Implementing DynamicIterator for TransformRepNoLock
Summary: What @haobo done with TransformRep, now in TransformRepNoLock. Similar implementation, except that I made DynamicIterator a subclass of Iterator which makes me have less iterator initializations. Test Plan: ./prefix_test. Seeing huge savings vs. TransformRep again! Reviewers: dhruba, haobo, sdong, kailiu Reviewed By: haobo CC: leveldb, haobo Differential Revision: https://reviews.facebook.net/D13953
This commit is contained in:
parent
fd075d6edd
commit
8b3379dc0a
@ -93,9 +93,8 @@ class PrefixTest {
|
||||
auto prefix_extractor = NewFixedPrefixTransform(8);
|
||||
options.prefix_extractor = prefix_extractor;
|
||||
if (FLAGS_use_nolock_version) {
|
||||
options.memtable_factory =
|
||||
std::make_shared<rocksdb::PrefixHashRepNoLockFactory>(
|
||||
prefix_extractor, FLAGS_bucket_count);
|
||||
options.memtable_factory.reset(NewHashSkipListRepFactory(
|
||||
prefix_extractor, FLAGS_bucket_count));
|
||||
} else {
|
||||
options.memtable_factory =
|
||||
std::make_shared<rocksdb::PrefixHashRepFactory>(
|
||||
|
@ -63,6 +63,11 @@ class SkipList {
|
||||
// The returned iterator is not valid.
|
||||
explicit Iterator(const SkipList* list);
|
||||
|
||||
// Change the underlying skiplist used for this iterator
|
||||
// This enables us not changing the iterator without deallocating
|
||||
// an old one and then allocating a new one
|
||||
void SetList(const SkipList* list);
|
||||
|
||||
// Returns true iff the iterator is positioned at a valid node.
|
||||
bool Valid() const;
|
||||
|
||||
@ -194,6 +199,11 @@ SkipList<Key,Comparator>::NewNode(const Key& key, int height) {
|
||||
|
||||
template<typename Key, class Comparator>
|
||||
inline SkipList<Key,Comparator>::Iterator::Iterator(const SkipList* list) {
|
||||
SetList(list);
|
||||
}
|
||||
|
||||
template<typename Key, class Comparator>
|
||||
inline void SkipList<Key,Comparator>::Iterator::SetList(const SkipList* list) {
|
||||
list_ = list;
|
||||
node_ = nullptr;
|
||||
}
|
||||
|
@ -260,67 +260,11 @@ public:
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
// NO LOCKS VERSION
|
||||
|
||||
// The same as TransformRepFactory except it doesn't use locks.
|
||||
// Experimental, will replace TransformRepFactory once we are sure
|
||||
// it performs better
|
||||
class TransformRepNoLockFactory : public MemTableRepFactory {
|
||||
public:
|
||||
explicit TransformRepNoLockFactory(const SliceTransform* transform,
|
||||
size_t bucket_count)
|
||||
: transform_(transform),
|
||||
bucket_count_(bucket_count) { }
|
||||
|
||||
virtual ~TransformRepNoLockFactory() { delete transform_; }
|
||||
|
||||
virtual std::shared_ptr<MemTableRep> CreateMemTableRep(
|
||||
MemTableRep::KeyComparator&, Arena*) override;
|
||||
|
||||
virtual const char* Name() const override {
|
||||
return "TransformRepNoLockFactory";
|
||||
}
|
||||
|
||||
const SliceTransform* GetTransform() { return transform_; }
|
||||
|
||||
protected:
|
||||
const SliceTransform* transform_;
|
||||
const size_t bucket_count_;
|
||||
};
|
||||
|
||||
// UnsortedReps bin user keys based on an identity function transform -- that
|
||||
// is, transform(key) = key. This optimizes for point look-ups.
|
||||
//
|
||||
// Parameters: See TransformRepNoLockFactory.
