path: root/swarm/storage/feed/lookup/lookup_test.go

// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum 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 go-ethereum 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 go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package lookup_test

import (
    "fmt"
    "math/rand"
    "testing"

    "github.com/dexon-foundation/dexon/swarm/log"
    "github.com/dexon-foundation/dexon/swarm/storage/feed/lookup"
)

type Data struct {
    Payload uint64
    Time    uint64
}

type Store map[lookup.EpochID]*Data

func write(store Store, epoch lookup.Epoch, value *Data) {
    log.Debug("Write: %d-%d, value='%d'\n", epoch.Base(), epoch.Level, value.Payload)
    store[epoch.ID()] = value
}

func update(store Store, last lookup.Epoch, now uint64, value *Data) lookup.Epoch {
    epoch := lookup.GetNextEpoch(last, now)

    write(store, epoch, value)

    return epoch
}

const Day = 60 * 60 * 24
const Year = Day * 365
const Month = Day * 30

func makeReadFunc(store Store, counter *int) lookup.ReadFunc {
    return func(epoch lookup.Epoch, now uint64) (interface{}, error) {
        *counter++
        data := store[epoch.ID()]
        var valueStr string
        if data != nil {
            valueStr = fmt.Sprintf("%d", data.Payload)
        }
        log.Debug("Read: %d-%d, value='%s'\n", epoch.Base(), epoch.Level, valueStr)
        if data != nil && data.Time <= now {
            return data, nil
        }
        return nil, nil
    }
}

func TestLookup(t *testing.T) {

    store := make(Store)
    readCount := 0
    readFunc := makeReadFunc(store, &readCount)

    // write an update every month for 12 months 3 years ago and then silence for two years
    now := uint64(1533799046)
    var epoch lookup.Epoch

    var lastData *Data
    for i := uint64(0); i < 12; i++ {
        t := uint64(now - Year*3 + i*Month)
        data := Data{
            Payload: t, //our "payload" will be the timestamp itself.
            Time:    t,
        }
        epoch = update(store, epoch, t, &data)
        lastData = &data
    }

    // try to get the last value

    value, err := lookup.Lookup(now, lookup.NoClue, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    readCountWithoutHint := readCount

    if value != lastData {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", lastData, value)
    }

    // reset the read count for the next test
    readCount = 0
    // Provide a hint to get a faster lookup. In particular, we give the exact location of the last update
    value, err = lookup.Lookup(now, epoch, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    if value != lastData {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", lastData, value)
    }

    if readCount > readCountWithoutHint {
        t.Fatalf("Expected lookup to complete with fewer or same reads than %d since we provided a hint. Did %d reads.", readCountWithoutHint, readCount)
    }

    // try to get an intermediate value
    // if we look for a value in now - Year*3 + 6*Month, we should get that value
    // Since the "payload" is the timestamp itself, we can check this.

    expectedTime := now - Year*3 + 6*Month

    value, err = lookup.Lookup(expectedTime, lookup.NoClue, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    data, ok := value.(*Data)

    if !ok {
        t.Fatal("Expected value to contain data")
    }

    if data.Time != expectedTime {
        t.Fatalf("Expected value timestamp to be %d, got %d", data.Time, expectedTime)
    }

}

func TestOneUpdateAt0(t *testing.T) {

    store := make(Store)
    readCount := 0

    readFunc := makeReadFunc(store, &readCount)
    now := uint64(1533903729)

    var epoch lookup.Epoch
    data := Data{
        Payload: 79,
        Time:    0,
    }
    update(store, epoch, 0, &data)

    value, err := lookup.Lookup(now, lookup.NoClue, readFunc)
    if err != nil {
        t.Fatal(err)
    }
    if value != &data {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", data, value)
    }
}

// Tests the update is found even when a bad hint is given
func TestBadHint(t *testing.T) {

    store := make(Store)
    readCount := 0

    readFunc := makeReadFunc(store, &readCount)
    now := uint64(1533903729)

    var epoch lookup.Epoch
    data := Data{
        Payload: 79,
        Time:    0,
    }

    // place an update for t=1200
    update(store, epoch, 1200, &data)

