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rocksdb/utilities/blob_db/blob_db_iterator.h

150 lines
3.6 KiB

// 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
#ifndef ROCKSDB_LITE
#include "db/arena_wrapped_db_iter.h"
#include "rocksdb/iterator.h"
#include "util/stop_watch.h"
#include "utilities/blob_db/blob_db_impl.h"
namespace ROCKSDB_NAMESPACE {
class Statistics;
class SystemClock;
namespace blob_db {
using ROCKSDB_NAMESPACE::ManagedSnapshot;
class BlobDBIterator : public Iterator {
public:
BlobDBIterator(ManagedSnapshot* snapshot, ArenaWrappedDBIter* iter,
BlobDBImpl* blob_db, SystemClock* clock,
Statistics* statistics)
: snapshot_(snapshot),
iter_(iter),
blob_db_(blob_db),
clock_(clock),
statistics_(statistics) {}
virtual ~BlobDBIterator() = default;
bool Valid() const override {
if (!iter_->Valid()) {
return false;
}
return status_.ok();
}
Status status() const override {
if (!iter_->status().ok()) {
return iter_->status();
}
return status_;
}
void SeekToFirst() override {
StopWatch seek_sw(clock_, statistics_, BLOB_DB_SEEK_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_SEEK);
iter_->SeekToFirst();
while (UpdateBlobValue()) {
iter_->Next();
}
}
void SeekToLast() override {
StopWatch seek_sw(clock_, statistics_, BLOB_DB_SEEK_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_SEEK);
iter_->SeekToLast();
while (UpdateBlobValue()) {
iter_->Prev();
}
}
void Seek(const Slice& target) override {
StopWatch seek_sw(clock_, statistics_, BLOB_DB_SEEK_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_SEEK);
iter_->Seek(target);
while (UpdateBlobValue()) {
iter_->Next();
}
}
void SeekForPrev(const Slice& target) override {
StopWatch seek_sw(clock_, statistics_, BLOB_DB_SEEK_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_SEEK);
iter_->SeekForPrev(target);
while (UpdateBlobValue()) {
iter_->Prev();
}
}
void Next() override {
assert(Valid());
StopWatch next_sw(clock_, statistics_, BLOB_DB_NEXT_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_NEXT);
iter_->Next();
while (UpdateBlobValue()) {
iter_->Next();
}
}
void Prev() override {
assert(Valid());
StopWatch prev_sw(clock_, statistics_, BLOB_DB_PREV_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_PREV);
iter_->Prev();
while (UpdateBlobValue()) {
iter_->Prev();
}
}
Slice key() const override {
assert(Valid());
return iter_->key();
}
Slice value() const override {
assert(Valid());
if (!iter_->IsBlob()) {
return iter_->value();
}
return value_;
}
// Iterator::Refresh() not supported.
private:
// Return true if caller should continue to next value.
bool UpdateBlobValue() {
value_.Reset();
status_ = Status::OK();
if (iter_->Valid() && iter_->status().ok() && iter_->IsBlob()) {
Status s = blob_db_->GetBlobValue(iter_->key(), iter_->value(), &value_);
if (s.IsNotFound()) {
return true;
} else {
if (!s.ok()) {
status_ = s;
}
return false;
}
} else {
return false;
}
}
std::unique_ptr<ManagedSnapshot> snapshot_;
std::unique_ptr<ArenaWrappedDBIter> iter_;
BlobDBImpl* blob_db_;
SystemClock* clock_;
Statistics* statistics_;
Status status_;
PinnableSlice value_;
};
} // namespace blob_db
} // namespace ROCKSDB_NAMESPACE
#endif // !ROCKSDB_LITE