bda9def2d4
Summary: somehow missed committing this update in D62217 Test Plan: make check Reviewers: sdong Reviewed By: sdong Subscribers: andrewkr, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D65361
845 lines
30 KiB
C++
845 lines
30 KiB
C++
// 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.
|
|
//
|
|
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
|
|
#include "db/memtable.h"
|
|
|
|
#include <memory>
|
|
#include <algorithm>
|
|
#include <limits>
|
|
|
|
#include "db/dbformat.h"
|
|
#include "db/merge_context.h"
|
|
#include "db/merge_helper.h"
|
|
#include "db/pinned_iterators_manager.h"
|
|
#include "rocksdb/comparator.h"
|
|
#include "rocksdb/env.h"
|
|
#include "rocksdb/iterator.h"
|
|
#include "rocksdb/merge_operator.h"
|
|
#include "rocksdb/slice_transform.h"
|
|
#include "rocksdb/write_buffer_manager.h"
|
|
#include "table/internal_iterator.h"
|
|
#include "table/merger.h"
|
|
#include "util/arena.h"
|
|
#include "util/coding.h"
|
|
#include "util/murmurhash.h"
|
|
#include "util/mutexlock.h"
|
|
#include "util/perf_context_imp.h"
|
|
#include "util/statistics.h"
|
|
#include "util/stop_watch.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
MemTableOptions::MemTableOptions(const ImmutableCFOptions& ioptions,
|
|
const MutableCFOptions& mutable_cf_options)
|
|
: write_buffer_size(mutable_cf_options.write_buffer_size),
|
|
arena_block_size(mutable_cf_options.arena_block_size),
|
|
memtable_prefix_bloom_bits(
|
|
static_cast<uint32_t>(
|
|
static_cast<double>(mutable_cf_options.write_buffer_size) *
|
|
mutable_cf_options.memtable_prefix_bloom_size_ratio) *
|
|
8u),
|
|
memtable_huge_page_size(mutable_cf_options.memtable_huge_page_size),
|
|
inplace_update_support(ioptions.inplace_update_support),
|
|
inplace_update_num_locks(mutable_cf_options.inplace_update_num_locks),
|
|
inplace_callback(ioptions.inplace_callback),
|
|
max_successive_merges(mutable_cf_options.max_successive_merges),
|
|
statistics(ioptions.statistics),
|
|
merge_operator(ioptions.merge_operator),
|
|
info_log(ioptions.info_log) {}
|
|
|
|
MemTable::MemTable(const InternalKeyComparator& cmp,
|
|
const ImmutableCFOptions& ioptions,
|
|
const MutableCFOptions& mutable_cf_options,
|
|
WriteBufferManager* write_buffer_manager,
|
|
SequenceNumber earliest_seq)
|
|
: comparator_(cmp),
|
|
moptions_(ioptions, mutable_cf_options),
|
|
refs_(0),
|
|
kArenaBlockSize(OptimizeBlockSize(moptions_.arena_block_size)),
|
|
arena_(moptions_.arena_block_size,
|
|
mutable_cf_options.memtable_huge_page_size),
|
|
allocator_(&arena_, write_buffer_manager),
|
|
table_(ioptions.memtable_factory->CreateMemTableRep(
|
|
comparator_, &allocator_, ioptions.prefix_extractor,
|
|
ioptions.info_log)),
|
|
range_del_table_(SkipListFactory().CreateMemTableRep(
|
|
comparator_, &allocator_, nullptr /* transform */,
|
|
ioptions.info_log)),
|
|
data_size_(0),
|
|
num_entries_(0),
|
|
num_deletes_(0),
|
|
flush_in_progress_(false),
|
|
flush_completed_(false),
|
|
file_number_(0),
|
|
first_seqno_(0),
|
|
earliest_seqno_(earliest_seq),
|
|
mem_next_logfile_number_(0),
|
|
min_prep_log_referenced_(0),
|
|
locks_(moptions_.inplace_update_support
|
|
? moptions_.inplace_update_num_locks
|
|
: 0),
|
|
prefix_extractor_(ioptions.prefix_extractor),
|
|
flush_state_(FLUSH_NOT_REQUESTED),
|
|
env_(ioptions.env) {
|
|
UpdateFlushState();
|
|
// something went wrong if we need to flush before inserting anything
|
|
assert(!ShouldScheduleFlush());
|
|
|
|
if (prefix_extractor_ && moptions_.memtable_prefix_bloom_bits > 0) {
|
|
prefix_bloom_.reset(new DynamicBloom(
|
|
&allocator_, moptions_.memtable_prefix_bloom_bits,
|
|
ioptions.bloom_locality, 6 /* hard coded 6 probes */, nullptr,
|
|
moptions_.memtable_huge_page_size, ioptions.info_log));
|
|
}
|
|
}
|
|
|
|
MemTable::~MemTable() { assert(refs_ == 0); }
|
|
|
|
size_t MemTable::ApproximateMemoryUsage() {
|
|
size_t arena_usage = arena_.ApproximateMemoryUsage();
|
|
size_t table_usage = table_->ApproximateMemoryUsage();
|
|
table_usage += range_del_table_->ApproximateMemoryUsage();
|
|
// let MAX_USAGE = std::numeric_limits<size_t>::max()
|
|
// then if arena_usage + total_usage >= MAX_USAGE, return MAX_USAGE.
