github.com/m3db/m3@v1.5.0/src/dbnode/storage/bootstrap/bootstrapper/ranges.go (about)

     1  // Copyright (c) 2020 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package bootstrapper
    22  
    23  import (
    24  	"math"
    25  	"time"
    26  
    27  	"github.com/m3db/m3/src/dbnode/storage/bootstrap/result"
    28  	xtime "github.com/m3db/m3/src/x/time"
    29  )
    30  
    31  // ShardTimeRangesTimeWindowGroup represents all time ranges for every shard w/in a block of time.
    32  type ShardTimeRangesTimeWindowGroup struct {
    33  	Ranges result.ShardTimeRanges
    34  	window xtime.Range
    35  }
    36  
    37  // NewShardTimeRangesTimeWindowGroups divides shard time ranges into grouped blocks.
    38  func NewShardTimeRangesTimeWindowGroups(
    39  	shardTimeRanges result.ShardTimeRanges,
    40  	windowSize time.Duration,
    41  ) []ShardTimeRangesTimeWindowGroup {
    42  	min, max := shardTimeRanges.MinMax()
    43  	estimate := int(math.Ceil(float64(max.Sub(min)) / float64(windowSize)))
    44  	grouped := make([]ShardTimeRangesTimeWindowGroup, 0, estimate)
    45  	for t := min.Truncate(windowSize); t.Before(max); t = t.Add(windowSize) {
    46  		currRange := xtime.Range{
    47  			Start: t,
    48  			End:   minTime(t.Add(windowSize), max),
    49  		}
    50  
    51  		group := result.NewShardTimeRanges()
    52  		for shard, tr := range shardTimeRanges.Iter() {
    53  			iter := tr.Iter()
    54  			for iter.Next() {
    55  				evaluateRange := iter.Value()
    56  				intersection, intersects := evaluateRange.Intersect(currRange)
    57  				if !intersects {
    58  					continue
    59  				}
    60  				// Add to this range.
    61  				group.GetOrAdd(shard).AddRange(intersection)
    62  			}
    63  		}
    64  
    65  		entry := ShardTimeRangesTimeWindowGroup{
    66  			Ranges: group,
    67  			window: currRange,
    68  		}
    69  
    70  		grouped = append(grouped, entry)
    71  	}
    72  	return grouped
    73  }
    74  
    75  func minTime(x, y xtime.UnixNano) xtime.UnixNano {
    76  	if x.Before(y) {
    77  		return x
    78  	}
    79  	return y
    80  }