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rocksdb/db/table_cache.cc

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// 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).
//
// 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/table_cache.h"
#include "db/dbformat.h"
#include "db/range_tombstone_fragmenter.h"
#include "db/snapshot_impl.h"
#include "db/version_edit.h"
#include "file/file_util.h"
#include "file/filename.h"
#include "file/random_access_file_reader.h"
#include "monitoring/perf_context_imp.h"
#include "rocksdb/advanced_options.h"
#include "rocksdb/statistics.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/get_context.h"
#include "table/internal_iterator.h"
#include "table/iterator_wrapper.h"
#include "table/multiget_context.h"
#include "table/table_builder.h"
#include "table/table_reader.h"
#include "test_util/sync_point.h"
#include "util/cast_util.h"
#include "util/coding.h"
#include "util/stop_watch.h"
namespace ROCKSDB_NAMESPACE {
namespace {
template <class T>
static void DeleteEntry(const Slice& /*key*/, void* value) {
T* typed_value = reinterpret_cast<T*>(value);
delete typed_value;
}
} // namespace
} // namespace ROCKSDB_NAMESPACE
// Generate the regular and coroutine versions of some methods by
// including table_cache_sync_and_async.h twice
// Macros in the header will expand differently based on whether
// WITH_COROUTINES or WITHOUT_COROUTINES is defined
// clang-format off
#define WITHOUT_COROUTINES
#include "db/table_cache_sync_and_async.h"
#undef WITHOUT_COROUTINES
#define WITH_COROUTINES
#include "db/table_cache_sync_and_async.h"
#undef WITH_COROUTINES
// clang-format on
namespace ROCKSDB_NAMESPACE {
namespace {
static void UnrefEntry(void* arg1, void* arg2) {
Cache* cache = reinterpret_cast<Cache*>(arg1);
Cache::Handle* h = reinterpret_cast<Cache::Handle*>(arg2);
cache->Release(h);
}
static Slice GetSliceForFileNumber(const uint64_t* file_number) {
return Slice(reinterpret_cast<const char*>(file_number),
sizeof(*file_number));
}
#ifndef ROCKSDB_LITE
void AppendVarint64(IterKey* key, uint64_t v) {
char buf[10];
auto ptr = EncodeVarint64(buf, v);
key->TrimAppend(key->Size(), buf, ptr - buf);
}
#endif // ROCKSDB_LITE
} // namespace
const int kLoadConcurency = 128;
TableCache::TableCache(const ImmutableOptions& ioptions,
const FileOptions* file_options, Cache* const cache,
BlockCacheTracer* const block_cache_tracer,
const std::shared_ptr<IOTracer>& io_tracer,
const std::string& db_session_id)
: ioptions_(ioptions),
file_options_(*file_options),
cache_(cache),
immortal_tables_(false),
block_cache_tracer_(block_cache_tracer),
loader_mutex_(kLoadConcurency, kGetSliceNPHash64UnseededFnPtr),
io_tracer_(io_tracer),
db_session_id_(db_session_id) {
if (ioptions_.row_cache) {
// If the same cache is shared by multiple instances, we need to
// disambiguate its entries.