|
||||
class UnsortedRepNoLockFactory : public TransformRepNoLockFactory {
|
||||
public:
|
||||
explicit UnsortedRepNoLockFactory(size_t bucket_count = 1000000)
|
||||
: TransformRepNoLockFactory(NewNoopTransform(),
|
||||
bucket_count) { }
|
||||
virtual const char* Name() const override {
|
||||
return "UnsortedRepNoLockFactory";
|
||||
}
|
||||
};
|
||||
|
||||
// PrefixHashReps bin user keys based on a fixed-size prefix. This optimizes for
|
||||
// short ranged scans over a given prefix.
|
||||
//
|
||||
// Parameters: See TransformRepNoLockFactory.
|
||||
class PrefixHashRepNoLockFactory : public TransformRepNoLockFactory {
|
||||
public:
|
||||
explicit PrefixHashRepNoLockFactory(const SliceTransform* prefix_extractor,
|
||||
size_t bucket_count = 1000000)
|
||||
: TransformRepNoLockFactory(prefix_extractor, bucket_count)
|
||||
{ }
|
||||
|
||||
virtual std::shared_ptr<MemTableRep> CreateMemTableRep(
|
||||
MemTableRep::KeyComparator&, Arena*) override;
|
||||
|
||||
virtual const char* Name() const override {
|
||||
return "PrefixHashRepNoLockFactory";
|
||||
}
|
||||
};
|
||||
extern MemTableRepFactory* NewHashSkipListRepFactory(
|
||||
const SliceTransform* transform, size_t bucket_count = 1000000);
|
||||
|
||||
}
|
||||
|
||||
|
@ -16,9 +16,9 @@
|
||||
namespace rocksdb {
|
||||
namespace {
|
||||
|
||||
class TransformRepNoLock : public MemTableRep {
|
||||
class HashSkipListRep : public MemTableRep {
|
||||
public:
|
||||
TransformRepNoLock(MemTableRep::KeyComparator& compare, Arena* arena,
|
||||
HashSkipListRep(MemTableRep::KeyComparator& compare, Arena* arena,
|
||||
const SliceTransform* transform, size_t bucket_size);
|
||||
|
||||
virtual void Insert(const char* key) override;
|
||||
@ -27,17 +27,21 @@ class TransformRepNoLock : public MemTableRep {
|
||||
|
||||
virtual size_t ApproximateMemoryUsage() override;
|
||||
|
||||
virtual ~TransformRepNoLock();
|
||||
virtual ~HashSkipListRep();
|
||||
|
||||
virtual std::shared_ptr<MemTableRep::Iterator> GetIterator() override;
|
||||
|
||||
virtual std::shared_ptr<MemTableRep::Iterator> GetIterator(
|
||||
const Slice& slice) override;
|
||||
const Slice& slice) override;
|
||||
|
||||
std::shared_ptr<MemTableRep::Iterator> GetTransformIterator(
|
||||
const Slice& transformed);
|
||||
virtual std::shared_ptr<MemTableRep::Iterator> GetPrefixIterator(
|
||||
const Slice& prefix) override;
|
||||
|
||||
virtual std::shared_ptr<MemTableRep::Iterator> GetDynamicPrefixIterator()
|
||||
override;
|
||||
|
||||
private:
|
||||
friend class DynamicIterator;
|
||||
typedef SkipList<const char*, MemTableRep::KeyComparator&> Bucket;
|
||||
|
||||
size_t bucket_size_;
|
||||
@ -76,50 +80,72 @@ class TransformRepNoLock : public MemTableRep {
|
||||
virtual ~Iterator() {
|
||||
// if we own the list, we should also delete it
|
||||
if (own_list_) {
|
||||
assert(list_ != nullptr);
|
||||
delete list_;
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
// Returns true iff the iterator is positioned at a valid node.
|
||||
virtual bool Valid() const {
|
||||
return iter_.Valid();
|
||||
return list_ != nullptr && iter_.Valid();
|
||||
}
|
||||
|
||||
// Returns the key at the current position.
