gpq

Thread-safe Generic Priority Queue for Golang
Usage

package gpq_test

import (
    "testing"

    "github.com/tigerinus/gpq"
)

// This is an example struct that is irrelevant to gpq
type Expirable[T any] struct {
    Data           T
    ExpirationTime int64
}

func TestPositive1(t *testing.T) {
    pq := gpq.NewPriorityQueue[Expirable[string]](func(i, j Expirable[string]) bool {
        return i.ExpirationTime > j.ExpirationTime
    })

    e1 := Expirable[string]{
        Data:           "test1",
        ExpirationTime: 1,
    }

    e2 := Expirable[string]{
        Data:           "test2",
        ExpirationTime: 2,
    }

    e3 := Expirable[string]{
        Data:           "test3",
        ExpirationTime: 3,
    }

    pq.Push(e2)
    {
        e := pq.Peek()
        if e.Data != e2.Data {
            t.Fail()
        }

        if e.ExpirationTime != e2.ExpirationTime {
            t.Fail()
        }
    }

    pq.Push(e1)
    {
        e := pq.Peek()
        if e.Data != e2.Data {
            t.Fail()
        }

        if e.ExpirationTime != e2.ExpirationTime {
            t.Fail()
        }
    }

    pq.Push(e3)
    {
        e := pq.Peek()
        if e.Data != e3.Data {
            t.Fail()
        }

        if e.ExpirationTime != e3.ExpirationTime {
            t.Fail()
        }
    }

    for i := 3; i > 0; i-- {
        if i != pq.Len() {
            t.Fail()
        }

        e := pq.Pop()

        if e.ExpirationTime != int64(i) {
            t.Fail()
        }
    }
}

func TestNegative1(t *testing.T) {
    pq := gpq.NewPriorityQueue[Expirable[string]](func(i, j Expirable[string]) bool {
        return i.ExpirationTime > j.ExpirationTime
    })

    e := pq.Peek()

    if e != nil {
        t.Fail()
    }

    e = pq.Pop()
    if e != nil {
        t.Fail()
    }
}