TDigest with custom equals and hashcode implementation

[nagarajatantry]

I have a use case to compare if 2 tdigest's are equal. Was wondering if it makes sense to override the equals and hashcode functions in MergingDigest class.

Sample code

 @Override
    public boolean equals(Object o) {
        if (o == this) return true;
        if (!(o instanceof MergingDigest)) {
            return false;
        }
        MergingDigest compare = (MergingDigest) o;

        if (compare.size() != this.size()){
            return false;
        }
        byte[] bBytes = new byte[compare.byteSize()];
        compare.asBytes(ByteBuffer.wrap(bBytes));

        byte[] aBytes = new byte[this.byteSize()];
        this.asBytes(ByteBuffer.wrap(aBytes));
        return Arrays.equals(aBytes,bBytes);
    }

    @Override
    public int hashCode() {
        byte[] aBytes = new byte[this.byteSize()];
        this.asBytes(ByteBuffer.wrap(aBytes));
        String sketch = Base64.getEncoder().encodeToString(aBytes);
        return new HashCodeBuilder(17, 37)
                .append(sketch)
                .toHashCode();
    }

[tdunning]

This makes sense and could even be implemented at the level of the TDigest class itself (with the addition of a comparison on class). I don't think that it will be terribly useful, but it is a plausible definition. Do you want to create a pull request?

…

On Thu, Jul 1, 2021 at 7:48 AM Naga ***@***.***> wrote: I have a use case to compare if 2 tdigest's are equal. Was wondering if it makes sense to override the equals and hashcode functions in MergingDigest class. Sample code @OverRide public boolean equals(Object o) { if (o == this) return true; if (!(o instanceof MergingDigest)) { return false; } MergingDigest compare = (MergingDigest) o; if (compare.size() != this.size()){ return false; } byte[] bBytes = new byte[compare.byteSize()]; compare.asBytes(ByteBuffer.wrap(bBytes)); byte[] aBytes = new byte[this.byteSize()]; this.asBytes(ByteBuffer.wrap(aBytes)); return Arrays.equals(aBytes,bBytes); } @OverRide public int hashCode() { byte[] aBytes = new byte[this.byteSize()]; this.asBytes(ByteBuffer.wrap(aBytes)); String sketch = Base64.getEncoder().encodeToString(aBytes); return new HashCodeBuilder(17, 37) .append(sketch) .toHashCode(); } — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#176>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAB5E6XPFX4PVRX4SSFIVPLTVR55HANCNFSM47U4FJKA> .

[nagarajatantry]

Thank you. I will send a PR