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rocksdb/db/table_cache_sync_and_async.h

145 lines
5.4 KiB

// Copyright (c) Meta Platforms, Inc. and its affiliates. 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).
#include "util/coro_utils.h"
#if defined(WITHOUT_COROUTINES) || \
(defined(USE_COROUTINES) && defined(WITH_COROUTINES))
namespace ROCKSDB_NAMESPACE {
#if defined(WITHOUT_COROUTINES)
#endif
// Batched version of TableCache::MultiGet.
DEFINE_SYNC_AND_ASYNC(Status, TableCache::MultiGet)
(const ReadOptions& options, const InternalKeyComparator& internal_comparator,
const FileMetaData& file_meta, const MultiGetContext::Range* mget_range,
const std::shared_ptr<const SliceTransform>& prefix_extractor,
HistogramImpl* file_read_hist, bool skip_filters, int level,
Cache::Handle* table_handle) {
auto& fd = file_meta.fd;
Status s;
TableReader* t = fd.table_reader;
Cache::Handle* handle = table_handle;
MultiGetRange table_range(*mget_range, mget_range->begin(),
mget_range->end());
if (handle != nullptr && t == nullptr) {
t = GetTableReaderFromHandle(handle);
}
#ifndef ROCKSDB_LITE
autovector<std::string, MultiGetContext::MAX_BATCH_SIZE> row_cache_entries;
IterKey row_cache_key;
size_t row_cache_key_prefix_size = 0;
KeyContext& first_key = *table_range.begin();
bool lookup_row_cache =
ioptions_.row_cache && !first_key.get_context->NeedToReadSequence();
// 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 (lookup_row_cache) {
GetContext* first_context = first_key.get_context;
CreateRowCacheKeyPrefix(options, fd, first_key.ikey, first_context,
row_cache_key);
row_cache_key_prefix_size = row_cache_key.Size();
for (auto miter = table_range.begin(); miter != table_range.end();
++miter) {
const Slice& user_key = miter->ukey_with_ts;
GetContext* get_context = miter->get_context;
if (GetFromRowCache(user_key, row_cache_key, row_cache_key_prefix_size,
get_context)) {
table_range.SkipKey(miter);
} else {
row_cache_entries.emplace_back();
get_context->SetReplayLog(&(row_cache_entries.back()));
}
}
}
#endif // ROCKSDB_LITE
// Check that table_range is not empty. Its possible all keys may have been
// found in the row cache and thus the range may now be empty
if (s.ok() && !table_range.empty()) {
if (t == nullptr) {
assert(handle == 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 */,
0 /*max_file_size_for_l0_meta_pin*/, file_meta.temperature);
TEST_SYNC_POINT_CALLBACK("TableCache::MultiGet:FindTable", &s);
if (s.ok()) {
t = GetTableReaderFromHandle(handle);
assert(t);
}
}
if (s.ok() && !options.ignore_range_deletions) {
std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter(
t->NewRangeTombstoneIterator(options));
if (range_del_iter != nullptr) {
for (auto iter = table_range.begin(); iter != table_range.end();
++iter) {
SequenceNumber* max_covering_tombstone_seq =
iter->get_context->max_covering_tombstone_seq();
*max_covering_tombstone_seq = std::max(
*max_covering_tombstone_seq,
range_del_iter->MaxCoveringTombstoneSeqnum(iter->ukey_with_ts));
}
}
}
if (s.ok()) {
CO_AWAIT(t->MultiGet)
(options, &table_range, prefix_extractor.get(), skip_filters);
} else if (options.read_tier == kBlockCacheTier && s.IsIncomplete()) {
for (auto iter = table_range.begin(); iter != table_range.end(); ++iter) {
Status* status = iter->s;
if (status->IsIncomplete()) {
// Couldn't find Table in cache but treat as kFound if no_io set
iter->get_context->MarkKeyMayExist();
s = Status::OK();
}
}
}
}
#ifndef ROCKSDB_LITE
if (lookup_row_cache) {
size_t row_idx = 0;
for (auto miter = table_range.begin(); miter != table_range.end();
++miter) {
std::string& row_cache_entry = row_cache_entries[row_idx++];
const Slice& user_key = miter->ukey_with_ts;
;
GetContext* get_context = miter->get_context;
get_context->SetReplayLog(nullptr);
// Compute row cache key.
row_cache_key.TrimAppend(row_cache_key_prefix_size, user_key.data(),
user_key.size());
// Put the replay log in row cache only if something was found.
if (s.ok() && !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.
ioptions_.row_cache
->Insert(row_cache_key.GetUserKey(), row_ptr, charge,
&DeleteEntry<std::string>)
.PermitUncheckedError();
}
}
}
#endif // ROCKSDB_LITE
if (handle != nullptr) {
ReleaseHandle(handle);
}
CO_RETURN s;
}
} // namespace ROCKSDB_NAMESPACE
#endif