|
|
// the following variation is to avoid numeric overflow.
|
|
if (arena_usage >= std::numeric_limits<size_t>::max() - table_usage) {
|
|
return std::numeric_limits<size_t>::max();
|
|
}
|
|
// otherwise, return the actual usage
|
|
return arena_usage + table_usage;
|
|
}
|
|
|
|
bool MemTable::ShouldFlushNow() const {
|
|
// In a lot of times, we cannot allocate arena blocks that exactly matches the
|
|
// buffer size. Thus we have to decide if we should over-allocate or
|
|
// under-allocate.
|
|
// This constant variable can be interpreted as: if we still have more than
|
|
// "kAllowOverAllocationRatio * kArenaBlockSize" space left, we'd try to over
|
|
// allocate one more block.
|
|
const double kAllowOverAllocationRatio = 0.6;
|
|
|
|
// If arena still have room for new block allocation, we can safely say it
|
|
// shouldn't flush.
|
|
auto allocated_memory = table_->ApproximateMemoryUsage() +
|
|
range_del_table_->ApproximateMemoryUsage() +
|
|
arena_.MemoryAllocatedBytes();
|
|
|
|
// if we can still allocate one more block without exceeding the
|
|
// over-allocation ratio, then we should not flush.
|
|
if (allocated_memory + kArenaBlockSize <
|
|
moptions_.write_buffer_size +
|
|
kArenaBlockSize * kAllowOverAllocationRatio) {
|
|
return false;
|
|
}
|
|
|
|
// if user keeps adding entries that exceeds moptions.write_buffer_size,
|
|
// we need to flush earlier even though we still have much available
|
|
// memory left.
|
|
if (allocated_memory > moptions_.write_buffer_size +
|
|
kArenaBlockSize * kAllowOverAllocationRatio) {
|
|
return true;
|
|
}
|
|
|
|
// In this code path, Arena has already allocated its "last block", which
|
|
// means the total allocatedmemory size is either:
|
|
// (1) "moderately" over allocated the memory (no more than `0.6 * arena
|
|
// block size`. Or,
|
|
// (2) the allocated memory is less than write buffer size, but we'll stop
|
|
// here since if we allocate a new arena block, we'll over allocate too much
|
|
// more (half of the arena block size) memory.
|
|
//
|
|
// In either case, to avoid over-allocate, the last block will stop allocation
|
|
// when its usage reaches a certain ratio, which we carefully choose "0.75
|
|
// full" as the stop condition because it addresses the following issue with
|
|
// great simplicity: What if the next inserted entry's size is
|
|
// bigger than AllocatedAndUnused()?
|
|
//
|
|
// The answer is: if the entry size is also bigger than 0.25 *
|
|
// kArenaBlockSize, a dedicated block will be allocated for it; otherwise
|
|
// arena will anyway skip the AllocatedAndUnused() and allocate a new, empty
|
|
// and regular block. In either case, we *overly* over-allocated.
|
|
//
|
|
// Therefore, setting the last block to be at most "0.75 full" avoids both
|
|
// cases.
|
|
//
|
|
// NOTE: the average percentage of waste space of this approach can be counted
|
|
// as: "arena block size * 0.25 / write buffer size". User who specify a small
|
|
// write buffer size and/or big arena block size may suffer.
|
|
return arena_.AllocatedAndUnused() < kArenaBlockSize / 4;
|
|
}
|
|
|
|
void MemTable::UpdateFlushState() {
|
|
auto state = flush_state_.load(std::memory_order_relaxed);
|
|
if (state == FLUSH_NOT_REQUESTED && ShouldFlushNow()) {
|
|
// ignore CAS failure, because that means somebody else requested
|
|
// a flush
|
|
flush_state_.compare_exchange_strong(state, FLUSH_REQUESTED,
|
|
std::memory_order_relaxed,
|
|
std::memory_order_relaxed);
|
|
}
|
|
}
|
|
|
|
int MemTable::KeyComparator::operator()(const char* prefix_len_key1,
|
|
const char* prefix_len_key2) const {
|
|
// Internal keys are encoded as length-prefixed strings.