PutVarint64(&row_cache_id_, ioptions_.row_cache->NewId());
}
}
TableCache::~TableCache() {
}
TableReader* TableCache::GetTableReaderFromHandle(Cache::Handle* handle) {
return reinterpret_cast<TableReader*>(cache_->Value(handle));
}
void TableCache::ReleaseHandle(Cache::Handle* handle) {
cache_->Release(handle);
}
Status TableCache::GetTableReader(
const ReadOptions& ro, const FileOptions& file_options,
const InternalKeyComparator& internal_comparator, const FileDescriptor& fd,
bool sequential_mode, bool record_read_stats, HistogramImpl* file_read_hist,
std::unique_ptr<TableReader>* table_reader,
const std::shared_ptr<const SliceTransform>& prefix_extractor,
bool skip_filters, int level, bool prefetch_index_and_filter_in_cache,
size_t max_file_size_for_l0_meta_pin, Temperature file_temperature) {
std::string fname =
TableFileName(ioptions_.cf_paths, fd.GetNumber(), fd.GetPathId());
std::unique_ptr<FSRandomAccessFile> file;
FileOptions fopts = file_options;
fopts.temperature = file_temperature;
Status s = PrepareIOFromReadOptions(ro, ioptions_.clock, fopts.io_options);
if (s.ok()) {
s = ioptions_.fs->NewRandomAccessFile(fname, fopts, &file, nullptr);
}
if (s.ok()) {
RecordTick(ioptions_.stats, NO_FILE_OPENS);
} else if (s.IsPathNotFound()) {
fname = Rocks2LevelTableFileName(fname);
s = PrepareIOFromReadOptions(ro, ioptions_.clock, fopts.io_options);
if (s.ok()) {
s = ioptions_.fs->NewRandomAccessFile(fname, file_options, &file,
nullptr);
}
if (s.ok()) {
RecordTick(ioptions_.stats, NO_FILE_OPENS);
}
}
if (s.ok()) {
if (!sequential_mode && ioptions_.advise_random_on_open) {
file->Hint(FSRandomAccessFile::kRandom);
}
StopWatch sw(ioptions_.clock, ioptions_.stats, TABLE_OPEN_IO_MICROS);
std::unique_ptr<RandomAccessFileReader> file_reader(
new RandomAccessFileReader(
std::move(file), fname, ioptions_.clock, io_tracer_,
record_read_stats ? ioptions_.stats : nullptr, SST_READ_MICROS,
file_read_hist, ioptions_.rate_limiter.get(), ioptions_.listeners,
file_temperature, level == ioptions_.num_levels - 1));
s = ioptions_.table_factory->NewTableReader(
ro,
TableReaderOptions(
ioptions_, prefix_extractor, file_options, internal_comparator,
skip_filters, immortal_tables_, false /* force_direct_prefetch */,
level, fd.largest_seqno, block_cache_tracer_,
max_file_size_for_l0_meta_pin, db_session_id_, fd.GetNumber()),
std::move(file_reader), fd.GetFileSize(), table_reader,
prefetch_index_and_filter_in_cache);
TEST_SYNC_POINT("TableCache::GetTableReader:0");
}
return s;
}
void TableCache::EraseHandle(const FileDescriptor& fd, Cache::Handle* handle) {
ReleaseHandle(handle);
uint64_t number = fd.GetNumber();
Slice key = GetSliceForFileNumber(&number);
cache_->Erase(key);
}
Status TableCache::FindTable(
const ReadOptions& ro, const FileOptions& file_options,
const InternalKeyComparator& internal_comparator, const FileDescriptor& fd,
Cache::Handle** handle,
const std::shared_ptr<const SliceTransform>& prefix_extractor,
const bool no_io, bool record_read_stats, HistogramImpl* file_read_hist,
bool skip_filters, int level, bool prefetch_index_and_filter_in_cache,
size_t max_file_size_for_l0_meta_pin, Temperature file_temperature) {
PERF_TIMER_GUARD_WITH_CLOCK(find_table_nanos, ioptions_.clock);
uint64_t number = fd.GetNumber();
Slice key = GetSliceForFileNumber(&number);
*handle = cache_->Lookup(key);
TEST_SYNC_POINT_CALLBACK("TableCache::FindTable:0",
const_cast<bool*>(&no_io));
if (*handle == nullptr) {
if (no_io) {
return Status::Incomplete("Table not found in table_cache, no_io is set");
}
MutexLock load_lock(loader_mutex_.get(key));
// We check the cache again under loading mutex
*handle = cache_->Lookup(key);
if (*handle != nullptr) {
return Status::OK();
}
std::unique_ptr<TableReader> table_reader;
Status s = GetTableReader(
ro, file_options, internal_comparator, fd, false /* sequential mode */,
record_read_stats, file_read_hist, &table_reader, prefix_extractor,
skip_filters, level, prefetch_index_and_filter_in_cache,
max_file_size_for_l0_meta_pin, file_temperature);
if (!s.ok()) {
assert(table_reader == nullptr);
RecordTick(ioptions_.stats, NO_FILE_ERRORS);
// We do not cache error results so that if the error is transient,
// or somebody repairs the file, we recover automatically.