    // come up with some evil hint
    badHint := lookup.Epoch{
        Level: 18,
        Time:  1200000000,
    }

    value, err := lookup.Lookup(now, badHint, readFunc)
    if err != nil {
        t.Fatal(err)
    }
    if value != &data {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", data, value)
    }
}

func TestLookupFail(t *testing.T) {

    store := make(Store)
    readCount := 0

    readFunc := makeReadFunc(store, &readCount)
    now := uint64(1533903729)

    // don't write anything and try to look up.
    // we're testing we don't get stuck in a loop

    value, err := lookup.Lookup(now, lookup.NoClue, readFunc)
    if err != nil {
        t.Fatal(err)
    }
    if value != nil {
        t.Fatal("Expected value to be nil, since the update should've failed")
    }

    expectedReads := now/(1<<lookup.HighestLevel) + 1
    if uint64(readCount) != expectedReads {
        t.Fatalf("Expected lookup to fail after %d reads. Did %d reads.", expectedReads, readCount)
    }
}

func TestHighFreqUpdates(t *testing.T) {

    store := make(Store)
    readCount := 0

    readFunc := makeReadFunc(store, &readCount)
    now := uint64(1533903729)

    // write an update every second for the last 1000 seconds
    var epoch lookup.Epoch

    var lastData *Data
    for i := uint64(0); i <= 994; i++ {
        T := uint64(now - 1000 + i)
        data := Data{
            Payload: T, //our "payload" will be the timestamp itself.
            Time:    T,
        }
        epoch = update(store, epoch, T, &data)
        lastData = &data
    }

    value, err := lookup.Lookup(lastData.Time, lookup.NoClue, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    if value != lastData {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", lastData, value)
    }

    readCountWithoutHint := readCount
    // reset the read count for the next test
    readCount = 0
    // Provide a hint to get a faster lookup. In particular, we give the exact location of the last update
    value, err = lookup.Lookup(now, epoch, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    if value != lastData {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", lastData, value)
    }

    if readCount > readCountWithoutHint {
        t.Fatalf("Expected lookup to complete with fewer or equal reads than %d since we provided a hint. Did %d reads.", readCountWithoutHint, readCount)
    }

    for i := uint64(0); i <= 994; i++ {
        T := uint64(now - 1000 + i) // update every second for the last 1000 seconds
        value, err := lookup.Lookup(T, lookup.NoClue, readFunc)
        if err != nil {
            t.Fatal(err)
        }
        data, _ := value.(*Data)
        if data == nil {
            t.Fatalf("Expected lookup to return %d, got nil", T)
        }
        if data.Payload != T {
            t.Fatalf("Expected lookup to return %d, got %d", T, data.Time)
        }
    }
}

func TestSparseUpdates(t *testing.T) {

    store := make(Store)
    readCount := 0
    readFunc := makeReadFunc(store, &readCount)

    // write an update every 5 years 3 times starting in Jan 1st 1970 and then silence

    now := uint64(1533799046)
    var epoch lookup.Epoch

    var lastData *Data
    for i := uint64(0); i < 5; i++ {
        T := uint64(Year * 5 * i) // write an update every 5 years 3 times starting in Jan 1st 1970 and then silence
        data := Data{
            Payload: T, //our "payload" will be the timestamp itself.
            Time:    T,
        }
        epoch = update(store, epoch, T, &data)
        lastData = &data
    }

    // try to get the last value

    value, err := lookup.Lookup(now, lookup.NoClue, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    readCountWithoutHint := readCount

    if value != lastData {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", lastData, value)
    }

    // reset the read count for the next test
    readCount = 0
    // Provide a hint to get a faster lookup. In particular, we give the exact location of the last update
    value, err = lookup.Lookup(now, epoch, readFunc)
    if err != nil {
        t.Fatal(err)
    }

    if value != lastData {
        t.Fatalf("Expected lookup to return the last written value: %v. Got %v", lastData, value)
    }

    if readCount > readCountWithoutHint {
        t.Fatalf("Expected lookup to complete with fewer reads than %d since we provided a hint. Did %d reads.", readCountWithoutHint, readCount)
    }

}

// testG will hold precooked test results
// fields are abbreviated to reduce the size of the literal below
type testG struct {
    e lookup.Epoch // last
    n uint64       // next level
    x uint8        // expected result
}