|
|
Slice k1 = GetLengthPrefixedSlice(prefix_len_key1);
|
|
Slice k2 = GetLengthPrefixedSlice(prefix_len_key2);
|
|
return comparator.Compare(k1, k2);
|
|
}
|
|
|
|
int MemTable::KeyComparator::operator()(const char* prefix_len_key,
|
|
const Slice& key)
|
|
const {
|
|
// Internal keys are encoded as length-prefixed strings.
|
|
Slice a = GetLengthPrefixedSlice(prefix_len_key);
|
|
return comparator.Compare(a, key);
|
|
}
|
|
|
|
Slice MemTableRep::UserKey(const char* key) const {
|
|
Slice slice = GetLengthPrefixedSlice(key);
|
|
return Slice(slice.data(), slice.size() - 8);
|
|
}
|
|
|
|
KeyHandle MemTableRep::Allocate(const size_t len, char** buf) {
|
|
*buf = allocator_->Allocate(len);
|
|
return static_cast<KeyHandle>(*buf);
|
|
}
|
|
|
|
// Encode a suitable internal key target for "target" and return it.
|
|
// Uses *scratch as scratch space, and the returned pointer will point
|
|
// into this scratch space.
|
|
const char* EncodeKey(std::string* scratch, const Slice& target) {
|
|
scratch->clear();
|
|
PutVarint32(scratch, static_cast<uint32_t>(target.size()));
|
|
scratch->append(target.data(), target.size());
|
|
return scratch->data();
|
|
}
|
|
|
|
class MemTableIterator : public InternalIterator {
|
|
public:
|
|
MemTableIterator(const MemTable& mem, const ReadOptions& read_options,
|
|
Arena* arena, bool use_range_del_table = false)
|
|
: bloom_(nullptr),
|
|
prefix_extractor_(mem.prefix_extractor_),
|
|
comparator_(mem.comparator_),
|
|
valid_(false),
|
|
arena_mode_(arena != nullptr),
|
|
value_pinned_(!mem.GetMemTableOptions()->inplace_update_support) {
|
|
if (use_range_del_table) {
|
|
iter_ = mem.range_del_table_->GetIterator(arena);
|
|
} else if (prefix_extractor_ != nullptr && !read_options.total_order_seek) {
|
|
bloom_ = mem.prefix_bloom_.get();
|
|
iter_ = mem.table_->GetDynamicPrefixIterator(arena);
|
|
} else {
|
|
iter_ = mem.table_->GetIterator(arena);
|
|
}
|
|
}
|
|
|
|
~MemTableIterator() {
|
|
#ifndef NDEBUG
|
|
// Assert that the MemTableIterator is never deleted while
|
|
// Pinning is Enabled.
|
|
assert(!pinned_iters_mgr_ ||
|
|
(pinned_iters_mgr_ && !pinned_iters_mgr_->PinningEnabled()));
|
|
#endif
|
|
if (arena_mode_) {
|
|
iter_->~Iterator();
|
|
} else {
|
|
delete iter_;
|
|
}
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
virtual void SetPinnedItersMgr(
|
|
PinnedIteratorsManager* pinned_iters_mgr) override {
|
|
pinned_iters_mgr_ = pinned_iters_mgr;
|
|
}
|
|
PinnedIteratorsManager* pinned_iters_mgr_ = nullptr;
|
|
#endif
|
|
|
|
virtual bool Valid() const override { return valid_; }
|
|
virtual void Seek(const Slice& k) override {
|
|
PERF_TIMER_GUARD(seek_on_memtable_time);
|
|
PERF_COUNTER_ADD(seek_on_memtable_count, 1);
|
|
if (bloom_ != nullptr) {
|
|
if (!bloom_->MayContain(
|
|
prefix_extractor_->Transform(ExtractUserKey(k)))) {
|
|
PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
|
|
valid_ = false;
|
|
return;
|
|
} else {
|
|
PERF_COUNTER_ADD(bloom_memtable_hit_count, 1);
|
|
}
|
|
}
|
|
iter_->Seek(k, nullptr);
|
|
valid_ = iter_->Valid();
|
|
}
|
|
virtual void SeekForPrev(const Slice& k) override {
|
|
PERF_TIMER_GUARD(seek_on_memtable_time);
|
|
PERF_COUNTER_ADD(seek_on_memtable_count, 1);
|
|
if (bloom_ != nullptr) {
|
