ISSUES-2973 support nested json struct for visitParamExtractRaw

dbms/src/Functions/FunctionsVisitParam.h

@@ -87,45 +87,47 @@ struct ExtractBool
 
 struct ExtractRaw
 {
-    inline static void skipAfterQuotationIfNeed(const UInt8 *& pos, const UInt8 * end, ColumnString::Chars_t & res_data)
-    {
-        if (pos + 1 < end && pos[1] == '"')
-        {
-            res_data.push_back(*pos);
-            ++pos;
-        }
-    }
+    static constexpr size_t bytes_on_stack = 64;
+    using ExpectChars = PODArray<char, bytes_on_stack, AllocatorWithStackMemory<Allocator<false>, bytes_on_stack>>;
 
     static void extract(const UInt8 * pos, const UInt8 * end, ColumnString::Chars_t & res_data)
     {
-        std::vector<char> expect_end;
+        ExpectChars expects_end;
+        UInt8 current_expect_end = 0;
 
-        for (; pos != end; ++pos)
+        for (auto extract_begin = pos; pos != end; ++pos)
         {
-            if (!expect_end.empty() && *pos == expect_end.back())
-                expect_end.pop_back();
+            if (*pos == current_expect_end)
+            {
+                expects_end.pop_back();
+                current_expect_end = (UInt8) (expects_end.empty() ? 0 : expects_end.back());
+            }
             else
             {
-                switch (*pos)
+                switch(*pos)
                 {
-                    case '[': 
-                        expect_end.push_back(']'); 
+                    case '[':
+                        expects_end.push_back((current_expect_end = ']'));
                         break;
-                    case '{': 
-                        expect_end.push_back('}'); 
+                    case '{':
+                        expects_end.push_back((current_expect_end = '}'));
                         break;
-                    case '"': 
-                        expect_end.push_back('"'); 
+                    case '"' :
+                        expects_end.push_back((current_expect_end = '"'));
                         break;
-                    case '\\': 
-                        skipAfterQuotationIfNeed(pos, end, res_data);
+                    case '\\':
+                        /// skip backslash
+                        if (pos + 1 < end && pos[1] == '"')
+                            pos++;
                         break;
                     default:
-                        if (expect_end.empty() && (*pos == ',' || *pos == '}'))
+                        if (!current_expect_end && (*pos == ',' || *pos == '}'))
+                        {
+                            res_data.insert(extract_begin, pos);
                             return;
+                        }
                 }
             }
-            res_data.push_back(*pos);
         }
     }
 };

dbms/tests/performance/functions_json/visit_param_extract_raw.xml

@@ -27,5 +27,5 @@
        </substitution>
     </substitutions>
 
-    <query>SELECT count() FROM system.numbers WHERE NOT ignore(visitParamExtractRaw({param}, 'myparam'))</query>
+    <query>SELECT count() FROM system.numbers WHERE NOT ignore(visitParamExtractRaw(materialize({param}), 'myparam'))</query>
 </test>

dbms/tests/queries/0_stateless/00539_functions_for_working_with_json.reference

@@ -9,5 +9,5 @@ test"string
  "test_string"
  "test\\"string"
  "test\\"string"
- [1,2,3]
+ ["]", "2", "3"]
  {"nested" : [1,2,3]}

dbms/tests/queries/0_stateless/00539_functions_for_working_with_json.sql

@@ -11,5 +11,5 @@ SELECT visitParamExtractRaw('{"myparam":"test_string"}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": "test_string"}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": "test\\"string"}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": "test\\"string", "other":123}', 'myparam');
-SELECT visitParamExtractRaw('{"myparam": [1,2,3], "other":123}', 'myparam');
+SELECT visitParamExtractRaw('{"myparam": ["]", "2", "3"], "other":123}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": {"nested" : [1,2,3]}, "other":123}', 'myparam');