You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
rocksdb/table/cuckoo_table_reader.cc

112 lines
4.3 KiB

// Copyright (c) 2014, 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.
#ifndef ROCKSDB_LITE
#include "table/cuckoo_table_reader.h"
#include <string>
#include "table/meta_blocks.h"
#include "util/coding.h"
namespace rocksdb {
extern const uint64_t kCuckooTableMagicNumber;
CuckooTableReader::CuckooTableReader(
const Options& options,
std::unique_ptr<RandomAccessFile>&& file,
uint64_t file_size,
uint64_t (*GetSliceHashPtr)(const Slice&, uint32_t, uint64_t))
: file_(std::move(file)),
file_size_(file_size),
GetSliceHash(GetSliceHashPtr) {
if (!options.allow_mmap_reads) {
status_ = Status::InvalidArgument("File is not mmaped");
}
TableProperties* props = nullptr;
status_ = ReadTableProperties(file_.get(), file_size, kCuckooTableMagicNumber,
options.env, options.info_log.get(), &props);
if (!status_.ok()) {
return;
}
table_props_.reset(props);
auto& user_props = props->user_collected_properties;
auto hash_funs = user_props.find(CuckooTablePropertyNames::kNumHashTable);
if (hash_funs == user_props.end()) {
status_ = Status::InvalidArgument("Number of hash functions not found");
return;
}
num_hash_fun_ = *reinterpret_cast<const uint32_t*>(hash_funs->second.data());
auto unused_key = user_props.find(CuckooTablePropertyNames::kEmptyKey);
if (unused_key == user_props.end()) {
status_ = Status::InvalidArgument("Empty bucket value not found");
return;
}
unused_key_ = unused_key->second;
key_length_ = props->fixed_key_len;
auto value_length = user_props.find(CuckooTablePropertyNames::kValueLength);
if (value_length == user_props.end()) {
status_ = Status::InvalidArgument("Value length not found");
return;
}
value_length_ = *reinterpret_cast<const uint32_t*>(
value_length->second.data());
bucket_length_ = key_length_ + value_length_;
auto num_buckets = user_props.find(CuckooTablePropertyNames::kMaxNumBuckets);
if (num_buckets == user_props.end()) {
status_ = Status::InvalidArgument("Num buckets not found");
return;
}
num_buckets_ = *reinterpret_cast<const uint64_t*>(num_buckets->second.data());
auto is_last_level = user_props.find(CuckooTablePropertyNames::kIsLastLevel);
if (is_last_level == user_props.end()) {
status_ = Status::InvalidArgument("Is last level not found");
return;
}
is_last_level_ = *reinterpret_cast<const bool*>(is_last_level->second.data());
status_ = file_->Read(0, file_size, &file_data_, nullptr);
}
Status CuckooTableReader::Get(
const ReadOptions& readOptions, const Slice& key, void* handle_context,
bool (*result_handler)(void* arg, const ParsedInternalKey& k,
const Slice& v),
void (*mark_key_may_exist_handler)(void* handle_context)) {
ParsedInternalKey ikey;
if (!ParseInternalKey(key, &ikey)) {
return Status::Corruption("Unable to parse key into inernal key.");
}
for (uint32_t hash_cnt = 0; hash_cnt < num_hash_fun_; ++hash_cnt) {
uint64_t hash_val = GetSliceHash(ikey.user_key, hash_cnt, num_buckets_);
assert(hash_val < num_buckets_);
uint64_t offset = hash_val * bucket_length_;
const char* bucket = &file_data_.data()[offset];
if (unused_key_.compare(0, key_length_, bucket, key_length_) == 0) {
return Status::OK();
}
// Here, we compare only the user key part as we support only one entry
// per user key and we don't support sanpshot.
if (ikey.user_key.compare(Slice(bucket, ikey.user_key.size())) == 0) {
Slice value = Slice(&bucket[key_length_], value_length_);
result_handler(handle_context, ikey, value);
// We don't support merge operations. So, we return here.
return Status::OK();
}
}
return Status::OK();
}
Iterator* CuckooTableReader::NewIterator(const ReadOptions&, Arena* arena) {
// TODO(rbs): Implement this as this will be used in compaction.
return nullptr;
}
} // namespace rocksdb
#endif