diff options
Diffstat (limited to 'sql/sql_type_json.cc')
| -rw-r--r-- | sql/sql_type_json.cc | 224 |
1 files changed, 212 insertions, 12 deletions
diff --git a/sql/sql_type_json.cc b/sql/sql_type_json.cc index a804366ec03..c12b868e6b9 100644 --- a/sql/sql_type_json.cc +++ b/sql/sql_type_json.cc @@ -1,5 +1,5 @@ /* - Copyright (c) 2019, MariaDB + Copyright (c) 2019, 2021 MariaDB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License @@ -20,17 +20,111 @@ #include "sql_class.h" -Type_handler_json_longtext type_handler_json_longtext; +Named_type_handler<Type_handler_string_json> + type_handler_string_json("char/json"); + +Named_type_handler<Type_handler_varchar_json> + type_handler_varchar_json("varchar/json"); + +Named_type_handler<Type_handler_tiny_blob_json> + type_handler_tiny_blob_json("tinyblob/json"); + +Named_type_handler<Type_handler_blob_json> + type_handler_blob_json("blob/json"); + +Named_type_handler<Type_handler_medium_blob_json> + type_handler_medium_blob_json("mediumblob/json"); + +Named_type_handler<Type_handler_long_blob_json> + type_handler_long_blob_json("longblob/json"); + + +// Convert general purpose string type handlers to their JSON counterparts +const Type_handler * +Type_handler_json_common::json_type_handler_from_generic(const Type_handler *th) +{ + // Test in the order of likelyhood. + if (th == &type_handler_long_blob) + return &type_handler_long_blob_json; + if (th == &type_handler_varchar) + return &type_handler_varchar_json; + if (th == &type_handler_blob) + return &type_handler_blob_json; + if (th == &type_handler_tiny_blob) + return &type_handler_tiny_blob_json; + if (th == &type_handler_medium_blob) + return &type_handler_medium_blob_json; + if (th == &type_handler_string) + return &type_handler_string_json; + DBUG_ASSERT(is_json_type_handler(th)); + return th; +} + + +/* + This method resembles what Type_handler::string_type_handler() + does for general purpose string type handlers. +*/ +const Type_handler * +Type_handler_json_common::json_type_handler(uint max_octet_length) +{ + if (max_octet_length >= 16777216) + return &type_handler_long_blob_json; + else if (max_octet_length >= 65536) + return &type_handler_medium_blob_json; + else if (max_octet_length >= MAX_FIELD_VARCHARLENGTH) + return &type_handler_blob_json; + return &type_handler_varchar_json; +} + + +/* + This method resembles what Field_blob::type_handler() + does for general purpose BLOB type handlers. +*/ +const Type_handler * +Type_handler_json_common::json_blob_type_handler_by_length_bytes(uint len) +{ + switch (len) { + case 1: return &type_handler_tiny_blob_json; + case 2: return &type_handler_blob_json; + case 3: return &type_handler_medium_blob_json; + } + return &type_handler_long_blob_json; +} + + +/* + This method resembles what Item_sum_group_concat::type_handler() + does for general purpose string type handlers. +*/ +const Type_handler * +Type_handler_json_common::json_type_handler_sum(const Item_sum *item) +{ + if (item->too_big_for_varchar()) + return &type_handler_blob_json; + return &type_handler_varchar_json; +} + + +bool Type_handler_json_common::has_json_valid_constraint(const Field *field) +{ + return field->check_constraint && + field->check_constraint->expr && + field->check_constraint->expr->type() == Item::FUNC_ITEM && + static_cast<const Item_func *>(field->check_constraint->expr)-> + functype() == Item_func::JSON_VALID_FUNC; +} /** Create JSON_VALID(field_name) expression */ + Virtual_column_info * -Type_handler_json_longtext::make_json_valid_expr(THD *thd, - const LEX_CSTRING *field_name) - const +Type_handler_json_common::make_json_valid_expr(THD *thd, + const LEX_CSTRING *field_name) { Lex_ident_sys_st str; Item *field, *expr; @@ -46,12 +140,118 @@ Type_handler_json_longtext::make_json_valid_expr(THD *thd, } -bool Type_handler_json_longtext:: - Column_definition_validate_check_constraint(THD *thd, - Column_definition * c) const +bool Type_handler_json_common::make_json_valid_expr_if_needed(THD *thd, + Column_definition *c) +{ + return !c->check_constraint && + !