path: root/core/test/scheduler-event.go

// Copyright 2018 The dexon-consensus-core Authors
// This file is part of the dexon-consensus-core library.
//
// The dexon-consensus-core library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus-core library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus-core library. If not, see
// <http://www.gnu.org/licenses/>.

package test

import (
    "time"

    "github.com/dexon-foundation/dexon-consensus-core/core/types"
)

// Event defines a scheduler event.
type Event struct {
    // HistoryIndex is the index of this event in history.
    HistoryIndex int
    // NodeID is the ID of handler that this event deginated to.
    NodeID types.NodeID
    // Time is the expected execution time of this event.
    Time time.Time
    // ExecError record the error when handling this event.
    ExecError error
    // Payload is application specific data carried by this event.
    Payload interface{}
    // ParentHistoryIndex is the index of parent event in history.
    ParentHistoryIndex int
    // ExecInterval is the latency to execute this event
    ExecInterval time.Duration
}

// eventQueue implements heap.Interface.
type eventQueue []*Event

func (eq eventQueue) Len() int { return len(eq) }

func (eq eventQueue) Less(i, j int) bool {
    return eq[i].Time.Before(eq[j].Time)
}

func (eq eventQueue) Swap(i, j int) {
    eq[i], eq[j] = eq[j], eq[i]
}

func (eq *eventQueue) Push(x interface{}) {
    *eq = append(*eq, x.(*Event))
}

func (eq *eventQueue) Pop() interface{} {
    pos := len(*eq) - 1
    item := (*eq)[pos]
    *eq = (*eq)[0:pos]
    return item
}

// NewEvent is the constructor for Event.
func NewEvent(
    nID types.NodeID, when time.Time, payload interface{}) *Event {

    return &Event{
        HistoryIndex:       -1,
        ParentHistoryIndex: -1,
        NodeID:             nID,
        Time:               when,
        Payload:            payload,
    }
}