(const BlobLogReader&) = delete;
 
-  ~Reader() = default;
+  ~BlobLogReader() = default;
 
   Status ReadHeader(BlobLogHeader* header);
 
@@ -77,6 +76,5 @@ class Reader {
   uint64_t next_byte_;
 };
 
-}  // namespace blob_db
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // ROCKSDB_LITE

db/blob/blob_log_writer.cc

@@ -17,11 +17,11 @@
 #include "util/stop_watch.h"
 
 namespace ROCKSDB_NAMESPACE {
-namespace blob_db {
 
-Writer::Writer(std::unique_ptr<WritableFileWriter>&& dest, Env* env,
-               Statistics* statistics, uint64_t log_number, uint64_t bpsync,
-               bool use_fs, uint64_t boffset)
+BlobLogWriter::BlobLogWriter(std::unique_ptr<WritableFileWriter>&& dest,
+                             Env* env, Statistics* statistics,
+                             uint64_t log_number, uint64_t bpsync, bool use_fs,
+                             uint64_t boffset)
     : dest_(std::move(dest)),
       env_(env),
       statistics_(statistics),
@@ -32,14 +32,14 @@ Writer::Writer(std::unique_ptr<WritableFileWriter>&& dest, Env* env,
       use_fsync_(use_fs),
       last_elem_type_(kEtNone) {}
 
-Status Writer::Sync() {
+Status BlobLogWriter::Sync() {
   StopWatch sync_sw(env_, statistics_, BLOB_DB_BLOB_FILE_SYNC_MICROS);
   Status s = dest_->Sync(use_fsync_);
   RecordTick(statistics_, BLOB_DB_BLOB_FILE_SYNCED);
   return s;
 }
 
-Status Writer::WriteHeader(BlobLogHeader& header) {
+Status BlobLogWriter::WriteHeader(BlobLogHeader& header) {
   assert(block_offset_ == 0);
   assert(last_elem_type_ == kEtNone);
   std::string str;
@@ -56,7 +56,7 @@ Status Writer::WriteHeader(BlobLogHeader& header) {
   return s;
 }
 
-Status Writer::AppendFooter(BlobLogFooter& footer) {
+Status BlobLogWriter::AppendFooter(BlobLogFooter& footer) {
   assert(block_offset_ != 0);
   assert(last_elem_type_ == kEtFileHdr || last_elem_type_ == kEtRecord);
 
@@ -76,7 +76,7 @@ Status Writer::AppendFooter(BlobLogFooter& footer) {
   return s;
 }
 
-Status Writer::AddRecord(const Slice& key, const Slice& val,
+Status BlobLogWriter::AddRecord(const Slice& key, const Slice& val,
                                 uint64_t expiration, uint64_t* key_offset,
                                 uint64_t* blob_offset) {
   assert(block_offset_ != 0);
@@ -89,7 +89,7 @@ Status Writer::AddRecord(const Slice& key, const Slice& val,
   return s;
 }
 
-Status Writer::AddRecord(const Slice& key, const Slice& val,
+Status BlobLogWriter::AddRecord(const Slice& key, const Slice& val,
                                 uint64_t* key_offset, uint64_t* blob_offset) {
   assert(block_offset_ != 0);
   assert(last_elem_type_ == kEtFileHdr || last_elem_type_ == kEtRecord);
@@ -101,7 +101,7 @@ Status Writer::AddRecord(const Slice& key, const Slice& val,
   return s;
 }
 
-void Writer::ConstructBlobHeader(std::string* buf, const Slice& key,
+void BlobLogWriter::ConstructBlobHeader(std::string* buf, const Slice& key,
                                         const Slice& val, uint64_t expiration) {
   BlobLogRecord record;
   record.key = key;
@@ -110,9 +110,10 @@ void Writer::ConstructBlobHeader(std::string* buf, const Slice& key,
   record.EncodeHeaderTo(buf);
 }
 
-Status Writer::EmitPhysicalRecord(const std::string& headerbuf,
+Status BlobLogWriter::EmitPhysicalRecord(const std::string& headerbuf,
                                          const Slice& key, const Slice& val,
-                                  uint64_t* key_offset, uint64_t* blob_offset) {
+                                         uint64_t* key_offset,
+                                         uint64_t* blob_offset) {
   StopWatch write_sw(env_, statistics_, BLOB_DB_BLOB_FILE_WRITE_MICROS);
   Status s = dest_->Append(Slice(headerbuf));
   if (s.ok()) {
@@ -134,6 +135,5 @@ Status Writer::EmitPhysicalRecord(const std::string& headerbuf,
   return s;
 }
 
-}  // namespace blob_db
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // ROCKSDB_LITE

db/blob/blob_log_writer.h

@@ -21,29 +21,27 @@ namespace ROCKSDB_NAMESPACE {
 
 class WritableFileWriter;
 
-namespace blob_db {
-
 /**
- * Writer is the blob log stream writer. It provides an append-only
+ * BlobLogWriter is the blob log stream writer. It provides an append-only
  * abstraction for writing blob data.
  *
  *
  * Look at blob_db_format.h to see the details of the record formats.
  */
 