// test cases
var testGetNextLevelCases []testG = []testG{{e: lookup.Epoch{Time: 989875233, Level: 12}, n: 989875233, x: 11}, {e: lookup.Epoch{Time: 995807650, Level: 18}, n: 995598156, x: 19}, {e: lookup.Epoch{Time: 969167082, Level: 0}, n: 968990357, x: 18}, {e: lookup.Epoch{Time: 993087628, Level: 14}, n: 992987044, x: 20}, {e: lookup.Epoch{Time: 963364631, Level: 20}, n: 963364630, x: 19}, {e: lookup.Epoch{Time: 963497510, Level: 16}, n: 963370732, x: 18}, {e: lookup.Epoch{Time: 955421349, Level: 22}, n: 955421348, x: 21}, {e: lookup.Epoch{Time: 968220379, Level: 15}, n: 968220378, x: 14}, {e: lookup.Epoch{Time: 939129014, Level: 6}, n: 939128771, x: 11}, {e: lookup.Epoch{Time: 907847903, Level: 6}, n: 907791833, x: 18}, {e: lookup.Epoch{Time: 910835564, Level: 15}, n: 910835564, x: 14}, {e: lookup.Epoch{Time: 913578333, Level: 22}, n: 881808431, x: 25}, {e: lookup.Epoch{Time: 895818460, Level: 3}, n: 895818132, x: 9}, {e: lookup.Epoch{Time: 903843025, Level: 24}, n: 895609561, x: 23}, {e: lookup.Epoch{Time: 877889433, Level: 13}, n: 877877093, x: 15}, {e: lookup.Epoch{Time: 901450396, Level: 10}, n: 901450058, x: 9}, {e: lookup.Epoch{Time: 925179910, Level: 3}, n: 925168393, x: 16}, {e: lookup.Epoch{Time: 913485477, Level: 21}, n: 913485476, x: 20}, {e: lookup.Epoch{Time: 924462991, Level: 18}, n: 924462990, x: 17}, {e: lookup.Epoch{Time: 941175128, Level: 13}, n: 941175127, x: 12}, {e: lookup.Epoch{Time: 920126583, Level: 3}, n: 920100782, x: 19}, {e: lookup.Epoch{Time: 932403200, Level: 9}, n: 932279891, x: 17}, {e: lookup.Epoch{Time: 948284931, Level: 2}, n: 948284921, x: 9}, {e: lookup.Epoch{Time: 953540997, Level: 7}, n: 950547986, x: 22}, {e: lookup.Epoch{Time: 926639837, Level: 18}, n: 918608882, x: 24}, {e: lookup.Epoch{Time: 954637598, Level: 1}, n: 954578761, x: 17}, {e: lookup.Epoch{Time: 943482981, Level: 10}, n: 942924151, x: 19}, {e: lookup.Epoch{Time: 963580771, Level: 7}, n: 963580771, x: 6}, {e: lookup.Epoch{Time: 993744930, Level: 7}, n: 993690858, x: 16}, {e: lookup.Epoch{Time: 1018890213, Level: 12}, n: 1018890212, x: 11}, {e: lookup.Epoch{Time: 1030309411, Level: 2}, n: 1030309227, x: 9}, {e: lookup.Epoch{Time: 1063204997, Level: 20}, n: 1063204996, x: 19}, {e: lookup.Epoch{Time: 1094340832, Level: 6}, n: 1094340633, x: 7}, {e: lookup.Epoch{Time: 1077880597, Level: 10}, n: 1075914292, x: 20}, {e: lookup.Epoch{Time: 1051114957, Level: 18}, n: 1051114957, x: 17}, {e: lookup.Epoch{Time: 1045649701, Level: 22}, n: 1045649700, x: 21}, {e: lookup.Epoch{Time: 1066198885, Level: 14}, n: 1066198884, x: 13}, {e: lookup.Epoch{Time: 1053231952, Level: 1}, n: 1053210845, x: 16}, {e: lookup.Epoch{Time: 1068763404, Level: 14}, n: 1068675428, x: 18}, {e: lookup.Epoch{Time: 1039042173, Level: 15}, n: 1038973110, x: 17}, {e: lookup.Epoch{Time: 1050747636, Level: 6}, n: 1050747364, x: 9}, {e: lookup.Epoch{Time: 1030034434, Level: 23}, n: 1030034433, x: 22}, {e: lookup.Epoch{Time: 1003783425, Level: 18}, n: 1003783424, x: 17}, {e: lookup.Epoch{Time: 988163976, Level: 15}, n: 988084064, x: 17}, {e: lookup.Epoch{Time: 1007222377, Level: 15}, n: 1007222377, x: 14}, {e: lookup.Epoch{Time: 1001211375, Level: 13}, n: 1001208178, x: 14}, {e: lookup.Epoch{Time: 997623199, Level: 8}, n: 997623198, x: 7}, {e: lookup.Epoch{Time: 1026283830, Level: 10}, n: 1006681704, x: 24}, {e: lookup.Epoch{Time: 1019421907, Level: 20}, n: 1019421906, x: 19}, {e: lookup.Epoch{Time: 1043154306, Level: 16}, n: 1043108343, x: 16}, {e: