rocksdb/db/table_properties_collector.h
sdong 6df589b446 Add TablePropertiesCollector::NeedCompact() to suggest DB to further compact output files
Summary:
It is experimental. Allow users to return from a call back function TablePropertiesCollector::NeedCompact(), based on the data in the file.
It can be used to allow users to suggest DB to clear up delete tombstones faster.

Test Plan: Add a unit test.

Reviewers: igor, yhchiang, kradhakrishnan, rven

Reviewed By: rven

Subscribers: yoshinorim, MarkCallaghan, maykov, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D39585
2015-06-05 20:18:21 -07:00

131 lines
4.0 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// This file defines a collection of statistics collectors.
#pragma once
#include "rocksdb/table_properties.h"
#include <memory>
#include <string>
#include <vector>
namespace rocksdb {
struct InternalKeyTablePropertiesNames {
static const std::string kDeletedKeys;
};
// Base class for internal table properties collector.
class IntTblPropCollector {
public:
virtual ~IntTblPropCollector() {}
virtual Status Finish(UserCollectedProperties* properties) = 0;
virtual const char* Name() const = 0;
// @params key the user key that is inserted into the table.
// @params value the value that is inserted into the table.
virtual Status InternalAdd(const Slice& key, const Slice& value,
uint64_t file_size) = 0;
virtual UserCollectedProperties GetReadableProperties() const = 0;
virtual bool NeedCompact() const { return false; }
};
// Facrtory for internal table properties collector.
class IntTblPropCollectorFactory {
public:
virtual ~IntTblPropCollectorFactory() {}
// has to be thread-safe
virtual IntTblPropCollector* CreateIntTblPropCollector() = 0;
// The name of the properties collector can be used for debugging purpose.
virtual const char* Name() const = 0;
};
// Collecting the statistics for internal keys. Visible only by internal
// rocksdb modules.
class InternalKeyPropertiesCollector : public IntTblPropCollector {
public:
virtual Status InternalAdd(const Slice& key, const Slice& value,
uint64_t file_size) override;
virtual Status Finish(UserCollectedProperties* properties) override;
virtual const char* Name() const override {
return "InternalKeyPropertiesCollector";
}
UserCollectedProperties GetReadableProperties() const override;
private:
uint64_t deleted_keys_ = 0;
};
class InternalKeyPropertiesCollectorFactory
: public IntTblPropCollectorFactory {
public:
virtual IntTblPropCollector* CreateIntTblPropCollector() override {
return new InternalKeyPropertiesCollector();
}
virtual const char* Name() const override {
return "InternalKeyPropertiesCollectorFactory";
}
};
// When rocksdb creates a new table, it will encode all "user keys" into
// "internal keys", which contains meta information of a given entry.
//
// This class extracts user key from the encoded internal key when Add() is
// invoked.
class UserKeyTablePropertiesCollector : public IntTblPropCollector {
public:
// transfer of ownership
explicit UserKeyTablePropertiesCollector(TablePropertiesCollector* collector)
: collector_(collector) {}
virtual ~UserKeyTablePropertiesCollector() {}
virtual Status InternalAdd(const Slice& key, const Slice& value,
uint64_t file_size) override;
virtual Status Finish(UserCollectedProperties* properties) override;
virtual const char* Name() const override { return collector_->Name(); }
UserCollectedProperties GetReadableProperties() const override;
virtual bool NeedCompact() const override {
return collector_->NeedCompact();
}
protected:
std::unique_ptr<TablePropertiesCollector> collector_;
};
class UserKeyTablePropertiesCollectorFactory
: public IntTblPropCollectorFactory {
public:
explicit UserKeyTablePropertiesCollectorFactory(
std::shared_ptr<TablePropertiesCollectorFactory> user_collector_factory)
: user_collector_factory_(user_collector_factory) {}
virtual IntTblPropCollector* CreateIntTblPropCollector() override {
return new UserKeyTablePropertiesCollector(
user_collector_factory_->CreateTablePropertiesCollector());
}
virtual const char* Name() const override {
return user_collector_factory_->Name();
}
private:
std::shared_ptr<TablePropertiesCollectorFactory> user_collector_factory_;
};
} // namespace rocksdb