/usr/share/gocode/src/github.com/DCSO/bloom/bloom_test.go is in golang-github-dcso-bloom-dev 0.2.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 | // DCSO go bloom filter
// Copyright (c) 2017, DCSO GmbH
package bloom
import (
"bytes"
"io/ioutil"
"log"
"math"
"math/rand"
"os"
"path/filepath"
"strings"
"testing"
)
func TestInitialization(t *testing.T) {
filter := Initialize(10000, 0.001)
if filter.k != 10 {
t.Error("k does not match expectation!")
}
if filter.m != 143775 {
t.Error("m does not match expectation: ", filter.m)
}
if filter.M != uint32(math.Ceil(float64(filter.m)/64)) {
t.Error("M does not match expectation: ", filter.M)
}
for i := uint32(0); i < filter.M; i++ {
if filter.v[i] != 0 {
t.Error("Filter value is not initialized to zero!")
}
}
}
func checkFilters(a BloomFilter, b BloomFilter, t *testing.T) bool {
if b.n != a.n ||
b.p != a.p ||
b.k != a.k ||
b.m != a.m ||
b.M != a.M ||
bytes.Compare(b.Data, a.Data) != 0 {
return false
}
for i := uint32(0); i < a.M; i++ {
if a.v[i] != b.v[i] {
return false
}
}
return true
}
func serializeToBuffer(filter BloomFilter) (*BloomFilter, error) {
var buf bytes.Buffer
filter.Write(&buf)
var newFilter BloomFilter
newFilter.Read(&buf)
return &newFilter, nil
}
func serializeToDisk(filter BloomFilter) (*BloomFilter, error) {
tempFile, err := ioutil.TempFile("", "filter")
if err != nil {
return nil, err
}
defer os.Remove(tempFile.Name())
filter.Write(tempFile)
tempFile.Sync()
tempFile.Seek(0, 0)
var newFilter BloomFilter
err = newFilter.Read(tempFile)
if err != nil {
return nil, err
}
return &newFilter, nil
}
func TestSerialization(t *testing.T) {
capacity := uint32(100000)
p := float64(0.01)
samples := uint32(1000)
filter, _ := GenerateExampleFilter(capacity, p, samples)
newFilter, err := serializeToBuffer(filter)
if err != nil {
t.Error("Cannot serialize filter to buffer!")
return
}
if !checkFilters(filter, *newFilter, t) {
t.Error("Filters do not match!")
}
newFilter, err = serializeToDisk(filter)
if err != nil {
t.Error("Cannot serialize filter to file!")
return
}
if !checkFilters(filter, *newFilter, t) {
t.Error("Filters do not match!")
}
filter.Add(GenerateTestValue(100))
newFilter.Add(GenerateTestValue(100))
newFilter, err = serializeToDisk(filter)
if err != nil {
t.Error("Cannot serialize filter to disk!")
return
}
if !checkFilters(filter, *newFilter, t) {
t.Error("Filters do not match!")
}
filter.Add(GenerateTestValue(100))
newFilter.Add(GenerateTestValue(100))
newFilter, err = serializeToDisk(filter)
if err != nil {
t.Error("Cannot serialize filter to disk!")
return
}
if !checkFilters(filter, *newFilter, t) {
t.Error("Filters do not match!")