|
if (!bloom_->MayContain(
|
|
prefix_extractor_->Transform(ExtractUserKey(k)))) {
|
|
PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
|
|
valid_ = false;
|
|
return;
|
|
} else {
|
|
PERF_COUNTER_ADD(bloom_memtable_hit_count, 1);
|
|
}
|
|
}
|
|
iter_->Seek(k, nullptr);
|
|
valid_ = iter_->Valid();
|
|
if (!Valid()) {
|
|
SeekToLast();
|
|
}
|
|
while (Valid() && comparator_.comparator.Compare(k, key()) < 0) {
|
|
Prev();
|
|
}
|
|
}
|
|
virtual void SeekToFirst() override {
|
|
iter_->SeekToFirst();
|
|
valid_ = iter_->Valid();
|
|
}
|
|
virtual void SeekToLast() override {
|
|
iter_->SeekToLast();
|
|
valid_ = iter_->Valid();
|
|
}
|
|
virtual void Next() override {
|
|
assert(Valid());
|
|
iter_->Next();
|
|
valid_ = iter_->Valid();
|
|
}
|
|
virtual void Prev() override {
|
|
assert(Valid());
|
|
iter_->Prev();
|
|
valid_ = iter_->Valid();
|
|
}
|
|
virtual Slice key() const override {
|
|
assert(Valid());
|
|
return GetLengthPrefixedSlice(iter_->key());
|
|
}
|
|
virtual Slice value() const override {
|
|
assert(Valid());
|
|
Slice key_slice = GetLengthPrefixedSlice(iter_->key());
|
|
return GetLengthPrefixedSlice(key_slice.data() + key_slice.size());
|
|
}
|
|
|
|
virtual Status status() const override { return Status::OK(); }
|
|
|
|
virtual bool IsKeyPinned() const override {
|
|
// memtable data is always pinned
|
|
return true;
|
|
}
|
|
|
|
virtual bool IsValuePinned() const override {
|
|
// memtable value is always pinned, except if we allow inplace update.
|
|
return value_pinned_;
|
|
}
|
|
|
|
private:
|
|
DynamicBloom* bloom_;
|
|
const SliceTransform* const prefix_extractor_;
|
|
const MemTable::KeyComparator comparator_;
|
|
MemTableRep::Iterator* iter_;
|
|
bool valid_;
|
|
bool arena_mode_;
|
|
bool value_pinned_;
|
|
|
|
// No copying allowed
|
|
MemTableIterator(const MemTableIterator&);
|
|
void operator=(const MemTableIterator&);
|
|
};
|
|
|
|
InternalIterator* MemTable::NewIterator(const ReadOptions& read_options,
|
|
Arena* arena) {
|
|
assert(arena != nullptr);
|
|
auto mem = arena->AllocateAligned(sizeof(MemTableIterator));
|
|
return new (mem) MemTableIterator(*this, read_options, arena);
|
|
}
|
|
|
|
InternalIterator* MemTable::NewRangeTombstoneIterator(
|
|
const ReadOptions& read_options, Arena* arena) {
|
|
assert(arena != nullptr);
|
|
auto mem = arena->AllocateAligned(sizeof(MemTableIterator));
|
|
return new (mem) MemTableIterator(*this, read_options, arena,
|
|
true /* use_range_del_table */);
|
|
}
|
|
|
|
port::RWMutex* MemTable::GetLock(const Slice& key) {
|
|
static murmur_hash hash;
|
|
return &locks_[hash(key) % locks_.size()];
|
|
}
|
|
|
|
uint64_t MemTable::ApproximateSize(const Slice& start_ikey,
|
|
const Slice& end_ikey) {
|
|
uint64_t entry_count = table_->ApproximateNumEntries(start_ikey, end_ikey);
|
|
entry_count += range_del_table_->ApproximateNumEntries(start_ikey, end_ikey);
|
|
if (entry_count == 0) {
|
|
return 0;
|
|
}
|
|
uint64_t n = num_entries_.load(std::memory_order_relaxed);
|
|
if (n == 0) {
|
|
return 0;
|
|
}
|
|
if (entry_count > n) {
|
|
// (range_del_)table_->ApproximateNumEntries() is just an estimate so it can
|
|
// be larger than actual entries we have. Cap it to entries we have to limit
|
|
// the inaccuracy.
