diff options
Diffstat (limited to 'common/probdist/weighted_dist_test.go')
-rw-r--r-- | common/probdist/weighted_dist_test.go | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/common/probdist/weighted_dist_test.go b/common/probdist/weighted_dist_test.go new file mode 100644 index 0000000..b705add --- /dev/null +++ b/common/probdist/weighted_dist_test.go @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2014, Yawning Angel <yawning at torproject dot org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +package probdist + +import ( + "fmt" + "testing" + + "git.torproject.org/pluggable-transports/obfs4.git/common/drbg" +) + +const debug = false + +func TestWeightedDist(t *testing.T) { + seed, err := drbg.NewSeed() + if err != nil { + t.Fatal("failed to generate a DRBG seed:", err) + } + + const nrTrials = 1000000 + + hist := make([]int, 1000) + + w := New(seed, 0, 999, true) + if debug { + // Dump a string representation of the probability table. + fmt.Println("Table:") + var sum float64 + for _, weight := range w.weights { + sum += weight + } + for i, weight := range w.weights { + p := weight / sum + if p > 0.000001 { // Filter out tiny values. + fmt.Printf(" [%d]: %f\n", w.minValue+w.values[i], p) + } + } + fmt.Println() + } + + for i := 0; i < nrTrials; i++ { + value := w.Sample() + hist[value]++ + } + + if debug { + fmt.Println("Generated:") + for value, count := range hist { + if count != 0 { + p := float64(count) / float64(nrTrials) + fmt.Printf(" [%d]: %f (%d)\n", value, p, count) + } + } + } +} |