go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/bisection/testfailuredetection/rank.go (about)

     1  // Copyright 2023 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package testfailuredetection
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  	"sort"
    21  	"strings"
    22  	"time"
    23  
    24  	"go.chromium.org/luci/bisection/model"
    25  	"go.chromium.org/luci/common/logging"
    26  )
    27  
    28  // First sorts the input slice and returns the first element in the sorted slice.
    29  func First(ctx context.Context, bundles []*model.TestFailureBundle) *model.TestFailureBundle {
    30  	Sort(bundles)
    31  	// Log the sorted bundles for debugging purpose.
    32  	lines := []string{}
    33  	for i, b := range bundles {
    34  		tf := b.Primary()
    35  		line := fmt.Sprintf("%d. primary test %s(%s), redundancy score %f, regression end position %d", i, tf.TestID, tf.VariantHash, tf.RedundancyScore, tf.RegressionEndPosition)
    36  		lines = append(lines, line)
    37  	}
    38  	logging.Infof(ctx, fmt.Sprintf("sorted bundles\n%s", strings.Join(lines, "\n")))
    39  	return bundles[0]
    40  }
    41  
    42  // Sort sorts slice of testFailureBundles by their
    43  // redundancy score and regression end position.
    44  func Sort(bundles []*model.TestFailureBundle) {
    45  	sort.Sort(sortableTestFailureBundles(bundles))
    46  }
    47  
    48  type sortableTestFailureBundles []*model.TestFailureBundle
    49  
    50  // Len is the number of elements in the collection.
    51  func (s sortableTestFailureBundles) Len() int {
    52  	return len(s)
    53  }
    54  
    55  // Less reports whether the element with
    56  // index i should sort before the element with index j.
    57  func (s sortableTestFailureBundles) Less(i int, j int) bool {
    58  	// We sort test bundle by recency descendingly first (truncated to day), and by redundancy score ascendingly.
    59  	di := s[i].Primary().StartHour.Truncate(time.Hour * 24)
    60  	dj := s[j].Primary().StartHour.Truncate(time.Hour * 24)
    61  	return di.After(dj) || (di == dj && s[i].Primary().RedundancyScore < s[j].Primary().RedundancyScore)
    62  }
    63  
    64  // Swap swaps the elements with indexes i and j.
    65  func (s sortableTestFailureBundles) Swap(i int, j int) {
    66  	s[i], s[j] = s[j], s[i]
    67  }