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authorGravatar Abseil Team <absl-team@google.com>2021-05-10 12:57:06 -0700
committerGravatar vslashg <gfalcon@google.com>2021-05-11 09:59:12 -0400
commit7ba826e50dff1878e6ecc6b9af44097c040c8968 (patch)
treea465938ae07904733beafdaa830866dbe8cbc7ac /absl/random/discrete_distribution_test.cc
parent079cf662544a14bd1cfaae6d6512645541ba10fb (diff)
Export of internal Abseil changes
-- 5f3c139695d5c497ca030e95a607537a7be7caa7 by Benjamin Barenblat <bbaren@google.com>: Don’t examine irrelevant destination buckets in DiscreteDistributionTest Abseil generates discrete distributions using Walker’s aliasing algorithm. This creates uniformly distributed buckets, each with a probability of sending traffic to a different bucket. Abseil represents a bucket as a pair (probability of retaining traffic × alternate bucket if traffic is passed) and a distribution as a vector of such pairs. For example, {(0.3, 1), (1.0, 1)} represents a distribution with two buckets, the zeroth of which passes 70% of its traffic to bucket 1 and the first of which holds on to all its traffic. This representation is not unique: When a bucket retains traffic with probability 1, the alternate bucket is irrelevant. Continuing the example above, {(0.3, 1), (1.0, 0)} _also_ represents a two-bucket distribution where the zeroth bucket passes 70% of its traffic to the first and the first hangs on to all traffic. Exactly what representation Abseil generates for a given input is related to how much precision is used in intermediate floating-point operations, which is an architectural implementation detail. Remove sensitivity to that detail by not examining the alternate bucket when the retention probability is 1.0. PiperOrigin-RevId: 372993410 -- 062ac80699f748831c09a061538abffec2cdea5c by Martijn Vels <mvels@google.com>: Avoid alredy sampled cord remaining sampled if not picked or source is sampled PiperOrigin-RevId: 372985990 -- a9f3537e1110b7bb6450fd72a03f0c5dc6b8c89b by Evan Brown <ezb@google.com>: Add tests for function pointer comparators, comparators that have SFINAE-visible comparison operators that are unimplemented, and for implicit construction from unadapted comparators. PiperOrigin-RevId: 372927616 GitOrigin-RevId: 5f3c139695d5c497ca030e95a607537a7be7caa7 Change-Id: I996a8452e7bd88f9dd2e59633b01bbc09f42620d
Diffstat (limited to 'absl/random/discrete_distribution_test.cc')
-rw-r--r--absl/random/discrete_distribution_test.cc7
1 files changed, 4 insertions, 3 deletions
diff --git a/absl/random/discrete_distribution_test.cc b/absl/random/discrete_distribution_test.cc
index 6d007006..415b14cc 100644
--- a/absl/random/discrete_distribution_test.cc
+++ b/absl/random/discrete_distribution_test.cc
@@ -99,6 +99,7 @@ TYPED_TEST(DiscreteDistributionTypeTest, Constructor) {
}
TEST(DiscreteDistributionTest, InitDiscreteDistribution) {
+ using testing::_;
using testing::Pair;
{
@@ -111,8 +112,8 @@ TEST(DiscreteDistributionTest, InitDiscreteDistribution) {
// Each bucket is p=1/3, so bucket 0 will send half it's traffic
// to bucket 2, while the rest will retain all of their traffic.
EXPECT_THAT(q, testing::ElementsAre(Pair(0.5, 2), //
- Pair(1.0, 1), //
- Pair(1.0, 2)));
+ Pair(1.0, _), //
+ Pair(1.0, _)));
}
{
@@ -135,7 +136,7 @@ TEST(DiscreteDistributionTest, InitDiscreteDistribution) {
EXPECT_THAT(q, testing::ElementsAre(Pair(b0, 3), //
Pair(b1, 3), //
- Pair(1.0, 2), //
+ Pair(1.0, _), //
Pair(b3, 2), //
Pair(b1, 3)));
}