-class Writer {
+class BlobLogWriter {
  public:
   // Create a writer that will append data to "*dest".
   // "*dest" must be initially empty.
-  // "*dest" must remain live while this Writer is in use.
-  Writer(std::unique_ptr<WritableFileWriter>&& dest, Env* env,
+  // "*dest" must remain live while this BlobLogWriter is in use.
+  BlobLogWriter(std::unique_ptr<WritableFileWriter>&& dest, Env* env,
                 Statistics* statistics, uint64_t log_number, uint64_t bpsync,
                 bool use_fsync, uint64_t boffset = 0);
   // No copying allowed
-  Writer(const Writer&) = delete;
-  Writer& operator=(const Writer&) = delete;
+  BlobLogWriter(const BlobLogWriter&) = delete;
+  BlobLogWriter& operator=(const BlobLogWriter&) = delete;
 
-  ~Writer() = default;
+  ~BlobLogWriter() = default;
 
   static void ConstructBlobHeader(std::string* buf, const Slice& key,
                                   const Slice& val, uint64_t expiration);
@@ -89,6 +87,5 @@ class Writer {
   ElemType last_elem_type_;
 };
 
-}  // namespace blob_db
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // ROCKSDB_LITE

utilities/blob_db/blob_compaction_filter.h

@@ -78,7 +78,7 @@ class BlobIndexCompactionFilterBase : public LayeredCompactionFilterBase {
   Statistics* statistics_;
 
   mutable std::shared_ptr<BlobFile> blob_file_;
-  mutable std::shared_ptr<Writer> writer_;
+  mutable std::shared_ptr<BlobLogWriter> writer_;
 
   // It is safe to not using std::atomic since the compaction filter, created
   // from a compaction filter factroy, will not be called from multiple threads.

utilities/blob_db/blob_db_impl.cc

@@ -742,11 +742,11 @@ Status BlobDBImpl::CreateWriterLocked(const std::shared_ptr<BlobFile>& bfile) {
                     boffset);
   }
 
-  Writer::ElemType et = Writer::kEtNone;
+  BlobLogWriter::ElemType et = BlobLogWriter::kEtNone;
   if (bfile->file_size_ == BlobLogHeader::kSize) {
-    et = Writer::kEtFileHdr;
+    et = BlobLogWriter::kEtFileHdr;
   } else if (bfile->file_size_ > BlobLogHeader::kSize) {
-    et = Writer::kEtRecord;
+    et = BlobLogWriter::kEtRecord;
   } else if (bfile->file_size_) {
     ROCKS_LOG_WARN(db_options_.info_log,
                    "Open blob file: %s with wrong size: %" PRIu64,
@@ -754,7 +754,7 @@ Status BlobDBImpl::CreateWriterLocked(const std::shared_ptr<BlobFile>& bfile) {
     return Status::Corruption("Invalid blob file size");
   }
 
-  bfile->log_writer_ = std::make_shared<Writer>(
+  bfile->log_writer_ = std::make_shared<BlobLogWriter>(
       std::move(fwriter), env_, statistics_, bfile->file_number_,
       bdb_options_.bytes_per_sync, db_options_.use_fsync, boffset);
   bfile->log_writer_->last_elem_type_ = et;
@@ -798,7 +798,7 @@ std::shared_ptr<BlobFile> BlobDBImpl::FindBlobFileLocked(
 
 Status BlobDBImpl::CheckOrCreateWriterLocked(
     const std::shared_ptr<BlobFile>& blob_file,
-    std::shared_ptr<Writer>* writer) {
+    std::shared_ptr<BlobLogWriter>* writer) {
   assert(writer != nullptr);
   *writer = blob_file->GetWriter();
   if (*writer != nullptr) {
@@ -814,7 +814,7 @@ Status BlobDBImpl::CheckOrCreateWriterLocked(
 Status BlobDBImpl::CreateBlobFileAndWriter(
     bool has_ttl, const ExpirationRange& expiration_range,
     const std::string& reason, std::shared_ptr<BlobFile>* blob_file,
-    std::shared_ptr<Writer>* writer) {
+    std::shared_ptr<BlobLogWriter>* writer) {
   TEST_SYNC_POINT("BlobDBImpl::CreateBlobFileAndWriter");
   assert(has_ttl == (expiration_range.first || expiration_range.second));
   assert(blob_file);
@@ -871,7 +871,7 @@ Status BlobDBImpl::SelectBlobFile(std::shared_ptr<BlobFile>* blob_file) {
     return Status::OK();
   }
 
-  std::shared_ptr<Writer> writer;
+  std::shared_ptr<BlobLogWriter> writer;
   const Status s = CreateBlobFileAndWriter(
       /* has_ttl */ false, ExpirationRange(),
       /* reason */ "SelectBlobFile", blob_file, &writer);
@@ -917,7 +917,7 @@ Status BlobDBImpl::SelectBlobFileTTL(uint64_t expiration,
   std::ostringstream oss;
   oss << "SelectBlobFileTTL range: [" << exp_low << ',' << exp_high << ')';
 
