1 | #pragma once |
2 | |
3 | #include "config_functions.h" |
4 | #if USE_SIMDJSON |
5 | |
6 | #include <common/StringRef.h> |
7 | #include <Common/Exception.h> |
8 | #include <Core/Types.h> |
9 | |
10 | #include <simdjson/jsonparser.h> |
11 | |
12 | |
13 | namespace DB |
14 | { |
15 | namespace ErrorCodes |
16 | { |
17 | extern const int CANNOT_ALLOCATE_MEMORY; |
18 | } |
19 | |
20 | /// This class can be used as an argument for the template class FunctionJSON. |
21 | /// It provides ability to parse JSONs using simdjson library. |
22 | struct SimdJSONParser |
23 | { |
24 | static constexpr bool need_preallocate = true; |
25 | |
26 | void preallocate(size_t max_size) |
27 | { |
28 | if (!pj.allocate_capacity(max_size)) |
29 | throw Exception{"Can not allocate memory for " + std::to_string(max_size) + " units when parsing JSON" , |
30 | ErrorCodes::CANNOT_ALLOCATE_MEMORY}; |
31 | } |
32 | |
33 | bool parse(const StringRef & json) { return !json_parse(json.data, json.size, pj); } |
34 | |
35 | using Iterator = simdjson::ParsedJson::Iterator; |
36 | Iterator getRoot() { return Iterator{pj}; } |
37 | |
38 | static bool isInt64(const Iterator & it) { return it.is_integer(); } |
39 | static bool isUInt64(const Iterator &) { return false; /* See https://github.com/lemire/simdjson/issues/68 */ } |
40 | static bool isDouble(const Iterator & it) { return it.is_double(); } |
41 | static bool isString(const Iterator & it) { return it.is_string(); } |
42 | static bool isArray(const Iterator & it) { return it.is_array(); } |
43 | static bool isObject(const Iterator & it) { return it.is_object(); } |
44 | static bool isBool(const Iterator & it) { return it.get_type() == 't' || it.get_type() == 'f'; } |
45 | static bool isNull(const Iterator & it) { return it.is_null(); } |
46 | |
47 | static Int64 getInt64(const Iterator & it) { return it.get_integer(); } |
48 | static UInt64 getUInt64(const Iterator &) { return 0; /* isUInt64() never returns true */ } |
49 | static double getDouble(const Iterator & it) { return it.get_double(); } |
50 | static bool getBool(const Iterator & it) { return it.get_type() == 't'; } |
51 | static StringRef getString(const Iterator & it) { return StringRef{it.get_string(), it.get_string_length()}; } |
52 | |
53 | static size_t sizeOfArray(const Iterator & it) |
54 | { |
55 | size_t size = 0; |
56 | Iterator it2 = it; |
57 | if (it2.down()) |
58 | { |
59 | do |
60 | ++size; |
61 | while (it2.next()); |
62 | } |
63 | return size; |
64 | } |
65 | |
66 | static bool firstArrayElement(Iterator & it) { return it.down(); } |
67 | |
68 | static bool arrayElementByIndex(Iterator & it, size_t index) |
69 | { |
70 | if (!it.down()) |
71 | return false; |
72 | while (index--) |
73 | if (!it.next()) |
74 | return false; |
75 | return true; |
76 | } |
77 | |
78 | static bool nextArrayElement(Iterator & it) { return it.next(); } |
79 | |
80 | static size_t sizeOfObject(const Iterator & it) |
81 | { |
82 | size_t size = 0; |
83 | Iterator it2 = it; |
84 | if (it2.down()) |
85 | { |
86 | do |
87 | ++size; |
88 | while (it2.next() && it2.next()); //-V501 |
89 | } |
90 | return size; |
91 | } |
92 | |
93 | static bool firstObjectMember(Iterator & it) { return it.down() && it.next(); } |
94 | |
95 | static bool firstObjectMember(Iterator & it, StringRef & first_key) |
96 | { |
97 | if (!it.down()) |
98 | return false; |
99 | first_key.data = it.get_string(); |
100 | first_key.size = it.get_string_length(); |
101 | return it.next(); |
102 | } |
103 | |
104 | static bool objectMemberByIndex(Iterator & it, size_t index) |
105 | { |
106 | if (!it.down()) |
107 | return false; |
108 | while (index--) |
109 | if (!it.next() || !it.next()) //-V501 |
110 | return false; |
111 | return it.next(); |
112 | } |
113 | |
114 | static bool objectMemberByName(Iterator & it, const StringRef & name) { return it.move_to_key(name.data); } |
115 | static bool nextObjectMember(Iterator & it) { return it.next() && it.next(); } //-V501 |
116 | |
117 | static bool nextObjectMember(Iterator & it, StringRef & next_key) |
118 | { |
119 | if (!it.next()) |
120 | return false; |
121 | next_key.data = it.get_string(); |
122 | next_key.size = it.get_string_length(); |
123 | return it.next(); |
124 | } |
125 | |
126 | static bool isObjectMember(const Iterator & it) { return it.get_scope_type() == '{'; } |
127 | |
128 | static StringRef getKey(const Iterator & it) |
129 | { |
130 | Iterator it2 = it; |
131 | it2.prev(); |
132 | return StringRef{it2.get_string(), it2.get_string_length()}; |
133 | } |
134 | |
135 | private: |
136 | simdjson::ParsedJson pj; |
137 | }; |
138 | |
139 | } |
140 | #endif |
141 | |