rocksdb/db/table_properties_collector.h
kailiu 1415f8820d Improve the "table stats"
Summary:
The primary motivation of the changes is to make it easier to figure out the inside of the tables.

* rename "table stats" to "table properties" since now we have more than "integers" to store in the property block.
* Add filter block size to the basic table properties.
* Whenever a table is built, we'll log the table properties (the sample output is in Test Plan).
* Make an api to expose deleted keys.

Test Plan:
Passed all existing test. and the sample output of table stats:

    ==================================================================
        Basic Properties
    ------------------------------------------------------------------
                  # data blocks: 1
                      # entries: 1

                   raw key size: 9
           raw average key size: 9
                 raw value size: 9
         raw average value size: 0

                data block size: 25
               index block size: 27
              filter block size: 18
         (estimated) table size: 70

                  filter policy: rocksdb.BuiltinBloomFilter
    ==================================================================
        User collected properties: InternalKeyPropertiesCollector
    ------------------------------------------------------------------
                    kDeletedKeys: 1
    ==================================================================

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14187
2013-11-19 16:29:42 -08:00

77 lines
2.2 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;
};
// Collecting the statistics for internal keys. Visible only by internal
// rocksdb modules.
class InternalKeyPropertiesCollector : public TablePropertiesCollector {
public:
virtual Status Add(const Slice& key, const Slice& value) override;
virtual Status Finish(
TableProperties::UserCollectedProperties* properties) override;
virtual const char* Name() const override {
return "InternalKeyPropertiesCollector";
}
TableProperties::UserCollectedProperties
GetReadableProperties() const override;
private:
uint64_t deleted_keys_ = 0;
};
// 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 TablePropertiesCollector {
public:
explicit UserKeyTablePropertiesCollector(
TablePropertiesCollector* collector) :
UserKeyTablePropertiesCollector(
std::shared_ptr<TablePropertiesCollector>(collector)
) {
}
explicit UserKeyTablePropertiesCollector(
std::shared_ptr<TablePropertiesCollector> collector) :
collector_(collector) {
}
virtual ~UserKeyTablePropertiesCollector() { }
virtual Status Add(const Slice& key, const Slice& value) override;
virtual Status Finish(
TableProperties::UserCollectedProperties* properties) override;
virtual const char* Name() const override { return collector_->Name(); }
TableProperties::UserCollectedProperties
GetReadableProperties() const override;
protected:
std::shared_ptr<TablePropertiesCollector> collector_;
};
} // namespace rocksdb