polardbxengine/storage/xengine/index/xdb_index_merge.h

295 lines
11 KiB
C++

/*
Portions Copyright (c) 2020, Alibaba Group Holding Limited
Copyright (c) 2016, Facebook, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#pragma once
/* MySQL header files */
#include "sql/log.h"
#include "handler.h" /* handler */
//#include "./my_global.h" /* ulonglong */
/* C++ standard header files */
#include <queue>
#include <set>
#include <vector>
/* XENGINE header files */
#include "xengine/db.h"
/* MyX header files */
#include "./xdb_comparator.h"
namespace myx {
/*
Length of delimiters used during inplace index creation.
*/
#define XDB_MERGE_CHUNK_LEN sizeof(size_t)
#define XDB_MERGE_REC_DELIMITER sizeof(size_t)
#define XDB_MERGE_KEY_DELIMITER XDB_MERGE_REC_DELIMITER
#define XDB_MERGE_VAL_DELIMITER XDB_MERGE_REC_DELIMITER
class Xdb_key_def;
class Xdb_tbl_def;
class Xdb_index_merge {
Xdb_index_merge(const Xdb_index_merge &p) = delete;
Xdb_index_merge &operator=(const Xdb_index_merge &p) = delete;
public:
/* Information about temporary files used in external merge sort */
struct merge_file_info {
File fd = -1; /* file descriptor */
ulong num_sort_buffers; /* number of sort buffers in temp file */
};
/* Buffer for sorting in main memory. */
struct merge_buf_info {
/* heap memory allocated for main memory sort/merge */
//std::unique_ptr<uchar[]> block;
uchar* block;
const ulonglong
block_len; /* amount of data bytes allocated for block above */
ulonglong curr_offset; /* offset of the record pointer for the block */
ulonglong disk_start_offset; /* where the chunk starts on disk */
ulonglong disk_curr_offset; /* current offset on disk */
ulonglong total_size; /* total # of data bytes in chunk */
void store_key_value(const xengine::common::Slice &key, const xengine::common::Slice &val)
MY_ATTRIBUTE((__nonnull__));
void store_slice(const xengine::common::Slice &slice) MY_ATTRIBUTE((__nonnull__));
size_t prepare(File fd, ulonglong f_offset) MY_ATTRIBUTE((__nonnull__));
int read_next_chunk_from_disk(File fd)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
inline bool is_chunk_finished() const {
return curr_offset + disk_curr_offset - disk_start_offset == total_size;
}
inline bool has_space(uint64 needed) const {
return curr_offset + needed <= block_len;
}
explicit merge_buf_info(const ulonglong merge_block_size)
: block(nullptr), block_len(merge_block_size), curr_offset(0),
disk_start_offset(0), disk_curr_offset(0),
total_size(merge_block_size) {
/* Will throw an exception if it runs out of memory here */
//block = std::unique_ptr<uchar[]>(new uchar[merge_block_size]);
block = static_cast<uchar *>(xengine::memory::base_malloc(merge_block_size, xengine::memory::ModId::kDDLSort));
/* Initialize entire buffer to 0 to avoid valgrind errors */
memset(block, 0, merge_block_size);
}
~merge_buf_info()
{
xengine::memory::base_free(block);
block = nullptr;
}
void clear() {
curr_offset = 0;
disk_start_offset = 0;
disk_curr_offset = 0;
total_size = block_len;
}
};
/* Represents an entry in the heap during merge phase of external sort */
struct merge_heap_entry {
std::shared_ptr<merge_buf_info> chunk_info; /* pointer to buffer info */
uchar *block; /* pointer to heap memory where record is stored */
const xengine::util::Comparator *const comparator;
xengine::common::Slice key; /* current key pointed to by block ptr */
xengine::common::Slice val;
size_t prepare(File fd, ulonglong f_offset, ulonglong chunk_size)
MY_ATTRIBUTE((__nonnull__));
int read_next_chunk_from_disk(File fd)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int read_rec(xengine::common::Slice *const key, xengine::common::Slice *const val)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int read_slice(xengine::common::Slice *const slice, const uchar **block_ptr)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
explicit merge_heap_entry(const xengine::util::Comparator *const comparator)
: chunk_info(nullptr), block(nullptr), comparator(comparator) {}
};
struct merge_heap_comparator {
bool operator()(const std::shared_ptr<merge_heap_entry> &lhs,
const std::shared_ptr<merge_heap_entry> &rhs) {
return lhs->comparator->Compare(rhs->key, lhs->key) < 0;
}
};
struct merge_record {
uchar *block; /* points to offset of key in sort buffer */
// const xengine::util::Comparator *const comparator;
// bool operator<(const merge_record &record) const {
// return merge_record_compare(this->block, record.block, comparator) < 0;
// }
merge_record(uchar *const block/*,
const xengine::util::Comparator *const comparator*/)