} else {
s = cache_->Insert(key, table_reader.get(), 1, &DeleteEntry<TableReader>,
handle);
if (s.ok()) {
// Release ownership of table reader.
table_reader.release();
}
}
return s;
}
return Status::OK();
}
InternalIterator* TableCache::NewIterator(
const ReadOptions& options, const FileOptions& file_options,
const InternalKeyComparator& icomparator, const FileMetaData& file_meta,
RangeDelAggregator* range_del_agg,
const std::shared_ptr<const SliceTransform>& prefix_extractor,
TableReader** table_reader_ptr, HistogramImpl* file_read_hist,
TableReaderCaller caller, Arena* arena, bool skip_filters, int level,
size_t max_file_size_for_l0_meta_pin,
const InternalKey* smallest_compaction_key,
const InternalKey* largest_compaction_key, bool allow_unprepared_value) {
PERF_TIMER_GUARD(new_table_iterator_nanos);
Status s;
TableReader* table_reader = nullptr;
Cache::Handle* handle = nullptr;
if (table_reader_ptr != nullptr) {
*table_reader_ptr = nullptr;
}
bool for_compaction = caller == TableReaderCaller::kCompaction;
auto& fd = file_meta.fd;
table_reader = fd.table_reader;
if (table_reader == nullptr) {
s = FindTable(
options, file_options, icomparator, fd, &handle, prefix_extractor,
options.read_tier == kBlockCacheTier /* no_io */,
!for_compaction /* record_read_stats */, file_read_hist, skip_filters,
level, true /* prefetch_index_and_filter_in_cache */,
max_file_size_for_l0_meta_pin, file_meta.temperature);
if (s.ok()) {
table_reader = GetTableReaderFromHandle(handle);
}
}
InternalIterator* result = nullptr;
if (s.ok()) {
if (options.table_filter &&
!options.table_filter(*table_reader->GetTableProperties())) {
result = NewEmptyInternalIterator<Slice>(arena);
} else {
result = table_reader->NewIterator(
options, prefix_extractor.get(), arena, skip_filters, caller,
file_options.compaction_readahead_size, allow_unprepared_value);
}
if (handle != nullptr) {
result->RegisterCleanup(&UnrefEntry, cache_, handle);
handle = nullptr; // prevent from releasing below
}
if (for_compaction) {
table_reader->SetupForCompaction();
}
if (table_reader_ptr != nullptr) {
*table_reader_ptr = table_reader;
}
}
if (s.ok() && range_del_agg != nullptr && !options.ignore_range_deletions) {
if (range_del_agg->AddFile(fd.GetNumber())) {
std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter(
static_cast<FragmentedRangeTombstoneIterator*>(
table_reader->NewRangeTombstoneIterator(options)));
if (range_del_iter != nullptr) {
s = range_del_iter->status();
}
if (s.ok()) {
const InternalKey* smallest = &file_meta.smallest;
const InternalKey* largest = &file_meta.largest;
if (smallest_compaction_key != nullptr) {
smallest = smallest_compaction_key;
}
if (largest_compaction_key != nullptr) {
largest = largest_compaction_key;
}
range_del_agg->AddTombstones(std::move(range_del_iter), smallest,
largest);
}
}
}
if (handle != nullptr) {
ReleaseHandle(handle);
}
if (!s.ok()) {
assert(result == nullptr);
result = NewErrorInternalIterator<Slice>(s, arena);
}
return result;
}
Status TableCache::GetRangeTombstoneIterator(
