Skip to content

[Link event damping] Add utility methods. #1313

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kcudnik merged 1 commit into from
Oct 25, 2023
Merged

[Link event damping] Add utility methods. #1313

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
39 changes: 39 additions & 0 deletions lib/Utils.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,8 @@ extern "C" {
#include "meta/sai_serialize.h"
#include "swss/logger.h"

#include <cmath>

using namespace sairedis;

void Utils::clearOidList(
Expand Down Expand Up @@ -80,3 +82,40 @@ void Utils::clearOidValues(

}
}

uint64_t Utils::timeToReachTargetValueUsingHalfLife(
_In_ uint64_t halfLifeUsec,
_In_ uint32_t initialValue,
_In_ uint32_t targetValue)
{
SWSS_LOG_ENTER();

// Check if all the input fields have positive values and targeted value is
// smaller than initial value.
if ((initialValue == 0) || (targetValue == 0) ||
(targetValue >= initialValue) || (halfLifeUsec == 0))
{
return 0;
}

// t = -half_life * log2[N(t)/N(0)] from half-life formula "N(t) = N(0) * 2 ^ (-t / half_life)"
return uint64_t(-double(halfLifeUsec) * (log(double(targetValue)/double(initialValue))/log(2.0)));
}

uint32_t Utils::valueAfterDecay(
_In_ uint64_t timeToDecayUsec,
_In_ uint64_t halfLifeUsec,
_In_ uint32_t initialValue)
{
SWSS_LOG_ENTER();

if ((initialValue == 0) || (timeToDecayUsec == 0) || (halfLifeUsec == 0))
{
return initialValue;
}

// Using half-life formula: N(t) = N(0) * 2 ^ (-t / half_life)
double ratio = double(timeToDecayUsec)/double(halfLifeUsec);

return uint32_t(double(initialValue) * pow(0.5, ratio));
}
11 changes: 11 additions & 0 deletions lib/Utils.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,5 +33,16 @@ namespace sairedis

static void clearOidList(
_Out_ sai_object_list_t& list);

static uint64_t timeToReachTargetValueUsingHalfLife(
_In_ uint64_t halfLifeUsec,
_In_ uint32_t initialValue,
_In_ uint32_t targetValue);

static uint32_t valueAfterDecay(
_In_ uint64_t timeToDecayUsec,
_In_ uint64_t halfLifeUsec,
_In_ uint32_t initialValue);

};
}
110 changes: 110 additions & 0 deletions unittest/lib/TestUtils.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@

#include <gtest/gtest.h>

#include <vector>

using namespace sairedis;

TEST(Utils, clearOidValues)
Expand Down Expand Up @@ -59,3 +61,111 @@ TEST(Utils, clearOidValues)
EXPECT_EQ(oids[0], 0);

}

struct ExpectedTimeToReachTargetData
{
uint64_t half_life_usec;
uint32_t initial_value;
uint32_t target_value;
uint64_t expected_time_to_reach_target_usec;
};

TEST(Utils, TimeToReachTargetValueUsingHalfLifeWithInvalidInput)
{
std::vector<struct ExpectedTimeToReachTargetData> testData = {
/*Invalid input when initial value is 0.*/ {5, 0, 10, 0},
/*Invalid input when target value is 0.*/ {5, 10, 0, 0},
/*Invalid input when target value is more than initial value.*/
{5, 5, 10, 0},
/*Invalid input when initial value is same as target value.*/
{5, 10, 10, 0},
/*Invalid input when half life duration is 0.*/ {0, 15, 10, 0}};

for (const auto &data : testData)
{
SCOPED_TRACE(::testing::Message()
<< "Testing half life(usec): " << data.half_life_usec
<< ", initial value: " << data.initial_value
<< ", final value: " << data.target_value
<< ", expected_time_to_reach_target(usec): "
<< data.expected_time_to_reach_target_usec);

EXPECT_EQ(Utils::timeToReachTargetValueUsingHalfLife(
data.half_life_usec, data.initial_value, data.target_value),
data.expected_time_to_reach_target_usec);
}
}

TEST(Utils, VerifyTimeToReachTargetValueUsingHalfLife)
{
std::vector<struct ExpectedTimeToReachTargetData> testData = {
{30000000, 4500, 500, 95097750}, {30000000, 4500, 1100, 60972644},
{30000000, 4500, 1700, 42131707}, {8000000, 17000, 1300, 29671609},
{8000000, 17000, 350, 44816288}, {8000000, 1532, 311, 18403438},
{8000000, 1532, 1, 84649604}, {5000000, 20000, 2500, 15000000},
{5000000, 20000, 133, 36162149}, {30000000, 2000, 1500, 12451124}};

for (const auto &data : testData)
{
SCOPED_TRACE(::testing::Message()
<< "Testing half life(usec): " << data.half_life_usec
<< ", initial value: " << data.initial_value
<< ", final value: " << data.target_value
<< ", expected_time_to_reach_target(usec): "
<< data.expected_time_to_reach_target_usec);

EXPECT_EQ(Utils::timeToReachTargetValueUsingHalfLife(
data.half_life_usec, data.initial_value, data.target_value),
data.expected_time_to_reach_target_usec);
}
}

struct ValueAFterDecayData
{
uint64_t time_to_decay_usec;
uint32_t half_life_usec;
uint32_t initial_value;
uint32_t expected_target_value;
};

TEST(Utils, ValueAfterDecayWithInvalidInput)
{
std::vector<struct ValueAFterDecayData> test_data = {
/*Invalid input when time to decay duration is 0.*/ {0, 5, 10, 10},
/*Invalid input when half life is 0.*/ {5, 0, 10, 10},
/*Invalid input when initial value is 0.*/ {5, 5, 0, 0}};

for (const auto &data : test_data)
{
SCOPED_TRACE(::testing::Message()
<< "Testing time to decay(usec): " << data.time_to_decay_usec
<< ", half life(usec): " << data.half_life_usec
<< ", initial value: " << data.initial_value
<< ", expected target value: " << data.expected_target_value);

EXPECT_EQ(Utils::valueAfterDecay(
data.time_to_decay_usec, data.half_life_usec, data.initial_value),
data.expected_target_value);
}
}

TEST(Utils, VerifyValueAfterDecay)
{
std::vector<struct ValueAFterDecayData> test_data = {
{15345678, 5000000, 20000, 2383},
{3000000, 5000000, 20000, 13195},
{37256870, 5000000, 15, 0}};

for (const auto &data : test_data)
{
SCOPED_TRACE(::testing::Message()
<< "Testing time to decay(usec): " << data.time_to_decay_usec
<< ", half life(usec): " << data.half_life_usec
<< ", initial value: " << data.initial_value
<< ", expected target value: " << data.expected_target_value);

EXPECT_EQ(Utils::valueAfterDecay(
data.time_to_decay_usec, data.half_life_usec, data.initial_value),
data.expected_target_value);
}
}