| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| #ifndef KUDU_CLIENT_SCAN_PREDICATE_H |
| #define KUDU_CLIENT_SCAN_PREDICATE_H |
| |
| #ifdef KUDU_HEADERS_NO_STUBS |
| #include "kudu/gutil/macros.h" |
| #include "kudu/util/slice.h" |
| #else |
| #include "kudu/client/stubs.h" |
| #endif |
| |
| // NOTE: using stdint.h instead of cstdint because this file is supposed |
| // to be processed by a compiler lacking C++11 support. |
| #include <stdint.h> |
| |
| #include <cstddef> |
| |
| #include "kudu/client/hash.h" |
| #include "kudu/util/kudu_export.h" |
| #include "kudu/util/status.h" |
| |
| namespace kudu { |
| namespace client { |
| |
| /// @brief A representation of comparison predicate for Kudu queries. |
| /// |
| /// Call KuduTable::NewComparisonPredicate() to create a predicate object. |
| class KUDU_EXPORT KuduPredicate { |
| public: |
| /// @brief Supported comparison operators. |
| enum ComparisonOp { |
| LESS_EQUAL, |
| GREATER_EQUAL, |
| EQUAL, |
| LESS, |
| GREATER, |
| }; |
| |
| ~KuduPredicate(); |
| |
| /// @return A new, identical, KuduPredicate object. |
| KuduPredicate* Clone() const; |
| |
| /// @brief Forward declaration for the embedded PIMPL class. |
| /// |
| /// The PIMPL class has to be public since it's actually just an interface, |
| /// and gcc gives an error trying to derive from a private nested class. |
| class KUDU_NO_EXPORT Data; |
| |
| private: |
| friend class ComparisonPredicateData; |
| friend class ErrorPredicateData; |
| friend class InListPredicateData; |
| friend class IsNotNullPredicateData; |
| friend class IsNullPredicateData; |
| friend class KuduTable; |
| friend class ScanConfiguration; |
| |
| explicit KuduPredicate(Data* d); |
| |
| Data* data_; |
| DISALLOW_COPY_AND_ASSIGN(KuduPredicate); |
| }; |
| |
| /// @brief Bloom filter to be used with IN Bloom filter predicate. |
| /// |
| /// A Bloom filter is a space-efficient probabilistic data-structure used to |
| /// test set membership with a possibility of false positive matches. |
| /// |
| /// Create a new KuduBloomFilter using @c KuduBloomFilterBuilder class and |
| /// populate column values that need to be scanned using |
| /// @c KuduBloomFilter::Insert() function. |
| /// |
| /// Supply the populated KuduBloomFilter to |
| /// @c KuduTable::NewInBloomFilterPredicate() to create an IN Bloom filter |
| /// predicate. |
| class KUDU_EXPORT KuduBloomFilter { |
| public: |
| ~KuduBloomFilter(); |
| |
| /// Insert key to the Bloom filter. |
| /// |
| /// @param[in] key |
| /// Column value as a @c Slice to insert into the Bloom filter. |
| void Insert(const Slice& key); |
| |
| private: |
| friend class InBloomFilterPredicateData; |
| friend class KuduBloomFilterBuilder; |
| |
| class KUDU_NO_EXPORT Data; |
| |
| // Owned ptr as per the PIMPL pattern. |
| Data* data_; |
| |
| /// Clone the Bloom filter. |
| /// |
| /// @return Raw pointer to the cloned Bloom filter. Caller owns the |
| /// Bloom filter till it's passed to |
| /// @c KuduTable::NewInBloomFilterPredicate() |
| KuduBloomFilter* Clone() const; |
| |
| KuduBloomFilter(); |
| |
| /// Construct a Bloom filter from the KuduBloomFilter::Data pointer. |
| /// |
| /// @param other_data |
| /// Constructed KuduBloomFilter takes ownership of the pointer. |
| explicit KuduBloomFilter(Data* other_data); |
| |
| DISALLOW_COPY_AND_ASSIGN(KuduBloomFilter); |
| }; |
| |
| /// @brief Builder class to help build @c KuduBloomFilter to be used with |
| /// IN Bloom filter predicate. |
| class KUDU_EXPORT KuduBloomFilterBuilder { |
| public: |
| /// @param [in] num_keys |
| /// Expected number of elements to be inserted in the Bloom filter. |
| explicit KuduBloomFilterBuilder(size_t num_keys); |
| ~KuduBloomFilterBuilder(); |
| |
| /// @param [in] fpp |
| /// Desired false positive probability between 0.0 and 1.0. |
| /// If not provided, defaults to 0.01. |
| /// @return Reference to the updated object. |
| KuduBloomFilterBuilder& false_positive_probability(double fpp); |
| |
| /// @param [in] hash_algorithm |
| /// Hash algorithm used to hash keys before inserting to the Bloom filter. |
| /// If not provided, defaults to FAST_HASH. |
| /// @note Currently only FAST_HASH is supported. |
| /// @return Reference to the updated object. |
| KuduBloomFilterBuilder& hash_algorithm(HashAlgorithm hash_algorithm); |
| |
| /// @param [in] hash_seed |
| /// Seed used with hash algorithm to hash the keys before inserting to |
| /// the Bloom filter. |
| /// If not provided, defaults to 0. |
| /// @return Reference to the updated object. |
| KuduBloomFilterBuilder& hash_seed(uint32_t hash_seed); |
| |
| /// Build a new Bloom filter to be used with IN Bloom filter predicate. |
| /// |
| /// @param [out] bloom_filter |
| /// On success, the created Bloom filter raw pointer. Caller owns the Bloom |
| /// filter until it's passed to @c KuduTable::NewInBloomFilterPredicate(). |
| /// @return On success, Status::OK() with the created Bloom filter in |
| /// @c bloom_filter output parameter. On failure to allocate memory or |
| /// invalid arguments, corresponding error status. |
| Status Build(KuduBloomFilter** bloom_filter); |
| |
| private: |
| class KUDU_NO_EXPORT Data; |
| |
| // Owned ptr as per the PIMPL pattern. |
| Data* data_; |
| |
| DISALLOW_COPY_AND_ASSIGN(KuduBloomFilterBuilder); |
| }; |
| |
| } // namespace client |
| } // namespace kudu |
| #endif // KUDU_CLIENT_SCAN_PREDICATE_H |