}
checkFilters(filter, *newFilter, t)
}
func TestSerializationToDisk(t *testing.T) {
capacity := uint32(100000)
p := float64(0.001)
samples := uint32(1000)
filter, _ := GenerateExampleFilter(capacity, p, samples)
var buf bytes.Buffer
filter.Write(&buf)
var newFilter BloomFilter
newFilter.Read(&buf)
checkFilters(filter, newFilter, t)
}
func TestSerializationWriteFail(t *testing.T) {
capacity := uint32(100000)
p := float64(0.001)
samples := uint32(1000)
filter, _ := GenerateExampleFilter(capacity, p, samples)
dir, err := ioutil.TempDir("", "bloomtest")
if err != nil {
log.Fatal(err)
}
defer os.RemoveAll(dir)
tmpfn := filepath.Join(dir, "tmpfile")
tmpfile, err := os.OpenFile(tmpfn, os.O_CREATE|os.O_RDONLY, 0000)
if err != nil {
t.Fatal(err)
}
defer tmpfile.Close()
err = filter.Write(tmpfile)
if err == nil {
t.Error("writing to read-only file should fail")
}
}
func TestSerializationReadFail(t *testing.T) {
var newFilter BloomFilter
dir, err := ioutil.TempDir("", "bloomtest")
if err != nil {
log.Fatal(err)
}
defer os.RemoveAll(dir)
tmpfn := filepath.Join(dir, "tmpfile")
tmpfile, err := os.OpenFile(tmpfn, os.O_CREATE, 0777)
if err != nil {
t.Fatal(err)
}
defer tmpfile.Close()
err = newFilter.Read(tmpfile)
if err == nil {
t.Error("reading from empty file should fail")
}
}
func GenerateTestValue(length uint32) []byte {
value := make([]byte, length)
for i := uint32(0); i < length; i++ {
value[i] = byte(rand.Int() % 256)
}
return value
}
func GenerateExampleFilter(capacity uint32, p float64, samples uint32) (BloomFilter, [][]byte) {
filter := Initialize(capacity, p)
filter.Data = []byte("foobar")
testValues := make([][]byte, 0, samples)
for i := uint32(0); i < samples; i++ {
testValue := GenerateTestValue(100)
testValues = append(testValues, testValue)
filter.Add(testValue)
}
return filter, testValues
}
func GenerateDisjointExampleFilter(capacity uint32, p float64, samples uint32, other BloomFilter) (BloomFilter, [][]byte) {
filter := Initialize(capacity, p)
testValues := make([][]byte, 0, samples)
for i := uint32(0); i < samples; {
testValue := GenerateTestValue(100)
if !other.Check(testValue) {
testValues = append(testValues, testValue)
filter.Add(testValue)
i++
}
}
return filter, testValues
}
//This tests the checking of values against a given filter
func TestChecking(t *testing.T) {
capacity := uint32(100000)
p := float64(0.001)
samples := uint32(100000)
filter, testValues := GenerateExampleFilter(capacity, p, samples)
fingerprint := make([]uint32, filter.k)
for _, value := range testValues {
filter.Fingerprint(value, fingerprint)
if !filter.CheckFingerprint(fingerprint) {
t.Error("Did not find test value in filter!")
}
}
}
//This tests the checking of values against a given filter after resetting it
func TestReset(t *testing.T) {
capacity := uint32(100000)
p := float64(0.001)
samples := uint32(100000)
filter, testValues := GenerateExampleFilter(capacity, p, samples)
filter.Reset()
fingerprint := make([]uint32, filter.k)
for _, value := range testValues {
filter.Fingerprint(value, fingerprint)
if filter.CheckFingerprint(fingerprint) {
t.Error("Did not find test value in filter!")
}
}
}
//This tests the checking of values against a given filter
//see https://en.wikipedia.org/wiki/Bloom_filter#Probability_of_false_positives
func TestFalsePositives(t *testing.T) {
capacity := uint32(10000)
p := float64(0.001)
fillingFactor := 0.9
N := uint32(float64(capacity) * fillingFactor)
filter, _ := GenerateExampleFilter(capacity, p, N)
pAcceptable := math.Pow(1-math.Exp(-float64(filter.k)*float64(N)/float64(filter.m)), float64(filter.k))
fingerprint := make([]uint32, filter.k)
cnt := 0.0
matches := 0.0
for {
cnt++
value := GenerateTestValue(100)
filter.Fingerprint(value, fingerprint)
if filter.CheckFingerprint(fingerprint) {
matches++
}
if cnt > float64(capacity)*10 {
break
}
}
//this might still fail sometimes...