(c->check_constraint= make_json_valid_expr(thd, &c->field_name)); +} + + +class Type_collection_json: public Type_collection +{ + const Type_handler *aggregate_common(const Type_handler *a, + const Type_handler *b) const + { + if (a == b) + return a; + if (a == &type_handler_null) + return b; + if (b == &type_handler_null) + return a; + return NULL; + } + + /* + Aggregate two JSON type handlers for result. + If one of the handlers is not JSON, NULL is returned. + */ + const Type_handler *aggregate_json_for_result(const Type_handler *a, + const Type_handler *b) const + { + if (!Type_handler_json_common::is_json_type_handler(a) || + !Type_handler_json_common::is_json_type_handler(b)) + return NULL; + // Here we have two JSON data types. Let's aggregate their base types. + const Type_handler *a0= a->type_handler_base(); + const Type_handler *b0= b->type_handler_base(); + // Base types are expected to belong to type_collection_std: + DBUG_ASSERT(a0->type_collection() == type_handler_null.type_collection()); + DBUG_ASSERT(b0->type_collection() == type_handler_null.type_collection()); + const Type_handler *c= a0->type_collection()->aggregate_for_result(a0, b0); + return Type_handler_json_common::json_type_handler_from_generic(c); + } +public: + const Type_handler *aggregate_for_result(const Type_handler *a, + const Type_handler *b) + const override + { + const Type_handler *h; + if ((h= aggregate_common(a, b)) || + (h= aggregate_json_for_result(a, b))) + return h; + /* + One of the types is not JSON. + Let the caller aggregate according to the derived rules: + COALESCE(VARCHAR/JSON, TEXT) -> COALESCE(VARCHAR, TEXT) + */ + return NULL; + } + + const Type_handler *aggregate_for_min_max(const Type_handler *a, + const Type_handler *b) + const override + { + /* + No JSON specific rules. + Let the caller aggregate according to the derived rules: + LEAST(VARCHAR/JSON, TEXT/JSON) -> LEAST(VARCHAR, TEXT) + */ + return NULL; + } + + const Type_handler *aggregate_for_comparison(const Type_handler *a, + const Type_handler *b) + const override + { + /* + All JSON types return &type_handler_long_blob + in type_handler_for_comparison(). We should not get here. + */ + DBUG_ASSERT(0); + return NULL; + } + + const Type_handler *aggregate_for_num_op(const Type_handler *a, + const Type_handler *b) + const override + { + /* + No JSON specific rules. + Let the caller aggregate according to the derived rules: + (VARCHAR/JSON + TEXT/JSON) -> (VARCHAR + TEXT) + */ + return NULL; + } + + const Type_handler *handler_by_name(const LEX_CSTRING &name) const override + { + /* + Name resolution is not needed yet. + JSON is not fully pluggable at the moment: + - It is parsed using a hard-coded rule in sql_yacc.yy + - It does not store extended data type information into + FRM file yet. JSON is detected by CHECK(JSON_VALID(col)) + and this detection is also hard-coded. + This will change in the future. + */ + return NULL; + } +}; + + +const Type_collection *Type_handler_json_common::type_collection() { - if (!c->check_constraint && - !(c->check_constraint= make_json_valid_expr(thd, &c->field_name))) - return true; - return Type_handler::Column_definition_validate_check_constraint(thd, c); + static Type_collection_json type_collection_json; + return &type_collection_json; } |