const ReadOptions& options,
const InternalKeyComparator& internal_comparator,
const FileMetaData& file_meta,
std::unique_ptr<FragmentedRangeTombstoneIterator>* out_iter) {
assert(out_iter);
const FileDescriptor& fd = file_meta.fd;
Status s;
TableReader* t = fd.table_reader;
Cache::Handle* handle = nullptr;
if (t == nullptr) {
s = FindTable(options, file_options_, internal_comparator, fd, &handle);
if (s.ok()) {
t = GetTableReaderFromHandle(handle);
}
}
if (s.ok()) {
// Note: NewRangeTombstoneIterator could return nullptr
out_iter->reset(t->NewRangeTombstoneIterator(options));
}
if (handle) {
if (*out_iter) {
(*out_iter)->RegisterCleanup(&UnrefEntry, cache_, handle);
} else {
ReleaseHandle(handle);
}
}
return s;
}
#ifndef ROCKSDB_LITE
void TableCache::CreateRowCacheKeyPrefix(const ReadOptions& options,
const FileDescriptor& fd,
const Slice& internal_key,
GetContext* get_context,
IterKey& row_cache_key) {
uint64_t fd_number = fd.GetNumber();
// We use the user key as cache key instead of the internal key,
// otherwise the whole cache would be invalidated every time the
// sequence key increases. However, to support caching snapshot
// reads, we append the sequence number (incremented by 1 to
// distinguish from 0) only in this case.
// If the snapshot is larger than the largest seqno in the file,
// all data should be exposed to the snapshot, so we treat it
// the same as there is no snapshot. The exception is that if
// a seq-checking callback is registered, some internal keys
// may still be filtered out.
uint64_t seq_no = 0;
// Maybe we can include the whole file ifsnapshot == fd.largest_seqno.
if (options.snapshot != nullptr &&
(get_context->has_callback() ||
static_cast_with_check<const SnapshotImpl>(options.snapshot)
->GetSequenceNumber() <= fd.largest_seqno)) {
// We should consider to use options.snapshot->GetSequenceNumber()
// instead of GetInternalKeySeqno(k), which will make the code
// easier to understand.
seq_no = 1 + GetInternalKeySeqno(internal_key);
}
// Compute row cache key.
row_cache_key.TrimAppend(row_cache_key.Size(), row_cache_id_.data(),
row_cache_id_.size());
AppendVarint64(&row_cache_key, fd_number);
AppendVarint64(&row_cache_key, seq_no);
}
bool TableCache::GetFromRowCache(const Slice& user_key, IterKey& row_cache_key,
size_t prefix_size, GetContext* get_context) {
bool found = false;
row_cache_key.TrimAppend(prefix_size, user_key.data(), user_key.size());
if (auto row_handle =
ioptions_.row_cache->Lookup(row_cache_key.GetUserKey())) {
// Cleanable routine to release the cache entry
Cleanable value_pinner;
auto release_cache_entry_func = [](void* cache_to_clean,
void* cache_handle) {
((Cache*)cache_to_clean)->Release((Cache::Handle*)cache_handle);
};
auto found_row_cache_entry =
static_cast<const std::string*>(ioptions_.row_cache->Value(row_handle));
// If it comes here value is located on the cache.
// found_row_cache_entry points to the value on cache,
// and value_pinner has cleanup procedure for the cached entry.
