Add parsing of mysql json object with string values(0xc)

- Added parsing of mysql binary wrt KEY_ENTRY_SIZE and VALUE_ENTRY_SIZE
of json object only (@todo- json array)
- Added parsing of string value  (@todo- add new function)
- (todo- add all other types supported by mysql)
- @todos- after review
- Output:
```
(gdb) p buffer->Ptr
$1 = 0x7fffe004ae48 "key1:val1,key2:val2"
```

1 files changed, 52 insertions, 2 deletions

diff --git a/sql/mysql_json.cc b/sql/mysql_json.cc
index 25d8f5cf44c..78fdfe6134f 100644
--- a/sql/mysql_json.cc
+++ b/sql/mysql_json.cc
@@ -57,7 +57,57 @@ bool parse_array_or_object(Field_mysql_json::enum_type t, const char *data,
   // The header should not be larger than the full size of the value.
   if (header_size > *bytes)
     return true;                             /* purecov: inspected */
-  //return Value(t, data, bytes, element_count, large);
+
+
+  if (t==Field_mysql_json::enum_type::OBJECT)
+  {
+    size_t key_json_offset, key_json_start, key_json_len;
+    size_t value_type_offset, value_counter(0);
+    size_t value_length, value_length_ptr;
+    //size_t value_json_type;
+    //String *buffer=(String *)malloc(sizeof(String)); // @anel v1
+    String *buffer= new String(); // @anel v2 which construction ?
+
+    char *key_element, *value_element;  
+    for (uint i=0; i<*element_count; i++)
+    {
+      
+      key_json_offset= 2*offset_size+i*(large?KEY_ENTRY_SIZE_LARGE:KEY_ENTRY_SIZE_SMALL);
+      key_json_start= read_offset_or_size(data+key_json_offset,large);
+      key_json_len= read_offset_or_size(data+key_json_offset+offset_size, large);
+      
+      //key_element=(char *)malloc(sizeof(char)*key_json_len+1); // v1
+      key_element= new char[key_json_len+1]; // v2
+      memmove(key_element, const_cast<char*>(&data[key_json_start]),                    key_json_len);
+      key_element[key_json_len]= '\0';
+
+    // @anel method: String::apppend(const char*) is not working 
+    //keys->append((const char*)key_element); // generating error
+    //keys->append(STRING_WITH_LEN(key_element));
+
+      buffer->append(String((const char *)key_element, &my_charset_bin));
+      delete key_element;
+
+      // @anel calculate value type and get a value
+      value_type_offset= 2*offset_size+ (large?KEY_ENTRY_SIZE_LARGE:KEY_ENTRY_SIZE_SMALL)*(*element_count)+(large ? VALUE_ENTRY_SIZE_LARGE : VALUE_ENTRY_SIZE_SMALL)*value_counter;
+     // value_json_type= data[value_type_offset];
+      value_counter++;
+
+      // this will go in separete function and depens on value_json_type
+      // For now value_json_type=12(0xc) is json_object
+      value_length_ptr= read_offset_or_size(data+value_type_offset+1, large);
+      value_length= (uint) data[value_length_ptr];
+      value_element= new char[value_length+1];
+      memmove(value_element, const_cast<char*>(&data[value_length_ptr+1]),              value_length);
+      value_element[value_length]= '\0';
+      buffer->append(":");
+      buffer->append(String((const char *)value_element, &my_charset_bin));
+      delete value_element;
+      if(i!=(*element_count-1))
+        buffer->append(",");
+    }
+  }
+
   return 1;
 }
 /**
@@ -87,7 +137,7 @@ bool get_mysql_string(String* buffer, size_t type, const char *data, size_t len,
     return true;
   switch(type)
   {
-    case J_OBJECT:
+    case JSONB_TYPE_STRING:
     {
       if (buffer->append('{'))
         return true;                           /* purecov: inspected */