Make sure (Shared)BlobFileMetaData are owned by shared_ptrs (#6749)

Summary:
The patch makes a couple of small cleanups to `SharedBlobFileMetaData` and `BlobFileMetaData`:
* It makes the constructors private and introduces factory methods to ensure these objects are always owned by `shared_ptr`s. Note that `SharedBlobFileMetaData` has an additional factory that takes a deleter object; we can utilize this to e.g. notify `VersionSet` when a blob file becomes obsolete (which is exactly when `SharedBlobFileMetaData` is destroyed).
* It disables move operations explicitly instead of relying on them being suppressed because of a user-declared destructor.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6749

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D21206947

Pulled By: ltamasi

fbshipit-source-id: 9094c14cc335b3e226f883e5a0df4f87a5cdeb95
This commit is contained in:
Levi Tamasi 2020-04-23 13:41:32 -07:00 committed by Facebook GitHub Bot
parent ae77880223
commit bc51e33d9c
4 changed files with 59 additions and 33 deletions

View File

@ -10,10 +10,6 @@
namespace ROCKSDB_NAMESPACE {
SharedBlobFileMetaData::~SharedBlobFileMetaData() {
// TODO: add the blob file to the list of obsolete files here
}
std::string SharedBlobFileMetaData::DebugString() const {
std::ostringstream oss;
oss << (*this);

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@ -23,6 +23,42 @@ namespace ROCKSDB_NAMESPACE {
class SharedBlobFileMetaData {
public:
static std::shared_ptr<SharedBlobFileMetaData> Create(
uint64_t blob_file_number, uint64_t total_blob_count,
uint64_t total_blob_bytes, std::string checksum_method,
std::string checksum_value) {
return std::shared_ptr<SharedBlobFileMetaData>(new SharedBlobFileMetaData(
blob_file_number, total_blob_count, total_blob_bytes,
std::move(checksum_method), std::move(checksum_value)));
}
template <typename Deleter>
static std::shared_ptr<SharedBlobFileMetaData> Create(
uint64_t blob_file_number, uint64_t total_blob_count,
uint64_t total_blob_bytes, std::string checksum_method,
std::string checksum_value, Deleter deleter) {
return std::shared_ptr<SharedBlobFileMetaData>(
new SharedBlobFileMetaData(blob_file_number, total_blob_count,
total_blob_bytes, std::move(checksum_method),
std::move(checksum_value)),
deleter);
}
SharedBlobFileMetaData(const SharedBlobFileMetaData&) = delete;
SharedBlobFileMetaData& operator=(const SharedBlobFileMetaData&) = delete;
SharedBlobFileMetaData(SharedBlobFileMetaData&&) = delete;
SharedBlobFileMetaData& operator=(SharedBlobFileMetaData&&) = delete;
uint64_t GetBlobFileNumber() const { return blob_file_number_; }
uint64_t GetTotalBlobCount() const { return total_blob_count_; }
uint64_t GetTotalBlobBytes() const { return total_blob_bytes_; }
const std::string& GetChecksumMethod() const { return checksum_method_; }
const std::string& GetChecksumValue() const { return checksum_value_; }
std::string DebugString() const;
private:
SharedBlobFileMetaData(uint64_t blob_file_number, uint64_t total_blob_count,
uint64_t total_blob_bytes, std::string checksum_method,
std::string checksum_value)
@ -34,20 +70,6 @@ class SharedBlobFileMetaData {
assert(checksum_method_.empty() == checksum_value_.empty());
}
~SharedBlobFileMetaData();
SharedBlobFileMetaData(const SharedBlobFileMetaData&) = delete;
SharedBlobFileMetaData& operator=(const SharedBlobFileMetaData&) = delete;
uint64_t GetBlobFileNumber() const { return blob_file_number_; }
uint64_t GetTotalBlobCount() const { return total_blob_count_; }
uint64_t GetTotalBlobBytes() const { return total_blob_bytes_; }
const std::string& GetChecksumMethod() const { return checksum_method_; }
const std::string& GetChecksumValue() const { return checksum_value_; }
std::string DebugString() const;
private:
uint64_t blob_file_number_;
uint64_t total_blob_count_;
uint64_t total_blob_bytes_;
@ -68,21 +90,19 @@ std::ostream& operator<<(std::ostream& os,
class BlobFileMetaData {
public:
BlobFileMetaData(std::shared_ptr<SharedBlobFileMetaData> shared_meta,
uint64_t garbage_blob_count, uint64_t garbage_blob_bytes)
: shared_meta_(std::move(shared_meta)),
garbage_blob_count_(garbage_blob_count),
garbage_blob_bytes_(garbage_blob_bytes) {
assert(shared_meta_);
assert(garbage_blob_count_ <= shared_meta_->GetTotalBlobCount());
assert(garbage_blob_bytes_ <= shared_meta_->GetTotalBlobBytes());
static std::shared_ptr<BlobFileMetaData> Create(
std::shared_ptr<SharedBlobFileMetaData> shared_meta,
uint64_t garbage_blob_count, uint64_t garbage_blob_bytes) {
return std::shared_ptr<BlobFileMetaData>(new BlobFileMetaData(
std::move(shared_meta), garbage_blob_count, garbage_blob_bytes));
}
~BlobFileMetaData() = default;
BlobFileMetaData(const BlobFileMetaData&) = delete;
BlobFileMetaData& operator=(const BlobFileMetaData&) = delete;
BlobFileMetaData(BlobFileMetaData&&) = delete;
BlobFileMetaData& operator=(BlobFileMetaData&&) = delete;
const std::shared_ptr<SharedBlobFileMetaData>& GetSharedMeta() const {
return shared_meta_;
}
@ -114,6 +134,16 @@ class BlobFileMetaData {
std::string DebugString() const;
private:
BlobFileMetaData(std::shared_ptr<SharedBlobFileMetaData> shared_meta,
uint64_t garbage_blob_count, uint64_t garbage_blob_bytes)
: shared_meta_(std::move(shared_meta)),
garbage_blob_count_(garbage_blob_count),
garbage_blob_bytes_(garbage_blob_bytes) {
assert(shared_meta_);
assert(garbage_blob_count_ <= shared_meta_->GetTotalBlobCount());
assert(garbage_blob_bytes_ <= shared_meta_->GetTotalBlobBytes());
}
std::shared_ptr<SharedBlobFileMetaData> shared_meta_;
uint64_t garbage_blob_count_;
uint64_t garbage_blob_bytes_;