|
||||
// REQUIRES: Valid()
|
||||
virtual const char* key() const {
|
||||
assert(Valid());
|
||||
return iter_.key();
|
||||
}
|
||||
|
||||
// Advances to the next position.
|
||||
// REQUIRES: Valid()
|
||||
virtual void Next() {
|
||||
assert(Valid());
|
||||
iter_.Next();
|
||||
}
|
||||
|
||||
// Advances to the previous position.
|
||||
// REQUIRES: Valid()
|
||||
virtual void Prev() {
|
||||
assert(Valid());
|
||||
iter_.Prev();
|
||||
}
|
||||
|
||||
// Advance to the first entry with a key >= target
|
||||
virtual void Seek(const char* target) {
|
||||
iter_.Seek(target);
|
||||
if (list_ != nullptr) {
|
||||
iter_.Seek(target);
|
||||
}
|
||||
}
|
||||
|
||||
// Position at the first entry in collection.
|
||||
// Final state of iterator is Valid() iff collection is not empty.
|
||||
virtual void SeekToFirst() {
|
||||
iter_.SeekToFirst();
|
||||
if (list_ != nullptr) {
|
||||
iter_.SeekToFirst();
|
||||
}
|
||||
}
|
||||
|
||||
// Position at the last entry in collection.
|
||||
// Final state of iterator is Valid() iff collection is not empty.
|
||||
virtual void SeekToLast() {
|
||||
iter_.SeekToLast();
|
||||
if (list_ != nullptr) {
|
||||
iter_.SeekToLast();
|
||||
}
|
||||
}
|
||||
protected:
|
||||
void Reset(Bucket* list) {
|
||||
if (own_list_) {
|
||||
assert(list_ != nullptr);
|
||||
delete list_;
|
||||
}
|
||||
list_ = list;
|
||||
iter_.SetList(list);
|
||||
own_list_ = false;
|
||||
}
|
||||
private:
|
||||
// if list_ is nullptr, we should NEVER call any methods on iter_
|
||||
// if list_ is nullptr, this Iterator is not Valid()
|
||||
Bucket* list_;
|
||||
Bucket::Iterator iter_;
|
||||
// here we track if we own list_. If we own it, we are also
|
||||
@ -127,6 +153,40 @@ class TransformRepNoLock : public MemTableRep {
|
||||
bool own_list_;
|
||||
};
|
||||
|
||||
class DynamicIterator : public HashSkipListRep::Iterator {
|
||||
public:
|
||||
explicit DynamicIterator(const HashSkipListRep& memtable_rep)
|
||||
: HashSkipListRep::Iterator(nullptr, false),
|
||||
memtable_rep_(memtable_rep) {}
|
||||
|
||||
// Advance to the first entry with a key >= target
|
||||
virtual void Seek(const char* target) {
|
||||
auto transformed = memtable_rep_.transform_->Transform(
|
||||
memtable_rep_.UserKey(target));
|
||||
Reset(memtable_rep_.GetBucket(transformed));
|
||||
HashSkipListRep::Iterator::Seek(target);
|
||||
}
|
||||
|
||||
// Position at the first entry in collection.
|
||||
// Final state of iterator is Valid() iff collection is not empty.
|
||||
virtual void SeekToFirst() {
|
||||
// Prefix iterator does not support total order.
|
||||
// We simply set the iterator to invalid state
|
||||
Reset(nullptr);
|
||||
}
|
||||
|
||||
// Position at the last entry in collection.
|
||||
// Final state of iterator is Valid() iff collection is not empty.
|
||||
virtual void SeekToLast() {
|
||||
// Prefix iterator does not support total order.