: block(block)/*, comparator(comparator) */{}
};
class Bg_merge {
private:
std::shared_ptr<Xdb_index_merge> m_xdb_merge;
std::vector<struct merge_file_info> m_sorted_files;
merge_buf_info m_buf;
std::vector<merge_heap_entry> m_entries;
std::vector<ulong> m_read_sort_buffers;
std::atomic<bool> m_interrupt{false};
const ulonglong m_buf_size;
size_t m_curr_part = 0;
bool m_exit_interrupt = false;
int write_buf();
int xdb_merge_sort(std::vector<xengine::common::Slice>& sample,
THD *mysql_thd);
int prepare_entry(size_t part_id);
public:
Bg_merge(const std::shared_ptr<Xdb_index_merge>& xdb_merge,
size_t max_partition_num) : m_xdb_merge(xdb_merge),
m_sorted_files(max_partition_num),
m_buf(xdb_merge->m_merge_buf_size),
m_read_sort_buffers(max_partition_num, 0),
m_buf_size(xdb_merge->m_merge_buf_size) {
for (size_t i = 0; i < max_partition_num; i++) {
m_entries.emplace_back(xdb_merge->m_comparator);
}
}
~Bg_merge();
int init() MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int merge(std::vector<xengine::common::Slice>& sample, THD *mysql_thd);
int next(xengine::common::Slice *const key,
xengine::common::Slice *const val, size_t part_id);
void set_interrupt() { m_interrupt = true; }
bool get_interrupt() { return m_exit_interrupt; }
};
private:
const char *m_tmpfile_path;
const ulonglong m_merge_buf_size;
const ulonglong m_merge_combine_read_size;
const xengine::util::Comparator *m_comparator;
struct merge_file_info m_merge_file;
std::shared_ptr<merge_buf_info> m_rec_buf_unsorted;
std::shared_ptr<merge_buf_info> m_output_buf;
std::vector<merge_record> m_offset_array;
std::priority_queue<std::shared_ptr<merge_heap_entry>,
std::vector<std::shared_ptr<merge_heap_entry>>,
merge_heap_comparator>
m_merge_min_heap;
bool m_buf_sorted = false;
xengine::common::Slice m_dup_key;
xengine::common::Slice m_dup_val;
bool m_has_dup_key = false;
// used for sample key deep_copy
std::shared_ptr<xengine::util::Arena> m_arena;
std::vector<xengine::common::Slice> m_sample;
std::function<bool(const struct merge_record&, const struct merge_record&)>
merge_record_compare_check_dup;
int m_point_per_block;
const size_t m_sample_mem_limit;
static inline void merge_store_uint64(uchar *const dst, uint64 n) {
memcpy(dst, &n, sizeof(n));
}
static inline void merge_read_uint64(const uchar **buf_ptr,
uint64 *const dst) {
DBUG_ASSERT(buf_ptr != nullptr);
memcpy(dst, *buf_ptr, sizeof(uint64));
*buf_ptr += sizeof(uint64);
}
static inline xengine::common::Slice as_slice(const uchar *block) {
uint64 len;
merge_read_uint64(&block, &len);
return xengine::common::Slice(reinterpret_cast<const char *>(block), len);
}
static int merge_record_compare(const uchar *a_block, const uchar *b_block,
const xengine::util::Comparator *const comparator)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
void merge_read_rec(const uchar *const block, xengine::common::Slice *const key,
xengine::common::Slice *const val) MY_ATTRIBUTE((__nonnull__));
void read_slice(xengine::common::Slice *slice, const uchar *block_ptr)
MY_ATTRIBUTE((__nonnull__));
public:
Xdb_index_merge(const char *const tmpfile_path, const ulonglong merge_buf_size,
const ulonglong merge_combine_read_size,
const xengine::util::Comparator *const comparator,
int point_per_block = 0, const size_t sample_mem_limit = 0);
~Xdb_index_merge();
int init() MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int merge_file_create(struct merge_file_info& file_info)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int add(const xengine::common::Slice &key, const xengine::common::Slice &val, bool &inserted)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int merge_buf_write() MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int next(xengine::common::Slice *const key, xengine::common::Slice *const val)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
int merge_heap_prepare() MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
void merge_heap_top(xengine::common::Slice *key, xengine::common::Slice *val)
MY_ATTRIBUTE((__nonnull__));
int merge_heap_pop_and_get_next(xengine::common::Slice *const key,
xengine::common::Slice *const val)
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
void merge_reset();
MY_ATTRIBUTE((__nonnull__, __warn_unused_result__));
void set_collect_sample(int point_per_block) {
m_point_per_block = point_per_block;}
void get_sample(std::vector<xengine::common::Slice>& sample);
xengine::common::Slice get_dup_key() { return m_dup_key; }
xengine::common::Slice get_dup_val() { return m_dup_val; }
};
} // namespace myx