|
|
entry_count = n;
|
|
}
|
|
uint64_t data_size = data_size_.load(std::memory_order_relaxed);
|
|
return entry_count * (data_size / n);
|
|
}
|
|
|
|
void MemTable::Add(SequenceNumber s, ValueType type,
|
|
const Slice& key, /* user key */
|
|
const Slice& value, bool allow_concurrent,
|
|
MemTablePostProcessInfo* post_process_info) {
|
|
// Format of an entry is concatenation of:
|
|
// key_size : varint32 of internal_key.size()
|
|
// key bytes : char[internal_key.size()]
|
|
// value_size : varint32 of value.size()
|
|
// value bytes : char[value.size()]
|
|
uint32_t key_size = static_cast<uint32_t>(key.size());
|
|
uint32_t val_size = static_cast<uint32_t>(value.size());
|
|
uint32_t internal_key_size = key_size + 8;
|
|
const uint32_t encoded_len = VarintLength(internal_key_size) +
|
|
internal_key_size + VarintLength(val_size) +
|
|
val_size;
|
|
char* buf = nullptr;
|
|
std::unique_ptr<MemTableRep>& table =
|
|
type == kTypeRangeDeletion ? range_del_table_ : table_;
|
|
KeyHandle handle = table->Allocate(encoded_len, &buf);
|
|
|
|
char* p = EncodeVarint32(buf, internal_key_size);
|
|
memcpy(p, key.data(), key_size);
|
|
p += key_size;
|
|
uint64_t packed = PackSequenceAndType(s, type);
|
|
EncodeFixed64(p, packed);
|
|
p += 8;
|
|
p = EncodeVarint32(p, val_size);
|
|
memcpy(p, value.data(), val_size);
|
|
assert((unsigned)(p + val_size - buf) == (unsigned)encoded_len);
|
|
if (!allow_concurrent) {
|
|
table->Insert(handle);
|
|
|
|
// this is a bit ugly, but is the way to avoid locked instructions
|
|
// when incrementing an atomic
|
|
num_entries_.store(num_entries_.load(std::memory_order_relaxed) + 1,
|
|
std::memory_order_relaxed);
|
|
data_size_.store(data_size_.load(std::memory_order_relaxed) + encoded_len,
|
|
std::memory_order_relaxed);
|
|
if (type == kTypeDeletion) {
|
|
num_deletes_.store(num_deletes_.load(std::memory_order_relaxed) + 1,
|
|
std::memory_order_relaxed);
|
|
}
|
|
|
|
if (prefix_bloom_) {
|
|
assert(prefix_extractor_);
|
|
prefix_bloom_->Add(prefix_extractor_->Transform(key));
|
|
}
|
|
|
|
// The first sequence number inserted into the memtable
|
|
assert(first_seqno_ == 0 || s > first_seqno_);
|
|
if (first_seqno_ == 0) {
|
|
first_seqno_.store(s, std::memory_order_relaxed);
|
|
|
|
if (earliest_seqno_ == kMaxSequenceNumber) {
|
|
earliest_seqno_.store(GetFirstSequenceNumber(),
|
|
std::memory_order_relaxed);
|
|
}
|
|
assert(first_seqno_.load() >= earliest_seqno_.load());
|
|
}
|
|
assert(post_process_info == nullptr);
|
|
UpdateFlushState();
|
|
} else {
|
|
table->InsertConcurrently(handle);
|
|
|
|
assert(post_process_info != nullptr);
|
|
post_process_info->num_entries++;
|
|
post_process_info->data_size += encoded_len;
|
|
if (type == kTypeDeletion) {
|
|
post_process_info->num_deletes++;
|
|
}
|
|
|
|
if (prefix_bloom_) {
|
|
assert(prefix_extractor_);
|
|
prefix_bloom_->AddConcurrently(prefix_extractor_->Transform(key));
|
|
}
|
|
|
|
// atomically update first_seqno_ and earliest_seqno_.