|
||||
// We simply set the iterator to invalid state
|
||||
Reset(nullptr);
|
||||
}
|
||||
private:
|
||||
// the underlying memtable
|
||||
const HashSkipListRep& memtable_rep_;
|
||||
};
|
||||
|
||||
class EmptyIterator : public MemTableRep::Iterator {
|
||||
// This is used when there wasn't a bucket. It is cheaper than
|
||||
// instantiating an empty bucket over which to iterate.
|
||||
@ -150,17 +210,7 @@ class TransformRepNoLock : public MemTableRep {
|
||||
std::shared_ptr<EmptyIterator> empty_iterator_;
|
||||
};
|
||||
|
||||
class PrefixHashRepNoLock : public TransformRepNoLock {
|
||||
public:
|
||||
PrefixHashRepNoLock(MemTableRep::KeyComparator& compare, Arena* arena,
|
||||
const SliceTransform* transform, size_t bucket_size)
|
||||
: TransformRepNoLock(compare, arena, transform, bucket_size) { }
|
||||
|
||||
virtual std::shared_ptr<MemTableRep::Iterator> GetPrefixIterator(
|
||||
const Slice& prefix) override;
|
||||
};
|
||||
|
||||
TransformRepNoLock::TransformRepNoLock(MemTableRep::KeyComparator& compare,
|
||||
HashSkipListRep::HashSkipListRep(MemTableRep::KeyComparator& compare,
|
||||
Arena* arena, const SliceTransform* transform, size_t bucket_size)
|
||||
: bucket_size_(bucket_size),
|
||||
transform_(transform),
|
||||
@ -175,11 +225,11 @@ TransformRepNoLock::TransformRepNoLock(MemTableRep::KeyComparator& compare,
|
||||
}
|
||||
}
|
||||
|
||||
TransformRepNoLock::~TransformRepNoLock() {
|
||||
HashSkipListRep::~HashSkipListRep() {
|
||||
delete[] buckets_;
|
||||
}
|
||||
|
||||
TransformRepNoLock::Bucket* TransformRepNoLock::GetInitializedBucket(
|
||||
HashSkipListRep::Bucket* HashSkipListRep::GetInitializedBucket(
|
||||
const Slice& transformed) {
|
||||
size_t hash = GetHash(transformed);
|
||||
auto bucket = GetBucket(hash);
|
||||
@ -191,14 +241,14 @@ TransformRepNoLock::Bucket* TransformRepNoLock::GetInitializedBucket(
|
||||
return bucket;
|
||||
}
|
||||
|
||||
void TransformRepNoLock::Insert(const char* key) {
|
||||
void HashSkipListRep::Insert(const char* key) {
|
||||
assert(!Contains(key));
|
||||
auto transformed = transform_->Transform(UserKey(key));
|
||||
auto bucket = GetInitializedBucket(transformed);
|
||||
bucket->Insert(key);
|
||||
}
|
||||
|
||||
bool TransformRepNoLock::Contains(const char* key) const {
|
||||
bool HashSkipListRep::Contains(const char* key) const {
|
||||
auto transformed = transform_->Transform(UserKey(key));
|
||||
auto bucket = GetBucket(transformed);
|
||||
if (bucket == nullptr) {
|
||||
@ -207,11 +257,11 @@ bool TransformRepNoLock::Contains(const char* key) const {
|
||||
return bucket->Contains(key);
|
||||
}
|
||||
|
||||
size_t TransformRepNoLock::ApproximateMemoryUsage() {
|
||||
size_t HashSkipListRep::ApproximateMemoryUsage() {
|
||||
return sizeof(buckets_);
|
||||
}
|
||||
|
||||
std::shared_ptr<MemTableRep::Iterator> TransformRepNoLock::GetIterator() {
|
||||
std::shared_ptr<MemTableRep::Iterator> HashSkipListRep::GetIterator() {
|
||||
auto list = new Bucket(compare_, arena_);
|
||||
for (size_t i = 0; i < bucket_size_; ++i) {
|
||||