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@ -388,7 +388,7 @@ class VersionBuilder::Rep {
return Status::Corruption("VersionBuilder", oss.str());
}
auto shared_meta = std::make_shared<SharedBlobFileMetaData>(
auto shared_meta = SharedBlobFileMetaData::Create(
blob_file_number, blob_file_addition.GetTotalBlobCount(),
blob_file_addition.GetTotalBlobBytes(),
blob_file_addition.GetChecksumMethod(),
@ -396,7 +396,7 @@ class VersionBuilder::Rep {
constexpr uint64_t garbage_blob_count = 0;
constexpr uint64_t garbage_blob_bytes = 0;
auto new_meta = std::make_shared<BlobFileMetaData>(
auto new_meta = BlobFileMetaData::Create(
std::move(shared_meta), garbage_blob_count, garbage_blob_bytes);
changed_blob_files_.emplace(blob_file_number, std::move(new_meta));
@ -417,7 +417,7 @@ class VersionBuilder::Rep {
assert(meta->GetBlobFileNumber() == blob_file_number);
auto new_meta = std::make_shared<BlobFileMetaData>(
auto new_meta = BlobFileMetaData::Create(
meta->GetSharedMeta(),
meta->GetGarbageBlobCount() + blob_file_garbage.GetGarbageBlobCount(),
meta->GetGarbageBlobBytes() + blob_file_garbage.GetGarbageBlobBytes());

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@ -82,10 +82,10 @@ class VersionBuilderTest : public testing::Test {
uint64_t total_blob_bytes, std::string checksum_method,
std::string checksum_value, uint64_t garbage_blob_count,
uint64_t garbage_blob_bytes) {
auto shared_meta = std::make_shared<SharedBlobFileMetaData>(
auto shared_meta = SharedBlobFileMetaData::Create(
blob_file_number, total_blob_count, total_blob_bytes,
std::move(checksum_method), std::move(checksum_value));
auto meta = std::make_shared<BlobFileMetaData>(
auto meta = BlobFileMetaData::Create(
std::move(shared_meta), garbage_blob_count, garbage_blob_bytes);
vstorage_.AddBlobFile(std::move(meta));