mirror of https://github.com/facebook/rocksdb.git
103 lines
2.9 KiB
C++
103 lines
2.9 KiB
C++
// 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 <cassert>
|
|
#include <cstdint>
|
|
#include <unordered_map>
|
|
|
|
#include "db/blob/blob_constants.h"
|
|
#include "rocksdb/rocksdb_namespace.h"
|
|
#include "rocksdb/status.h"
|
|
|
|
namespace ROCKSDB_NAMESPACE {
|
|
|
|
class Slice;
|
|
|
|
// A class that can be used to compute the amount of additional garbage
|
|
// generated by a compaction. It parses the keys and blob references in the
|
|
// input and output of a compaction, and aggregates the "inflow" and "outflow"
|
|
// on a per-blob file basis. The amount of additional garbage for any given blob
|
|
// file can then be computed by subtracting the outflow from the inflow.
|
|
class BlobGarbageMeter {
|
|
public:
|
|
// A class to store the number and total size of blobs on a per-blob file
|
|
// basis.
|
|
class BlobStats {
|
|
public:
|
|
void Add(uint64_t bytes) {
|
|
++count_;
|
|
bytes_ += bytes;
|
|
}
|
|
void Add(uint64_t count, uint64_t bytes) {
|
|
count_ += count;
|
|
bytes_ += bytes;
|
|
}
|
|
|
|
uint64_t GetCount() const { return count_; }
|
|
uint64_t GetBytes() const { return bytes_; }
|
|
|
|
private:
|
|
uint64_t count_ = 0;
|
|
uint64_t bytes_ = 0;
|
|
};
|
|
|
|
// A class to keep track of the "inflow" and the "outflow" and to compute the
|
|
// amount of additional garbage for a given blob file.
|
|
class BlobInOutFlow {
|
|
public:
|
|
void AddInFlow(uint64_t bytes) {
|
|
in_flow_.Add(bytes);
|
|
assert(IsValid());
|
|
}
|
|
void AddOutFlow(uint64_t bytes) {
|
|
out_flow_.Add(bytes);
|
|
assert(IsValid());
|
|
}
|
|
|
|
const BlobStats& GetInFlow() const { return in_flow_; }
|
|
const BlobStats& GetOutFlow() const { return out_flow_; }
|
|
|
|
bool IsValid() const {
|
|
return in_flow_.GetCount() >= out_flow_.GetCount() &&
|
|
in_flow_.GetBytes() >= out_flow_.GetBytes();
|
|
}
|
|
bool HasGarbage() const {
|
|
assert(IsValid());
|
|
return in_flow_.GetCount() > out_flow_.GetCount();
|
|
}
|
|
uint64_t GetGarbageCount() const {
|
|
assert(IsValid());
|
|
assert(HasGarbage());
|
|
return in_flow_.GetCount() - out_flow_.GetCount();
|
|
}
|
|
uint64_t GetGarbageBytes() const {
|
|
assert(IsValid());
|
|
assert(HasGarbage());
|
|
return in_flow_.GetBytes() - out_flow_.GetBytes();
|
|
}
|
|
|
|
private:
|
|
BlobStats in_flow_;
|
|
BlobStats out_flow_;
|
|
};
|
|
|
|
Status ProcessInFlow(const Slice& key, const Slice& value);
|
|
Status ProcessOutFlow(const Slice& key, const Slice& value);
|
|
|
|
const std::unordered_map<uint64_t, BlobInOutFlow>& flows() const {
|
|
return flows_;
|
|
}
|
|
|
|
private:
|
|
static Status Parse(const Slice& key, const Slice& value,
|
|
uint64_t* blob_file_number, uint64_t* bytes);
|
|
|
|
std::unordered_map<uint64_t, BlobInOutFlow> flows_;
|
|
};
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|