auto bucket = GetBucket(i);
|
||||
@ -225,38 +275,56 @@ std::shared_ptr<MemTableRep::Iterator> TransformRepNoLock::GetIterator() {
|
||||
return std::make_shared<Iterator>(list);
|
||||
}
|
||||
|
||||
std::shared_ptr<MemTableRep::Iterator> TransformRepNoLock::GetTransformIterator(
|
||||
const Slice& transformed) {
|
||||
auto bucket = GetBucket(transformed);
|
||||
std::shared_ptr<MemTableRep::Iterator> HashSkipListRep::GetPrefixIterator(
|
||||
const Slice& prefix) {
|
||||
auto bucket = GetBucket(prefix);
|
||||
if (bucket == nullptr) {
|
||||
return empty_iterator_;
|
||||
}
|
||||
return std::make_shared<Iterator>(bucket, false);
|
||||
}
|
||||
|
||||
std::shared_ptr<MemTableRep::Iterator> TransformRepNoLock::GetIterator(
|
||||
const Slice& slice) {
|
||||
auto transformed = transform_->Transform(slice);
|
||||
return GetTransformIterator(transformed);
|
||||
std::shared_ptr<MemTableRep::Iterator> HashSkipListRep::GetIterator(
|
||||
const Slice& slice) {
|
||||
return GetPrefixIterator(transform_->Transform(slice));
|
||||
}
|
||||
|
||||
std::shared_ptr<MemTableRep::Iterator>
|
||||
HashSkipListRep::GetDynamicPrefixIterator() {
|
||||
return std::make_shared<DynamicIterator>(*this);
|
||||
}
|
||||
|
||||
} // anon namespace
|
||||
|
||||
std::shared_ptr<MemTableRep> TransformRepNoLockFactory::CreateMemTableRep(
|
||||
MemTableRep::KeyComparator& compare, Arena* arena) {
|
||||
return std::make_shared<TransformRepNoLock>(compare, arena, transform_,
|
||||
bucket_count_);
|
||||
}
|
||||
class HashSkipListRepFactory : public MemTableRepFactory {
|
||||
public:
|
||||
explicit HashSkipListRepFactory(const SliceTransform* transform,
|
||||
size_t bucket_count = 1000000)
|
||||
: transform_(transform),
|
||||
bucket_count_(bucket_count) { }
|
||||
|
||||
std::shared_ptr<MemTableRep> PrefixHashRepNoLockFactory::CreateMemTableRep(
|
||||
MemTableRep::KeyComparator& compare, Arena* arena) {
|
||||
return std::make_shared<PrefixHashRepNoLock>(compare, arena, transform_,
|
||||
bucket_count_);
|
||||
}
|
||||
virtual ~HashSkipListRepFactory() { delete transform_; }
|
||||
|
||||
std::shared_ptr<MemTableRep::Iterator> PrefixHashRepNoLock::GetPrefixIterator(
|
||||
const Slice& prefix) {
|
||||
return TransformRepNoLock::GetTransformIterator(prefix);
|
||||
virtual std::shared_ptr<MemTableRep> CreateMemTableRep(
|
||||
MemTableRep::KeyComparator& compare, Arena* arena) override {
|
||||
return std::make_shared<HashSkipListRep>(compare, arena, transform_,
|
||||
bucket_count_);
|
||||
}
|
||||
|
||||
virtual const char* Name() const override {
|
||||
return "HashSkipListRepFactory";
|
||||
}
|
||||
|
||||
const SliceTransform* GetTransform() { return transform_; }
|
||||
|
||||
private:
|
||||
const SliceTransform* transform_;
|
||||
const size_t bucket_count_;
|
||||
};
|
||||
|
||||
MemTableRepFactory* NewHashSkipListRepFactory(
|
||||
const SliceTransform* transform, size_t bucket_count) {
|
||||
return new HashSkipListRepFactory(transform, bucket_count);
|
||||
}
|
||||
|
||||
} // namespace rocksdb
|
Loading…
Reference in New Issue
Block a user