1 | #pragma once |
2 | |
3 | #include <Common/Exception.h> |
4 | #include <Common/NamePrompter.h> |
5 | #include <Core/Types.h> |
6 | #include <Poco/String.h> |
7 | |
8 | #include <unordered_map> |
9 | |
10 | namespace DB |
11 | { |
12 | |
13 | namespace ErrorCodes |
14 | { |
15 | extern const int LOGICAL_ERROR; |
16 | } |
17 | |
18 | /** If stored objects may have several names (aliases) |
19 | * this interface may be helpful |
20 | * template parameter is available as Creator |
21 | */ |
22 | template <typename CreatorFunc> |
23 | class IFactoryWithAliases : public IHints<2, IFactoryWithAliases<CreatorFunc>> |
24 | { |
25 | protected: |
26 | using Creator = CreatorFunc; |
27 | |
28 | String getAliasToOrName(const String & name) const |
29 | { |
30 | if (aliases.count(name)) |
31 | return aliases.at(name); |
32 | else if (String name_lowercase = Poco::toLower(name); case_insensitive_aliases.count(name_lowercase)) |
33 | return case_insensitive_aliases.at(name_lowercase); |
34 | else |
35 | return name; |
36 | } |
37 | |
38 | public: |
39 | /// For compatibility with SQL, it's possible to specify that certain function name is case insensitive. |
40 | enum CaseSensitiveness |
41 | { |
42 | CaseSensitive, |
43 | CaseInsensitive |
44 | }; |
45 | |
46 | /** Register additional name for creator |
47 | * real_name have to be already registered. |
48 | */ |
49 | void registerAlias(const String & alias_name, const String & real_name, CaseSensitiveness case_sensitiveness = CaseSensitive) |
50 | { |
51 | const auto & creator_map = getCreatorMap(); |
52 | const auto & case_insensitive_creator_map = getCaseInsensitiveCreatorMap(); |
53 | const String factory_name = getFactoryName(); |
54 | |
55 | String real_dict_name; |
56 | if (creator_map.count(real_name)) |
57 | real_dict_name = real_name; |
58 | else if (auto real_name_lowercase = Poco::toLower(real_name); case_insensitive_creator_map.count(real_name_lowercase)) |
59 | real_dict_name = real_name_lowercase; |
60 | else |
61 | throw Exception(factory_name + ": can't create alias '" + alias_name + "', the real name '" + real_name + "' is not registered" , |
62 | ErrorCodes::LOGICAL_ERROR); |
63 | |
64 | String alias_name_lowercase = Poco::toLower(alias_name); |
65 | |
66 | if (creator_map.count(alias_name) || case_insensitive_creator_map.count(alias_name_lowercase)) |
67 | throw Exception( |
68 | factory_name + ": the alias name '" + alias_name + "' is already registered as real name" , ErrorCodes::LOGICAL_ERROR); |
69 | |
70 | if (case_sensitiveness == CaseInsensitive) |
71 | if (!case_insensitive_aliases.emplace(alias_name_lowercase, real_dict_name).second) |
72 | throw Exception( |
73 | factory_name + ": case insensitive alias name '" + alias_name + "' is not unique" , ErrorCodes::LOGICAL_ERROR); |
74 | |
75 | if (!aliases.emplace(alias_name, real_dict_name).second) |
76 | throw Exception(factory_name + ": alias name '" + alias_name + "' is not unique" , ErrorCodes::LOGICAL_ERROR); |
77 | } |
78 | |
79 | std::vector<String> getAllRegisteredNames() const override |
80 | { |
81 | std::vector<String> result; |
82 | auto getter = [](const auto & pair) { return pair.first; }; |
83 | std::transform(getCreatorMap().begin(), getCreatorMap().end(), std::back_inserter(result), getter); |
84 | std::transform(aliases.begin(), aliases.end(), std::back_inserter(result), getter); |
85 | return result; |
86 | } |
87 | |
88 | bool isCaseInsensitive(const String & name) const |
89 | { |
90 | String name_lowercase = Poco::toLower(name); |
91 | return getCaseInsensitiveCreatorMap().count(name_lowercase) || case_insensitive_aliases.count(name_lowercase); |
92 | } |
93 | |
94 | const String & aliasTo(const String & name) const |
95 | { |
96 | if (auto it = aliases.find(name); it != aliases.end()) |
97 | return it->second; |
98 | else if (auto jt = case_insensitive_aliases.find(Poco::toLower(name)); jt != case_insensitive_aliases.end()) |
99 | return jt->second; |
100 | |
101 | throw Exception(getFactoryName() + ": name '" + name + "' is not alias" , ErrorCodes::LOGICAL_ERROR); |
102 | } |
103 | |
104 | bool isAlias(const String & name) const |
105 | { |
106 | return aliases.count(name) || case_insensitive_aliases.count(name); |
107 | } |
108 | |
109 | virtual ~IFactoryWithAliases() override {} |
110 | |
111 | private: |
112 | using InnerMap = std::unordered_map<String, Creator>; // name -> creator |
113 | using AliasMap = std::unordered_map<String, String>; // alias -> original type |
114 | |
115 | virtual const InnerMap & getCreatorMap() const = 0; |
116 | virtual const InnerMap & getCaseInsensitiveCreatorMap() const = 0; |
117 | virtual String getFactoryName() const = 0; |
118 | |
119 | /// Alias map to data_types from previous two maps |
120 | AliasMap aliases; |
121 | |
122 | /// Case insensitive aliases |
123 | AliasMap case_insensitive_aliases; |
124 | }; |
125 | |
126 | } |
127 | |