|
|
uint64_t cur_seq_num = first_seqno_.load(std::memory_order_relaxed);
|
|
while ((cur_seq_num == 0 || s < cur_seq_num) &&
|
|
!first_seqno_.compare_exchange_weak(cur_seq_num, s)) {
|
|
}
|
|
uint64_t cur_earliest_seqno =
|
|
earliest_seqno_.load(std::memory_order_relaxed);
|
|
while (
|
|
(cur_earliest_seqno == kMaxSequenceNumber || s < cur_earliest_seqno) &&
|
|
!first_seqno_.compare_exchange_weak(cur_earliest_seqno, s)) {
|
|
}
|
|
}
|
|
}
|
|
|
|
// Callback from MemTable::Get()
|
|
namespace {
|
|
|
|
struct Saver {
|
|
Status* status;
|
|
const LookupKey* key;
|
|
bool* found_final_value; // Is value set correctly? Used by KeyMayExist
|
|
bool* merge_in_progress;
|
|
std::string* value;
|
|
SequenceNumber seq;
|
|
const MergeOperator* merge_operator;
|
|
// the merge operations encountered;
|
|
MergeContext* merge_context;
|
|
MemTable* mem;
|
|
Logger* logger;
|
|
Statistics* statistics;
|
|
bool inplace_update_support;
|
|
Env* env_;
|
|
};
|
|
} // namespace
|
|
|
|
static bool SaveValue(void* arg, const char* entry) {
|
|
Saver* s = reinterpret_cast<Saver*>(arg);
|
|
MergeContext* merge_context = s->merge_context;
|
|
const MergeOperator* merge_operator = s->merge_operator;
|
|
|
|
assert(s != nullptr && merge_context != nullptr);
|
|
|
|
// entry format is:
|
|
// klength varint32
|
|
// userkey char[klength-8]
|
|
// tag uint64
|
|
// vlength varint32
|
|
// value char[vlength]
|
|
// Check that it belongs to same user key. We do not check the
|
|
// sequence number since the Seek() call above should have skipped
|
|
// all entries with overly large sequence numbers.
|
|
uint32_t key_length;
|
|
const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (s->mem->GetInternalKeyComparator().user_comparator()->Equal(
|
|
Slice(key_ptr, key_length - 8), s->key->user_key())) {
|
|
// Correct user key
|
|
const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
|
|
ValueType type;
|
|
UnPackSequenceAndType(tag, &s->seq, &type);
|
|
|
|
switch (type) {
|
|
case kTypeValue: {
|
|
if (s->inplace_update_support) {
|
|
s->mem->GetLock(s->key->user_key())->ReadLock();
|
|
}
|
|
Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
*(s->status) = Status::OK();
|
|
if (*(s->merge_in_progress)) {
|
|
*(s->status) = MergeHelper::TimedFullMerge(
|
|
merge_operator, s->key->user_key(), &v,
|
|
merge_context->GetOperands(), s->value, s->logger, s->statistics,
|
|
s->env_);
|
|
} else if (s->value != nullptr) {
|
|
s->value->assign(v.data(), v.size());
|
|
}
|
|
if (s->inplace_update_support) {
|
|
s->mem->GetLock(s->key->user_key())->ReadUnlock();
|
|
}
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
case kTypeDeletion:
|
|
case kTypeSingleDeletion: {
|
|
if (*(s->merge_in_progress)) {
|
|
*(s->status) = MergeHelper::TimedFullMerge(
|
|
merge_operator, s->key->user_key(), nullptr,
|
|
merge_context->GetOperands(), s->value, s->logger, s->statistics,
|
|
s->env_);
|
|
} else {
|
|
*(s->status) = Status::NotFound();
|
|
}
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
case kTypeMerge: {
|
|
if (!merge_operator) {
|
|
*(s->status) = Status::InvalidArgument(
|
|
"merge_operator is not properly initialized.");
|
|
// Normally we continue the loop (return true) when we see a merge
|
|
// operand. But in case of an error, we should stop the loop
|
|
// immediately and pretend we have found the value to stop further
|
|
// seek. Otherwise, the later call will override this error status.
|
|
*(s->found_final_value) = true;
|
|
return false;
|
|
}
|
|
Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
*(s->merge_in_progress) = true;
|
|
merge_context->PushOperand(
|
|
v, s->inplace_update_support == false /* operand_pinned */);
|
|
return true;
|
|
}
|
|
default:
|
|
assert(false);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// s->state could be Corrupt, merge or notfound
|
|
return false;
|
|
}
|
|
|
|
bool MemTable::Get(const LookupKey& key, std::string* value, Status* s,
|
|
MergeContext* merge_context, SequenceNumber* seq) {
|
|
// The sequence number is updated synchronously in version_set.h
|
|
if (IsEmpty()) {
|
|
// Avoiding recording stats for speed.