-  std::shared_ptr<Writer> writer;
+  std::shared_ptr<BlobLogWriter> writer;
   const Status s =
       CreateBlobFileAndWriter(/* has_ttl */ true, expiration_range,
                               /* reason */ oss.str(), blob_file, &writer);
@@ -1070,7 +1070,8 @@ Status BlobDBImpl::PutBlobValue(const WriteOptions& /*options*/,
     Slice value_compressed = GetCompressedSlice(value, &compression_output);
 
     std::string headerbuf;
-    Writer::ConstructBlobHeader(&headerbuf, key, value_compressed, expiration);
+    BlobLogWriter::ConstructBlobHeader(&headerbuf, key, value_compressed,
+                                       expiration);
 
     // Check DB size limit before selecting blob file to
     // Since CheckSizeAndEvictBlobFiles() can close blob files, it needs to be
@@ -1342,7 +1343,7 @@ Status BlobDBImpl::AppendBlob(const std::shared_ptr<BlobFile>& bfile,
   uint64_t key_offset = 0;
   {
     WriteLock lockbfile_w(&bfile->mutex_);
-    std::shared_ptr<Writer> writer;
+    std::shared_ptr<BlobLogWriter> writer;
     s = CheckOrCreateWriterLocked(bfile, &writer);
     if (!s.ok()) {
       return s;

utilities/blob_db/blob_db_impl.h

@@ -268,7 +268,7 @@ class BlobDBImpl : public BlobDB {
                                  const ExpirationRange& expiration_range,
                                  const std::string& reason,
                                  std::shared_ptr<BlobFile>* blob_file,
-                                 std::shared_ptr<Writer>* writer);
+                                 std::shared_ptr<BlobLogWriter>* writer);
 
   // Get the open non-TTL blob log file, or create a new one if no such file
   // exists.
@@ -373,10 +373,10 @@ class BlobDBImpl : public BlobDB {
   // creates a sequential (append) writer for this blobfile
   Status CreateWriterLocked(const std::shared_ptr<BlobFile>& bfile);
 
-  // returns a Writer object for the file. If writer is not
+  // returns a BlobLogWriter object for the file. If writer is not
   // already present, creates one. Needs Write Mutex to be held
   Status CheckOrCreateWriterLocked(const std::shared_ptr<BlobFile>& blob_file,
-                                   std::shared_ptr<Writer>* writer);
+                                   std::shared_ptr<BlobLogWriter>* writer);
 
   // checks if there is no snapshot which is referencing the
   // blobs

utilities/blob_db/blob_file.cc

@@ -61,7 +61,7 @@ std::string BlobFile::PathName() const {
   return BlobFileName(path_to_dir_, file_number_);
 }
 
-std::shared_ptr<Reader> BlobFile::OpenRandomAccessReader(
+std::shared_ptr<BlobLogReader> BlobFile::OpenRandomAccessReader(
     Env* env, const DBOptions& db_options,
     const EnvOptions& env_options) const {
   constexpr size_t kReadaheadSize = 2 * 1024 * 1024;
@@ -78,7 +78,7 @@ std::shared_ptr<Reader> BlobFile::OpenRandomAccessReader(
   sfile_reader.reset(new RandomAccessFileReader(
       NewLegacyRandomAccessFileWrapper(sfile), path_name));
 
-  std::shared_ptr<Reader> log_reader = std::make_shared<Reader>(
+  std::shared_ptr<BlobLogReader> log_reader = std::make_shared<BlobLogReader>(
       std::move(sfile_reader), db_options.env, db_options.statistics.get());
 
   return log_reader;

utilities/blob_db/blob_file.h

@@ -86,7 +86,7 @@ class BlobFile {
   SequenceNumber obsolete_sequence_{0};
 
   // Sequential/Append writer for blobs
-  std::shared_ptr<Writer> log_writer_;
+  std::shared_ptr<BlobLogWriter> log_writer_;
 
   // random access file reader for GET calls
   std::shared_ptr<RandomAccessFileReader> ra_file_reader_;
@@ -208,7 +208,7 @@ class BlobFile {
 
   CompressionType GetCompressionType() const { return compression_; }
 
-  std::shared_ptr<Writer> GetWriter() const { return log_writer_; }
+  std::shared_ptr<BlobLogWriter> GetWriter() const { return log_writer_; }
 
   // Read blob file header and footer. Return corruption if file header is
   // malform or incomplete. If footer is malform or incomplete, set
@@ -220,7 +220,7 @@ class BlobFile {
                    bool* fresh_open);
 
  private:
-  std::shared_ptr<Reader> OpenRandomAccessReader(
+  std::shared_ptr<BlobLogReader> OpenRandomAccessReader(
       Env* env, const DBOptions& db_options,
       const EnvOptions& env_options) const;