github.com/m3db/m3@v1.5.0/src/query/storage/m3/encoded_step_iterator.go (about)

     1  // Copyright (c) 2018 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 m3
    22  
    23  import (
    24  	"github.com/m3db/m3/src/query/block"
    25  	"github.com/m3db/m3/src/query/storage/m3/consolidators"
    26  )
    27  
    28  type encodedStepIter struct {
    29  	collectors []*consolidators.StepLookbackConsolidator
    30  	encodedStepIterWithCollector
    31  	values []float64
    32  }
    33  
    34  func (b *encodedBlock) StepIter() (
    35  	block.StepIter,
    36  	error,
    37  ) {
    38  	var (
    39  		cs       = b.consolidation
    40  		iters    = b.seriesBlockIterators
    41  		lookback = b.options.LookbackDuration()
    42  
    43  		collectors       = make([]*consolidators.StepLookbackConsolidator, len(iters))
    44  		seriesCollectors = make([]consolidators.StepCollector, len(iters))
    45  	)
    46  
    47  	for i := range iters {
    48  		collectors[i] = consolidators.NewStepLookbackConsolidator(
    49  			lookback,
    50  			cs.bounds.StepSize,
    51  			cs.currentTime,
    52  			cs.consolidationFn,
    53  		)
    54  	}
    55  
    56  	for i := range collectors {
    57  		seriesCollectors[i] = collectors[i]
    58  	}
    59  
    60  	iter := &encodedStepIter{
    61  		collectors: collectors,
    62  		values:     make([]float64, 0, len(iters)),
    63  		encodedStepIterWithCollector: encodedStepIterWithCollector{
    64  			lastBlock: b.lastBlock,
    65  
    66  			stepTime:   cs.currentTime,
    67  			blockEnd:   b.meta.Bounds.End(),
    68  			meta:       b.meta,
    69  			seriesMeta: b.seriesMetas,
    70  
    71  			seriesPeek:       make([]peekValue, len(iters)),
    72  			seriesIters:      iters,
    73  			seriesCollectors: seriesCollectors,
    74  
    75  			workerPool: b.options.ReadWorkerPool(),
    76  		},
    77  	}
    78  
    79  	iter.encodedStepIterWithCollector.updateFn = iter.update
    80  	return iter, nil
    81  }
    82  
    83  func (it *encodedStepIter) update() {
    84  	it.values = it.values[:0]
    85  	for _, consolidator := range it.collectors {
    86  		it.values = append(it.values, consolidator.ConsolidateAndMoveToNext())
    87  	}
    88  }
    89  
    90  func (it *encodedStepIter) Current() block.Step {
    91  	return block.NewColStep(
    92  		it.stepTime,
    93  		it.values,
    94  	)
    95  }