1 files changed, 75 insertions, 0 deletions
diff --git a/src/rocksdb/include/rocksdb/flush_block_policy.h b/src/rocksdb/include/rocksdb/flush_block_policy.h
new file mode 100644
index 000000000..7a5dd957e
--- /dev/null
+++ b/src/rocksdb/include/rocksdb/flush_block_policy.h
@@ -0,0 +1,75 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <string>
+
+#include "rocksdb/customizable.h"
+#include "rocksdb/table.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Slice;
+class BlockBuilder;
+struct ConfigOptions;
+struct Options;
+
+// FlushBlockPolicy provides a configurable way to determine when to flush a
+// block in the block based tables.
+//
+// Exceptions MUST NOT propagate out of overridden functions into RocksDB,
+// because RocksDB is not exception-safe. This could cause undefined behavior
+// including data loss, unreported corruption, deadlocks, and more.
+class FlushBlockPolicy {
+ public:
+  // Keep track of the key/value sequences and return the boolean value to
+  // determine if table builder should flush current data block.
+  virtual bool Update(const Slice& key, const Slice& value) = 0;
+
+  virtual ~FlushBlockPolicy() {}
+};
+
+class FlushBlockPolicyFactory : public Customizable {
+ public:
+  static const char* Type() { return "FlushBlockPolicyFactory"; }
+
+  // Creates a FlushBlockPolicyFactory based on the input value.
+  // By default, this method can create EveryKey or BySize PolicyFactory,
+  // which take now config_options.
+  static Status CreateFromString(
+      const ConfigOptions& config_options, const std::string& value,
+      std::shared_ptr<FlushBlockPolicyFactory>* result);
+
+  // Return a new block flush policy that flushes data blocks by data size.
+  // FlushBlockPolicy may need to access the metadata of the data block
+  // builder to determine when to flush the blocks.
+  //
+  // Callers must delete the result after any database that is using the
+  // result has been closed.
+  virtual FlushBlockPolicy* NewFlushBlockPolicy(
+      const BlockBasedTableOptions& table_options,
+      const BlockBuilder& data_block_builder) const = 0;
+
+  virtual ~FlushBlockPolicyFactory() {}
+};
+
+class FlushBlockBySizePolicyFactory : public FlushBlockPolicyFactory {
+ public:
+  FlushBlockBySizePolicyFactory();
+
+  static const char* kClassName() { return "FlushBlockBySizePolicyFactory"; }
+  const char* Name() const override { return kClassName(); }
+
+  FlushBlockPolicy* NewFlushBlockPolicy(
+      const BlockBasedTableOptions& table_options,
+      const BlockBuilder& data_block_builder) const override;
+
+  static FlushBlockPolicy* NewFlushBlockPolicy(
+      const uint64_t size, const int deviation,
+      const BlockBuilder& data_block_builder);
+};
+
+}  // namespace ROCKSDB_NAMESPACE