lookup.Epoch{Time: 1075643767, Level: 17}, n: 1075325898, x: 18}, {e: lookup.Epoch{Time: 1043726309, Level: 20}, n: 1043726308, x: 19}, {e: lookup.Epoch{Time: 1056415324, Level: 17}, n: 1056415324, x: 16}, {e: lookup.Epoch{Time: 1088650219, Level: 13}, n: 1088650218, x: 12}, {e: lookup.Epoch{Time: 1088551662, Level: 7}, n: 1088543355, x: 13}, {e: lookup.Epoch{Time: 1069667265, Level: 6}, n: 1069667075, x: 7}, {e: lookup.Epoch{Time: 1079145970, Level: 18}, n: 1079145969, x: 17}, {e: lookup.Epoch{Time: 1083338876, Level: 7}, n: 1083338875, x: 6}, {e: lookup.Epoch{Time: 1051581086, Level: 4}, n: 1051568869, x: 14}, {e: lookup.Epoch{Time: 1028430882, Level: 4}, n: 1028430864, x: 5}, {e: lookup.Epoch{Time: 1057356462, Level: 1}, n: 1057356417, x: 5}, {e: lookup.Epoch{Time: 1033104266, Level: 0}, n: 1033097479, x: 13}, {e: lookup.Epoch{Time: 1031391367, Level: 11}, n: 1031387304, x: 14}, {e: lookup.Epoch{Time: 1049781164, Level: 15}, n: 1049781163, x: 14}, {e: lookup.Epoch{Time: 1027271628, Level: 12}, n: 1027271627, x: 11}, {e: lookup.Epoch{Time: 1057270560, Level: 23}, n: 1057270560, x: 22}, {e: lookup.Epoch{Time: 1047501317, Level: 15}, n: 1047501317, x: 14}, {e: lookup.Epoch{Time: 1058349035, Level: 11}, n: 1045175573, x: 24}, {e: lookup.Epoch{Time: 1057396147, Level: 20}, n: 1057396147, x: 19}, {e: lookup.Epoch{Time: 1048906375, Level: 18}, n: 1039616919, x: 25}, {e: lookup.Epoch{Time: 1074294831, Level: 20}, n: 1074294831, x: 19}, {e: lookup.Epoch{Time: 1088946052, Level: 1}, n: 1088917364, x: 14}, {e: lookup.Epoch{Time: 1112337595, Level: 17}, n: 1111008110, x: 22}, {e: lookup.Epoch{Time: 1099990284, Level: 5}, n: 1099968370, x: 15}, {e: lookup.Epoch{Time: 1087036441, Level: 16}, n: 1053967855, x: 25}, {e: lookup.Epoch{Time: 1069225185, Level: 8}, n: 1069224660, x: 10}, {e: lookup.Epoch{Time: 1057505479, Level: 9}, n: 1057505170, x: 14}, {e: lookup.Epoch{Time: 1072381377, Level: 12}, n: 1065950959, x: 22}, {e: lookup.Epoch{Time: 1093887139, Level: 8}, n: 1093863305, x: 14}, {e: lookup.Epoch{Time: 1082366510, Level: 24}, n: 1082366510, x: 23}, {e: lookup.Epoch{Time: 1103231132, Level: 14}, n: 1102292201, x: 22}, {e: lookup.Epoch{Time: 1094502355, Level: 3}, n: 1094324652, x: 18}, {e: lookup.Epoch{Time: 1068488344, Level: 12}, n: 1067577330, x: 19}, {e: lookup.Epoch{Time: 1050278233, Level: 12}, n: 1050278232, x: 11}, {e: lookup.Epoch{Time: 1047660768, Level: 5}, n: 1047652137, x: 17}, {e: lookup.Epoch{Time: 1060116167, Level: 11}, n: 1060114091, x: 12}, {e: lookup.Epoch{Time: 1068149392, Level: 21}, n: 1052074801, x: 24}, {e: lookup.Epoch{Time: 1081934120, Level: 6}, n: 1081933847, x: 8}, {e: lookup.Epoch{Time: 1107943693, Level: 16}, n: 1107096139, x: 25}, {e: lookup.Epoch{Time: 1131571649, Level: 9}, n: 1131570428, x: 11}, {e: lookup.Epoch{Time: 1123139367, Level: 0}, n: 1122912198, x: 20}, {e: lookup.Epoch{Time: 1121144423, Level: 6}, n: 1120568289, x: 20}, {e: lookup.Epoch{Time: 1089932411, Level: 17}, n: 1089932410, x: 16}, {e: lookup.Epoch{Time: 1104899012, Level: 22}, n: 1098978789, x: 22}, {e: lookup.Epoch{Time: 1094588059, Level: 21}, n: 1094588059, x: 20}, {e: lookup.Epoch{Time: 1114987438, Level: 24}, n: 1114987437, x: 23}, {e: lookup.Epoch{Time: 1084186305, Level: 7}, n: 1084186241, x: 6}, {e: lookup.Epoch{Time: 1058827111, Level: 8}, n: 1058826504, x: 9}, {e: lookup.Epoch{Time: 1090679810, Level: 12}, n: 1090616539, x: 17}, {e: lookup.Epoch{Time: 1084299475, Level: 23}, n: 1084299475, x: 22}}

