Tian Jiang created THRIFT-5483:
----------------------------------
Summary: Support customized comparator in Java
Key: THRIFT-5483
URL: https://issues.apache.org/jira/browse/THRIFT-5483
Project: Thrift
Issue Type: Improvement
Reporter: Tian Jiang
The generated comparator (and hash code) of Thrift Structs compares two objects
by all of their fields, which may cause trouble when used in hash structures.
For example, I defined a struct like:
{code:thrift}
struct Person{
1: required i64 id
2: required string phoneNumber
}
{code}
The id of a Person is final, while its phoneNumber can be changed.
Then I use it as a key in a map to record a Person's supervisors:
{code:java}
Map<Person, Person> supervisorMap;
{code}
Apparently, as the generated comparator of Person will use both id and
phoneNumber for comparison and hash so if I change the phoneNumber of a Person,
I can no longer get it from the map as its hash value changes and it will be
distributed to another hash slot.
Therefore, I wish I could specify the fields that are to be used in comparator
and hash code generation. One preferable grammar may be like:
{code:thrift}
struct Person{
1: required comparable i64 id
2: required string phoneNumber
}
{code}
Then the generated comparator and hash code will only use fields marked with
`comparable`, and if no fields are marked with comparable, Java's default
comparison and hashcode (using object address) will be used.
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
