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Diffstat (limited to 'plugin/type_uuid/sql_type_uuid.h')
| -rw-r--r-- | plugin/type_uuid/sql_type_uuid.h | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/plugin/type_uuid/sql_type_uuid.h b/plugin/type_uuid/sql_type_uuid.h new file mode 100644 index 00000000000..ee39f542f05 --- /dev/null +++ b/plugin/type_uuid/sql_type_uuid.h @@ -0,0 +1,186 @@ +#ifndef SQL_TYPE_UUID_INCLUDED +#define SQL_TYPE_UUID_INCLUDED + +/* Copyright (c) 2019,2021 MariaDB Corporation + + 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +#include "sql_type_fixedbin_storage.h" +class UUID: public FixedBinTypeStorage<MY_UUID_SIZE, MY_UUID_STRING_LENGTH> +{ +public: + using FixedBinTypeStorage::FixedBinTypeStorage; + bool ascii_to_fbt(const char *str, size_t str_length); + size_t to_string(char *dst, size_t dstsize) const; + static const Name &default_value(); + + /* + Binary (in-memory) UUIDv1 representation: + + llllllll-mmmm-Vhhh-vsss-nnnnnnnnnnnn + + Binary sortable (in-record) representation: + + nnnnnnnnnnnn-vsss-Vhhh-mmmm-llllllll + + Sign Section Bits Bytes Pos PosBinSortable + ------------- ------- ---- ----- --- -------------- + llllllll time low 32 4 0 12 + mmmm time mid 16 2 4 10 + Vhhh version and time hi 16 2 6 8 + vsss variant and clock seq 16 2 8 6 + nnnnnnnnnnnn node ID 48 6 10 0 + */ + + class Segment + { + size_t m_memory_pos; + size_t m_record_pos; + size_t m_length; + public: + constexpr Segment(size_t memory_pos, size_t record_pos, size_t length) + :m_memory_pos(memory_pos), m_record_pos(record_pos), m_length(length) + { } + void memory_to_record(char *to, const char *from) const + { + memcpy(to + m_record_pos, from + m_memory_pos, m_length); + } + void record_to_memory(char *to, const char * from) const + { + memcpy(to + m_memory_pos, from + m_record_pos, m_length); + } + int cmp_memory(const char *a, const char *b) const + { + return memcmp(a + m_memory_pos, b + m_memory_pos, m_length); + } + void hash_record(const uchar *ptr, Hasher *hasher) const + { + hasher->add(&my_charset_bin, ptr + m_record_pos, m_length); + } + }; + + static const Segment & segment(uint i) + { + static Segment segments[]= + { + {0, 12, 4}, // llllllll + {4, 10, 2}, // mmmm + {6, 8, 2}, // Vhhh + {8, 6, 2}, // vsss + {10, 0, 6} // nnnnnnnnnnnn + }; + return segments[i]; + } + + // Convert the in-memory representation to the in-record representation + static void memory_to_record(char *to, const char *from) + { + segment(0).memory_to_record(to, from); + segment(1).memory_to_record(to, from); + segment(2).memory_to_record(to, from); + segment(3).memory_to_record(to, from); + segment(4).memory_to_record(to, from); + } + + // Convert the in-record representation to the in-memory representation + static void record_to_memory(char *to, const char *from) + { + segment(0).record_to_memory(to, from); + segment(1).record_to_memory(to, from); + segment(2).record_to_memory(to, from); + segment(3).record_to_memory(to, from); + segment(4).record_to_memory(to, from); + } + + /* + Calculate a hash of the in-record representation. + Used in Field_uuid::hash(), e.g. for KEY partitioning. This + makes partition distribution for UUID and BINARY(16) equal, + so for example: + + CREATE OR REPLACE TABLE t1 (c1 UUID) PARTITION BY KEY(c1) PARTITIONS 5; + INSERT INTO t1 (c1) VALUES (UUID()); + + and + + CREATE OR REPLACE TABLE t1 (c1 BINARY(16)) PARTITION BY KEY(c1) PARTITIONS 5; + INSERT INTO t1 (c1) VALUES (UUID()); + + put values into the same partition. + */ + static void hash_record(const uchar *ptr, Hasher *hasher) + { + segment(0).hash_record(ptr, hasher); + segment(1).hash_record(ptr, hasher); + segment(2).hash_record(ptr, hasher); + segment(3).hash_record(ptr, hasher); + segment(4).hash_record(ptr, hasher); + } + + // Compare two in-memory values + static int cmp(const LEX_CSTRING &a, const LEX_CSTRING &b) + { + DBUG_ASSERT(a.length == binary_length()); + DBUG_ASSERT(b.length == binary_length()); + int res; + if ((res= segment(4).cmp_memory(a.str, b.str)) || + (res= segment(3).cmp_memory(a.str, b.str)) || + (res= segment(2).cmp_memory(a.str, b.str)) || + (res= segment(1).cmp_memory(a.str, b.str)) || + (res= segment(0).cmp_memory(a.str, b.str))) + return res; + return 0; + } + + static ulong KEY_pack_flags(uint column_nr) + { + return HA_PACK_KEY; + } + + /* + Convert in-record representation to binlog representation. + We tranfer UUID values in binlog by compressing in-memory representation. + This makes replication between UUID and BINARY(16) simpler: + + Transferring by compressing the in-record representation would require + extending the binary log format to put the extact data type name into + the column metadata. + */ + static uchar *pack(uchar *to, const uchar *from, uint max_length) + { + uchar buf[binary_length()]; + record_to_memory((char *) buf, (const char *) from); + return StringPack(&my_charset_bin, binary_length()). + pack(to, buf, max_length); + } + + // Convert binlog representation to in-record representation + static const uchar *unpack(uchar *to, + const uchar *from, const uchar *from_end, + uint param_data) + { + uchar buf[binary_length()]; + const uchar *rc= StringPack(&my_charset_bin, binary_length()). + unpack(buf, from, from_end, param_data); + memory_to_record((char *) to, (const char *) buf); + return rc; + } + +}; + + +#include "sql_type_fixedbin.h" +typedef FixedBinTypeBundle<UUID> UUIDBundle; + +#endif // SQL_TYPE_UUID_INCLUDED |