func TestGetNextLevel(t *testing.T) {

    // First, test well-known cases
    last := lookup.Epoch{
        Time:  1533799046,
        Level: 5,
    }

    level := lookup.GetNextLevel(last, last.Time)
    expected := uint8(4)
    if level != expected {
        t.Fatalf("Expected GetNextLevel to return %d for same-time updates at a nonzero level, got %d", expected, level)
    }

    level = lookup.GetNextLevel(last, last.Time+(1<<lookup.HighestLevel)+3000)
    expected = lookup.HighestLevel
    if level != expected {
        t.Fatalf("Expected GetNextLevel to return %d for updates set 2^lookup.HighestLevel seconds away, got %d", expected, level)
    }

    level = lookup.GetNextLevel(last, last.Time+(1<<last.Level))
    expected = last.Level
    if level != expected {
        t.Fatalf("Expected GetNextLevel to return %d for updates set 2^last.Level seconds away, got %d", expected, level)
    }

    last.Level = 0
    level = lookup.GetNextLevel(last, last.Time)
    expected = 0
    if level != expected {
        t.Fatalf("Expected GetNextLevel to return %d for same-time updates at a zero level, got %d", expected, level)
    }

    // run a batch of 100 cooked tests
    for _, s := range testGetNextLevelCases {
        level := lookup.GetNextLevel(s.e, s.n)
        if level != s.x {
            t.Fatalf("Expected GetNextLevel to return %d for last=%s when now=%d, got %d", s.x, s.e.String(), s.n, level)
        }
    }

}

// cookGetNextLevelTests is used to generate a deterministic
// set of cases for TestGetNextLevel and thus "freeze" its current behavior
func CookGetNextLevelTests(t *testing.T) {
    st := ""
    var last lookup.Epoch
    last.Time = 1000000000
    var now uint64
    var expected uint8
    for i := 0; i < 100; i++ {
        last.Time += uint64(rand.Intn(1<<26)) - (1 << 25)
        last.Level = uint8(rand.Intn(25))
        v := last.Level + uint8(rand.Intn(lookup.HighestLevel))
        if v > lookup.HighestLevel {
            v = 0
        }
        now = last.Time + uint64(rand.Intn(1<<v+1)) - (1 << v)
        expected = lookup.GetNextLevel(last, now)
        st = fmt.Sprintf("%s,testG{e:lookup.Epoch{Time:%d, Level:%d}, n:%d, x:%d}", st, last.Time, last.Level, now, expected)
    }
    fmt.Println(st)
}