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+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef STORAGE_LEVELDB_DB_LOG_WRITER_H_
+#define STORAGE_LEVELDB_DB_LOG_WRITER_H_
+
+#include <stdint.h>
+
+#include "db/log_format.h"
+#include "leveldb/slice.h"
+#include "leveldb/status.h"
+
+namespace leveldb {
+
+class WritableFile;
+
+namespace log {
+
+class Writer {
+ 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.
+ explicit Writer(WritableFile* dest);
+
+ // Create a writer that will append data to "*dest".
+ // "*dest" must have initial length "dest_length".
+ // "*dest" must remain live while this Writer is in use.
+ Writer(WritableFile* dest, uint64_t dest_length);
+
+ Writer(const Writer&) = delete;
+ Writer& operator=(const Writer&) = delete;
+
+ ~Writer();
+
+ Status AddRecord(const Slice& slice);
+
+ private:
+ Status EmitPhysicalRecord(RecordType type, const char* ptr, size_t length);
+
+ WritableFile* dest_;
+ int block_offset_; // Current offset in block
+
+ // crc32c values for all supported record types. These are
+ // pre-computed to reduce the overhead of computing the crc of the
+ // record type stored in the header.
+ uint32_t type_crc_[kMaxRecordType + 1];
+};
+
+} // namespace log
+} // namespace leveldb
+
+#endif // STORAGE_LEVELDB_DB_LOG_WRITER_H_