/usr/local/lib64/python3.6/site-packages/pyarrow/include/arrow/compute/exec
Edit: /usr/local/lib64/python3.6/site-packages/pyarrow/include/arrow/compute/exec/key_map.h (8945B)
// 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.
#pragma once
#include
#include "arrow/compute/exec/util.h"
#include "arrow/memory_pool.h"
#include "arrow/result.h"
#include "arrow/status.h"
namespace arrow {
namespace compute {
class SwissTable {
public:
SwissTable() = default;
~SwissTable() { cleanup(); }
using EqualImpl =
std::function;
using AppendImpl = std::function;
Status init(int64_t hardware_flags, MemoryPool* pool, util::TempVectorStack* temp_stack,
int log_minibatch, EqualImpl equal_impl, AppendImpl append_impl);
void cleanup();
void early_filter(const int num_keys, const uint32_t* hashes,
uint8_t* out_match_bitvector, uint8_t* out_local_slots) const;
void find(const int num_keys, const uint32_t* hashes, uint8_t* inout_match_bitvector,
const uint8_t* local_slots, uint32_t* out_group_ids) const;
Status map_new_keys(uint32_t num_ids, uint16_t* ids, const uint32_t* hashes,
uint32_t* group_ids);
private:
// Lookup helpers
/// \brief Scan bytes in block in reverse and stop as soon
/// as a position of interest is found.
///
/// Positions of interest:
/// a) slot with a matching stamp is encountered,
/// b) first empty slot is encountered,
/// c) we reach the end of the block.
///
/// Optionally an index of the first slot to start the search from can be specified.
/// In this case slots before it will be ignored.
///
/// \param[in] block 8 byte block of hash table
/// \param[in] stamp 7 bits of hash used as a stamp
/// \param[in] start_slot Index of the first slot in the block to start search from. We
/// assume that this index always points to a non-empty slot, equivalently
/// that it comes before any empty slots. (Used only by one template
/// variant.)
/// \param[out] out_slot index corresponding to the discovered position of interest (8
/// represents end of block).
/// \param[out] out_match_found an integer flag (0 or 1) indicating if we reached an
/// empty slot (0) or not (1). Therefore 1 can mean that either actual match was found
/// (case a) above) or we reached the end of full block (case b) above).
///
template
inline void search_block(uint64_t block, int stamp, int start_slot, int* out_slot,
int* out_match_found) const;
/// \brief Extract group id for a given slot in a given block.
///
inline uint64_t extract_group_id(const uint8_t* block_ptr, int slot,
uint64_t group_id_mask) const;
void extract_group_ids(const int num_keys, const uint16_t* optional_selection,
const uint32_t* hashes, const uint8_t* local_slots,
uint32_t* out_group_ids) const;
template
void extract_group_ids_imp(const int num_keys, const uint16_t* selection,
const uint32_t* hashes, const uint8_t* local_slots,
uint32_t* out_group_ids, int elements_offset,
int element_mutltiplier) const;
inline uint64_t next_slot_to_visit(uint64_t block_index, int slot,
int match_found) const;
inline uint64_t num_groups_for_resize() const;
inline uint64_t wrap_global_slot_id(uint64_t global_slot_id) const;
void init_slot_ids(const int num_keys, const uint16_t* selection,
const uint32_t* hashes, const uint8_t* local_slots,
const uint8_t* match_bitvector, uint32_t* out_slot_ids) const;
void init_slot_ids_for_new_keys(uint32_t num_ids, const uint16_t* ids,
const uint32_t* hashes, uint32_t* slot_ids) const;
// Quickly filter out keys that have no matches based only on hash value and the
// corresponding starting 64-bit block of slot status bytes. May return false positives.
//
void early_filter_imp(const int num_keys, const uint32_t* hashes,
uint8_t* out_match_bitvector, uint8_t* out_local_slots) const;
#if defined(ARROW_HAVE_AVX2)
void early_filter_imp_avx2_x8(const int num_hashes, const uint32_t* hashes,
uint8_t* out_match_bitvector,
uint8_t* out_local_slots) const;
void early_filter_imp_avx2_x32(const int num_hashes, const uint32_t* hashes,
uint8_t* out_match_bitvector,
uint8_t* out_local_slots) const;
void extract_group_ids_avx2(const int num_keys, const uint32_t* hashes,
const uint8_t* local_slots, uint32_t* out_group_ids,
int byte_offset, int byte_multiplier, int byte_size) const;
#endif
void run_comparisons(const int num_keys, const uint16_t* optional_selection_ids,
const uint8_t* optional_selection_bitvector,
const uint32_t* groupids, int* out_num_not_equal,
uint16_t* out_not_equal_selection) const;
inline bool find_next_stamp_match(const uint32_t hash, const uint32_t in_slot_id,
uint32_t* out_slot_id, uint32_t* out_group_id) const;
inline void insert_into_empty_slot(uint32_t slot_id, uint32_t hash, uint32_t group_id);
// Slow processing of input keys in the most generic case.
// Handles inserting new keys.
// Pre-existing keys will be handled correctly, although the intended use is for this
// call to follow a call to find() method, which would only pass on new keys that were
// not present in the hash table.
//
Status map_new_keys_helper(const uint32_t* hashes, uint32_t* inout_num_selected,
uint16_t* inout_selection, bool* out_need_resize,
uint32_t* out_group_ids, uint32_t* out_next_slot_ids);
// Resize small hash tables when 50% full (up to 8KB).
// Resize large hash tables when 75% full.
Status grow_double();
static int num_groupid_bits_from_log_blocks(int log_blocks) {
int required_bits = log_blocks + 3;
return required_bits <= 8 ? 8
: required_bits <= 16 ? 16 : required_bits <= 32 ? 32 : 64;
}
// Use 32-bit hash for now
static constexpr int bits_hash_ = 32;
// Number of hash bits stored in slots in a block.
// The highest bits of hash determine block id.
// The next set of highest bits is a "stamp" stored in a slot in a block.
static constexpr int bits_stamp_ = 7;
// Padding bytes added at the end of buffers for ease of SIMD access
static constexpr int padding_ = 64;
int log_minibatch_;
// Base 2 log of the number of blocks
int log_blocks_ = 0;
// Number of keys inserted into hash table
uint32_t num_inserted_ = 0;
// Data for blocks.
// Each block has 8 status bytes for 8 slots, followed by 8 bit packed group ids for
// these slots. In 8B status word, the order of bytes is reversed. Group ids are in
// normal order. There is 64B padding at the end.
//
// 0 byte - 7 bucket | 1. byte - 6 bucket | ...
// ---------------------------------------------------
// | Empty bit* | Empty bit |
// ---------------------------------------------------
// | 7-bit hash | 7-bit hash |
// ---------------------------------------------------
// * Empty bucket has value 0x80. Non-empty bucket has highest bit set to 0.
//
uint8_t* blocks_;
// Array of hashes of values inserted into slots.
// Undefined if the corresponding slot is empty.
// There is 64B padding at the end.
uint32_t* hashes_;
int64_t hardware_flags_;
MemoryPool* pool_;
util::TempVectorStack* temp_stack_;
EqualImpl equal_impl_;
AppendImpl append_impl_;
};
} // namespace compute
} // namespace arrow