[Bug]: Performance degradation observed in Ballerina version 2201.8.5 compared to 2201.8.4

[gabilang]

Description

A slowness is observed in the version 2201.8.5 when using fromJsonWithType() for binding a large json to a record. It's taking much time for conversion than 2201.8.4

Steps to Reproduce

import ballerina/io;
import ballerina/time;


public type Person record {
    int id;
    string name;
    int age;
    string address;
    string? email;
    string? contact;
    string qualification;
    boolean isEmployed;
    decimal salary;
    boolean married;
    string? spouse;
    string[]? children;
};

public function main() returns error? {
    json responseJson = check io:fileReadJson("./random_data.json");
    time:Utc startTime = time:utcNow();
    Person[] _ = check responseJson.fromJsonWithType();
    time:Utc endTime = time:utcNow();
    time:Seconds difference = time:utcDiffSeconds(endTime, startTime);
    io:println("Time taken to parse the JSON: ", difference);
}

Output with 2201.8.5 ->

Time taken to parse the JSON: 7.038689

Output with 2201.8.4 ->

Time taken to parse the JSON: 0.235574

random_data.json

No response

Affected Version(s)

No response

OS, DB, other environment details and versions

No response

Related area

-> Runtime

Related issue(s) (optional)

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Suggested label(s) (optional)

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Suggested assignee(s) (optional)

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[gabilang]

Changes introduced with the PR #41936 caused this.
In the above PR, a fix has been introduced by making a shallow copy of unresolvedValues set, which can cause performance implications depending on the size of the unresolvedValues set.

[gabilang]

The fix added with the PR #41936 tries to address the following problem.

import ballerina/io;

type Element record {|
    Element ...;
|};

type A record {|
    *Element;
|};

type B record {|
    *Element;
|};

type C record {|
    *Element;
    D d;
|};

type D record {|
    *Element;
    string display?;
|};

type U A|B|C;


public function main() returns error? {
    json val = {
        "d": {
            "display": "hello"
        }
    };

    U u = check val.cloneWithType();
    io:println(u);
}

which gives

error: {ballerina/lang.value}ConversionError {"message":"'map<json>' value cannot be converted to 'Element': 
                value of field 'display' adding to the record 'Element' should be of type 'Element', found '"hello"'"}

But, defining the type U as type U A|C|B; or type U C|A|B; is not giving the error.

[gabilang]

With the introduced fix the observed average time taken for conversion is 0.223682.

[github-actions]

This issue is NOT closed with a proper Reason/ label. Make sure to add proper reason label before closing. Please add or leave a comment with the proper reason label now.

      - Reason/EngineeringMistake - The issue occurred due to a mistake made in the past.
      - Reason/Regression - The issue has introduced a regression.
      - Reason/MultipleComponentInteraction - Issue occured due to interactions in multiple components.
      - Reason/Complex - Issue occurred due to complex scenario.
      - Reason/Invalid - Issue is invalid.
      - Reason/Other - None of the above cases.