|
|
return false;
|
|
}
|
|
PERF_TIMER_GUARD(get_from_memtable_time);
|
|
|
|
Slice user_key = key.user_key();
|
|
bool found_final_value = false;
|
|
bool merge_in_progress = s->IsMergeInProgress();
|
|
bool const may_contain =
|
|
nullptr == prefix_bloom_
|
|
? false
|
|
: prefix_bloom_->MayContain(prefix_extractor_->Transform(user_key));
|
|
if (prefix_bloom_ && !may_contain) {
|
|
// iter is null if prefix bloom says the key does not exist
|
|
PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
|
|
*seq = kMaxSequenceNumber;
|
|
} else {
|
|
if (prefix_bloom_) {
|
|
PERF_COUNTER_ADD(bloom_memtable_hit_count, 1);
|
|
}
|
|
Saver saver;
|
|
saver.status = s;
|
|
saver.found_final_value = &found_final_value;
|
|
saver.merge_in_progress = &merge_in_progress;
|
|
saver.key = &key;
|
|
saver.value = value;
|
|
saver.seq = kMaxSequenceNumber;
|
|
saver.mem = this;
|
|
saver.merge_context = merge_context;
|
|
saver.merge_operator = moptions_.merge_operator;
|
|
saver.logger = moptions_.info_log;
|
|
saver.inplace_update_support = moptions_.inplace_update_support;
|
|
saver.statistics = moptions_.statistics;
|
|
saver.env_ = env_;
|
|
table_->Get(key, &saver, SaveValue);
|
|
|
|
*seq = saver.seq;
|
|
}
|
|
|
|
// No change to value, since we have not yet found a Put/Delete
|
|
if (!found_final_value && merge_in_progress) {
|
|
*s = Status::MergeInProgress();
|
|
}
|
|
PERF_COUNTER_ADD(get_from_memtable_count, 1);
|
|
return found_final_value;
|
|
}
|
|
|
|
void MemTable::Update(SequenceNumber seq,
|
|
const Slice& key,
|
|
const Slice& value) {
|
|
LookupKey lkey(key, seq);
|
|
Slice mem_key = lkey.memtable_key();
|
|
|
|
std::unique_ptr<MemTableRep::Iterator> iter(
|
|
table_->GetDynamicPrefixIterator());
|
|
iter->Seek(lkey.internal_key(), mem_key.data());
|
|
|
|
if (iter->Valid()) {
|
|
// entry format is:
|
|
// key_length varint32
|
|
// userkey char[klength-8]
|
|
// tag uint64
|
|
// vlength varint32
|
|
// value char[vlength]
|
|
// Check that it belongs to same user key. We do not check the
|
|
// sequence number since the Seek() call above should have skipped
|
|
// all entries with overly large sequence numbers.
|
|
const char* entry = iter->key();
|
|
uint32_t key_length = 0;
|
|
const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (comparator_.comparator.user_comparator()->Equal(
|
|
Slice(key_ptr, key_length - 8), lkey.user_key())) {
|
|
// Correct user key
|
|
const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
|
|
ValueType type;
|
|
SequenceNumber unused;
|
|
UnPackSequenceAndType(tag, &unused, &type);
|
|
switch (type) {
|
|
case kTypeValue: {
|
|
Slice prev_value = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
|
|
uint32_t new_size = static_cast<uint32_t>(value.size());
|
|
|
|
// Update value, if new value size <= previous value size
|
|
if (new_size <= prev_size ) {
|
|
char* p = EncodeVarint32(const_cast<char*>(key_ptr) + key_length,
|
|
new_size);
|
|
WriteLock wl(GetLock(lkey.user_key()));
|
|
memcpy(p, value.data(), value.size());
|
|
assert((unsigned)((p + value.size()) - entry) ==
|
|
(unsigned)(VarintLength(key_length) + key_length +
|
|
VarintLength(value.size()) + value.size()));
|
|
return;
|
|
}
|
|
}
|
|
default:
|
|
// If the latest value is kTypeDeletion, kTypeMerge or kTypeLogData
|
|
// we don't have enough space for update inplace
|
|
Add(seq, kTypeValue, key, value);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
// key doesn't exist
|
|
Add(seq, kTypeValue, key, value);
|
|
}
|
|
|
|
bool MemTable::UpdateCallback(SequenceNumber seq,
|
|
const Slice& key,
|
|
const Slice& delta) {
|
|
LookupKey lkey(key, seq);
|
|
Slice memkey = lkey.memtable_key();
|
|
|
|
std::unique_ptr<MemTableRep::Iterator> iter(
|
|
table_->GetDynamicPrefixIterator());
|
|
iter->Seek(lkey.internal_key(), memkey.data());
|
|
|
|
if (iter->Valid()) {
|
|
// entry format is:
|
|
// key_length varint32
|
|
// userkey char[klength-8]
|
|
// tag uint64
|
|
// vlength varint32
|
|
// value char[vlength]
|
|
// Check that it belongs to same user key. We do not check the
|
|
// sequence number since the Seek() call above should have skipped
|
|
// all entries with overly large sequence numbers.