// After replayGetContextLog() returns, get_context.pinnable_slice_
// will point to cache entry buffer (or a copy based on that) and
// cleanup routine under value_pinner will be delegated to
// get_context.pinnable_slice_. Cache entry is released when
// get_context.pinnable_slice_ is reset.
value_pinner.RegisterCleanup(release_cache_entry_func,
ioptions_.row_cache.get(), row_handle);
replayGetContextLog(*found_row_cache_entry, user_key, get_context,
&value_pinner);
RecordTick(ioptions_.stats, ROW_CACHE_HIT);
found = true;
} else {
RecordTick(ioptions_.stats, ROW_CACHE_MISS);
}
return found;
}
#endif // ROCKSDB_LITE
Status TableCache::Get(
const ReadOptions& options,
const InternalKeyComparator& internal_comparator,
const FileMetaData& file_meta, const Slice& k, GetContext* get_context,
const std::shared_ptr<const SliceTransform>& prefix_extractor,
HistogramImpl* file_read_hist, bool skip_filters, int level,
size_t max_file_size_for_l0_meta_pin) {
auto& fd = file_meta.fd;
std::string* row_cache_entry = nullptr;
bool done = false;
#ifndef ROCKSDB_LITE
IterKey row_cache_key;
std::string row_cache_entry_buffer;
// Check row cache if enabled. Since row cache does not currently store
// sequence numbers, we cannot use it if we need to fetch the sequence.
if (ioptions_.row_cache && !get_context->NeedToReadSequence()) {
auto user_key = ExtractUserKey(k);
CreateRowCacheKeyPrefix(options, fd, k, get_context, row_cache_key);
done = GetFromRowCache(user_key, row_cache_key, row_cache_key.Size(),
get_context);
if (!done) {
row_cache_entry = &row_cache_entry_buffer;
}
}
#endif // ROCKSDB_LITE
Status s;
TableReader* t = fd.table_reader;
Cache::Handle* handle = nullptr;
if (!done) {
assert(s.ok());
if (t == nullptr) {
s = FindTable(options, file_options_, internal_comparator, fd, &handle,
prefix_extractor,
options.read_tier == kBlockCacheTier /* no_io */,
true /* record_read_stats */, file_read_hist, skip_filters,
level, true /* prefetch_index_and_filter_in_cache */,
max_file_size_for_l0_meta_pin, file_meta.temperature);
if (s.ok()) {
t = GetTableReaderFromHandle(handle);
}
}
SequenceNumber* max_covering_tombstone_seq =
get_context->max_covering_tombstone_seq();
if (s.ok() && max_covering_tombstone_seq != nullptr &&
!options.ignore_range_deletions) {
std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter(
t->NewRangeTombstoneIterator(options));
if (range_del_iter != nullptr) {
*max_covering_tombstone_seq = std::max(
*max_covering_tombstone_seq,
range_del_iter->MaxCoveringTombstoneSeqnum(ExtractUserKey(k)));
}
}
if (s.ok()) {
get_context->SetReplayLog(row_cache_entry); // nullptr if no cache.
s = t->Get(options, k, get_context, prefix_extractor.get(), skip_filters);
get_context->SetReplayLog(nullptr);
} else if (options.read_tier == kBlockCacheTier && s.IsIncomplete()) {
// Couldn't find Table in cache but treat as kFound if no_io set
get_context->MarkKeyMayExist();
s = Status::OK();
done = true;
}
}
#ifndef ROCKSDB_LITE
// Put the replay log in row cache only if something was found.
if (!done && s.ok() && row_cache_entry && !row_cache_entry->empty()) {
size_t charge = row_cache_entry->capacity() + sizeof(std::string);
void* row_ptr = new std::string(std::move(*row_cache_entry));
// If row cache is full, it's OK to continue.
ioptions_.row_cache
->Insert(row_cache_key.GetUserKey(), row_ptr, charge,
&DeleteEntry<std::string>)
.PermitUncheckedError();
}
#endif // ROCKSDB_LITE
if (handle != nullptr) {
ReleaseHandle(handle);
}
return s;
}
Status TableCache::GetTableProperties(
const FileOptions& file_options,
const InternalKeyComparator& internal_comparator, const FileDescriptor& fd,
std::shared_ptr<const TableProperties>* properties,
const std::shared_ptr<const SliceTransform>& prefix_extractor, bool no_io) {
auto table_reader = fd.table_reader;
// table already been pre-loaded?
