rocksdb/db/compacted_db_impl.cc

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// Copyright (c) 2011-present, 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 source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
#ifndef ROCKSDB_LITE
#include "db/compacted_db_impl.h"
#include "db/db_impl.h"
#include "db/version_set.h"
#include "table/get_context.h"
namespace rocksdb {
extern void MarkKeyMayExist(void* arg);
extern bool SaveValue(void* arg, const ParsedInternalKey& parsed_key,
const Slice& v, bool hit_and_return);
CompactedDBImpl::CompactedDBImpl(
const DBOptions& options, const std::string& dbname)
: DBImpl(options, dbname) {
}
CompactedDBImpl::~CompactedDBImpl() {
}
size_t CompactedDBImpl::FindFile(const Slice& key) {
size_t left = 0;
size_t right = files_.num_files - 1;
while (left < right) {
size_t mid = (left + right) >> 1;
const FdWithKeyRange& f = files_.files[mid];
if (user_comparator_->Compare(ExtractUserKey(f.largest_key), key) < 0) {
// Key at "mid.largest" is < "target". Therefore all
// files at or before "mid" are uninteresting.
left = mid + 1;
} else {
// Key at "mid.largest" is >= "target". Therefore all files
// after "mid" are uninteresting.
right = mid;
}
}
return right;
}
Status CompactedDBImpl::Get(const ReadOptions& options, ColumnFamilyHandle*,
const Slice& key, PinnableSlice* value) {
GetContext get_context(user_comparator_, nullptr, nullptr, nullptr,
GetContext::kNotFound, key, value, nullptr, nullptr,
nullptr, nullptr);
LookupKey lkey(key, kMaxSequenceNumber);
files_.files[FindFile(key)].fd.table_reader->Get(
options, lkey.internal_key(), &get_context);
if (get_context.State() == GetContext::kFound) {
return Status::OK();
}
return Status::NotFound();
}
std::vector<Status> CompactedDBImpl::MultiGet(const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>&,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
autovector<TableReader*, 16> reader_list;
for (const auto& key : keys) {
const FdWithKeyRange& f = files_.files[FindFile(key)];
if (user_comparator_->Compare(key, ExtractUserKey(f.smallest_key)) < 0) {
reader_list.push_back(nullptr);
} else {
LookupKey lkey(key, kMaxSequenceNumber);
f.fd.table_reader->Prepare(lkey.internal_key());
reader_list.push_back(f.fd.table_reader);
}
}
std::vector<Status> statuses(keys.size(), Status::NotFound());
values->resize(keys.size());
int idx = 0;
for (auto* r : reader_list) {
if (r != nullptr) {
PinnableSlice pinnable_val;
std::string& value = (*values)[idx];
GetContext get_context(user_comparator_, nullptr, nullptr, nullptr,
GetContext::kNotFound, keys[idx], &pinnable_val,
nullptr, nullptr, nullptr, nullptr);
LookupKey lkey(keys[idx], kMaxSequenceNumber);
r->Get(options, lkey.internal_key(), &get_context);
value.assign(pinnable_val.data(), pinnable_val.size());
if (get_context.State() == GetContext::kFound) {
statuses[idx] = Status::OK();
}
}
++idx;
}
return statuses;
}
Status CompactedDBImpl::Init(const Options& options) {
mutex_.Lock();
ColumnFamilyDescriptor cf(kDefaultColumnFamilyName,
ColumnFamilyOptions(options));
Status s = Recover({cf}, true /* read only */, false, true);
if (s.ok()) {
cfd_ = reinterpret_cast<ColumnFamilyHandleImpl*>(
DefaultColumnFamily())->cfd();
delete cfd_->InstallSuperVersion(new SuperVersion(), &mutex_);
}
mutex_.Unlock();
if (!s.ok()) {
return s;
}
NewThreadStatusCfInfo(cfd_);
version_ = cfd_->GetSuperVersion()->current;
user_comparator_ = cfd_->user_comparator();
auto* vstorage = version_->storage_info();
if (vstorage->num_non_empty_levels() == 0) {
return Status::NotSupported("no file exists");
}
const LevelFilesBrief& l0 = vstorage->LevelFilesBrief(0);
// L0 should not have files
if (l0.num_files > 1) {
return Status::NotSupported("L0 contain more than 1 file");
}
if (l0.num_files == 1) {
if (vstorage->num_non_empty_levels() > 1) {
return Status::NotSupported("Both L0 and other level contain files");
}
files_ = l0;
return Status::OK();
}
for (int i = 1; i < vstorage->num_non_empty_levels() - 1; ++i) {
if (vstorage->LevelFilesBrief(i).num_files > 0) {
return Status::NotSupported("Other levels also contain files");
}
}
int level = vstorage->num_non_empty_levels() - 1;
if (vstorage->LevelFilesBrief(level).num_files > 0) {
files_ = vstorage->LevelFilesBrief(level);
return Status::OK();
}
return Status::NotSupported("no file exists");
}
Status CompactedDBImpl::Open(const Options& options,
const std::string& dbname, DB** dbptr) {
*dbptr = nullptr;
if (options.max_open_files != -1) {
return Status::InvalidArgument("require max_open_files = -1");
}
if (options.merge_operator.get() != nullptr) {
return Status::InvalidArgument("merge operator is not supported");
}
DBOptions db_options(options);
std::unique_ptr<CompactedDBImpl> db(new CompactedDBImpl(db_options, dbname));
Status s = db->Init(options);
if (s.ok()) {
ROCKS_LOG_INFO(db->immutable_db_options_.info_log,
"Opened the db as fully compacted mode");
LogFlush(db->immutable_db_options_.info_log);
*dbptr = db.release();
}
return s;
}
} // namespace rocksdb
#endif // ROCKSDB_LITE