//we allow for a probability that is two times higher than the normally acceptable probability
if matches/cnt > pAcceptable*2 {
t.Error("False positive probability is too high at ", matches/cnt*100, "% vs ", pAcceptable*100, "%")
}
}
func TestJoiningRegularMisdimensioned(t *testing.T) {
a := Initialize(100000, 0.0001)
b := Initialize(10000, 0.0001)
err := a.Join(&b)
if err == nil {
t.Error("joining filters with different capacity should fail")
}
if !strings.Contains(err.Error(), "different dimensions") {
t.Error("wrong error message returned")
}
a = Initialize(100000, 0.0001)
b = Initialize(100000, 0.001)
err = a.Join(&b)
if err == nil {
t.Error("joining filters with different FP prob should fail")
}
if !strings.Contains(err.Error(), "different dimensions") {
t.Error("wrong error message returned")
}
a = Initialize(100000, 0.0001)
b = Initialize(100000, 0.0001)
b.k = 1
err = a.Join(&b)
if err == nil {
t.Error("joining filters with different number of hash funcs should fail")
}
if !strings.Contains(err.Error(), "different dimensions") {
t.Error("wrong error message returned")
}
a = Initialize(100000, 0.0001)
b = Initialize(100000, 0.0001)
b.m = 1
err = a.Join(&b)
if err == nil {
t.Error("joining filters with different number of bits should fail")
}
if !strings.Contains(err.Error(), "different dimensions") {
t.Error("wrong error message returned")
}
a = Initialize(100000, 0.0001)
b = Initialize(100000, 0.0001)
b.M = 1
err = a.Join(&b)
if err == nil {
t.Error("joining filters with different int array size should fail")
}
if !strings.Contains(err.Error(), "different dimensions") {
t.Error("wrong error message returned")
}
}
func TestAccessors(t *testing.T) {
a, _ := GenerateExampleFilter(100000, 0.0001, 10000)
if a.MaxNumElements() != 100000 {
t.Error("unexpected capacity in filter")
}
if a.NumBits() != 1917011 {
t.Error("unexpected number of bits in filter")
}
if a.NumHashFuncs() != 14 {
t.Error("unexpected number of hash funcs in filter")
}
if a.FalsePositiveProb() != 0.0001 {
t.Error("unexpected FP prob in filter")
}
}
func TestJoiningRegular(t *testing.T) {
a, aval := GenerateExampleFilter(100000, 0.0001, 10000)
b, bval := GenerateDisjointExampleFilter(100000, 0.0001, 20000, a)
for _, v := range bval {
if a.Check(v) {
t.Errorf("value not missing in joined filter: %s", string(v))
}
}
if a.N != 10000 {
t.Error("unexpected number of elements in filter")
}
if b.N != 20000 {
t.Error("unexpected number of elements in filter")
}
err := a.Join(&b)
if a.N != 30000 {
t.Errorf("unexpected number of elements in filter")
}
if err != nil {
t.Fatal(err)
}
for _, v := range aval {
if !a.Check(v) {
t.Errorf("value not found in joined filter: %s", string(v))
}
}
for _, v := range bval {
if !a.Check(v) {
t.Errorf("value not found in joined filter: %s", string(v))
}
}
}
//This benchmarks the checking of values against a given filter
func BenchmarkChecking(b *testing.B) {
capacity := uint32(1e9)
p := float64(0.001)
samples := uint32(100000)
filter, testValues := GenerateExampleFilter(capacity, p, samples)
fingerprint := make([]uint32, filter.k)
b.ResetTimer()
for i := 0; i < b.N; i++ {
value := testValues[rand.Int()%len(testValues)]
filter.Fingerprint(value, fingerprint)
if !filter.CheckFingerprint(fingerprint) {
b.Error("Did not find test value in filter!")
}
}
}
//This benchmarks the checking without using a fixed fingerprint variable (instead a temporary variable is created each time)
func BenchmarkSimpleChecking(b *testing.B) {
capacity := uint32(1e9)
p := float64(0.001)
samples := uint32(100000)
filter, testValues := GenerateExampleFilter(capacity, p, samples)
b.ResetTimer()
for i := 0; i < b.N; i++ {
value := testValues[rand.Int()%len(testValues)]
if !filter.Check(value) {
b.Error("Did not find test value in filter!")
}
}
}
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