|
|
const char* entry = iter->key();
|
|
uint32_t key_length = 0;
|
|
const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (comparator_.comparator.user_comparator()->Equal(
|
|
Slice(key_ptr, key_length - 8), lkey.user_key())) {
|
|
// Correct user key
|
|
const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
|
|
ValueType type;
|
|
uint64_t unused;
|
|
UnPackSequenceAndType(tag, &unused, &type);
|
|
switch (type) {
|
|
case kTypeValue: {
|
|
Slice prev_value = GetLengthPrefixedSlice(key_ptr + key_length);
|
|
uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
|
|
|
|
char* prev_buffer = const_cast<char*>(prev_value.data());
|
|
uint32_t new_prev_size = prev_size;
|
|
|
|
std::string str_value;
|
|
WriteLock wl(GetLock(lkey.user_key()));
|
|
auto status = moptions_.inplace_callback(prev_buffer, &new_prev_size,
|
|
delta, &str_value);
|
|
if (status == UpdateStatus::UPDATED_INPLACE) {
|
|
// Value already updated by callback.
|
|
assert(new_prev_size <= prev_size);
|
|
if (new_prev_size < prev_size) {
|
|
// overwrite the new prev_size
|
|
char* p = EncodeVarint32(const_cast<char*>(key_ptr) + key_length,
|
|
new_prev_size);
|
|
if (VarintLength(new_prev_size) < VarintLength(prev_size)) {
|
|
// shift the value buffer as well.
|
|
memcpy(p, prev_buffer, new_prev_size);
|
|
}
|
|
}
|
|
RecordTick(moptions_.statistics, NUMBER_KEYS_UPDATED);
|
|
UpdateFlushState();
|
|
return true;
|
|
} else if (status == UpdateStatus::UPDATED) {
|
|
Add(seq, kTypeValue, key, Slice(str_value));
|
|
RecordTick(moptions_.statistics, NUMBER_KEYS_WRITTEN);
|
|
UpdateFlushState();
|
|
return true;
|
|
} else if (status == UpdateStatus::UPDATE_FAILED) {
|
|
// No action required. Return.
|
|
UpdateFlushState();
|
|
return true;
|
|
}
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
// If the latest value is not kTypeValue
|
|
// or key doesn't exist
|
|
return false;
|
|
}
|
|
|
|
size_t MemTable::CountSuccessiveMergeEntries(const LookupKey& key) {
|
|
Slice memkey = key.memtable_key();
|
|
|
|
// A total ordered iterator is costly for some memtablerep (prefix aware
|
|
// reps). By passing in the user key, we allow efficient iterator creation.
|
|
// The iterator only needs to be ordered within the same user key.
|
|
std::unique_ptr<MemTableRep::Iterator> iter(
|
|
table_->GetDynamicPrefixIterator());
|
|
iter->Seek(key.internal_key(), memkey.data());
|
|
|
|
size_t num_successive_merges = 0;
|
|
|
|
for (; iter->Valid(); iter->Next()) {
|
|
const char* entry = iter->key();
|
|
uint32_t key_length = 0;
|
|
const char* iter_key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
|
|
if (!comparator_.comparator.user_comparator()->Equal(
|
|
Slice(iter_key_ptr, key_length - 8), key.user_key())) {
|
|
break;
|
|
}
|
|
|
|
const uint64_t tag = DecodeFixed64(iter_key_ptr + key_length - 8);
|
|
ValueType type;
|
|
uint64_t unused;
|
|
UnPackSequenceAndType(tag, &unused, &type);
|
|
if (type != kTypeMerge) {
|
|
break;
|
|
}
|
|
|
|
++num_successive_merges;
|
|
}
|
|
|
|
return num_successive_merges;
|
|
}
|
|
|
|
void MemTableRep::Get(const LookupKey& k, void* callback_args,
|
|
bool (*callback_func)(void* arg, const char* entry)) {
|
|
auto iter = GetDynamicPrefixIterator();
|
|
for (iter->Seek(k.internal_key(), k.memtable_key().data());
|
|
iter->Valid() && callback_func(callback_args, iter->key());
|
|
iter->Next()) {
|
|
}
|
|
}
|
|
|
|
void MemTable::RefLogContainingPrepSection(uint64_t log) {
|
|
assert(log > 0);
|
|
auto cur = min_prep_log_referenced_.load();
|
|
while ((log < cur || cur == 0) &&
|
|
!min_prep_log_referenced_.compare_exchange_strong(cur, log)) {
|
|
cur = min_prep_log_referenced_.load();
|
|
}
|
|
}
|
|
|
|
uint64_t MemTable::GetMinLogContainingPrepSection() {
|
|
return min_prep_log_referenced_.load();
|
|
}
|
|
|
|
} // namespace rocksdb
|