#include "rocksdb/options.h"
#include "rocksdb/flush_block_policy.h"
#include "rocksdb/slice.h"
#include "table/block_builder.h"
#include <cassert>
namespace rocksdb {
class FlushBlockBySizePolicy : public FlushBlockPolicy {
public:
FlushBlockBySizePolicy(const uint64_t block_size,
const uint64_t block_size_deviation,
const BlockBuilder& data_block_builder)
: block_size_(block_size),
block_size_deviation_limit_(
((block_size * (100 - block_size_deviation)) + 99) / 100),
data_block_builder_(data_block_builder) {}
virtual bool Update(const Slice& key,
const Slice& value) override {
if (data_block_builder_.empty()) {
return false;
}
auto curr_size = data_block_builder_.CurrentSizeEstimate();
return curr_size >= block_size_ || BlockAlmostFull(key, value);
}
private:
bool BlockAlmostFull(const Slice& key, const Slice& value) const {
if (block_size_deviation_limit_ == 0) {
return false;
}
const auto curr_size = data_block_builder_.CurrentSizeEstimate();
const auto estimated_size_after =
data_block_builder_.EstimateSizeAfterKV(key, value);
return estimated_size_after > block_size_ &&
curr_size > block_size_deviation_limit_;
}
const uint64_t block_size_;
const uint64_t block_size_deviation_limit_;
const BlockBuilder& data_block_builder_;
};
FlushBlockPolicy* FlushBlockBySizePolicyFactory::NewFlushBlockPolicy(
const BlockBasedTableOptions& table_options,
const BlockBuilder& data_block_builder) const {
return new FlushBlockBySizePolicy(
table_options.block_size, table_options.block_size_deviation,
data_block_builder);
}
FlushBlockPolicy* FlushBlockBySizePolicyFactory::NewFlushBlockPolicy(
const uint64_t size, const int deviation,
const BlockBuilder& data_block_builder) {
return new FlushBlockBySizePolicy(size, deviation, data_block_builder);
}
}