if (table_reader) {
*properties = table_reader->GetTableProperties();
return Status::OK();
}
Cache::Handle* table_handle = nullptr;
Status s = FindTable(ReadOptions(), file_options, internal_comparator, fd,
&table_handle, prefix_extractor, no_io);
if (!s.ok()) {
return s;
}
assert(table_handle);
auto table = GetTableReaderFromHandle(table_handle);
*properties = table->GetTableProperties();
ReleaseHandle(table_handle);
return s;
}
size_t TableCache::GetMemoryUsageByTableReader(
const FileOptions& file_options,
const InternalKeyComparator& internal_comparator, const FileDescriptor& fd,
const std::shared_ptr<const SliceTransform>& prefix_extractor) {
auto table_reader = fd.table_reader;
// table already been pre-loaded?
if (table_reader) {
return table_reader->ApproximateMemoryUsage();
}
Cache::Handle* table_handle = nullptr;
Status s = FindTable(ReadOptions(), file_options, internal_comparator, fd,
&table_handle, prefix_extractor, true);
if (!s.ok()) {
return 0;
}
assert(table_handle);
auto table = GetTableReaderFromHandle(table_handle);
auto ret = table->ApproximateMemoryUsage();
ReleaseHandle(table_handle);
return ret;
}
bool TableCache::HasEntry(Cache* cache, uint64_t file_number) {
Cache::Handle* handle = cache->Lookup(GetSliceForFileNumber(&file_number));
if (handle) {
cache->Release(handle);
return true;
} else {
return false;
}
}
void TableCache::Evict(Cache* cache, uint64_t file_number) {
cache->Erase(GetSliceForFileNumber(&file_number));
}
uint64_t TableCache::ApproximateOffsetOf(
const Slice& key, const FileDescriptor& fd, TableReaderCaller caller,
const InternalKeyComparator& internal_comparator,
const std::shared_ptr<const SliceTransform>& prefix_extractor) {
uint64_t result = 0;
TableReader* table_reader = fd.table_reader;
Cache::Handle* table_handle = nullptr;
if (table_reader == nullptr) {
const bool for_compaction = (caller == TableReaderCaller::kCompaction);
Status s = FindTable(ReadOptions(), file_options_, internal_comparator, fd,
&table_handle, prefix_extractor, false /* no_io */,
!for_compaction /* record_read_stats */);
if (s.ok()) {
table_reader = GetTableReaderFromHandle(table_handle);
}
}
if (table_reader != nullptr) {
result = table_reader->ApproximateOffsetOf(key, caller);
}
if (table_handle != nullptr) {
ReleaseHandle(table_handle);
}
return result;
}
uint64_t TableCache::ApproximateSize(
const Slice& start, const Slice& end, const FileDescriptor& fd,
TableReaderCaller caller, const InternalKeyComparator& internal_comparator,
const std::shared_ptr<const SliceTransform>& prefix_extractor) {
uint64_t result = 0;
TableReader* table_reader = fd.table_reader;
Cache::Handle* table_handle = nullptr;
if (table_reader == nullptr) {
const bool for_compaction = (caller == TableReaderCaller::kCompaction);
Status s = FindTable(ReadOptions(), file_options_, internal_comparator, fd,
&table_handle, prefix_extractor, false /* no_io */,
!for_compaction /* record_read_stats */);
if (s.ok()) {
table_reader = GetTableReaderFromHandle(table_handle);
}
}
if (table_reader != nullptr) {
result = table_reader->ApproximateSize(start, end, caller);
}
if (table_handle != nullptr) {
ReleaseHandle(table_handle);
}
return result;
}
} // namespace ROCKSDB_NAMESPACE
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