github.com/m3db/m3@v1.5.0/src/dbnode/encoding/series_iterators.go (about)

     1  // Copyright (c) 2016 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 encoding
    22  
    23  type seriesIterators struct {
    24  	iters []SeriesIterator
    25  }
    26  
    27  // NewSeriesIterators creates a new series iterators collection with given SeriesIterator.
    28  func NewSeriesIterators(iters []SeriesIterator) MutableSeriesIterators {
    29  	return &seriesIterators{iters: iters}
    30  }
    31  
    32  // NewSizedSeriesIterators creates a new MutableSeriesIterators for a given number of iterators.
    33  func NewSizedSeriesIterators(numSeries int) MutableSeriesIterators {
    34  	return &seriesIterators{
    35  		iters: make([]SeriesIterator, numSeries),
    36  	}
    37  }
    38  
    39  func (iters *seriesIterators) Iters() []SeriesIterator {
    40  	return iters.iters
    41  }
    42  
    43  func (iters *seriesIterators) Close() {
    44  	for i := range iters.iters {
    45  		if iters.iters[i] != nil {
    46  			iters.iters[i].Close()
    47  			iters.iters[i] = nil
    48  		}
    49  	}
    50  }
    51  
    52  func (iters *seriesIterators) Len() int {
    53  	return len(iters.iters)
    54  }
    55  
    56  func (iters *seriesIterators) SetAt(idx int, iter SeriesIterator) {
    57  	iters.iters[idx] = iter
    58  }
    59  
    60  func (iters *seriesIterators) Reset(size int) {
    61  	for i := range iters.iters {
    62  		iters.iters[i] = nil
    63  	}
    64  	iters.iters = iters.iters[:size]
    65  }
    66  
    67  // EmptySeriesIterators is an empty SeriesIterators.
    68  var EmptySeriesIterators SeriesIterators = emptyIters{}
    69  
    70  type emptyIters struct{}
    71  
    72  func (e emptyIters) Iters() []SeriesIterator { return nil }
    73  func (e emptyIters) Len() int                { return 0 }
    74  func (e emptyIters) Close()                  {}